BigBang Lifecycles

Forward Dr. Steven H. Edelman is a widely published research geologist interested in earth tectonics and cosmology. In Big Bang Lifecycles, Dr. Edelman combines these interests and takes a new approach to understanding the natural history of the universe through big bangs. The resulting conceptual model of the universe is based on current mainstream cosmological models such as the standard big bang model (ΛCDM). The approach is conceptual, not mathematical, and can be understood by anyone with a scientific background. Dr. Edelman leads the reader on an easy-to-read journey through relativity, non-equilibrium thermodynamics, and the observable universe, to a simple new paradigm that explains the low entropy of the early universe in terms of life processes. The resulting conceptual model of the cosmos through big bang cycles reconciles relativistic spacetime with time-asymmetric chaos theory. The amazing upshot is that the mysteries of life and time directionality are two sides of the same coin. As argued in Big Bang Lifecycles, all matter in the universe is alive in one direction of time or the other. Thus, life on earth is a life system only as experienced or considered from past to future, but we are not life when considered from future to past. Stars, on the other hand, when considered from future to past, are alive and photosynthesize matter on a cosmic scale.

Steven H. Edelman, PhD

STEVEN H. EDELMAN BIG BANG LIFECYCLES

© 1999-2011 Steven H. Edelman

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Contents

1. PHYSICAL LAWS AND NATURAL PROCESSES ................................................1

2. TIME IS NOT A CLOCK............................................................................................7

3. SPACETIME CONTINUUM – PARTICLES ARE LINES.....................................12

4. TIME DIRECTIONALITY AND ARROWS OF TIME..........................................20

5. ENTROPY AND STATISTICAL TIME DIRECTIONALITY...............................26

6. ENTROPY AND ARROWS OF TIME......................................................................34

7. THE BIG BANG AND HEAT DEATH – THE ENDS OF TIME? .........................39

8. SPACETIME, DIRECTIONAL TIME, AND ENTROPY GRADIENTS ..............49

9. NATURAL PROCESSES IN REVERSE...................................................................52

10. NON-EQUILIBRIUM SYSTEMS AND CHAOS THEORY.................................55

11. ENTROPY GRADIENT OF LIFE ...........................................................................64

12. MEMORY AND TIME ASYMMETRY ..................................................................72

13. COSMOLOGICAL ROLE OF LIFE .......................................................................79

14. THE UNIVERSAL LIFE AND NONLIFE SYSTEMS ..........................................84

15. LIFE, DEATH, AND BIG BANGS...........................................................................89

16. STARS AS AN ADVANCED LIFE PROCESS.......................................................94

17. ENERGY SOURCE AND LIFECYCLE OF STARLIFE......................................99

18. LIGHT AND DARK LIFE ........................................................................................105

19. THE BIG BANG STATE...........................................................................................114

20. THE UNIVERSE AS A PHOTON............................................................................120

21. TESTING THE CONCEPTUAL MODEL..............................................................130



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Figures

Figure 1. Conceptual model of seafloor spreading. ..................................................................................................3 Figure 2. Photographs of erosional features in the universe. Left: Water erosion of earth exposing

volcaniclastic rock, New Mexico (height 50 feet). Right: Photonic (ultraviolet light) erosion of a cosmic gas cloud exposing protostars, Eagle Nebula (height 4 light years). .............................................................5

Figure 3. Continuous structure of real particles. ....................................................................................................15 Figure 4. Long-exposure photographs of portions of spacetime illustrate the linear structure of particles. ....18 Figure 5. Worldlines of photons organized into an electron that absorbs or emits a photon.............................19 Figure 6. Order vs. complexity. ................................................................................................................................23 Figure 7. Continuous vs. dispersed systems. ...........................................................................................................27 Figure 8. Scales of photon organization...................................................................................................................36 Figure 9. The standard (ΛCDM) big bang model, showing spacetime locations the four pillars of the big bang

(red numbers): 1 = light element abundances; 2 = CMB radiation; 3 & 4 = distribution and expansion of galaxies. ........................................................................................................................................................43

Figure 10. Symmetry breaking: Salt water has infinite symmetry planes (dashed lines), but more ordered crystalline salt has only two symmetry planes (plus one in the plane of the page in the third dimension)............................................................................................................................................................................56

Figure 11. Amplification of effects; the fourth ball deviates so far from the straight shot that it misses the next ball entirely. .............................................................................................................................................58

Figure 12. General bifurcation diagram. An actual system would have many more branches with unlimited branches toward the top..................................................................................................................................59

Figure 13. An actual evolution of states, indicated in red, of a far-from-equilibrium system............................61 Figure 14. Emergent structures in bird flocks and schools of fish. .......................................................................63 Figure 15. Conceptualization of the organization of the line-particles (photons/atoms/molecules) of a tree

(outlined in red dashes) in spacetime. ............................................................................................................66 Figure 16. Some depictions of the evolutionary tree of the earth life system, showing that evolution is a

process of bifurcation (speciation) of life forms............................................................................................69 Figure 17. Partial bifurcation diagram of the earth life system, illustrating conceptually the possible (black)

and realized (red) states of the life system.....................................................................................................70 Figure 18. Formation of memories of the sight of a volcanic eruption in the future direction of time. On the

bifurcation diagrams, the actual evolutions of the brain and volcano are in red......................................74 Figure 19. Extrapolation (dashed lines) of the known universal life system (solid lines) into the past and

future.................................................................................................................................................................85 Figure 20. Two representations of the same real system (portion of spacetime), considered in opposite

directions of time (indicated by red arrows). Life has choices, nonlife does not. .....................................87 Figure 21. Conceptual model of a big bang cycle. “Life” and “nonlife” systems are arbitrarily defined and

would be switched using the opposite sign convention for time. .................................................................90 Figure 22. Entropy and mass of the A and B systems about a big bang...............................................................91



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Figure 23. Photographs of organisms in the universe. Four of the photographs are jellyfish, and the other 18 are Hubble Space Telescope photographs of galaxy “organisms” made of photosynthesizing stellar “cells.” ...............................................................................................................................................................97

Figure 24. Nucleosynthesis and nuclear photosynthesis are the same process considered in opposite directions of time (H=hydrogen, He= helium). .............................................................................................................100

Figure 25. Exchange of photons within a big bang cycle. ....................................................................................101 Figure 26. Reverse-time evolution of “primitive” dark life to photosynthesizing light life to a hydrogen cloud.

.........................................................................................................................................................................108 Figure 27. The major branches of the bifurcation diagram of the earth life system, showing reverse time

converging branches of the tree of evolution (entropy increasing nonlife system). ................................111 Figure 28. The earth life system in reverse time is nonlife...................................................................................112 Figure 29. Conceptualization of limiting case in which the big bang state is the primordial nucleosynthesis

event. ...............................................................................................................................................................116 Figure 30. Hubble Space Telescope photographs of protostars forming from hydrogen clouds. In reverse

time, the hydrogen forms by nuclear photosynthesis in stars and disperses into hydrogen clouds toward the big bang. ...................................................................................................................................................117

Figure 31. Conceptual model of a big bang cycle, with big bangs at the primordial nucleosynthesis event. ..118 Figure 32. The evolutions of the two universal entropy-gradient systems A and B through spacetime (heavy

green and red lines) are two among an unlimited number of possible evolutions for each system, as represented by the opposing bifurcation diagrams (thin lines).................................................................122

Figure 33. Conceptual model of mass (matter-energy) distribution between the two universal entropy-gradient systems A and B..............................................................................................................................123

Figure 34. Total entropy and free energy of the universe through big bang cycles. .........................................124 Figure 35. Waveform of the universe, which reflects the change of direction of matter-energy transfer

between the A and B systems at big bangs. .................................................................................................126 Figure 36. Frequency of big bangs is less than 1 per 28 billion years (b.y) by an unknown amount (? b.y.)..127 Figure 37. If the A life system exists only on earth, the entropy gradient would be discontinuous (Scenario 1).

Life systems other than the earth life system must exist for the A (or B) system to persist through big bangs and contribute to a continuous entropy gradient (Scenario 2).......................................................141

The ideas presented herein are based entirely data and interpretations presented by other scientists; if I can see farther it is because I stand on their shoulders. Any errors or misinterpretations are my sole responsibility. This work was funded and motivated by the author. This book is not a product of, was not funded by, and is in no way related to or associated with, any work performed by the author for any current or former employer or client.

© 1999-2011 Steven H. Edelman p. 1

1. PHYSICAL LAWS AND NATURAL PROCESSES

The natural sciences, such as geology, astronomy, and biology, rely on the development and testing of “models” to make sense of natural systems. In the most general sense, a model is anything used in any way to represent anything else. The most basic type of model in the natural sciences is a “conceptual” model, which is a mental representation of a natural system. A conceptual model of a system is generally represented in drawings and/or words. Based on a conceptual model, more quantitative models may be developed, such as physical and numerical models. A “physical model” is a constructed system that represents a real system, such as a model of an atom made of little balls (electrons) around a big ball (nucleus) or a model of a beach that is sand in a wave tank. A “numerical model” uses equations and physical laws to represent a natural system. The advent of computers significantly increased the power of numerical models. The natural sciences use models to represent natural systems and to design experiments that “test” the conceptual model; the experiments are typically measurements of some aspect of a natural system. Based on the experimental results, the model is supported, modified to be consistent with the new results, or rejected in favor of other models. This approach has been called “multiple working hypotheses.”

This book presents a conceptual model of the universe. Conceptual models and all models that describe natural systems are distinct from “physical laws.” Physical laws are the realm of physics and chemistry, where equations and formulas make precise predictions of particle interactions. Examples of physical laws include the inverse square law of gravitational attraction or the matter-energy equivalence of special relativity (E=mc2). Conceptual models are the realm of the natural sciences, where words and diagrams make qualitative predictions of natural processes. Conceptual models include biologic evolution, the Copernican solar system, and the hydrologic cycle. Numerical and physical models are used to support the conceptual model with quantitative predictions. Physical laws, by contrast, make exact predictions (within the error of measurement).


© 1999-2011 Steven H. Edelman 2

An example of a conceptual model in the natural sciences is plate tectonics in geology. In the early 1900’s, some geologists had proposed a hypothesis of “continental drift” to explain correlative rocks on either side of the Atlantic Ocean. However, nobody could explain how continents could possibly move, and there was no direct evidence for “drift,” so the hypothesis wasn’t well accepted. More to the point, the geologic data available at the time did not “need” continental drift; there were simpler explanations for the existing data set.

Then, in the late 1960’s, geophysicists began interpreting new data on magnetic signatures contained in ocean floor rocks. The ocean floor is composed of basalt lava rock. After eruption, the lava solidifies with the magnetic minerals oriented in the lava parallel to the earth’s magnetic field. Once solidified, the magnetic minerals remain frozen in the rock in this orientation, even if the magnetic field of the earth changes or the rock moves. Indeed, the magnetic field of the earth is in constant motion and has completely flipped many times in the geologic past, when the magnetic north pole was at the geographic south pole and visa versa. Thus, the orientations of the magnetic minerals in the ocean floor basalts record whether they solidified during a “normal” or “reversed” magnetic polarity epoch.

The results of new geophysical surveys of the “fossil magnetism” of ocean-floor basalts beneath the Atlantic Ocean were surprising; the magnetic polarity signatures occur in north-south-trending stripes that are symmetrical on either side of the Mid-Atlantic Ridge. Basalts at the ridge have normal polarity, and away from the ridge the magnetic stripes have alternating reversed and normal polarities that continue westward to the American continent and eastward to Europe and Africa. Additionally, radiometric age dating indicates that basalts at the Mid-Atlantic Ridge are recent and are progressively older away from the ridge. The interpretation was clear – the continents were once together and had been pushed apart by “seafloor spreading” (see figure below).



Figure 1. Conceptual model of seafloor spreading.

From there the pieces fell quickly into place. If oceans expand, the earth’s surface must contract elsewhere. Oceanic trenches with their associated deep earthquakes became “subduction zones,” where old ocean floor returns to the earth’s interior and balances the seafloor spreading. Large strike-slip faults became transform faults that allowed rigid earth “plates” to move past one another as continents move passively with spreading and subducting oceans. “Plate tectonics” was the new conceptual model in geology and continues to elegantly explain many aspects of sedimentology, earth structure, paleontology, igneous petrology, and virtually every other aspect of earth composition, structure, and history. The model contains no equations, but has great power to make testable predictions.

Conceptual models (hypotheses) of natural systems are constrained by physical laws. Physical laws are expressed mathematically and make quantitative predictions. For example, the process of subduction requires, due to the physical laws of buoyancy, that the subducting oceanic crust and upper mantle, which constitute the subducting oceanic plate, be denser than the mantle into which the oceanic plate sinks. Subduction is consistent with physical laws but cannot be predicted from physical laws. Physicists hand down the laws that must be obeyed by natural systems; for example, forces must balance in non-accelerating systems and two hydrogen atoms are needed to form a water molecule.

But within these physical laws, nature behaves in complex, unpredictable ways. For example, although the climatic history of the earth, as ascertained from the geologic record, is consistent with physical laws, no theory exists that predicts the warm periods and ice ages that have



occurred in the past billion years. Although the orbits of planets around the sun obey physical laws of gravity and angular momentum, no theory predicts that the solar system would consist of eight planets (excluding Pluto), that the third planet from the sun would have one moon, or even that there would be a solar system. Physical laws, though capable of predicting individual particle interactions with mathematical precision, are completely incapable of, and are not designed to, predict the behavior of the countless billions of billions of particle interactions involved in natural processes.

Geologists walk around in the mountains, look at rocks, make maps, piece together the data, and describe a completely unpredictable, but physically possible, earth history of drifting continents, colliding plates that pile up to form mountains, volcanoes that form above subducting oceanic plates, dinosaurs that roamed the earth for 160 million years, meteorite impacts, and much more. None of these natural processes are predicted from physical laws, and it is in fact not possible to do so.

The universe is the ultimate natural system, and the evolution of the universe is the sum of the evolutions of all natural systems. Cosmological models are constrained by physical laws, most notably relativity and high energy particle physics, and must explain the astrophysical data. “Astrophysical” is used here in a broad sense, meaning any data on the universe, which is in a sense all data. Any viable cosmological model must explain the astrophysical data and be possible within the constraints of the physical laws. But physical laws cannot predict the actual evolution of the universe any more than these laws can predict the actual evolutions of its component natural systems.

* * *

A mere 500 years ago, the cutting edge of science was Copernicus’ notion that the sun, not the earth, is at the center of the universe. Copernicus’ heliocentric conceptualization was not a calculation; rather, it was a conceptualization consistent with physical laws but used to explain observational data. Since the time of Copernicus, more detailed data, primarily from more powerful telescopes and other equipment for collecting astrophysical data, have continued to expand our conceptual model of the universe. Thus, the sun became just another star among billions in the Milky Way. Many nebulae were recognized as being outside the Milky Way and



were then recognized as being other galaxies like the Milky Way, each containing billions more stars. Most recently, the Hubble Space Telescope has revealed spectacular, unpredictable natural formations in the cosmos, such as the pillars of the Eagle Nebulae (see figure below).

Figure 2. Photographs of erosional features in the universe. Left: Water erosion of earth exposing volcaniclastic rock, New Mexico (height 50 feet). Right: Photonic (ultraviolet light) erosion of a cosmic gas cloud exposing

protostars, Eagle Nebula (height 4 light years).

Physical laws didn’t predict any of these discoveries, but all the discoveries obey physical laws. The frontiers of the universe now lie at the big bang and heat death. All of the previous discoveries lie within the boundaries of these “ends” of the universe. Whatever the nature of these states of the universe may be, and in fact whether they even exist, are not predictable from physical laws and is in the realm of natural science.

I offer the following ideas as a natural scientist’s view of cosmology. The approach is the same one used in all the natural sciences – develop a conceptual model that is consistent with a wide range of data, is not disproven by any of the data, is consistent with physical laws, and is the simplest model that meets these criteria. This book contains no references, because the model presented herein is based on data and interpretations that are mainstream scientific information that is easily found on the Internet. Some of the key people in the development of these data and interpretations are mentioned, such as attributing relativity to Albert Einstein. The book



summarizes existing information sufficiently to set the context of the concepts described herein, and the reader is encouraged to search the Internet and other references for more background information on basic cosmology as understood today by most authors. The first aspect we’ll tackle is the notion of time.



2. TIME IS NOT A CLOCK

The first conceptual hurdle in understanding the universe is a firm conceptualization of time. The universe is not a three dimensional space in which objects move, but rather a four dimensional spacetime. However, it is not easy to conceptualize a four dimensional system like the universe. Our conceptualization of the “ends” of the four dimensional universe, the big bang and heat death, are in the past and future. An understanding of these states requires a firm concept of time, but time is an elusive concept. Space does not seem to have the same conceptual difficulties that time does. For example, space travel seems to be easy whereas time travel is science fiction. Therefore, the first step in conceptualizing the universe is sorting through our understanding time.

We have a very complex understanding of “time.” Anybody reading this has some awareness, if not an understanding, of the time-confounding principles of special relativity. First, relativity dashes our intuitive notion of “simultaneity,” the simple notion that two things can happen at the “same time.” Special relativity reveals that whether an event actually occurs before or after another event is defined only relative to a frame of reference, such as a coordinate system or the location of an observer. Second, light travels at velocity c relative to any and all frames of reference, even frames of reference moving near light speed. Third, the “pace” of time and even the mass of an object are relative and depend on the velocity of an object relative to a frame of reference. As material objects accelerate and approach the speed of light relative to some reference frame, time “slows” relative to that reference frame.

Our concept of time is further confounded by our perceptions of “passing” time, alternate futures (“possibilities”), and language (especially verb tense). Then add to those complexities a consideration of the question “what is time, anyway?” Time has never been observed. It has no location. Physics books don’t have a chapter on it – “time” is just a word to explain other concepts, such as “time slows near light speed.” What does that mean? How fast does time move at low speeds or at rest? How can time even have a velocity? Albert Einstein is reputed to have answered the question “What is time?” by saying “time is what the clock on the wall says.” He was saying, I think, that our intuitive concept of time does not extend beyond us humans



coordinating our activities according to a time convention – “clocks on the wall” synchronized to the earth’s rotation. To see through the various complexities of time, let’s start with the deceptions.

Special relativity precipitated a conceptual shift in our conceptualization of time. The shift was not away from a previous scientific concept, but rather it was a shift from our intuitive concept of time. Our intuitive concept of time is based on measurements of time using clocks and on events that occur from past to future. Our intuitive concept of time is so basic to our experience of the universe that our language must have verbs with temporal tenses in every sentence. We are unable to communicate effectively, or more to the present point, we are unable to describe the universe effectively, without distinguishing past events from future events or without communicating the temporal ordering of events. For example, even though the same event is described, the statement “I went to the store” is different than “I will go to the store.” This trip to the store is the same event in the universe, but our perception is that one event is in the past and the other is in the future; one is definite and the other is uncertain; one is remembered and the other is not. But both statements mean the exact same thing, the only difference being when the statement is made. In other words, the only difference between the two statements is the temporal location of the “observer” making the statement. The part of spacetime described as “I went to the store” or “I will go to the store” is the same part of spacetime in both statements.

* * *

Our intuitive perception of time has two primary aspects, which can be described as “time measurement” and “progressive time.” Time measurement is accomplished using clocks. In the broadest sense, “clocks” include all forms of time measurement, and all clocks work the same way. All clocks involve a motion that, from the physics of the motion, appear to be cyclic. Specifically, the clock has a repeated motion that occurs at constant velocity. A mechanical clock, for example, has hands designed to rotate at constant angular velocity, so equal distances on the face of the clock represent equal increments of time. Because the angular spatial distances between the numbers on the clock face are equal, constant angular velocity (angular distance divided by time) means equal time. Today’s clocks utilize the cyclic vibration of a crystal, and all are standardized to the cyclic rotation and revolution of the earth (days and years).



Evaluation of time measurement techniques reveals that time is not itself a measurable property of the universe, but rather is a component, like space, of the relative motions (velocities) of particles. In other words, the lesson from clocks regarding the true nature of time is that we have no way to measure time or even observe time. Rather, the universe is composed of particles in relative motion. The way we measure the relative motions of particles is by measuring the components – or “dimensions” – of the motion using standardized distances and times, i.e. rulers and clocks. Thus arise our concepts of space and time, neither of which has an existence separate from the particles. About “space,” Einstein said something like “matter does not occupy space, but rather matter is spatially extended.” Matter is the reality and it has a property of spatial extent, the three spatial dimensions.

The other primary aspect of our intuitive understanding of time is “progressive time.” Past events are remembered and cannot be changed, future events are not remembered and can be changed. Every time is perceived as a “now” that moves into an unknown “future” from a remembered “past.” Every “now” appears to be as “real” as every other “now.” These statements are intuitively obvious, but in fact an objective definition of "now" does not exist. Rather, the concept of "now" is defined only in terms of an observer who declares that this time is "now." And by the time the word “now” is out of the observer’s mouth, it is no longer “now.” “Now" is no more a property of time than "here" is a property of space. Both terms are subjective declarations by an observer that this is “here” and “now,” and all other times and places are “then” and “there.” Additionally, because the "past" and "future" are defined only as being in opposite directions of time from "now," they too are subjective. The future is just as “real,” or “unreal,” as the past.

One might argue that the future is objectively different than the past because the future can happen in many different ways, whereas the past happens in only one way. The future has many possibilities, whereas the past has only one history. Of course, the perception of many possible futures is another of time’s masks. Although our thought processes must evaluate the possibilities in order to make everyday decisions, we know that one and only one of the possibilities is real. Without exception, the future’s possibilities become the past’s realities, and all of it reflects the actual events in the universe around us, including us. Clearly, the concept that the future can happen in many different ways is a subjective viewpoint that depends entirely, as before, on when the possibilities are considered. In other words, the point at which the certain



past borders the uncertain future is, by definition, “now,” which is completely subjective. The universe actually occurs in only one way.

As discussed, time, like space, is a component of the relative velocities of particles. The way in which the relative motions of real particles manifest themselves to us as time and space can be visualized by considering a universe without relative motions of particles. Imagine all particles have zero relative velocity, a “frozen” universe with no relative motion of particles. In an absolutely static universe, time would in fact not exist. Clearly, “time” would have no meaning in a frozen universe with no motion; there is no way to build a clock in a frozen universe. Equally true, but a little more difficult to visualize, “space” would have no meaning in a frozen universe. Space would be undefined in a frozen universe because the distances between particles are undefined. The distance between two particles in a frozen universe cannot be traversed by anything in that universe, so the inter-particle distance cannot be measured and a frozen universe has neither spatial nor temporal dimensionality. Time and space are properties of moving particles and only of moving particles, and we live in a universe in which all particles are in continuous relative motion.

* * *

The gap between our intuitive understanding of time and the reality of time is illustrated very nicely by our ideas of “time travel.” To be clear, the point here isn’t whether time travel is possible, but rather to illustrate that the question itself manifests the flaws in our intuitive notion of time. When we think of time travel, we think of traveling through time in the same way we travel through space. We believe we can “travel” in any direction of space, so it makes sense that we should be able to “travel” in any direction in time. The fact is, time travel like space travel, is not only possible, but it is inevitable. The reason time and space travel are inevitable is that the motion of particles is inevitable. Each particle is always “traveling” to the next point in time and space, and there is no other place and no other time to which the particle actually travels.

But wait, you say; “time travel” means I can go to another time, like to Philadelphia in 1776 to see the signing of the Declaration of Independence. Unfortunately, a trip from here and now to there and then would mean “skipping over time.” In other words, the “time travel” we imagine



to be possible, as in H.G. Wells’ The Time Machine, means to “skip over” time without experiencing or “waiting” for the intervening time. That kind of time travel is not possible, and that kind of space travel is not possible either. You cannot go from “here” to “there” without experiencing or “waiting” as you travel the intervening space. The bottom line is, we can travel through time just as well as we travel through space, and the fact that this is not intuitively obvious illustrates the gap between our intuitive understanding of time and the reality of time. The best way to get a handle on the idea of time and the temporal dimension of the universe is to go back to what is real – particles.



3. SPACETIME CONTINUUM – PARTICLES ARE LINES

The behavior of real particles is at the heart of time and space. No matter how you define time, no time measurement or time progression exists without particles, or even in a hypothetical universe with particles but without relative motion of the particles. The astrophysical data set (all data) indicates that our universe has particles, that those particles are in continuous relative motion, and that their relative motions define natural processes such as the big bang. Therefore, the nature of those particles holds the key to understanding time and the universe.

Our universe is composed of “real particles,” which include photons, subatomic particles, antiparticles, and atoms. Other “particles” used in quantum physics are “virtual particles,” such as gravitons (gravity particles), that are constructs of quantum mechanics. Virtual particles are not particles that can be measured or actually exist, but rather represent the forces associated with real particles (such as gravity associated with real matter). Thus, real particles constitute the energy and matter in the universe. A “photon” is a real particle, the particle form of energy, which can exist in one of two states: as matter (sub atomic and atomic particles) or as light (including the entire electromagnetic spectrum). The famous relation E=mc2 from special relativity states that a given mass m contains within it an amount of energy E, where c2 is a constant (the square of the speed of light). In other words, matter and energy are fundamentally made of the same thing, as both ice and water are made of H2O. Matter can be thought of as photons that are “organized” into matter particles. The energy that holds the photons in place in matter is nuclear energy, which is emitted when matter particles convert to energy (photons) in nuclear reactions, according to E=mc2.

The mass-energy equivalence of special relativity means that our universe consists entirely of photons, some of which are organized into matter. Subatomic particles, such as electrons and quarks, are made of photons and are manifestations of the organization of photons into subatomic and ultimately atomic particles.



Particles are typically conceptualized as “points in space,” which can be located in space by three numbers that represent a location in an imagined and arbitrary x,y,z-type coordinate system. Additionally, the particles move relative to one another, i.e. each pair of particles has a relative velocity, which provides another dimension, time. In this conceptual model, the reality is the particles in relative motion, not their measurable dimensions of space and time, which have no existence separate from the particles.

In addition to matter-energy equivalence, special relativity gave rise to the idea of a “spacetime continuum,” or “block time.” The spacetime continuum, or “spacetime,” is the idea that all points in time “exist,” just as all points in space “exist.” In fact, in this 4-space, time has no special place or status among the 4 dimensions; time and space are just two names we give to our experience and measurement of the 4-space. The idea that every “now” is equally “real,” past and future, is consistent with the block time concept. The spacetime continuum envisions a universe that is “laid out” for us to experience “one now at a time.” All of time and space “exists” and therefore time, like space, has no directionality in special relativity – no progression of time from past to future.

A useful analogy to block time is a movie. Each frame of the movie is a projection of the three-dimensional universe onto a two dimensional surface and the successive frames of the movie represent the time dimension. We can look at a reel of film (or a DVD or icon for a video file) and easily conceptualize that the entire movie “exists.” The entire space and time of the movie, from beginning to end (or end to beginning), can be viewed all at once when we look at the reel of file digital video disk, and thus the “block time” of the movie is easy to conceptualize. When we look at the reel of film sitting on a table or mounted on a projector, all times in the movie can be perceived at once, and the conceptualization of the reel of film is analogous to block time or the spacetime continuum. However, the reel of film is not our experience of the universe. The cinematic analogy to our experience of the universe is realized when the film is run through a projector. Then, the reel of film becomes a sequence of events that we can recognize as our experience of the universe. And just like our universe, the scene we happen to be watching “now,” and our uncertainty as to how the hero will save the day, are in no way properties of the film, all of which exists. Rather, the current scene is our experience of the reality, the reality being the entire film.



But what is “real” spacetime or block time conceptually? Let’s start with our concept that space and time are measurable components of the relative motions of particles (relative velocities). Every process in the universe – whether it be me writing this paper, a rotating planet, or the big bang – can be described as an assemblage of particles in relative motion. The relative motions of the particles can, in principle at least, be described by the space and time coordinates of the particles through the process. The “coordinate system” is defined arbitrarily, by conceptually attaching the coordinate system to easily identified particles. Thus we have north-south coordinates, elevation above mean sea level, and years since the birth of Christ to describe the spacetime locations of events ranging from earth processes (for example, the tectonic evolution of a continent) to the news (for example, the where and when of a shooting). But we must realize in conceptualizing the universe that these everyday coordinate systems of space and time have no objective, physical significance beyond our arbitrary systems of measurement of the movements of particles.

Let’s make an analogy to earth history in the broadest sense, including events such as the US Civil War and the geologic evolution of the Asian continent. Every event that has ever occurred on earth, and every event that ever will occur on earth, can be completely described, in principle, by the latitude, longitude, elevation, and time location of every particle that ever was or will be on earth. We could call this system “placetime.” Clearly, the reality is the particle motions – the fighting soldiers and the collision of India with Asia – not their placetime coordinates (latitude, longitude, elevation above mean sea level, and time before present). By the same token, the reality in the universe is the particles, not the coordinate system.

The meaning of “spacetime” in terms of particle motions is well illustrated by general relativity, in which “curved spacetime” is used to describe gravitational attraction. The key prediction of general relativity is that photons, like matter particles, have the property of gravity. Einstein’s prediction was famously tested in the 1920’s by observing starlight that passed close to the sun during a solar eclipse. Comparison of the apparent location of the star to its known location showed that the starlight was bent around the sun, as predicted by general relativity. This experiment to test Einstein’s prediction confirmed that light has gravity. If you look into the role of spacetime in this, you quickly find that spacetime coordinates are defined by the trajectories of light. In other words, the shortest distance between two points – a straight line – is by definition the path followed by light. If light follows a curved path, then spacetime is by definition curved.



So conceptually, the reality is that light has the property of gravity, not that spacetime is curved, although a curved coordinate system is very useful for calculation. Another way to look at this is to consider the question, if spacetime is curved near massive objects, is spacetime straight away from massive objects? The conceptual significance of “straight space” is unclear and, because gravity permeates the entire universe, spacetime is at least minimally curved everywhere.

* * *

Clearly, there is no space or time that themselves can be measured or observed, let alone bent. Rather, the real universe is the particles. The idea that particles move from one point to the next and are capable of having a velocity at all reflects a very fundamental property of real particles – that real particles are continuous (see figure below).

Figure 3. Continuous structure of real particles.

We should not that in quantum physics, virtual particles do appear and disappear, thus producing the uncertainty inherent in the behavior of real (continuous) particles. In general, real particles trace linear (including curvilinear) paths in spacetime and cannot “skip over” increments of spacetime. For an object at point A at time 1 and at point B at time 2, the object must have occupied a continuous line of spatial and temporal locations. In particular, photons are



continuous, and matter, which is composed of photons, is also continuous. The conceptualization of a particle as a linear object in spacetime has been called a “worldline.” The term “worldline” comes from special relativity and is generally described as the unique path of an object as it travels through 4-dimensional spacetime. The worldline has proven to be a powerful concept, and the physics of worldlines is well developed.

From a conceptual point of view, one could ask whether the particle is best conceptualized as a “point” that “moves through” spacetime or is a line that exists in spacetime. Given that all the points along the worldline are equally real and none is preferred or special, and the relativistic idea that two points can’t exist simultaneously in any objective way, the idea of a “point-particle” becomes untenable. The observations are more simply explained by a conceptualization of particles not as points in space that move but rather as lines in spacetime that exist. The worldline is the particle, and the assemblage of worldlines that define the universe is spacetime.

Thus, the concept of spacetime is viewed as a manifestation of the linear nature of the real particles of which the universe is composed. As mentioned already, the particles we are talking about are photons, which are sometimes organized into matter particles (E=mc2). The matter particles (atoms and subatomic particles) are also lines, reflecting the linear structure of their constituent photons. The relativistic spacetime continuum tells us that these linear particles “exist” both before and after our subjective “now.”

Particles are linear objects, and we perceive parallel line-particles as mutually stationary points. Straight-line but non-parallel particles are moving at a mutual constant velocity, and curved particles are mutually accelerating. All the laws of physics apply perfectly well to a universe of line-particles (worldlines). For example, the collision of two particles and resulting velocity (direction) change of both particles are in reality two non-parallel lines that intersect at the collision point (in time and space) and diverge as two non-parallel lines beyond the collision point. The resulting angle of divergence in spacetime can be predicted by the pre-collision angle of the particles and the physics of the collision. The mathematics and physics of worldlines have been worked out in detail, and the term “line-particle” or just “particle” as used herein is intended to be synonymous with “worldline,” except that “line-particle” emphasizes the concept that particles are lines, not points that trace lines.



To convince ourselves that the universe is composed of linear particles, let’s consider taking a photograph of part of the universe. A photograph may be more objective than our experience of the universe. So let’s consider taking a photograph of a part of the universe where a family is all dressed up posing for a picture. In the early days of photography, the family members had to stay very still, because any movement while the shutter was open would blur the picture. Anyone who moved made a streak, tracing out the entire movement that occurred during the long exposure. So more sensitive (“faster”) films were made that allowed families to start smiling for pictures. The objective of more sensitive films was, of course, to “freeze” a moment as we remember it. So even though sensitive films (and sensitive digital photo-electric cells) need a finite time while the shutter is open to get an adequate exposure, the shutter speed is sufficiently fast, and the streakiness is thus sufficiently minimized, to give the appearance of a “frozen memory.” But memory is subjective, whereas the photograph, perhaps, is a more objective picture of the universe. And the judgment of every photograph that has ever been taken is that particles are linear. The older photographs, or any photographs with longer exposure times, record a larger sampling of the 4-space and even more obviously demonstrate the linear nature of the constituent particles that constitute the universe (see figure below).



Figure 4. Long-exposure photographs of portions of spacetime illustrate the

linear structure of particles.

* * *

Based on this discussion, we can conceptualize the universe as a network of linear particles. The line-particles are photons, some of which are organized into matter along parts of their lengths. To the extent that photons are continuous in spacetime, all real line-particles extend throughout spacetime. In 4-space, a group of photons that is organized into an electron, for example, appear as approximately parallel lines because their relative positions do not change much as along as the photons remain assembled into an electron. If decay of the electron results in the emission of a photon, the process appears in 4-space as a “kink” in the emitted line-photon, such that the line-photon becomes non-parallel relative to the photons that remain in the electron (see figure below).



Figure 5. Worldlines of photons organized into an electron that absorbs or

emits a photon.

The line-particles do not “move” but rather they “exist.” Our perception of this network of line-particles is a continuously moving series of “cross sections” of the network. Each cross section is our instantaneous perception, specifically the instantaneous making of a memory of sensory signals, particularly light and sound waves produced by particle interactions. This cross section is a 3-dimensional cross section that is constrained to be within the current “light cone” or “event horizon” of the observer, and each observer has a different light cone and progression of sensory cross sections of the universe. Because the cross section intersects each line-particle at a point, our intuitive experience of our surroundings is point-particles that move, rather than as static lines that we perceive in one direction of time (from past to future). In other words, our perception of the universe “moving” in one direction of time, from past to future, reflects the order in which we make memories, but not necessarily anything real or objective about the universe. Rather, we experience a static 4-dimensional network of line-particles (spacetime) as a 3-dimensional cross section that moves through the network of line-particles in the direction of time in which we make memories.



4. TIME DIRECTIONALITY AND ARROWS OF TIME

The spacetime continuum (block time) envisions a time-symmetric universe. All of time “exists.” In fact, in general, physical laws do not involve any time directionality. The laws of physics (but not the second law of thermodynamics, to be discussed later), including gravity, relativity, Newtonian mechanics, and many others, have no time directionality or asymmetry. For example, let’s consider again a collision between two particles, where you can use the worldlines (trajectories) of the particles before the collision to calculate their worldlines after the collision. No matter how you do the calculation, you could use the same physics to calculate the worldlines of the particles before the collision from their trajectories after the collision. The problem can be solved in either direction of time, and that is true for all physical laws. The process of photon emission from an electron discussed previously is the same process as photon absorption, just considered in the opposite direction of time. Matter and energy obey physical laws that have no time direction; all processes, such as photon emission/absorption, “exist” in both directions of time and are physically just as possible in both directions of time. Again, that is the relativistic concept of block time.

However, some physicists have nonetheless argued for an "arrow of time," that is, one direction of time that is objectively different from the other. The idea of an arrow of time means that the "positive” and “negative” directions of time are physically different. A time arrow can be defined as a quantitative property of the universe that consistently changes – continuously increases or decreases – in one direction of time. In other words, if we can observe a property of the universe “X” that consistently decreases (or increases) in one direction of time, that property is an arrow of time.

Numerous arrows of time have been defined. Arrows of time that we’ll discuss are the thermodynamic arrow of time, the cosmological arrow of time, the nuclear arrow of time, the radiative arrow of time, the biomass arrow of time, the biological evolution arrow of time, the memory arrow of time, the causal arrow of time, and the quantum arrow of time. This list includes the main of arrows of time discussed in the literature, but others can be defined.



The thermodynamic arrow of time is defined by the increase in entropy of chemical systems with time. Entropy is an arrow of time because one direction of time has states of lower entropy (the past) relative to the other direction of time, which has states of higher entropy (the future). The increase of the entropy of the universe with time is the second law of thermodynamics, which states that any sample of the universe that is isolated will increase its entropy until it reaches “equilibrium.” Boltzmann's law identifies the particle nature of matter (atoms) and the tendency of these particles to randomize with time as the underlying mechanisms for this arrow of time.

The cosmological arrow of time is the expansion of the universe with time, in which the volume of the universe increases with time. The cosmological arrow of time includes a unique event in the universe, the big bang, which exists in the past but not in the future. The future of the universe is predicted to be “heat death,” which is a universe in which entropy has increased to a state of universal equilibrium and the universe continues to expand indefinitely.

The nuclear arrow of time is the consistent decrease in the amount of matter in the universe with time. In nuclear reactions, matter turns into energy according to E=mc2. The photons (E) released from the matter (m) instantaneously travel at velocity c with respect to all matter in the universe. The time-reversed reaction – from energy to mass – is not observed in nature. All atoms are meta-stable and have non-zero decay constants; no natural process results in a net transformation of photons into matter (with the exception of photosynthesis, to be discussed later). There is no process that focuses light spontaneously to form matter, and all nuclear reactions are irreversible. The nuclear reaction of mass to energy may be written as mc2 E, where the arrow means a one-way, irreversible reaction, as in chemical equations that show the direction of irreversible (“spontaneous”) reactions. The decrease in matter, or increase in photons, in the universe toward the future direction of time (mc2 E) is the nuclear arrow of time.

The radiative arrow of time is the tendency for waves, from radio waves to sound waves to waves on a pond from throwing a stone, to expand outward from their source. This arrow is the increase with time of the average distances between particles (including energy) emitted from a common source. The radiative arrow of time is the reason that divergent waves are ubiquitous in nature, for example starlight emanating in all directions, whereas parallel waves do not occur naturally. Special engineering is needed to create parallel emissions, for example a laser beam,



which cannot be exactly parallel and only approach defeating this arrow of time. Convergent waves, of course, cross then diverge indefinitely.

The total biomass in the universe defines another arrow of time. Based on contemporary observations of life on earth, as well as on evaluation of the paleontological record, the mass of life (biomass) increases with time. Assuming that, at some time during the formation of the solar system, the early earth contained little or no life, the biomass of the earth has increased since the formation of the solar system. The paleontological record documents the spread of life forms to new niches during earth history, for example vertebrate life moving from the oceans onto the land in the Paleozoic Era. The observation that life overproduces and saturates niches indicates that appropriate habitat is the only constraint on increasing biomass. Thus, contemporary and paleontological observations are consistent with a biomass arrow of time.

The biological evolution arrow of time is defined by the increase in the complexity and order of life forms with time. “Complexity” generally refers to the number and types of parts of a system and “order” refers to the degree of correlation of movements of the parts. Herein, “order,” “complexity,” and “organization” will be used more or less interchangeably, as real processes generally result in changes in all these properties (see figure below).



Figure 6. Order vs. complexity.

Whereas “disordered” systems are near equilibrium, ordered systems are far from equilibrium and, absent a process to maintain the order of the parts of the system, will spontaneously slide toward equilibrium according to the second law of thermodynamics. With regard to life, evolution has resulted in an increase in the complexity and order of organisms with time, both in structure and behavior (space and time dimensions of the organisms). This complexity has been quantified and the degree of order and complexity of organisms has actually accelerated with time. For example, whereas the first 2 billion years of life was bacteria that changed little, the second 2 billion years went from bacteria to humans. Based on the paleontologic record, the life system has consistently increased in complexity and order for at least the past 3.5 billion years, which is one-quarter of the age of the universe (time since the big bang) and defines the biological evolution arrow of time.

The memory arrow of time is defined by the capacity of systems to remember prior times but not future times. Two forms of memory need to be distinguished with respect to an arrow of time. One type is psychological memory, our ability as humans to remember past events but not future events. Events that can be recalled are in the "past," whereas events that cannot be recalled are in the "future." Our entire perception of time is based on the concepts of past and future and the ordering of memories. The continual creation of memories creates the perception of a continuous



“movement” or “flow” of time from the known past to the unknown future. “Now” is the point in time, and “here” is the point in space, at which a memory of a sensory input is created. The other type of memory is physical memory. Physical memory is the idea that a physical system is the result of, and contains a “memory” of, past processes but not of future processes. For example, fossils and DNA contain information of past life on earth but not of future life. All systems have physical memory to some degree, thus all systems, including our brains, have some memory of past events. No system has “perfect” memory, i.e. a complete record of every particle motion, and no system contains no information as to its past.

Although memory is tied to time directionality, it is unclear whether memory is a valid arrow of time. Specifically, there is no property of the universe that consistently changes with time due to memory. One could argue that the total memory of the universe increases with time, but this is not necessarily the case. Both psychological and physical memories are continuously made and lost, so the total memory of the universe may not accumulate as it does in an individual organism. For example, consider the total memory of all human beings. Human beings are born, accumulate memories, and die. Although each individual accumulates memories, the population as a whole does not increase its cumulative psychological memory.

Two other arrows of time that have been mentioned in the literature are the causal arrow of time and the quantum arrow of time. The causal arrow of time is based on the notion that a cause precedes its effect. Birth, for example, follows a successful conception and not vice versa. However, it is surprisingly difficult to provide a clear explanation of what the terms "cause" and "effect" really mean. This difficulty arises from the fact that “cause-and-effect” is another subjective perception that masks the true nature of the universe. Specifically, just because processes occur in a consistent temporal order, for example birth before death, does not mean that birth “caused” death. Although birth is necessary for death, it is equally valid to say that death is necessary for birth. All organisms involve both death and birth and there is no reason to suppose that one “causes” the other. Additionally, it is not clear what property of the universe changes consistently to define a causal arrow of time.

I won’t pretend to understand quantum mechanics, and its conceptual underpinnings are as vague as its predictions are accurate. The quantum arrow of time arises from the wavefunction collapse, which is time irreversible. As the mechanism of wavefunction collapse is conceptually obscure,



it is not completely clear how this arrow links to the others, but a link to the thermodynamic arrow of time has been proposed. According to the modern physical view of wavefunction collapse, the quantum arrow of time is a consequence of the thermodynamic arrow of time (according to today’s Wikipedia). So, the quantum arrow of time, whatever it is, is a manifestation of the thermodynamic arrow of time.

What do all these arrows of time mean? In particular, does the universe have a real time directionality that must be reconciled with a universe of linear particles (spacetime)? At first glance, all these arrows of time appear to be independent processes, so the question becomes whether there is an underlying commonality to these arrows of time. The answer is “yes,” that all the arrows of time are related to the thermodynamic arrow of time, i.e. entropy. So let’s explore the thermodynamic arrow of time and how it could produce a spacetime with a past and a future.



5. ENTROPY AND STATISTICAL TIME DIRECTIONALITY

Before we proceed into the arena of thermodynamics, we need to define some concepts and terminology for thermodynamic “systems.” A “system” is any part of the universe we wish to consider, including the entire universe itself. The only requirement for defining a system is that we can measure or model the flux of matter and energy into and out of the system. The system “surroundings” is the source or sink for the matter-energy exchanged with the system. Thermodynamics can be viewed as an accounting system for changes in the matter-energy of a system. Three types of thermodynamic system can be defined: isolated, closed, and open.

An “isolated” system has no energy or mass transfer across its boundaries. The “surroundings” of an isolated system has no meaning because isolated systems have no matter or energy exchange, which is the only role of surroundings. In principle, according to the second law of thermodynamics, any part of the universe that is so isolated from the rest of the universe “spontaneously” approaches equilibrium, if it has not done so already. A “closed” system allows energy in and out, but not matter. Closed systems are useful to consider because we can attach the system boundary to material points and evaluate how the material behaves in response to addition or loss of energy. The energy flux into or out of a closed system results in changes of thermodynamic parameters such as temperature (heat transfer in-out of the system), pressure (work performed on or by the system), and other measurable properties of the overall system. The third and final type of system is an “open” system, which allows energy and matter exchange. Open systems are the most difficult to deal with, but also all natural systems are open systems. Nature has no test tubes or other apparatus to close or isolate systems and, to a small degree at least, even test tubes and other laboratory equipment are unable to completely prevent energy and mass transfer. In nature, celestial bodies come close to being closed systems, but even celestial bodies in space receive matter from meteorites and other celestial matter and of course receive energy in the form of starlight.



The only natural system that may be truly closed, and in fact isolated, is the universe itself. If the universe is, by definition, everything, there can be no energy or matter “outside” the universe to exchange with the universe. In thermodynamic terms, the universe is the only natural system that does not have an identifiable “surroundings,” because we have no evidence for anything “outside” the universe. Identification of the universe as an isolated system means only that the universe does not exchange matter-energy with the surroundings. The total matter-energy of the universe is constant if the universe is an isolated system. By contrast, all of the subsystems of the universe do have surroundings in the form of the other subsystems. As soon as we subdivide the universe into even two systems, one system becomes the surroundings of the other system and a trading partner for matter and energy. Therefore, the simplest interpretation of the universe from a systems point of view is that the universe is an isolated system composed of open subsystems. The open subsystems can be arbitrarily defined, but are typically defined as the boundaries of natural structures and processes we wish to consider, such as a planet, a galaxy, a snail, an ocean current, or any other part of spacetime we can map.

Systems can be continuous or dispersed. A continuous system is what we normally think of as a “system” and is defined by having one enclosing surface. But systems can also be “dispersed.” A dispersed system is a group of continuous systems that are so similar that we model them as thermodynamically identical (see figure below).

Figure 7. Continuous vs. dispersed systems.



The only requirement of a dispersed system is that we can measure or model energy and mass transfer in and out of all the constituent continuous subsystems, and the subsystems are all in contact with the same surroundings. The classic example of a dispersed system is a colloid, in which the colloids in an emulsion are treated as a single system. Other examples of dispersed systems are the individual organisms of a species, the quartz grains in a granite rock, falling raindrops, or the stars.

* * *

With the systems concept in mind, let’s explore the thermodynamic parameter called “entropy.” The idea of entropy arose from the analysis of steam engines in the early nineteenth century as a quantitative measure of the inefficiency of converting heat energy to measureable kinetic energy (thermodynamic “work”). “Work” is any net movement of matter, such as a breaking wave, a walking dog, or a solar flare. “Net movement” of matter means a measureable change in the structure of a system. The important point of classical thermodynamic entropy is that it is theoretically impossible, not just practically impossible, to convert heat to work without loss of “useful” energy, where “useful” energy is energy that can perform more work. In other words, any real process converts the work that defines that process into heat that can never be recovered as an equal amount of work. Therefore, real processes approach “equilibrium” with time, with equilibrium being the state in which all energy has been irreversibly converted to heat and no more work can be performed.

Entropy is a measure of the unavailability of a system’s energy to do work. “Spontaneous” natural processes, meaning processes that occur without human intervention, tend to smooth out differences in temperature, pressure, density, and chemical potential that may exist in a system. Entropy is thus a measure of how far this smoothing-out process has progressed. When a system's energy is defined as the sum of its "useful" energy – for example, the energy to push a piston – and its "useless” energy, i.e. the energy that cannot be used to perform work on the surroundings, then entropy may be visualized as the "useless" energy. The production of frictional heat when work is performed is an example of entropy creation and is the reason a perpetual motion machine is not possible.



The amount of entropy increase (dS) of a system due to addition of an amount of heat energy (dQ) in an isothermal and reversible process in which the system goes from one state to another is dS = dQ/T, where T is the absolute temperature at which the process is occurring. Thus, the increase in entropy is small when heat is added at high temperature and is greater when that same amount of heat (dQ) is added at lower temperature. To visualize how this definition of entropy works, imagine a large warm room with a cold drink that is getting warm. The cold drink is the system, and an increment of warming results in transfer of an amount of heat (dQ) from the room to the drink. The entropy change for the drink is dQ/T, where T is the temperature of the drink. The warm room (surroundings) loses the same amount of heat and actually decreases entropy by an amount dQ/T, where T this time is the higher temperature of the warmer room. Because T is greater for the room than for the drink, the entropy loss of the room due to transfer of an amount of heat dQ to the drink is smaller than the entropy gained by the lower T drink. Thus, the warming of the drink reflects a net increase in the total entropy of the room and drink, and the drink gets warmer spontaneously. The warming of the cold drink in the warm room increases the entropy of the universe, as do all real processes. The tendency for all processes to approach equilibrium in the same direction of time (our “future”) is a consistent arrow of time, the thermodynamic arrow of time.

Isolated and closed systems contain a constant amount of mass. The total entropy of an isolated system increases with time until it reaches equilibrium. The total entropy of a closed system also increases with time until it reaches equilibrium, unless energy is added that creates or sustains disequilibrium. The total entropy of an open system is more complicated to evaluate because its mass changes. For example, consider a 2 kg system at equilibrium with total entropy S. If we add to that system 2 kg of the same substance at equilibrium, that is, add another identical system to the original system, then the total entropy of the new 4 kg system is 2S (doubled), although no process occurred and there was no real entropy increase. A more useful way to express entropy (and many thermodynamic quantities) is “specific entropy,” which is defined as entropy per unit mass. Specific entropy is an “intensive” parameter, as opposed to an “extensive” parameter that depends on the amount of mass involved. For example, the specific entropy of our 2 kg system is 0.5S/kg, which is also the specific entropy of the combined 4 kg system. Specific entropy can be viewed as “entropy density,” which increases when work is performed in any process, but is not dependent on the amount of mass.



* * *

The idea of entropy was figured out without any assumption of the atomic (particle) basis of matter. In the late nineteenth century, when the atomic model of matter was still controversial, Ludwig Boltzmann proposed that entropy is a reflection of the atomic nature of matter and the tendency for those atoms to assume more probable configurations. Thus, entropy is just one example of a more fundamental arrow of time: the tendency of assemblages of particles, by virtue only of their particle nature (relative velocities), to “randomize” with time. The particles progress to more probable arrangements because they are moving relative to one another in random motion, within the constraints imposed by physical laws. Particle randomization occurs at all scales of particles, and this random particle motion at the atomic scale is “heat.” Conversion of heat to work involves converting the random heat motions of atomic particles into coordinated motion of particles, which is work, and all natural processes in the universe reflect the performance of work.

Boltzmann’s advance in understanding entropy is profound and is a key cosmological concept. His famous equation, which is imprinted on his gravestone, is S = klnW, where S is the entropy of a system, W is the number of distinct microscopic states available to the system, and k is a proportionality constant, Boltzmann’s constant. This equation means that increasing entropy is the randomization of atomic particles. The classical definition of entropy (dS = dQ/T) is only valid for a system at equilibrium, because temperature is defined only for a system at equilibrium, while Boltzmann’s statistical definition of entropy applies to any system. Thus the statistical definition is the fundamental definition of entropy.

In addition to being more general than the classical definition of entropy, Boltzmann’s statistical entropy has a conceptually simple underpinning, the tendency for particles to randomize in the future direction of time. Entropy change has been defined as a change to a more disordered state at a molecular level, but in recent years, entropy has been interpreted in terms of the "dispersal" of energy. In either case, the statistical definition of entropy is the most fundamental definition of entropy from which all other definitions and all properties of entropy can be derived. Entropy is a measure of the degree of randomization of the constituent particles in any system, and the most



random configuration – the most probable distribution of particles consistent with the physics of the system – is the stable equilibrium state.

One way to visualize entropy is to imagine a box of 100 pennies. Imagine the pennies in the box are all heads up. When you start shaking the box and create random flipping of the pennies (motion), some tails start popping up. The tails will pop back to heads, but overall the number of tails will increase until there are about 50 heads and 50 tails. From the physics of the system we know that each coin has a 50% chance of being heads, and this property of the individual coins predicts that the equilibrium configuration of the box of coins is about an equal number of heads and tails. Additional shaking will not change this state, which is the equilibrium state of the box of pennies. A frequency diagram of head-tail ratios would be a bell curve centered on a ratio of 50-50, and the lower frequencies of ratios away from 50-50 reflects “dynamic” equilibrium.

Since Boltzmann’s time, there appears to be a convergence of opinion that all arrows of time directly reflect the fact that a group of particles in relative motion will progress with time to their statistically most likely configurations. The term “arrow of time” was proposed in the 1920’s by British astronomer Arthur Eddington to distinguish a direction of time in 4-dimensional spacetime. Eddington stated something to the effect that the introduction of randomness is the only thing in nature that cannot be undone, and time's arrow is a property of entropy alone. The conceptual relationship between particle randomization and time directionality is still the accepted model. Thus, all time directionality is a manifestation of the particle nature of matter-energy and the statistical tendency for particles to randomize in a consistent direction of time (the future). The box of pennies reflects statistical time directionality; given two states of the box of pennies, state A with a lot more tails than heads and state B with about equal numbers of heads and tails, state A came first.

* * *

We now have time directionality that is defined by randomization of particles in the future direction of time. Now let’s consider if and how this statistical time directionality squares with the laws of physics, which are time symmetric. As we discussed, particles are linear, one-dimensional structures in spacetime. Time directionality and entropy tell us that cross sections of the particle network are progressively more disordered in the future direction of spacetime



and, equivalently, more ordered in the past direction. As discussed, the laws of physics apply to individual particle interactions, like particle collisions, subatomic particle interactions, and gravitational attraction. So if we focus on an individual particle and its interactions with other particles, all laws of physics are followed exactly. And because the laws of physics are time-symmetric, individual particles and particle interactions have no time directionality. Time directionality is defined only by randomization of an assemblage of particles, thus the statistical basis of time directionality.

The box of pennies is very instructive. Consider a single penny – a particle – in the shaking box. Over time, the penny will be heads half the time tails half the time. The half-heads and half-tails property of the penny is time symmetric, because the bouncing penny individually follows the laws of physics. In other words, if you take a movie of a single penny, you can run the movie backward and forward and you can’t tell which direction of the movie is the original direction. The individual particle has no time directionality. Each of the 100 pennies is like that, and none of them has an arrow of time. However, as a group, the progression from all heads to equal numbers of heads and tails is a very definite arrow of time, and you could easily tell whether a movie of the group of pennies in the shaking box is being played in the correct direction of time. Again, time directionality is a statistical property of a group of particles, but not of the individual particles.

Matter-energy particles are the same way. Individual particles do not display a time evolution. A hydrogen atom is always a hydrogen atom (excepting nuclear reactions, to be discussed later). Most importantly, a photon is always a photon. As we’ve discussed, the universe is composed fundamentally only of photons; a photon can’t be created or destroyed. A photon can be a “free” photon that wanders the universe at speed c (light speed), and groups of photons can be organized into matter that can travel only at velocities less than c. The universe is composed only of photons, and the network of line-photons that is our universe becomes more disordered in the future direction of time. Time-asymmetric natural processes (work) in the subsystems of the universe reflect the overall disordering process, and these processes have been identified as arrows of time.

* * *



Thermodynamic “free energy” refers to the amount of work that can be extracted from a system. Free energy is calculated as the total energy of a system minus the product of the entropy of the system and its absolute temperature. Recall, the product of the entropy and temperature is the "unusable energy" (heat) and the difference between the total energy and the unusable energy is the “useful energy" or free energy.

Free energy is subject to irreversible loss in the course of performing work, because total energy is conserved and the entropy is subject to irreversible gain. As the entropy of the system increases to equilibrium, the free energy of the system decreases to equilibrium. At equilibrium, entropy is maximized and free energy is minimized, both totaling the total energy of the system throughout. Free energy has been formulated in many ways for various conditions, for example the Gibbs energy for systems at constant pressure and temperature and the Helmholtz energy for more general conditions. The main point for us is that the free energy of the universe decreases in the future direction of time, commensurate with the entropy increases.

Free energy is similar to “potential” energy in mechanics, and in both cases the process of converting free or potential energy to kinetic energy (work) results in a permanent, irreversible loss of at least some of the free or potential energy. Also in both cases, “permanent” and “irreversible” have meaning only with respect to time directionality. Mechanical potential energy is an example of the more general term “free energy,” which we will take to mean all usable energy in a system. All arrows of time are defined by natural processes that reflect the loss of free energy to heat.



6. ENTROPY AND ARROWS OF TIME

Ever since Eddington’s arrow of time, a consensus has grown that the various arrows of time reflect the tendency of particles toward more probable configurations in the future direction of time (higher entropy). The second law of thermodynamics, in the classical sense, expresses the tendency of networks of line-atoms to “spontaneously” progress toward more probable configurations with time. At the subatomic scale, the second law of thermodynamics, in a general sense, expresses the tendency of networks of line-photons to “spontaneously” progress toward more probable configurations, as manifested by nuclear decay (mc2 E). Thus, nuclear decay is a time-asymmetric process, the nuclear arrow of time. Special relativity does not prohibit conversion of energy to mass (E mc2); rather, this reaction is just not observed because it is so unlikely to occur. At the particle scale of nuclear decay, photons that are organized into matter lose that organization as they are emitted at the speed of light c. All nuclear reactions lead to a state of greater entropy, i.e. to a more probable configuration of the photons that constitute matter. In quantum terms, the total energy of the system is distributed over a larger number of quantum states. In thermodynamic terms, the parent nucleus is a lower entropy (higher free energy) state of its constituent photons than the daughter nucleus plus the emitted photons.

We live in a universe in which all matter is unstable, i.e. undergoes some finite rate of nuclear decay, and ultimately decays to energy, albeit over extremely large time scales for the more stable matter particles (mc2 E). This observation raises the question of the origin of all this unstable matter. The matter in our universe was and is created by “nucleosynthesis” in a two step process, the first step being “primordial” nucleosynthesis, which was a one-time event soon after the big bang, and the second step was and continues to be nucleosynthesis in stars via nuclear fusion. Stellar nucleosynthesis is an entropy-increasing process that emits energy (photons) during the fusion reactions that form heavier atoms from lighter atoms. Therefore, the net result of nucleosynthesis is loss of mass by conversion to starlight. In stellar nucleosynthesis, the lighter atoms (mostly hydrogen) created in the primordial nucleosynthesis are fused to form



heavier elements, then the resulting heavier matter is either further fused or decays (fission), both of which result in net conversion of matter to free photons (mc2 E). Thus, the rate of nucleosynthesis is slowing with time as the lighter elements formed during primordial nucleosynthesis are depleted during stellar nucleosynthesis.

Stellar fusion appears to be by far the most important entropy increasing process in the universe, as matter irreversibly decays to free photons (starlight). Thus, in addition to the “heat death” of matter as the constituent atoms are randomized, we can imagine a “light death” of energy in which atoms are further randomized into starlight. The “absolute” equilibrium state of the universe – the maximum entropy that the universe can attain – is a universe of free photons traveling at velocity c. A universe of random photons would contain no information of its origin, except that it was smaller in the past because the universe would continue to expand. In this state of absolute equilibrium, it is statistically impossible for photons to coagulate into matter or for any natural process to occur. Fortunately, there is no evidence that this state is actually achieved in nature. The main point here is that the nuclear arrow of time is clearly related to the second law of thermodynamics, both of which reflect the randomization of particles – photons and atoms – in a consistent direction of time (toward the future).

* * *

The statistically based time directionality of nuclear and chemical systems is a direct reflection of the scales at which matter and energy particles are organized: photons are organized into atoms and atoms are organized into molecules. The organization of these particles takes energy. The energy that holds the photons together in atoms is nuclear energy, which is a form of free energy that is lost to entropy in nuclear reactions. Matter is a high free energy, low entropy state of photons, and all matter “spontaneously” decays to the lower energy, higher entropy state of free photons (light) in a consistent direction of time. More generally, the matter-energy that defines our universe is an assemblage of photons that are organized at several scales, and together these scales of organization build up the observed universe (see figure below).



Figure 8. Scales of photon organization.

These scales of organization directly reflect the physics of photons. Physics recognizes four fundamental “forces” that govern all particle interaction: the electromagnetic force, strong force, weak force, and gravity. These forces are all properties of photons. The strong and weak forces are short range forces that create the subatomic, atomic, and molecular scales, and gravity is a long range force that creates the celestial, galactic, and universal scales of organization of the photons of the universe. In spacetime, these forces govern the relative orientations of line-particles according to the physics of worldlines.

Natural processes that increase entropy in the future direction of time characterize each scale of organization. Beginning at the largest scale, the universe is composed of galaxies in mutual motion, the net result of which is that they are moving farther apart and the universe is expanding against their mutual gravitational attraction. This expansion can be described as a large number of objects with a random spectrum of relative velocities, ranging from nearly zero to nearly the speed of light. Galaxies are composed of celestial bodies, which are themselves composed of molecules (including ions and single atoms), which are held together in celestial bodies by gravity. The strong, weak, and electromagnetic forces hold photons together in molecular, atomic, and subatomic particles.



These scales of organization reflect the total state of organization of the photons that constitute the universe. In principle, we can define the total entropy of the universe as the total entropy of its constituent photons based on various Boltzmann-type calculations for the various scales of organization. In the forward direction of time, the photons in the universe, including those organized into matter, overall move up the table, from galaxies to photons, with a theoretical “absolute” equilibrium state of free photons at the top of the table. Note that at “absolute” equilibrium, all the scales of organization shown in the above figure disappear, except the largest and smallest scales, that is, the universe and its constituent photons (which are all free photons at equilibrium).

Statistically based time directionality is defined by the randomization of ordered systems and is ubiquitous in everyday experience. All structures, such as automobiles, computers, and our bodies, require maintenance (work) just to maintain the precise structure (organization) needed to function. Seemingly small deviations from the required configuration, such as a fracture in an engine block, a scratch on a hard drive, or a constricted artery, cause malfunctions that must be “repaired,” which is work performed on the system to restore the system to its former, less probable structure.

* * *

The cosmological and the radiative arrows of time are based on the principle that disordering of a system includes expansion (unless the system is somehow constrained). So with our box of pennies, imagine the box is large and the universe of 100 pennies, all heads, are in the middle of the large box. Shaking will not only produce more tails but, as the pennies bounce randomly around, the outer boundary of the area containing pennies increases. Similarly, at the big bang, all the matter-energy in the universe was “emitted” randomly in all directions, which is manifested 14 billion years later in the red shift and our concept of an expanding universe. The radiative arrow of time is the same phenomenon, but for matter-energy emitting processes on a smaller scale, such as emission of photons from stars.

As mentioned, the causal and quantum arrows of time, to the extent they are arrows of time, are both manifestations of the second law of thermodynamics in the general sense, that is, the statistical necessity, given the huge numbers of particles involved in natural processes, toward



more probable configurations of those particles with time. Other arrows of time can be defined, but the underlying mechanism of all time directionality is randomization, the “random walk” of large numbers of particles, and the “particles” can be photons, atoms, or galaxies.

It has been argued that the life-related arrows of time, identified here as the biomass, biologic evolution, and the psychological memory arrows of time, may disobey the second law of thermodynamics. The basis of this argument is that life forms are highly organized systems. However, life systems (organisms) increase the entropy of their surroundings more than their own entropy decreases. Thus, life is inefficient in creating organization, and life processes result in a net increase in the entropy of the universe, just like any other real process. Life is no exception to the second law. Life is like the warm room and the cold drink; the warm room decreased entropy, but not as much as the entropy of the cold drink increased. However, although life obeys the second law of thermodynamics, life is different from nonlife. We’ll return the phenomenon of life later and explore more fully the biomass, biologic evolution, and the psychological memory arrows of time. For now, suffice it to say that life, like any real system, obeys the second law, and the second law of thermodynamics – in the most general sense meaning all forward-time randomization of particles – explains all time directionality in the universe.



7. THE BIG BANG AND HEAT DEATH – THE ENDS OF TIME?

We’ve boiled down time directionality in our universe to an inexorable randomization and disorganization of the photons that constitute the universe. That directionality commenced with the big bang and, assuming that the randomization of photons will continue into the future, will end in heat death and ultimately light death – unless some other process intervenes. However, the fact the universe is not free photons at equilibrium indicates that some other process is at play to create disequilibrium. Similarly, the fact the universe is not a super-dense mass held at the big bang state forever by all the gravity in the universe also indicates that some other process is at play to counteract gravity. So let’s look more closely at where the arrows of time begin and end, the big bang and heat death.

The current frontiers of our conceptualization of the spacetime continuum are the big bang at one end and, at the other end of spacetime, the heat death of the universe. We’ll use the term “heat death” in a general way to mean “light death,” the equilibrium state of the universe predicted by the “general” second law of thermodynamics, meaning the randomization of all particles toward free photons with time. The big bang is in the “past” and heat death is in the “future.” Both concepts are extrapolations – extrapolations in both directions of time from our location in time – of the expanding and randomizing nature of the universe. The idea of the big bang is an extrapolation into the past to a smaller, more organized universe, and heat death is an extrapolation into the future of a larger, less organized universe.

The idea of the big bang developed in the early twentieth century based on an observed Doppler effect, a “red-shift” of light from other galaxies. The consistent red shift of galaxies indicates that galaxies are not static but rather are moving away from the earth and, assuming that the earth is not in any special vantage point in the universe, that galaxies are moving away from one another. During the 1920’s, Edwin Hubble’s measurements of the distances to these galaxies culminated in 1929 with "Hubble's law." Hubble's law is the observation that the magnitudes of the red shifts, and thus of the velocities of the galaxies (relative to our galaxy), are proportional to their distances from our galaxy. Galaxies that are farther away are moving faster. This observation is



interpreted as “expansion of the universe,” or more precisely that all galaxies are growing farther apart with time. Furthermore, the starlight from galaxies, and all light generated since the big bang, including the cosmic microwave background (CMB) radiation generated soon after the big bang, is traveling randomly in all directions at speed c. The universe is growing larger, so in the past it was smaller and, at the “beginning” of the universe, the universe was at some minimum size. The idea that our universe began in a much denser state than today and from that dense state commenced expanding to its current state is called the “big bang.” The initial, maximum density state is the “big bang state,” and the entire evolution of the knowable universe is a continuation of the big bang process (expanding universe).

The proportionality between the velocities and distances of galaxies (Hubble’s law) is predicted by a big bang in which matter-energy is emitted randomly. Matter-energy that was emitted at higher velocity at the big bang should now be farther away, and that is observed. Like all arrows of time, the expanding universe can be derived from the statistical definition of entropy, the randomization of particles in a consistent direction of time. Alternatively, the expanding universe can be described mathematically as “expanding spacetime,” a coordinate system that expands, but conceptually the real process is galaxies and photons in random relative motion. However, the galaxies themselves are not expanding; the stars within each galaxy are not growing farther apart, and individual stars and planets are not getting larger. Hubble’s law applies only to the relative motions of galaxies, not to smaller scale structures. The expanding universe and the cosmological arrow of time reflect intergalactic-scale entropy increase – randomization of galaxies as an assemblage of particles.

The reverse-time extrapolation of the expanding universe to zero volume projects this state of the universe – the “singularity” – has having occurred about 14 billion years ago (a current measurement is 13.75 ± 0.17 billion years). The actual initial state of the universe, the big bang state, has been evaluated in several ways. The first approach to the big bang state is general relativity. Today’s Wikipedia defines a “singularity” as “a point at which a given mathematical object is not defined, or a point of an exceptional set where it fails to be well-behaved in some particular way.” The relativistic prediction for the state of spacetime at the big bang is that the universe was infinitely dense, the gravitational field was infinitely high, the universe was infinitely small, and all laws of physics broke down. The universe was undefined at the big bang. A singularity is a mathematical concept, but it is uncertain whether real particles actually



achieve these infinite magnitudes or disobey the laws of physics. Because a singularity has not been observed in nature or the laboratory, a conceptual model of the universe with a singularity at the big bang is more complex without explaining any more data. By definition, a singularity has not been and cannot be observed and there is no reason to suspect that real particles can disobey the laws of physics or disappear into nothing. Moreover, the singularity concept of the big bang requires that our finite universe is capable of being infinitely dense, but again there is no way to test this prediction. The singularity idea is a boundary condition for concepts of the big bang; the singularity can be approached but may not be achieved in nature. A cosmology with a singularity requires a conceptual mechanism for real particles to achieve infinite magnitudes and to disobey physical laws while explaining no additional data, so a cosmology in which a singularity is never achieved is a simpler hypothesis consistent with the data. However, such a model needs a way to avoid the singularity.

The inclusion of particle properties leads to the second approach to the big bang, particle physics. Particle accelerators have provided critical data on particle properties at energies that are very high and approach the singularity conditions. From this information and calculations of the total gravity of the particles of the universe, physicists have constructed models of the big bang to within a fraction of a second of the singularity. The models are based on the physics of particles at high energies, which further constrain models for the big bang state. Particle physics thus provides a boundary condition for the big bang state, and this boundary is “after” the singularity.

The inclusion of observations of the cosmos – astrophysical or cosmological “field data” – leads to the third approach to the big bang, astrophysical data. Astrophysical observations are the “hard data” of cosmology – the aspects of today’s universe that reflect its natural history. The big bang model is based on four observations, sometimes called the “four pillars” of the big bang theory, which can be explained by a single conceptual model, the big bang model. The first pillar is the observed abundances of light elements formed during “primordial nucleosynthesis,” which occurred 3 to 20 minutes into the big bang. The relative abundances of helium, lithium, and deuterium in the universe match quantitative predictions. The second pillar is the CMB (cosmic microwave background) radiation, which permeates the universe. The CMB radiation is predicted to have been emitted during the recombination period, about 380,000 years after the singularity, and was famously and accidentally measured in the early 1960’s at Bell Laboratories



by Arno Penzias and Robert Wilson. The third pillar is the observed expanding universe, Hubble’s measurements. The fourth pillar is the structure and distribution of galaxies, which agree with big bang simulations but most importantly are not compatible with a steady state (unchanging radius) universe.

All three approaches – general relativity, particle physics, and astrophysical data – are combined in the current “standard” model of the big bang, also called the “Lambda-Cold Dark Matter” (ΛCDM) model. The ΛCDM model is a numerical model based on general relativity and other physical laws, and quantitatively relates six parameters: physical baryon density, physical dark matter density, dark energy density, scalar spectral index, curvature fluctuation amplitude, and reionization optical depth. Amazingly, properties of the universe such as the Hubble constant and the age of the universe can be quantitatively predicted from these parameters. The model describes a dynamic, evolving, non-equilibrium universe with a fixed quantity of matter-energy (isolated system). The (ΛCDM) model has been called the “standard” model of the big bang and provides a detailed natural history of the universe (see figure below).



Figure 9. The standard (ΛCDM) big bang model, showing spacetime locations the four pillars of the big bang (red numbers): 1 = light element abundances;

2 = CMB radiation; 3 & 4 = distribution and expansion of galaxies.

The upper-left diagram in the above figure depicts all of spacetime from the singularity to the present time, and the other three diagrams show increasing detail of the universe near the singularity. The earliest event in the universe that has left an observable imprint is the primordial nucleosynthesis event (“1” in the above figure).

The lambda (Λ) in ΛCDM stands for a cosmological constant, which is associated with “dark energy” that drives the expansion of the galaxies against the attractive effects of gravity. According to the ΛCDM model, about 73% of the energy density of the universe is estimated to be dark energy. The current values of the six model parameters indicate that expansion of the universe is accelerating and the universe will expand forever.



Cold dark matter is the “CDM” in ΛCDM and is a form of matter necessary to account for gravitational effects observed in very large scale structures, including anomalies in the rotation of galaxies, the gravitational lensing of light by galaxy clusters, and enhanced clustering of galaxies, which cannot be accounted for by the quantity of observed matter. CDM is described as being “cold,” which means its speed is far below the speed of light, and is possibly “non-baryonic,” meaning it may consist of matter other than protons and neutrons. CDM is currently estimated to constitute about 23% of the mass-energy density of the universe. The remaining 4% of the matter-energy of the universe, after the 73% dark energy and 23% CDM, is the observable universe, including the subatomic particles, chemical elements, and electromagnetic radiation of which all the visible planets, stars, and galaxies – “our world” – are made.

Conceptually, dark energy and cold dark matter represent the equivalent amount of energy and matter required to produce the otherwise inexplicable behavior of observable matter-energy. The real observation is that observable matter-energy has some inexplicable behaviors, which could be a limitation of the model rather than meaning that 96% of the universe goes unobserved. Therefore, for our conceptual model, the best view of dark energy and CDM is that these terms represent the unexplained behaviors of observable matter. Essentially, dark energy represents expansion of the galaxies against gravity, and CDM represents local motions of galaxies that cannot be explained by the gravity of observed matter or by any other own force.

The ΛCDM model includes a single originating event, the initial singularity, which was the abrupt appearance of expanding spacetime at an extreme temperature. All ideas concerning the appearance of the universe (cosmogony) are speculative and within the realms of philosophy and the quest for quantum gravity. From a conceptual point of view, the “singularity” is the reverse-time projection, or extrapolation, of the reverse-time “shrinking” universe to zero volume. This concept of the singularity does not mean the singularity is ever achieved in nature, it only means that we can conceptually extrapolate our forward-time expanding universe backward in time, an extrapolation backward to the point in spacetime at which the volume of the universe would be zero if the universe did indeed appear from nothing. Based on the standard model, the actual big bang state of the universe is a singularity or is constrained to be between the singularity and the primordial nucleosynthesis event, that is, within the “first” three minutes of spacetime. Again, the primordial nucleosynthesis event is the earliest of the four pillars of the big bang model (see above figure).



The standard big bang model of the universe prior to primordial nucleosynthesis is based on general relativity, high-energy particle physics, and other physical laws. The earliest part of the universe in this model is the Planck epoch, which extends from the singularity to 10–43 second after the singularity. Between 10–43 seconds and 10–36 second was the “grand unification epoch” in which gravitation begins to separate from the other three fundamental forces (electromagnetism and the strong and weak nuclear forces). This was followed by the “inflationary epoch” (10–36 seconds and 10–32 second), during which some photons became virtual quarks and other particles that decay quickly. Later, the four forces all separated and various subatomic particles formed during the electroweak epoch, quark epoch, hadron epoch, and other states of the universe predicted by the physics of particles at extremely high energies, supersymmetry theory, and other physical laws and models (see above figure).

By about a second after the singularity, protons and neutrons formed. After 10 seconds, leptons and anti-leptons are annihilated and the universe is dominated by photons during the photon epoch, during which photons interact with protons, electrons, and (eventually) nuclei, and continue to do so until 380,000 years after the singularity. During the photon epoch, from 3 to 20 minutes after the singularity, protons (hydrogen ions) and neutrons combine into atomic nuclei in the process of nuclear fusion. After 20 minutes, the temperature and density of the universe fall to the point where nuclear fusion cannot continue. At this time, there is about three times more hydrogen than helium-4 (by mass) and only trace quantities of other nuclei, a ratio that can be measured today and is the earliest of the four pillars of the big bang (“1” in above figure). No evidence of earlier events has been found.

By about 380,000 years, the hydrogen and helium from primordial nucleosynthesis, which are actually just nuclei, begin to capture electrons, making them neutral atoms. This process is relatively fast (actually faster for the helium than for the hydrogen) and is known as recombination. Because the atoms in the universe are neutral, the photons can travel freely; these photons are the cosmic microwave background (CMB) radiation observable today (“2” in above figure). The release of the CMB photons during recombination and neutralization of matter was followed by the “dark ages,” which lasted until stars began forming about 100 million years after the singularity. The first stars start the process stellar nucleosynthesis, which is the process of fusing the light elements that were formed in the primordial nucleosynthesis



(hydrogen, helium and lithium) into heavier elements (“3” & “4” in above figure). Stellar fusion continues to generate heavier elements today, which form planets and life.

* * *

As discussed above, time directionality in our universe is an inexorable randomization and disorganization of the photons that constitute the universe. That directionality commenced with the big bang and, assuming that the randomization of photons (increasing entropy) has occurred continuously since the big bang, the big bang represents the minimum entropy state of the universe. In other words, at the big bang, the particles that constitute the universe were more organized than today, and from that state the particles have been continuously becoming more disordered, according to the generalized second law of thermodynamics (randomization of particles at all scales in the future direction of time). The disordering of the universe is manifested in all natural processes at all scales, from nuclear decay to plate tectonics to the expanding universe.

The idea that the universe began in an ordered (low entropy) state, as Eddington first suggested, is well accepted. The only other explanation for our disequilibrium universe is that the universe is supplied with energy and matter from “outside” the universe. According to this idea, “externally” supplied energy and matter maintain disequilibrium (organization) in the universe and could even reverse randomization of particles. This “open universe” model envisions a universe that is an open system that receives matter-energy from unspecified surroundings. However, there is no evidence for an outside source of energy-matter, so this hypothesis is a more complex model than a low-entropy big bang, without explaining any more data. Additionally, the “outside matter-energy” hypothesis begs questions about how this energy-matter moves “into” the expanding universe, not to mention the question of what it even means for matter-energy to have come from “outside” the universe if the universe is everything. Clearly, a minimum entropy big bang is the simplest model consistent with the randomization of particles in the future direction of time and is consistent with the ΛCDM model of the universe as an isolated system.

Because the big bang is the minimum entropy state of the universe, the big bang problem requires a mechanism to achieve this low entropy state, within the constraints of the ΛCDM



model. Although the big bang is entirely defined by particle randomization, no model currently exists for the minimum entropy state of the universe at the big bang. However, it seems clear that a singularity or disappearance of everything does not explain the extreme order and complexity of all the real particles at the “beginning of time.” In fact, there is no direct evidence that the universe even existed prior to the primordial nucleosynthesis, which is the earliest of the big bang “pillars.” Recall, the first 3 minutes of the standard big bang timeline, including the singularity, hadron epoch, etc., are based on theoretical extrapolations, not on astrophysical data, and thus constrain but do not predict the evolution of the early universe (pre-primordial nucleosynthesis).

* * *

Now let’s consider the “other end” of spacetime. Whereas the second law of thermodynamics predicts a highly ordered beginning to the universe, it also predicts a highly disordered future to the universe, the heat death of the universe. Heat death is nothing more than equilibrium and represents the maximum entropy state of the universe. This happens when all free energy has dissipated via natural processes. Since energy ceases to flow, no more work can be acquired from energy transfer. Since no more work can be extracted from the universe, the universe is effectively “dead.” As discussed previously, given sufficient time, matter will degrade ultimately to light, and we can define an “absolute equilibrium” or “light death” of the universe consisting only of photons traveling at speed c. Heat death has also been called the “big freeze,” because the temperature of the universe approaches absolute zero.

Obviously, gravity works against the expanding universe and has the potential to counteract heat death, at least in part. The “big crunch” idea proposes that the expanding universe is counteracted by the attraction of gravity sometime in the future, such that gravity slows the expansion. Ultimately, the expansion comes to a halt, and then the universe contracts back on itself under the mutual gravitational attraction of the matter-energy of the universe. If only gravity is at work, this mechanism could produce big bang “cycles,” with a universe that repeatedly expands, as at the current time, then contracts due to gravitational attraction to another big bang. This hypothesis avoids heat death, in part, and explains how the big bang state may be attained via gravitational collapse. The “in part” means that gravity can collapse the universe, potentially to a singularity, but gravity does not seem to have the potential to create the



organization needed for a minimum entropy big bang. On this point, current thinking on the big crunch, as summarized in today’s Wikipedia states “because entropy continues to increase in the contracting phase, the contraction would appear very different from the time reversal of the expansion.” The big crunch envisions a gravitational reversal of the cosmological arrow of time without reversing the other arrows of time. The big crunch is a model that simply states what would be expected to occur if only gravity were at work. The mutual gravitational attraction of the matter-energy of the universe is certainly a physical constraint on concepts of the natural history of the universe, but entropy is also at play. In order to avoid heat death and to achieve a big bang state, something is needed that reverses the inexorable randomization of particles at all scales.

The road to heat death involves creation of more heavy elements via stellar nucleosynthesis, nuclear decay of the heavy elements, and an over increase in the number of photons released from matter to travel the universe at speed c. The decreasing amount of matter will be increasingly concentrated in neutron stars and black holes. Based on the decay constants of the more stable elements, the rate of conversion of matter to photons during equilibration of the big bang state will slow asymptotically over trillions of years. Unlike age of the “beginning” of the universe, which can be accurately calculated to be about 14 billion years, the “end” of the universe is predicted to be a slow process that can last trillions of years with no clear definition of the “end state.”

The singularity and heat death are the current boundary conditions placed on spacetime. Whether these states are actually achieved in nature is unknown, and no evidence exists that the universe was ever in either of these states. Additionally, from the point of view of spacetime being the assemblage of the line-particles that constitute that universe, these boundary conditions (big bang and heat death) are based only on the organization of the particles that constitute the universe and does not address their continued existence (or nonexistence) beyond these boundaries. In other words, the big bang and heat death define temporal “endpoints” of spacetime based on the limiting conditions of organization and disorganization of the assemblage of line particles, but in no way terminate the existence of the line-particles themselves nor their relative motions and thus do not terminate spacetime. This statement is certainly true of heat death, but the behavior of particles as the universe vanishes to zero toward the singularity is less clear.



8. SPACETIME, DIRECTIONAL TIME, AND ENTROPY GRADIENTS

As we’ve discussed, time directionality is defined by randomization of particle assemblages. This directionality extends through the known extent of spacetime, which as currently understood extends from the big bang to heat death. The big bang is the minimum entropy state of the universe and heat death is the maximum entropy state of the universe. With these concepts in mind, let’s return to the question of reconciling block time and directional time.

Particles of all observable scales – all built from photons – become more disorganized with time. This tendency toward more probable configurations defines time asymmetry/directionality. Time directionality is a property of groups of particles, but not of individual particles, and time directionality is defined statistically, not by physical laws. In particular, one “end” of our network of line-particles (spacetime continuum) is more ordered than the other “end.” The universe has an “entropy gradient,” defined by the increasingly disorganized state of the particles of the universe in the “future” direction of time. In other words, for any cross section of the 4-dimensional line-particle network, which we perceive as an “instant in time” in a 3-dimensional point-particle universe, the entropy of the universe at that cross section of spacetime is less than in the next cross section of spacetime, where “next” refers to the future direction of time.

These conceptualizations of spacetime and of time directionality are completely compatible. All of time “exists,” as envisioned by relativistic block time, and one end of the network of line-particles (worldlines) is more organized than the other end. Time can be conceptualized as a gradient in the entropy of the universe, rather than a “progressing” property. The entropy gradient is defined by an assemblage of one-dimensional linear particles, and these line-particles as a group display a statistically based entropy gradient. Past and future exist, and the arrows of time are compatible with the block time.

The concept of “entropy-gradient time” means that the time dimension has directionality but does not “progress.” Time is asymmetric and directional, which we take here to be synonymous, but is not “progressive,” which we take here to mean an objective “now” in the universe that



progresses toward the future. As is the case with the spacetime continuum (block time), an entropy gradient does not have a “preferred” direction; one direction is no more “real” or “valid” than the other direction. Like the north and south poles of a magnet, future and past are defined only by being in opposite directions of each other. An entropy gradient is analogous to a railroad or highway grade to go over a hill. The reality of the hill is the gradient, which may be 2 feet per 100 feet (2% grade). The experience of the gradient – working hard to climb the hill versus coasting down the hill – is subjective. The hill, like block time or entropy gradient time, is just as real regardless of which way it is traveled or considered. “Uphill” and “downhill” are subjective, the “hill” is real. The entropy gradient concept of time directionality is the same, and is consistent with both relativistic block time and the arrows of time.

From the point of view of entropy gradient time, all the arrows of time can be described and are equally valid in either direction of time. For an arrow of time for which a universal quantity increases in the future direction of time, for example the increasing radius of the universe (cosmological arrow of time), the same arrow of time can be described as a universal quantity that decreases in the reverse direction of time, for example the decreasing radius of the universe in reverse time. Thus, the cosmological arrow of time can be described as the decreasing radius of the universe in the reverse direction of time. Neither direction of time is “preferred” or more “real” in any objective sense. By contrast, there is no viable conceptual model of the universe with an objective time that moves or progresses from past to future.

The physical manifestation of the entropy gradient is the increase in the organization of worldlines in one direction of time. The universe consists only of line-photons, and the relative orientations of the line-particles in 4-space are controlled by the physical properties of photons, specifically the strong, weak, electromagnetic, and gravitational forces. These forces constrain (but cannot predict) the organization of photons into matter and celestial bodies. All these forces keep the line-photons together throughout their lengths, so the universe has the structure of a cable made of many strands (line-photons), not of separate strands strewn about randomly. However, the strands become more “frayed,” more disorganized, in one direction of the cable. This linear structure of the universe, which is a function of the linear structure of its constituent photons, is the factor that distinguishes the time dimension from the three space dimensions. The time dimension is measured parallel to the “cable” universe, and the three space dimensions are measured perpendicular to the cable length. The entropy gradient is the increase in the



organization of the line-particles (worldlines) in one direction of time, toward the past, or described in another way, the decrease in the organization of the line-particles in the other direction of time, toward the future. The only problem with this conceptualization, as Arthur Eddington pointed out in the 1920’s, is that real processes just don’t make sense in reverse time.



9. NATURAL PROCESSES IN REVERSE

As discussed already, all particles obey – exactly – the laws of physics, which are time symmetrical and thus work just as well “backwards” (future to past) as forward. Additionally, the concepts of the spacetime continuum, and even of asymmetric entropy-gradient time, envision that real processes are just as valid – just as real – in both directions of time. If birth leads to death in one direction of time, then death leads to birth in the other direction of time. Both statements are two different views of the same assemblage of line-particles that make up the subject organism’s lifecycle. The only problem with both directions of time being valid is that natural processes, at first glance, just don’t make sense in backward time.

A movie run backwards shows a universe that obeys the laws of physics, but does not obey the second law of thermodynamics. In fact, in reverse time, every frame of the movie violates the second law, just as every frame obeys the second law when run in the forward direction. But block time requires that the movie run in reverse reflects the real universe, the same universe, regardless of the way an observer runs the movie through his subjective projector. The spacetime continuum and entropy-gradient time do not include objective events that “unfold” in one direction of time; there is no “progressive” or objectively “unfolding” time, and there is no objective “now” in the universe.

Time directionality is manifested by arrows of time, which are natural processes that consistently increase or decrease some measurable aspect of the universe in one direction of time. These arrows of time reflect a common underlying mechanism, i.e. the statistical necessity for all natural process to result in assemblages of particles at all scales to become more disordered. If we say the arrows of time are just as valid or real when considered in reverse time, then we have a shrinking universe with decreasing entropy. We also have children that get younger and enter their mothers, basalt rock that melts and flows uphill into volcanoes, and spilled milk that goes back in the bottle. Again, things that don’t make sense, but are allowed by physical laws. Because “forward time” is defined entirely by particle randomization, “reverse time” is defined entirely by particle ordering. Backward time does not make sense because entropy decreases in backward time.



Making sense of backward processes and decreasing entropy starts with remembering first that all the laws of physics – gravity, relativity, Newtonian mechanics, particle physics, etc. – have no time directionality. Time directionality, and thus processes that don’t make sense in reverse time, are defined only by the entropy gradient. For example, imagine dropping a rock onto the ground. When you let go of the rock, it “irreversibly” accelerates due to gravity, but not as quickly as it might due to friction with the air, until it hits the ground. Then, the rock stays on the ground and it all makes sense. Now, the reverse process is a rock sitting on the ground that suddenly pops up from the ground and you catch it. Weird? Maybe. But the backward process is completely compatible with the laws of physics. The energy that was transferred in forward time from the rock to the air while it was falling and to the ground when it landed – energy in the forms of acoustic waves and heat in the ground and air – in reverse time all rushes back to the rock. First, the energy in the ground hits the rock all at once and with precisely enough energy to pop the rock up and, buoyed slightly by the energy from the forward-time friction with the air but overall decelerating as it rises according to the laws of gravity (which is attractive in both directions of time), slows down and comes to rest comfortably in your hand. That all works according to the physics we understand, the only “weird” thing about the backward process is that it is so unlikely that it never occurs. The reverse process involves a focusing of the acoustic waves and heat into the rock all at once to kick the rock up into your waiting hand. The number of particles is so large and the odds of this happening are so small that the process does not occur in the forward direction of time.

Therefore, making sense of backward time – if there is sense to be made – means making sense of processes with decreasing entropy. In fact, to the extent that increasing entropy defines forward time, the proverbial “other side of the same coin” is that decreasing entropy defines reverse time. To approach the question of decreasing entropy, let’s step back and ask why increasing entropy makes sense. Increasing entropy makes sense only because that is the order in which we experience the universe. There is nothing in the second law or any other theory or data that prohibits the statement or concept that “entropy decreases in reverse time.” In fact, decreasing entropy in reverse time is the observation, provided we accept that the universal “movie” we’re watching is a reel of film that has no “correct” direction to play the movie, no “preferred” direction of time. Although it makes all the sense in the world, particle randomization in one direction of time has no explanation, it is simply observed. Similarly, particle ordering in the other direction of time has no explanation, it is simply observed.



Where does this leave us with regard to natural process in reverse time? On the one hand, we have special relativity, all the laws of physics, the second law of thermodynamics, and even the arrows of time consistent with entropy-gradient time, with no “progressive” time or “preferred” direction of time. On the other hand, against all this, is the notion that backward processes just don’t make sense. Then, given that we make memories in just one direction of time, and thus experience the entropy gradient in just one direction of time, it then “makes sense” that backward time does not make sense to us. But that does not mean that spacetime is not equally real whether described, or perceived, in the forward or backward direction of time.

We will delve deeper into out perception of time progressing toward the future, but for now let’s explore the origin of the entropy gradient. In order to have an entropy gradient, a progression to disequilibrium, we must start with a non-equilibrium system.



10. NON-EQUILIBRIUM SYSTEMS AND CHAOS THEORY

Changes in entropy occur only in non-equilibrium systems. The entropy of the universe increases in the future direction of time because the universe is not at equilibrium. All natural processes reflect the increasing entropy of the universe, the conversion of free energy to heat/light, as a result of non-equilibrium processes. Therefore, to understand the randomization of particles in one direction of time or, equivalently, the ordering particles in the other direction of time, or to understand any real process in any direction of time, we must explore non-equilibrium systems and chaos theory.

The very fact that real processes occur is in itself proof that we live in a universe that is not at equilibrium. And again, progress toward equilibrium is of crucial cosmological significance because only the progress toward equilibrium, from non-equilibrium, defines an objective directionality of time and evolution of the universe. The most accepted approach to non-equilibrium systems is chaos theory, or “deterministic chaos,” which means that real processes, although intrinsically unpredictable, still obey the laws of physics. In that sense, the cosmology described herein is a deterministic chaos model.

Before going into non-equilibrium, let’s review some aspects of equilibrium systems. The equilibrium state of a system is the highest entropy, lowest free energy, most disordered state possible for a system, and the laws of physics define the “possible” states. For example, the equilibrium state of a chemical system – a “thermodynamic system” in the classical sense – is tightly constrained by atomic bonding, temperature, pressure, and other physical aspects of the system. When sodium and chloride ions precipitate from aqueous solution, the resulting equilibrium solid is not a random mass of sodium and chlorine atoms; rather, the physics of these atoms prescribes the lattice structure of rock salt (see figure below).



Figure 10. Symmetry breaking: Salt water has infinite symmetry planes (dashed lines), but more ordered crystalline salt has only two symmetry

planes (plus one in the plane of the page in the third dimension).

The structure of a salt crystal is quite ordered, with evenly spaced rows of atoms that are manifested macroscopically as a crystal. The atomic-scale order in rock salt compared to dissolved NaCl in sea water is quantified by “symmetry breaking;” more ordered systems have lower symmetry (see figure above). However, rock salt is the most disordered configuration possible within the laws of physics, in this case the laws of ionic bonding of Na and Cl atoms. Salt water has “isotropic” symmetry in that it is the same in all directions. The system is symmetrical across planes of any orientation, and can “spin” around an axis of any orientation and still look the same. However, salt crystals have “isometric” symmetry, with just three mutually perpendicular symmetry planes. Although rock salt is quite ordered, rock salt is the most disordered configuration possible within the laws of physics (which have no time directionality). Again, an equilibrium system is in the most disordered configuration allowed by the physics of the particles, but this state of maximum disorder contains some degree of order.

Another aspect of equilibrium is that, in principle if not always in practice, the equilibrium state of a system is predictable. Each system has, for a given set of conditions of temperature, pressure, and other parameters, just one equilibrium state. For example, the equilibrium state of H2O at one atmosphere pressure and -56°C temperature is a solid (ice). At 340°C and one



atmosphere pressure, the equilibrium state of H2O is a gas (steam). Only one equilibrium state is possible under given conditions, and that state is the maximum entropy, minimum free energy state that is allowed by the physics of the system.

Non-equilibrium systems are, by definition, more ordered than the same systems at equilibrium. By contrast with equilibrium systems, which have only one possible equilibrium state, far-from-equilibrium systems are ordered and have many possible states. For example, the equilibrium state of all life forms is a mixture of water and carbon dioxide, with a few percent other chemicals. However, when water and carbon dioxide are organized into complex life structures, an unlimited number of possible plants and animals are possible, including all extinct and future species. Because there are so many ways a system can be far from equilibrium, non-equilibrium processes are intrinsically unpredictable and thus “chaotic.” In the case of life systems, for example, the laws of physics are completely incapable of predicting elephants, barrel cactus, or even the existence of life. Furthermore, because all real processes in the universe occur because the universe is not at equilibrium, all natural processes are intrinsically unpredictable.

Chaos theory does not propose that the laws of physics, with their mathematical precision, are invalid or incapable of making accurate predictions. To the contrary, “deterministic chaos” envisions individual particles that obey the physical laws exactly, but the group behavior of particles in non-equilibrium systems is not predictable. The reason for the unpredictability of far-from-equilibrium systems is that future events are very sensitive to slight variations in previous events. These variations are so slight as to be practically and theoretically unpredictable. A good example of this principle of “amplification of deviations” can be visualized with billiard balls. Imagine being challenged to line up several balls on the table in line and hit the first ball sufficiently straight that each ball hits the next ball straight on and the last ball goes straight into the pocket (see figure below).



Figure 11. Amplification of effects; the fourth ball deviates so far from the

straight shot that it misses the next ball entirely.

The problem with this shot is that each ball down the line will amplify even the slightest deviation from a precisely straight first shot. The trajectory of each successive ball deviates more from the predicted straight shot, and a fairly straight first shot may not even hit the last few balls as an earlier ball deviates so much that it misses the next ball and breaks the chain. We should note that amplification of effects operates in both directions of time, and the amplification is a function only of increasing time between events without regard to the direction of time. Thus, in the billiard ball example, the prediction of the trajectory of the first shot from the trajectory of the last ball to move is just as unpredictable – the deviations just as amplified – as in the forward direction of time.

The unpredictability of far-from-equilibrium systems results in the many possible ordered configurations of a system compared to the lower number of less ordered configurations, including the single equilibrium state of minimum order. A “bifurcation diagram” is useful to represent the possible states of a system at and away from equilibrium (see figure below).



Figure 12. General bifurcation diagram. An actual system would have many

more branches with unlimited branches toward the top.

To see how the bifurcation diagram works, let’s imagine a system at equilibrium, which is then driven away from the unique equilibrium state, by addition of matter and/or energy from the surroundings. Moving up the bifurcation tree from the single equilibrium state at its base, the system will reach a “bifurcation point,” where two states of the system are stable. At this point the system can assume either of the two stable states, or go back and forth between the two states (“atomic clocks”). Farther from equilibrium, the system assumes one of the two possible stable states, and addition of more matter-energy drives the system in this state to another bifurcation point, where again the system takes one path or the other. The two stable states at the second bifurcation point are not the same two stable states at the end of the other bifurcation point. If the system had assumed the other state at the first bifurcation, the possible states at the second bifurcation would be different.

A “bifurcation diagram” represents the stable states of a system at equilibrium and away from equilibrium. The diagram can be thought of as a branching tree with branches that bifurcate upward from equilibrium at the based of the tree. The base of the tree represents the single equilibrium state of the system and higher branches represent the possible non-equilibrium states of the system. The top of the tree is the chaos state, which represents the unlimited number of



stable states at the lowest entropy of the system. We should note that any bifurcation diagram we could possibly draw could represent only a few of the unlimited number of possible non-equilibrium states of even simple systems. In systems that are far from equilibrium, it is not possible to predict which branch the system is on, which is why small deviations in the starting conditions of a non-equilibrium system result in large differences in the path to equilibrium (amplification of effects).

The bifurcation diagram helps visualize the relationship between the total entropy and the possible physical states of a system. As a system at equilibrium is stressed due to exchange of mass and/or energy with the surroundings and moves "up" the tree, the system meets bifurcation points and the system evolves to more ordered, less probable, lower entropy states. The branch followed at each bifurcation point determines all future states of the system, because all future branches stem only from that particular “lower” branch. In other words, each bifurcation point, like each proverbial “fork in the road,” leads to a whole different set of possible lower entropy (more complex) states depending on which branch is followed. However, like a cat that climbs a tree and on the way up has a choice at each branch, the cat has but one way back down the tree. The one way back down the tree represents the “spontaneous” processes that occur as far-from-equilibrium systems attain equilibrium.

Although the system’s slide down the tree to equilibrium is completely predictable, the structures formed during this process are not predictable. Specifically, for real systems there are limitless branches in the tree, so characterization of all the possible states of a real system is not possible. This unpredictability has been used to argue for a “progressive” time with many possible futures. The bifurcation diagram, in principle, quantifies the many possible ways the future could unfold. So at first blush, chaos theory, with its many possible, unpredictable futures, suggests that “progressive, unfolding” time may actually exist.

However, as in the old argument between “free will” versus “destiny,” we know that the future will actually occur in just one way. Furthermore, a future with many possibilities is subjective, because the definition of “future” depends on defining “now,” which we’ve shown is not an objective property of spacetime. From the point of view of any given “now,” the future does have many possibilities. But the real universe is the set of possibilities that is actually realized.



On a bifurcation diagram, the real system is the one route on the tree that the system actually follows (see figure below).

Figure 13. An actual evolution of states, indicated in red, of a far-from-

equilibrium system.

The tree itself, and all the possible states of the system that the branches of the tree represent, are nothing more or less than unrealized possibilities. The other branches are simply possible states of the system at given entropy levels. But once an unpredictable natural process, such as a hurricane or supernova, is completely dissipated, all the movements of all the photons of all the atoms that define the hurricane or supernova are completely defined. The hurricane or supernova is the existing worldlines of all the involved particles, which “obey” the laws of physics like clockwork; but the bifurcation diagram of the hurricane or supernova tells us this network of worldlines is just one of an unlimited number of ways the hurricane or supernova could have been. And every hurricane of every season and every supernova in every galaxy represents another of those “possibilities.”

* * *

The line-particles that constitute a far-from-equilibrium system are, by definition, more ordered than the same line-particles at equilibrium. Let’s explore what this order looks like. As



discussed previously, even equilibrium systems display considerable order because of the physics of the particles. Thus, fluids at equilibrium display consistent molecular spacings and solids at equilibrium display consistent ionic lattice structures, as in rock salt. When a system is far-from-equilibrium and performs work to progress to equilibrium, the individual particles move and the physics of particle interactions become very complex. The evolution of a system to equilibrium, such as a hurricane that performs work to dissipate thermal gradients, results in very complex structures that are a function of the particle physics, as for equilibrium systems, and of the particle movements that define work. These complex, organized structures are called “dissipative systems” or “emergent systems.”

Emergence is the way complex systems and patterns arise out of a multiplicity of relatively simple interactions. Emergent systems display “novelty,” meaning features not previously observed or predicted from the system’s parts. The interacting particles in emergent systems thus exhibit correlations that result in properties that are not properties of the constituent particles. Marching soldiers are a good example of the idea – the organization of the overall formation, the neat rank and file formation, is the result of each soldier (particle) keeping a constant distance (intermolecular spacing) from his neighboring soldiers (adjacent particles). Similarly, flocks of birds and schools of fish that seem to move as a flowing mass are emergent systems that reflects each bird or fish maintaining its distance from surrounding birds and fish (see figure below).



Figure 14. Emergent structures in bird flocks and schools of fish.

All structures in the universe and all natural processes are emergent systems that reflect a far-from-equilibrium state of an assemblage of photons. Each scale of organization of photons, from free photons to subatomic particles to atoms to the universe, is an emergent phenomenon that is completely different than its constituent particles. Photons organized into matter make emergent quarks, neutrons, and gold. Atoms organized into molecules make emergent water, DNA, and sandstone. These scales of organization reflect emergent structures that are static, at least temporarily, and represent more or less stable states of the system governed by particle properties, like rock salt. By contrast, “dynamical” emergent systems are governed by particle properties and by motion of the particles. The motion results from the work performed as the system equilibrates and creates the very complex, unpredictable structures usually associated with emergent systems. The most famous example of the complexity of dynamical emergent systems is life, which dissipates the energy of sunlight via far-from-equilibrium life structures.



11. ENTROPY GRADIENT OF LIFE

With the concepts of bifurcation diagrams and emergent systems to help us understand non-equilibrium systems, let’s return to the question of life and how it may help with the idea of decreasing entropy. Recall, understanding reverse time requires us to make sense of decreasing entropy. To be clear, life processes obey the second law, but life does not appear to be process of equilibration like other emergent systems. To the contrary, life evolves, becoming more complex and ordered with time. Other emergent systems don’t do that.

I once gave a geology presentation to my daughter’s third grade science class. I was showing the class a nice hexagonal quartz crystal and explained that the shape was due to the atomic structure of quartz. A boy raised his hand, “Quartz is made of atoms?” “Yes, in fact all minerals and even all rocks are made of atoms,” I replied. The boy was puzzled, “Rocks are made of atoms?” Then some kid shouted “yeah, everything is made of atoms.” “Everything is made of atoms?” the boy asked incredulously. “Yeah,” another kid replied, “even you are made of atoms.” “I’m made of atoms?! Argh!”

That boy will never forget the day he realized he is made of atoms, but that is the sad truth. We, and all life, are classic thermodynamic systems that are assemblages of molecules. Life processes convert energy (from light or food) into the work that defines life processes, and obey the second law of thermodynamics by increasing the entropy of the universe. But at the same time, there is an organization to life that has prompted notions that life systems, unlike other emergent systems, may defy the second law and decrease entropy. However, the thermodynamics of life are identical to other systems – the amount of order created by life systems is less than the amount of disorder discharged to the surroundings by life processes. Therefore, the net effect of life processes is to increase the total entropy of the universe, just like a cold drink that gets warmer in a warm room, and life obeys the second law. The organization of matter by life can be interpreted simply as an emergent structure reflecting dissipation of solar energy.



The biomass of an organism, or the biomass of a species or the biomass of all life on earth, is in a more organized state than the same mass in a non-living state. Life systems decrease the entropy of the matter that constitutes these systems. Life uses energy, primarily solar energy obtained by photosynthesis in “plants” (including seaweed, algae, and other photosynthesizing organisms), to create and sustain its organization. Because organisms are far-from-equilibrium, they “spontaneously” decay upon death, if not eaten first by another organism to utilize the low entropy, high energy biomass to maintain its own low entropy. Again, organisms are dissipative structures that dissipate solar energy and other energy.

However, life processes are much more complex than other emergent systems. Additionally, life is not just today’s organisms, but is a system that exists in the temporal dimension. Today’s life on earth is the product of more than 3.5 billion years of continuous evolution to more ordered and more complex forms. Evolution has produced the ordering and complexity of today’s life, which is sufficiently ordered that it is clearly different from nonlife. Life represents a system that has continuously decreased entropy per unit biomass, or “specific entropy,” with time, in the opposite direction of time than nonlife increases specific entropy. Thus, an individual organism temporarily organizes earth materials, like any emergent system. The difference with life is that the specific entropy of individual organisms decreases with time via biologic evolution; this is the biological evolution arrow of time.

* * *

The continuous decrease in specific entropy resulting from evolution may help us with the problem of decreasing entropy in reverse time, so let’s look more closely at the physical role of life in the universe. The first basic question is whether there is any difference between life and everything else in the universe. At first glance it seems we can easily tell life from nonlife, but pinning down the real physical differences, if any, is more problematic. As the boy in my daughter’s class now knows, life systems like all real systems are made of matter and energy, so life and nonlife have no compositional differences. Life is not defined by being carbon-based; methane, diamonds, and other carbon-containing molecules are not life. Life is a dissipative/emergent structure, but dissipative structures are not life; hurricanes and solar flares are not life. Life systems are born, grow, and die, but so do glaciers, stars, and businesses. Finally, viruses display properties of both life and nonlife, and represent a gray boundary



between living organisms and the rest of the universe. So there is no clear “boundary” between life and nonlife.

Intuitively and quantitatively, the difference between life and nonlife boils down to organization. The organization represented by life is not just the 3-dimensional structure of the biomass. Life is also the 4-dimensional network of line-particles that constitute a life system in spacetime, which defines all growth and all behaviors of the system. An individual organism, like any real system, is the worldlines of all particles incorporated into the organism from the death to the birth (or visa versa) of the organism (see figure below).

Figure 15. Conceptualization of the organization of the line-particles

(photons/atoms/molecules) of a tree (outlined in red dashes) in spacetime.

The above figure conceptually depicts a tree as an organization of line-particles in spacetime. Matter particles (minerals, carbon dioxide, water) and photons (sunlight) are continuously incorporated and discharged by the system. In principle, an old tree may have none of the molecules it started with; the molecules in an organism are interchangeable but the organization is continuous. The tree is not defined by individual particles but by the organization of particles. At birth, only a few particles are involved. Net addition of particles results in growth and ultimately death. After death, the “corpse” decays because, by definition, the life process no longer operates to maintain the organization of the line particles. The corpse would decay more



slowly if the tree were harvested and used in fine furniture, or it would decay more rapidly if the tree were burned. In any case, the organization that was the tree inexorably randomizes after death and the low entropy, high energy biomass approaches equilibrium according to the second law of thermodynamics. All the particles dissipate into other systems and all traces of the organization of the tree ultimately disappear. This process cannot be changed and that particular tree will not exist again. In this respect, individual life systems (cells, organs, organisms, species) are like any dissipative system, a temporary organization of particles that grows and dissipates.

Life is organization. When Captain Kirk and Dr. McCoy of television’s Star Trek happened upon a rock that responded to them, they realized the rock was a silicon-based life form, a “Horta.” We, the viewers, knew that the Horta was alive because it responded with organized motions – behaviors. Another example of life being defined by organization is the Search for Extra-Terrestrial Intelligence (SETI), which is a search for extra-terrestrial life that may be broadcasting radio transmissions. The entire basis for recognizing an “intelligent” transmission hinges on separating an organized electromagnetic signal from the myriad random electromagnetic signals in the universe. In other words, SETI is based entirely on the premise that a radio signal could be sufficiently organized that it must represent life. If an alien SETI technician one day heard Beethoven’s Ninth Symphony among the electromagnetic noise of the cosmos, she would know she had discovered “extra-terrestrial” life. Again, life forms on earth, which are our only examples of life, are nothing except local organizations of earth materials. Additionally, we know intuitively that life can be made of rock (“Horta”) or radio signals (SETI) as long as it is organized and complex in 4-space.

Life on earth is the organization of earth materials, and life decreases the entropy of earth materials through mechanisms other than just creating “biomass” in the strict sense of the word. These other mechanisms for decreasing entropy can be collectively called “technology” and include all manipulation of matter-energy by life to create more ordered matter. The ordering is usually performed to support some life function, but the ordering may also be performed for no obvious reason. Examples of technology are a bird’s nest or a hit record.

Biological evolution involves "desirable" innovations of physical structure and behavior, and replication of the desirable innovations. “Desirable” innovations enhance the capability of a life



system to decrease its specific entropy (biological evolution arrow of time) and increase its mass (biomass arrow of time) and thus survive. Technology development represents the same process; "desirable" innovations enhance the capability of a technology to better perform its complex (low entropy) function. “Mass production” is a technology involving replication of desirable innovations on a large scale, again to increase the mass of lower entropy systems and fulfilling the basic physical role of life. Going forward, we’ll use the term “biomass” in a broad sense, meaning all order in the universe created by life processes, including technology in the broadest sense.

Our box of 100 pennies contains a life lesson. Recall, the pennies started all heads. Shaking of the box led to individual pennies bouncing around between heads and tails, each one following its laws of physics by being heads half the time and tails half the time. Each penny has no time directionality, but the group of pennies has a time directionality defined by the increasing number of tails, from 100-0 to 50-50 heads and tails. Now, let’s ask how the pennies became all heads to begin with? Obviously, the very fact that the box started all heads tells us that someone turned the pennies to all heads before we started the experiment. “Spontaneous” nonlife processes cannot flip the pennies to all heads. The all-heads initial state of the box of pennies is the most ordered state of the system consistent with physical laws; the improbability and degree of order of this initial state is equaled only by the all-tails state. Clearly, the all-heads initial configuration is part of a life process (technology), specifically a person or other “intelligence” who turns them all to heads. Life is organization, and no other natural process creates organization as life does.

The entropy-decreasing capability of the life system is the result of evolution. Evolution results in the overall life system on earth becoming more organized (lower entropy) with time. Modern life forms are, overall, more complex and ordered than ancient life forms. This is the biological evolution arrow of time. Other emergent structures do not evolve complexity. Hurricane Katrina was no different than hurricanes a billion years ago. Nonlife dissipative structures do not exhibit long-term changes and definitely do not “improve” or “adapt.” Although each hurricane season has different numbers, strengths, and locations of hurricanes, there is no consistent long-term change in hurricanes. Hurricanes don’t become more sophisticated each season.



Life is different. Life becomes more complex and more ordered with time, and in fact the rate of increase in complexity is exponential. Let’s define the “earth life system” as all life that ever existed or will exist on earth. The earth life system is a dispersed, open system, which exchanges matter and energy with the surrounding earth and with the sun (sunlight). The life system is composed of segments of the line-particles that have resided or will reside in one or more organisms. The constituent organisms and cells of the earth life system reproduce, making similar, but not exact, copies of themselves. Through the process of “speciation,” a population of organisms becomes reproductively isolated from the rest of the population, and the copying of the two separated populations progress independently. After time, the populations are so different that they are separate “species.” Fundamentally, the process of speciation involves one type of organism becoming two types of organisms in the future direction of time. The two daughter species are variations of a single species – with additional complexities – thus are more organized and of lower specific entropy than the one parent species. The living and extinct species that constitute the life system can be viewed as “states” of the life system, which is a far-from-equilibrium system that can be represented by a bifurcation diagram (see figure below).

Figure 16. Some depictions of the evolutionary tree of the earth life system, showing that evolution is a process of bifurcation (speciation) of life forms.



The speciation process defines the bifurcation diagram of a system that decreases entropy with time. Life on earth, as a system, has a bifurcation diagram that bifurcates toward the future direction of time. The evolutionary trees shown in the above figure by no means represent all the millions of species that have existed and do exist on earth. The diagrams only show some selected groups and, obviously, a single diagram cannot capture the millions of species of dinosaurs, bacteria, fungi, and other states of the life system. Furthermore, even if such a diagram were constructed, it would represent only an infinitesimal fraction of all the possible non-equilibrium states (species) of carbon-based life on earth. Thus, the full evolutionary tree of every species that ever existed or will exist is just part of the unlimited bifurcation diagram of the earth life system. Specifically, the tree of life is the part of the full bifurcation diagram that is actually realized in nature (see figure below).

Figure 17. Partial bifurcation diagram of the earth life system, illustrating conceptually the possible (black) and realized (red) states of the life system.

The above diagram depicts conceptually how the tree of evolution reflects the part of the full system bifurcation diagram that is actually realized. Each branch is a possible species; the black branches are a few of the unlimited possible states (species) of the matter-energy that constitutes the life system. The red line represents the species (states) that are or have been actually realized by the life system on earth. Some branches end in extinct species and the remaining branches



end in living species. Branches along which evolution was more rapid end in contemporary species at lower states of entropy (higher order and complexity). Less complex species are more “primitive,” so today’s elephants are more primitive (higher entropy) than humans. Note also that the lowest entropy (most complex) species highest in the tree have the largest number of possible states (species).

* * *

Because life becomes more organized with time, life systems are currently quite organized compared to anything else on earth and are usually easy to tell from nonlife (with the exception of some viruses). But the defining difference between life and nonlife is that life systems decrease entropy with time or, more precisely, life systems are open systems that decrease specific entropy with time. The definition of life used herein is based on the temporal specific entropy gradient. The defining characteristic of the life system is that its specific entropy decreases with time and its total mass increases with time. Evolution is the natural process by which the system decreases specific entropy with time, and overproduction is the natural process by which the system increases mass with time.

The specific entropy and total mass gradients that define life processes allow us to compare life and nonlife processes. Specifically, the life system on earth defines an entropy gradient opposite to that of the rest of the matter in the universe. Whereas nonlife increases specific entropy in forward time, life specific increases entropy in reverse time. Thus, to the extent that time directionality is defined by the positive entropy gradient of nonlife processes (increase in specific entropy in forward time), life may represent a negative entropy gradient and an opposing temporal polarity. This possibility will be elaborated upon more, but first let’s use our conceptualization of life processes to shed more light on the making of memories and our perception of time moving toward the future.



12. MEMORY AND TIME ASYMMETRY

The life system is a network of line-particles within the larger network of line-particles that comprise our universe. Matter and energy particles, such as water and sunlight, enter and leave the life system continuously, reflecting the open-system nature of the life system and also, by necessity, of the surrounding nonlife system. The life system is a dispersed system that consists of myriad subsystems – organisms, cells, organs, genes, etc. – each an identifiable, local, moving region of spacetime defined by the organization of particles during their residence in the living system.

The life system and its subsystems decrease specific entropy and perform life processes in the future direction of time. Therefore, life systems are “alive” in the future direction of time, but not in the past direction of time. A life system, like any real system, exists in both directions of time, but meets the definition of life only in the future direction. The life processes that define being “alive” exist only in the future direction of time; in reverse time, the same processes are not life processes. For example, birth is a life process, but an infant entering its mother’s womb in reverse time is not a life process. More generally, the definition of life as a system that decreases specific entropy and increases mass in the future direction of time means that the life system meets the definition of life, and is “alive,” only in the future direction of time. With regard to the process of making memories, we make memories only in the direction of time in which we are alive – toward the future – because the making of memories is a life process.

Life processes display time directionality in many aspects, including speciation, extinction, birth, growth, death, and learning. These processes are life processes only in one direction of time. A dead organism that comes to life, grows smaller and younger, and enters a broken egg that repairs itself, does not represent a life process and is in fact not an organism at all. We’ll return to the question of what life is in reverse time, but for now it should be clear that life is only living in one direction of time, toward the future. Life processes all are manifestations of increasing mass and decreasing specific entropy in the future direction of time.



Among the life processes that are time directional is memory. Life has several types of memory, such as genes that are the products of more than 3.5 billion years of organizational refinement. Let’s focus here on psychological memory, specifically human memory. Memory is nothing more than our recollections of past events, which we call upon to make decisions about the future. We make memories in the direction of time in which we are alive, which is the reason we experience the universe to “progress” from past to future. We are alive from past to future so we make memories from past to future.

“Consciousness” is the process of making memories, which is the ordering (decrease of specific entropy) of particles in the brain (e.g. neurons). The ordering of the brain in the future direction of time, like any system, can be represented by a bifurcation diagram, and each memory is a branch on the bifurcation diagram of the brain. In the direction of decreasing entropy (future), each branch on the bifurcation diagram of the brain is an apparent "choice" that creates more information in the brain. The choice that exists in the forward direction of time as memories are made is consciousness. The brain “exists” in both directions of time, but is conscious only in the direction of time in which it becomes more organized (is alive). In other words, the reason we are conscious in the future direction of time is because the actual “route” taken by the bifurcation diagram of the brain faces “choices” in the direction of decreasing specific entropy. This explains how the life system makes memories, and thus perceives time as moving “forward,” in the same direction of time as the nonlife system increases entropy.

We don’t actually have memories of external “events,” but rather of sensory information. Most memories are of sights and sounds, i.e. information from organs (eyes and ears), which gather electromagnetic and acoustic waves and convert them to memories. Of course, we also make memories of smells, tastes, and physical contacts (touch), where the nose, mouth, and body sense airborne chemicals, food (or anything placed in the mouth), and physical interactions. The “current” gathering and processing of memories, the “here and now,” is consciousness. Events in the surroundings increase entropy and create the electromagnetic and acoustic waves that are sensed by our eyes and ears and remembered. This process creates the “illusion,” as Einstein put it, of time progressing toward the future. To illustrate the concept, the making of a memory of a volcanic eruption in forward time illustrates the relationships between the entropy gradients and bifurcation diagrams of the life and nonlife systems (see figure below).



Figure 18. Formation of memories of the sight of a volcanic eruption in the

future direction of time. On the bifurcation diagrams, the actual evolutions of the brain and volcano are in red.

As can be seen in the above figure, the human brain faces choices only in the future direction of time, thus makes memories in the future direction of time. The brain exists in the reverse direction of time, but does not make memories and is not alive in reverse time. Memory making reflects brain processes that result in a net increase in the entropy of the universe, like any life process, and in a local decrease of the specific entropy of the brain. The work performed in this process results in a re-configuration of brain particles, which reflects decreasing entropy of the brain itself. This decrease in entropy reflects the highly unlikely arrangement of neurons needed to create memories. Thus, the actual memory as it exists physically in the brain is an example of a more general kind of memory, “physical memory.”

* * *

“Physical memory” refers to the idea that a physical system is the result of past processes and not of future processes. For example, the earth appears to contain a wealth of information on past earth events, from dinosaur bones that result from past life forms to mountain belts that reflect



past continental plate collisions. The physical universe appears to have memory of the past but not of the future. All systems have physical memory to some degree and, just like psychological memory, physical memory represents just a small proportion of the “information” from past events. From this point of view, all systems, including our brains, have some memory of past events. However, no system has “perfect” memory, i.e. a complete record of every particle motion.

Physical memory has been used to argue for “progressive” time. Again, a preferred direction means that, separate from our subjective notions of time progression, there is a real, objective progression to time; one direction of time real and the other is not. Progressive time is a universe that progresses from past to future, but not from future to past, a concept that directly conflicts with relativistic block time. The argument for time progression is based on the observation that memory of all types, which exists in all systems to various degrees, contains information of the past but not of the future of that system. Furthermore, this past-only memory is the same for entropy-increasing nonlife systems and entropy-decreasing life systems. Obviously, the life system contains strong memories – morphologically, behaviorally, and genetically – of past evolution. Our examination of the physical memory of the earth indicates that life on earth is the product of more than 3.5 billion years of evolution, but the physical memory appears to contain no information of the next 3.5 billion years of evolution.

Physical memory is the same idea as “cause-and-effect,” which has been a controversial arrow of time. Cause-and-effect is intuitively appealing and we indeed do things to cause other things to happen in the direction of time in which we are alive (toward the future). However, hard as people have tried to argue for cause-and-effect, there is no objective cause-and-effect in the universe. Cause-and-effect is the same as physical memory because physical memory means that past events caused the current “effect” (system state). By contrast, future events do not cause the current “effect.” For example, let’s consider a rock face that contains a fossil trilobite. The current state or “effect” of this system, the fossil in the rock, was “caused” by a trilobite that died and was buried, then the continent rose above sea level due to tectonic movements and the ocean sediments were eroded to expose the fossil. All these “causes” resulted in the current “effect,” all are all in the past and not in the future, and this all makes good sense. Thus, the concepts of physical memory and of and cause-and-effect are intuitively compelling. When we



look around at how everything is a product of past events but not of future events, it is hard to understand why the past is not more real than the future.

But let’s see if we can understand the equal reality of future and past and save block time. First and importantly, physical laws have no cause-and-effect and do not predict that physical memory should exist. Physical laws have no time directionality and do not distinguish cause from effect; all equations are time symmetric. For example, contrary to popular belief, unbalanced Newtonian forces cannot “cause” something to accelerate; rather, things that accelerate have associated unbalanced forces.

Arguments for progressive time based on cause-and-effect and physical memory point to entropy. The basic argument is that the second law of thermodynamics requires randomization of particles in the future direction of time. Therefore, the only scientific measure of time asymmetry says that the universe is “really” progressing from past to future (not future to past). The argument thus concludes that particle motions are “caused” by previous particle motions (not by future particle motions), and systems contain physical and psychological memory of the past (not the future). Again, this is the argument for progressive time and basically says that the second law implies more than time asymmetry but also implies a preferred direction of time.

However, nothing in the second law singles out the future as the direction that time is “moving.” Rather, the second law is arbitrarily expressed in terms of the future as “positive.” There is nothing in the second law that implies progressive time. More to the point, there is no scientific explanation for randomization of particles in one direction of time. Again, randomization in the future direction of time makes all the sense in the world, but nothing in the second law implies that increasing entropy toward the future is any different from decreasing entropy toward the past.

Although the second law cannot be used to argue for progressive time or cause-and-effect, physical memory still seems to favor past events to record but not future events. In order to reconcile block time with physical memory, let’s take a closer look at physical memory. Physical memory is in all cases a dissipative structure that has not completed dissipation of all free energy and thus has not attained equilibrium. As a dissipative structure, the trilobite that died 500 million years ago is still dissipating energy. In a sense, the lifecycle of the trilobite is



not through until the organization of earth materials created by its life process is dissipated back into other systems. The physical memory of the fossil in the rock is an organization of matter; let’s say the fossil is made of calcium carbonate. As long as the outline of the mass of calcium carbonate retains the ordered shape and symmetry of the trilobite, the organization of the trilobite has not completely dissipated. Physical memory is in all cases an ordered, emergent feature, and in all cases the “current” state of order is less than all the ordered processes that have occurred in the system (imperfect memory).

By contrast, an equilibrium system has no information of its history, and the bifurcation diagram explains why; all “routes” down the bifurcation tree lead to the same equilibrium state, regardless of how the system was previously ordered. At equilibrium, all the order that was created by dissipative-emergent structures on the system’s “road” to equilibrium is dissipated and all information of the road is lost. For example, at equilibrium, the fossil trilobite will have eroded from the rock face, the calcium carbonate dispersing, dissolving, and incorporating into other systems such as soil cements, groundwater, and the atmosphere. Then, all physical memory of the trilobite will be lost, its entropy maximized.

This conceptualization explains how physical memory records past events, but also points out that systems do contain information about the future and do not need progressive time for their explanations. Let’s look again at the trilobite fossil. We thought we knew only the past of the trilobite, but as described above, we also have information on its future, in fact its entire future (until equilibrium). The only objective information contained in the fossil about its past is that the fossil is an assemblage of particles that at some time in the past organized into this life form. This is the same information we have about the future of the fossil, which is that the calcium carbonate will disperse back into other systems and all physical memory of the trilobite will be lost, just as before the trilobite lived. One might argue that this future is not inevitable, but it is; the degradation process can be slowed but not halted if the fossil is collected and preserved in a museum rather than being eroded. Preservation of the fossil will slow but not completely stop the randomization of the particles of the trilobite. Randomization of all systems can be slowed but never stopped. All organizations of particles, all emergent structures, are temporary, as predicted by heat death. In the case of the fossil trilobite, the physical fossil does contain as much information about the future as the past. Specifically, the fossil is a temporary organization of particles that becomes disorganized in both directions of time, but the



organization increases the entropy of the universe only in the future direction of time. Therefore, physical memory and cause-and-effect, although intuitively attractive, are not objective aspects of the universe. All dissipative systems create and lose order, so the universe contains “memory” only of “currently” dissipating systems. Similarly, psychological memory making and consciousness itself are the subjective experience of a local decrease of entropy and facing “choices” at bifurcation points in the bifurcation diagrams of our brains.

From this point of view, it is unclear whether memory, physical or psychological, is a valid arrow of time. Specifically, it is unclear whether any property of the universe increases or decreases systematically in one direction of time due to memory. Furthermore, it is unclear how memory can be quantified in order to determine whether the total memory of the universe increases or decreases consistently with time. Memory is a property of individual systems and is clearly a time asymmetric process for individual systems, but memory may not accumulate on a universal basis. Memory is certainly a time asymmetric property of far-from-equilibrium systems, including both life and nonlife systems, and appears to be present in all arrows of time but not to be an arrow of time in its own right. Cause and effect does not appear to exist in nature at all, at least not beyond our subjective notions of making things happen. Again, the important point from this discussion of memory is that our perception of time progression from past to future reflects only our human memory-making process. Memories are made, and time thus appears to progress, in the direction of time in which we are alive, but this apparent progression is not an objective property of the universe.



13. COSMOLOGICAL ROLE OF LIFE

The life system is a network of line-particles that decreases specific entropy in the future direction of time and is “alive” only in that direction of time. A life system, like any system, “exists” in both directions of time and thus increases specific entropy in the past direction of time; life systems are not alive in the past direction of time. This view of life is simple and provides a common explanation for both time asymmetry and life.

One possible objection to this concept of life is that life processes, like nonlife processes, “just don’t make sense” in reverse time. What does it mean for an infant to enter its mother and then the mother becoming un-pregnant? What does it mean for atmospheric carbon dioxide to un-mix from the atmosphere and be inhaled by a person who then exhales oxygen? What does it mean for plants to grow smaller as they emit photons that travel to the sun to create hydrogen from helium (fusion in reverse)? These strange happenings are all observed phenomena, and the only question surrounding the reality of these processes is whether natural processes are equally real in both directions of time. One answer to this question is provided by the conceptualization of memory discussed above. Specifically, natural processes appear to make sense in the future direction of time because that is the direction of time in which we make memories of the universe. The objective universe has a real, objective time asymmetry defined by an entropy gradient, and therefore the universe makes sense to us in the direction of the gradient in which we make memories, and the reverse direction does not make sense. Thus, the reverse direction of time can be objectively just as real as the forward direction, and it “makes sense” that the the reverse direction of time does not “makes sense.”

Another way to ease into the idea of life processes in reverse time is to take into account that life processes “don’t make sense” even in forward time. No theory or model predicts anything about life or that life should even exist. Our science has no theory or model that predicts life. Life is simply observed. To be clear, there are many viable theories as to how life could have started from the organic molecules that exist on many celestial bodies and existed on the early earth. Organic molecules occur in many parts of the universe as nonlife states of carbon and hydrogen.



Compounds such as methane, formaldehyde, and methanol are observed in cosmic dust clouds, on moons and planets, and in comets. The same organic molecules existed on the early earth, but life processes have long since consumed those original molecules.

The problem of creating life from nonlife boils down to making a cell from organic molecules in the early earth environment, and many plausible ideas have been proposed for “spontaneous generation” of a cell from organic molecules. The main ingredients are the organic molecules and some energy to combine the molecules. Many theories can be easily found on the Internet, including lightning catalyzing the creation of certain small molecules (monomers) of life such as amino acids (which was demonstrated experimentally in 1953 by Stanley Miller and Harold Urey), phospholipids spontaneously forming lipid bilayers (a basic component of the cell membrane), self replicating by polymerization of nucleotides into random RNA molecules, origin at deep sea hydrothermal vents, organic molecules that use clay minerals as an organizational template, use of the bubbles (as a cell membrane template) and radioactive energy to form cells on radioactive beaches (where uranium-rich zircon minerals are concentrated), ultraviolet light-assisted replication (based on the thermodynamic role of life to dissipate solar energy), and many others. Extraterrestrial origins of primitive life have also been proposed, which of course just pushes the problem of spontaneous generation to another planet.

As of 2010, no one has created a cell from nonliving matter. The main point for us is that, even given the fact that life is observed, science cannot “reproduce the experiment” of generating life, and even if it could, there is certainly no model that predicts just from the existence of organic molecules that a cell will form. Life an observed, unpredictable, emergent process, and in no way do life processes “make sense” in either direction of time. If life did not exist (except for a scientific observer outside the universe!), science would not predict the emergence of life. The existence of life is not predicted by theory, it is simply observed and, like all natural phenomena, is observed by humans in the direction of time in which humans make memories of it. And the key observation that distinguishes life from nonlife is the polarity of its specific entropy gradient, decreasing rather than increasing toward the future.

* * *



As we’ve discussed, to the extent that increasing specific entropy defines forward time, the proverbial “other side of the same coin” is that decreasing specific entropy defines reverse time. Increasing entropy makes sense only because that is the order in which we experience the universe, but it is equally valid to say “entropy decreases in reverse time.” Although it makes all the sense in the world, particle randomization in one direction of time has no explanation, and particle ordering in the other direction of time similarly has no explanation. In short, the entropy gradient has no explanation, it is simply observed, and it is observed in every process that ever has occurred or will occur in the universe.

As has been pointed out in the philosophical literature, probability alone does not explain time directionality. Probability does not explain or predict that particles should randomize in the future direction of time rather than in the past direction. Consider a system that is far from equilibrium. Because the system is in an improbable state, the system is expected to be in a more probable, higher entropy state in the future. However, probability alone tells us that the system is also expected to be in a more probable, higher entropy state in the past. In fact, this view of organized system behavior -- randomization in both directions of time -- is the observation for individual emergent systems. Recall the trilobite that grew, died, was fossilized, and ultimately dissipated back to its surroundings until no organization remained. All emergent systems – all real processes in the universe – organize then disorganize matter-energy. Collectively, however, the net result of these processes, individually and collectively, is to randomize the real particles of the universe in the future direction of time. And it is this net randomization of all nonlife systems in a consistent direction of time that has no explanation; it is simply observed. Similarly, the decreasing entropy of life in forward time is also just observed. With this conceptual model of life and time directionality, life may have a cosmological role.

Life is an open thermodynamic system that has the properties of, in forward time, increasing its mass, i.e. net retention of mass or “growth,” and decreasing the specific entropy of the retained mass (biologic evolution). Life is an energy-dissipation process that requires mass and energy from the surroundings to sustain the growth and organization. The energy is used to organize the mass into biomass, and the organization is controlled by information contained in DNA. In today’s life forms on earth, DNA contains at least 3.5 billion years of evolutionary refinement that has led to progressively more organized genetic information and commensurately more complex (lower specific entropy) organisms.



So what can we say cosmologically about life? First, we can say life is an organization of earth materials. Life decreases specific entropy with time and increases the quantity of matter so organized, limited only by the mass and energy available from the surroundings. Second, there is no scientific explanation of life; there is no theory that predicts the existence of life. The inexplicability of life boils down to the decreasing specific entropy of life, which is just as inexplicable as increasing specific entropy of nonlife. Third, we know that life was present on earth as soon as conditions on earth could support it and has persisted for a length of time greater than one quarter of the age of the universe itself. This calculation is based on a 14 billion year age for the universe and a minimum 3.5 billion year age for the first life on earth. Additionally, there is no constraint on how far back in time the life system might extend. It is possible that life has existed since the big bang, but such early “life” could not be carbon-based “life as we know it.”

Let’s take a broader view of the origin of life. The problem of early life is typically framed in terms of some sort of a “seed” of organization from which organization can grow, such as the radioactive beach hypothesis. However, from the point of view of life as an entropy gradient, a “seed” may not be necessary or may be the wrong question. What is necessary for life is high-entropy matter to organize. For carbon-based life, the necessary particles are carbon dioxide, water, and energy, all of which are products of stellar evolution, specifically of nuclear fusion. Carbon and oxygen are products of fusion in past large stars (supernovae) and the energy source is primarily photons produced by fusion in the sun and secondarily radioactive heat in the earth, which arises from decay or heavy elements (e.g. uranium) that was produced in large star fusion. The hydrogen in the water is a product of the primordial nucleosynthesis. Energy sources for early life, such as radioactive beaches, hydrothermal submarine vents, and lightening, are also products of earlier of stellar fusion. Stars, of course, formed from hydrogen generated in the primordial nucleosynthesis event. Thus, our ancestry can be clearly traced back to the big bang.

Ultimately, the properties of photons – the strong, weak, and electromagnetic forces – govern the organization of photons into the hydrogen, carbon, and other matter particles required for life. To the extent that life is an unexplained natural process characterized by decreasing specific entropy and increasing mass, no constraints can be placed on the types of life that could occur in the universe. This broad view of life allows life to be a silicon-based “Horta” or a quark-based organization that existed close to the big bang.



* * *

To the extent that the universe is an isolated system, the fact that life is made of matter and energy requires that all the matter and energy needed for life were present at the big bang. Additionally, the properties of these particles at the big bang had all the necessary properties to ultimately organize into life. The only unexplainable aspect of life is the entropy gradient, and the entropy gradient is the only thing that distinguishes life from nonlife (and visa versa). And, because a given life system is “life” in just one direction time, the question of the “origin” of a life system is the same question as the “ending” of a nonlife system. In reverse time, our life system is a nonlife system, “spontaneously” increasing entropy; in reverse time earth life is a typical nonlife emergent system. The “end” of this system (in reverse time) is the beginning of life (in forward time).

We can observe only one example of life, the earth life system, and that example may or may not be the only example in the universe. The uncertainty as to whether life exists only on earth or on a billion celestial bodies is a significant gap in the cosmological data set, and this data gap may never be closed by our science. So our conceptual model of the universe must allow for life only “as we know it” on earth or for life on many celestial bodies. In either case, life increases its mass and decreases its specific entropy in forward time. Because life increases mass and that mass comes from nonlife matter, the mass of the nonlife system decreases in forward time, the same direction of time in which it increases specific entropy. Thus, the specific entropy gradients and the total mass gradients of the life and nonlife system are temporally reversed, which may have cosmological significance.



14. THE UNIVERSAL LIFE AND NONLIFE SYSTEMS

Life on earth is a thermodynamic process in the classical sense, that is, life is a chemical system. As we’ve discussed already, the organization of atoms into thermodynamic systems is just one scale of organization of the photons that constitute the universe. Photons are organized into subatomic particles, which are organized into atoms, which are organized into molecules, which are organized into celestial bodies, which are organized into galaxies, which are organized into the universe. Our definition of life as increasing mass and organization with time could apply to any of these scales of organization, not just the organization of molecules.

The view of life described herein permits life forms that use matter-energy to organize photons at any scale. Additionally, once we define a universal life system, which may or may not consist only of earth life, the “surroundings” is the rest of the universe. Thus, we have a universal life system that differs from the universal nonlife system (surroundings) only by the directions of time in which their respective total masses increase and specific entropies decrease (and visa versa).

Observed life on earth consists of populations of physically discrete, open systems, which incorporate more nonlife matter in the future direction of time. The property of increasing biomass with time is manifested by growth of individual organisms, overproduction, and saturation of niches. Life also displays the property of decreasing its specific entropy (entropy per unit mass) with time, as manifested by evolution. The current cosmological life system (all life in the universe) is known to science only on earth, and may or may not be present in other parts of the universe (in space and time). Extrapolation of the properties of the universal life system into the future, specifically increasing total mass and decreasing specific entropy, produces a higher mass, lower specific entropy system. This statement does not mean we have data to indicate that the life system will continue to increase its mass and become more organized, but rather that extrapolation of past and current trends, if they continue, would produce a higher mass, lower specific entropy, universal life system with time (see figure below).



Figure 19. Extrapolation (dashed lines) of the known universal life system

(solid lines) into the past and future.

In the above diagram, the curvature of the specific entropy curve is based on the accelerating (exponentially increasing) rate of evolution of earth life, and the curvature of the biomass curve is based on the accelerating rate of reproduction of earth life (provided sufficient energy-matter). The surroundings of the universal life system – whether the universal life system is only life on earth or is life on a billion other planets – is the rest of the universe. Assuming the universe is an isolated system, the nonlife system is the other system in the universe. In other words, all the matter in the universe can be conceptually divided into two systems, the life system and the nonlife system. The isolated system concept of the universe requires that mass-energy exchanged between the two systems (life and nonlife) be equal and opposite. The increasing mass of the life system requires decreasing mass of the nonlife system. A ton of mass that leaves one system is one ton of mass that enters the other system. The “life” and “nonlife” in the above figure illustrates this concept; the increase in biomass of the life system is equal to the mass loss by the nonlife system.



The nonlife system, in addition to increasing specific entropy according to the second law, receives the high-entropy “waste” mass and energy discharged from the life system as the life system increases the entropy of the surroundings more than it decreases its own entropy. In the future direction of time, the life system uses energy to incorporate nonlife matter into its biomass, which is an entropy-decreasing process, and the work performed to create biomass creates entropy of greater magnitude in the remaining matter of the nonlife system. In other words, the life process creates more disorganization of the nonlife system than organization of its own biomass, thus resulting in a net increase of the entropy of the universe and conformance with the second law of thermodynamics.

* * *

Now let’s consider what the life and nonlife systems do in the reverse direction of time, from future to past. In the reverse direction of time, the nonlife system decreases its specific entropy and increases its mass -- again, only by describing the system in the other direction of time or by switching the sign convention for time. The life and nonlife systems have reciprocal temporal gradients of total mass and specific entropy. In this respect, the nonlife system is life in reverse time, because it decreases its specific entropy and increases its mass, as defines life in the forward direction of time. Thus, all matter in the universe is life in one direction of time or the other direction of time, and all matter is nonlife in one direction of time or the other. The only difference between life and nonlife is the direction of time in which one chooses to consider or describe the system, which exists in both directions of time.

One "route" on the bifurcation diagram of a given system can, in principle, represent a particular life or nonlife system in spacetime. For a given "route" between a low and high entropy state (entropy gradient), the direction of decreasing entropy is life and the same "route" in the direction of increasing entropy is nonlife (see figure below).



Figure 20. Two representations of the same real system (portion of

spacetime), considered in opposite directions of time (indicated by red arrows). Life has choices, nonlife does not.

The above figure illustrates that "life" and "nonlife" are subjective terms that depend only on the direction of time in which the system is considered. Life is the subjective progression "up" the bifurcation tree, and thus it perceives a "choice" at each bifurcation point, that is, to proceed up one "branch" or the other. This perception of choices in the direction of decreasing specific entropy is predicted by chaos theory (bifurcation diagram) and is manifested by many life processes, including memory making and evolution. But just as a cat climbing a tree makes a choice at each branch going up the tree, the cat has but one way back down. The bifurcation diagram shows how the same system considered in the opposite direction of time – the nonlife view of the same system ”down” the tree – does not present "choices” and reflects “spontaneous” (entropy increasing) nonlife processes.

This relationship between life and time directionality explains both the physical role of life in the universe and time directionality within the constraints of special relativity (block time) and the second law of thermodynamics. Thus, the material universe can be modeled as two open systems, which decrease specific entropy in opposite directions of time or, equivalently, increase specific entropy in opposite directions of time. We can call these systems A and B, and “our” life system, which is nonlife in reverse time, is by convention the A system. All matter in the universe is, at a given point in time, in one or the other of these two systems. Currently, the A



system contains all earth life and any other systems in the universe that decrease specific entropy and increase mass in the forward direction of time, and the B system contains all nonlife in the universe, which decreases specific entropy and increases mass in the reverse direction of time.

The current nonlife system B is interpreted to be a life system in reverse time because it decreases specific entropy and increases mass in the past direction of time. Extrapolation of those trends into the past is the logic behind the big bang, particularly extrapolation into the past of the expanding universe (Hubble’s law). Thus, “our” big bang could be the result, in reverse time, of the B life system “evolving” to the big bang state. Similarly, the A life system – our life system in forward time – may be evolving to the “next” big bang.



15. LIFE, DEATH, AND BIG BANGS

As we’ve discussed, gravity works against the expanding universe and has the potential to counteract heat death, or at least to reverse the cosmological arrow of time (expanding universe). The “big crunch” proposes that the expanding universe is eventually counteracted by the attraction of gravity, which slows and ultimately reverses the expansion. However, gravity does not organize matter-energy, which is needed for a minimum entropy big bang and the beginning of all arrows of time, i.e. all scales of particle randomization. If we can organize the matter-energy of the universe, which includes contraction of the universe but also includes the organization of matter-energy on all scales, then we have a complete mechanism for creating a big bang state of the universe in the future and avoid heat death.

The universal life system increases mass and decreases specific entropy in the future direction of time. Extrapolation of these trends into the future produces a high mass, low-entropy, universal life system. If these trends continue until the organized life mass becomes a significant proportion of the mass-energy in the universe, the life system has the potential to evolve to the big bang state of the universe. In other words, because life is defined only by mass increase and entropy-per-unit-mass (specific entropy) decrease, regardless of scale (planets, galaxies, subatomic particles, etc.), life could potentially reverse the second law of thermodynamics and, more generally, reverse the net randomization of particles that defines time directionality itself. In fact, as we just discussed, the current life system A is alive – decreasing entropy and increasing mass – only in the future direction of time. In the past direction of time, the nonlife B system performs the life process toward “our” big bang (see figure below).



Figure 21. Conceptual model of a big bang cycle. “Life” and “nonlife”

systems are arbitrarily defined and would be switched using the opposite sign convention for time.

Extrapolation into the future of the increase in mass and decrease in specific entropy of the life system could produce the minimum entropy state of the universe, i.e. the “next” big bang state. From the point of view of a life system, i.e. in the direction of time in which the system decreases entropy, the life system grows larger and more organized (higher specific free energy) until the nonlife system, the surroundings of the life system, no longer contains sufficient mass and energy to sustain the life system. The dependency of life on surroundings to supply matter and energy to sustain increasing mass and decreasing entropy predicts that the life system “dies” when the nonlife system is depleted. The death of the life system could explain the organization of the big bang state at all scales. The “corpse” of this cosmological-scale life system, which is in



the minimum specific entropy state of the universe, becomes the nonlife, increasing-entropy system of the "next" big bang cycle as it “decays” (randomizes) after death.

The death of the universal life system could be the fundamental event that defines the big bang by providing a viable mechanism for commencement of the second law of thermodynamics for most or all of the mass in the universe. Specifically, this model provides the organized big bang state from which entropy can increase according to the second law. Using our analogy of the box of pennies, life produces the big bang state by turning all the pennies to heads, as only life can do. The model predicts, because the universe is isolated, that the life process that creates the organized big bang state dies as the nonlife system approaches equilibrium and zero mass, and thus cannot provide free energy to sustain organization. The decay of this organized system is the big bang, and the gradients of specific entropy and total mass of the A and B systems are compatible across a big bang (see figure below).

Figure 22. Entropy and mass of the A and B systems about a big bang.



In the above figure, system A, our life system, has little or no mass at the big bang. If the A system has any mass at the big bang, it is at maximum specific entropy at the big bang. As system A begins organizing matter from system B away from the big bang, the specific entropy of the A system decreases (is life) away from the big bang in both directions of time. The specific entropy of the B system increases (is nonlife) away from the big bang in both directions of time.

Again, the material universe can be modeled as two open systems, A and B, which are defined only by opposing entropy and mass gradients. The high mass system (B) is modeled as retaining its identity through the big bang, and its mass gradient and specific entropy gradient switch direction (sign) at the big bang. For example, if we follow system B from left to right in the above figure, system B at first decreases specific entropy and increases mass (life), then to the right of the big bang the system increases specific entropy and decreases mass (nonlife). The low mass system A may vanish at the big bang and lose its identity at the big bang.

The big bang state of the universe, that is, the location in spacetime at which the universe is at its lowest entropy, is envisioned as a cosmological entropy-gradient node. All the matter and energy of the universe is in a compact volume and is very organized, but exactly how compact and how organized is uncertain. It is possible that the universe never gets close to the singularity and it is also possible that the big bang occurs over a period of time. For example, perhaps several or many individual “organisms” die over some period of time during the big bang process.

The big bang state is constrained by physical laws and astrophysical observations, as summarized in the standard ΛCDM model, and we will return to these constraints and possible big bang states later. Let’s turn first to a more immediate concern, the fact that our sampling of the universal life system – life on earth – is not capable of decreasing the entropy of the universe. Again, life “as we know it” creates more disorder than order, thus a net increase in the entropy of the universe due to life. There is no obvious process by which the current life system can accomplish net decreasing entropy of the universe in the future. However, the current nonlife system, system B, considered in reverse time, is living. From the point of view of system B living in reverse time, this life form looks “forward” (in reverse time) to “our” big bang in 14 billion years’ time. Thus, the nonlife system offers an opportunity to evaluate a life system



heading toward a big bang and a model for the future of our life system, including how our life system may evolve to a future big bang state of the universe. The primary reverse-time life form in the B system is stars.



16. STARS AS AN ADVANCED LIFE PROCESS

A gaze into the evening sky reveals that we live in a universe of stars. Stars are by far the most energetic systems in the universe (excepting dark energy, the nature of which is unclear). Other systems, such as the CMB (cosmic microwave background) radiation and planets, are all relatively close to equilibrium compared to stars. Nuclear reactions in stars produce unimaginable quantities of energy over periods of billions of years. The miniscule proportion of the sun’s energy that radiates onto our small planet provides all the energy for all the life and weather that have ever existed or ever will exist on earth. And there are billions of suns.

The energy from the sun is produced by hydrogen fusion, a reaction that releases the photons that we recognize as sunlight. The reaction goes forward and produces energy because the photons that constitute hydrogen atoms are in a more organized, lower entropy state than the same photons configured as helium (the fusion daughter product) and free photons (sunlight). The reaction is a self-sustaining (chain) reaction in which gravitational confinement of a huge mass of hydrogen raises the temperature and density within the sun to the levels needed to meet the “Lawson criterion” and overcome the energy barrier (“activation energy”) at which fusion is self-sustaining. Fusion releases photons (starlight) according to mc2 E. Larger stars attain sufficient density and temperature to fuse helium into larger atoms, and each fusion step to form larger nuclei also results in emission of photons (more starlight).

The basic reason for this fusion is that the parent atoms are less stable than the daughter atoms plus photons. In other words, the constituent photons of the parent atoms are in a lower entropy, higher free energy, more ordered configuration than the same photons configured as the daughter atoms plus free photons. These nuclear reactions are analogous to the burning of wood. The wood is more organized and less stable than the same atoms as water and carbon dioxide, and a log left to itself will ultimately decay to water and carbon dioxide according to the second law of thermodynamics. This process can be accelerated by biologic processing, as is the case for a log decaying on a forest floor. Raising the temperature of the log to its ignition temperature in the presence of oxygen, which is a kind of “Lawson criterion” for wood, accelerates the process



even more. After ignition, the burning is a self-sustaining chain reaction that rapidly oxidizes the complex molecules in the wood to a more stable, higher entropy state, a combination of carbon dioxide, water, and free photons (fire light). Indeed, the literature often refers to fusion in stars as “burning” the hydrogen (or larger fusing atoms) and to the commencement of fusion as “ignition.”

Stars are the energy producing process in the universe. On earth, nuclear and geothermal energy take a distant second and third place to sunlight as the main source of energy, and there is no evidence that this situation is any different anywhere else in the universe. The view of the universe from anywhere in the universe is only of stars. The vast space between the stars and the vaster space between galaxies are filled with starlight. Stars are by far the most energetic manifestations of the increasing entropy of the universe and thus the strongest testament to the low entropy (high free energy) nature of the big bang state. Stellar fusion is dissipation of the free energy that maintained the universe in its organized state at the big bang. To the extent that fusion in stars is the primary manifestation of the increasing entropy of the universe, stars represent “burning” of the universe. The big bang state can be thought of as a “log” and the stars can be thought of the “burning” of that log.

* * *

Now let’s consider what stars do in reverse time, the direction of time in which the stars are alive (decrease specific entropy and increase mass). In the past direction of time, the stars draw starlight toward themselves and convert photonic energy into matter (fusion in reverse). This focusing of starlight in reverse time is the radiative arrow of time, just considered in reverse time. In reverse time, stars are accomplishing the reaction E mc2, in which photons are organized into matter. This absorption of photons to organize matter is a form of photosynthesis. Life “as we know it” depends on chemical photosynthesis in which incident starlight from the sun provides the energy to organize nonlife earth materials into a life system (plants). In reverse time, stars perform nuclear photosynthesis in which starlight is drawn toward the star and is organized into atoms (fusion in reverse). The process of starlight converging upon a star to convert one helium atom into two hydrogen atoms is an observation, simply the fusion process considered in the opposite direction of time from the direction in which we make memories.



The stars are, in reverse time, converting high specific entropy free photons (light) into lower entropy matter. In reverse time, a star increases its mass and decreases its specific entropy and thus is a life system, according to the definition of life used herein. The scale and rate of this decrease in entropy represents a life form that dwarfs “life as we know it.” The billions of more or less similar stars in the universe may be individual members of a "species" or products of a "technology" that result from replication of the innovation of the capacity to organize light into matter via nuclear photosynthesis.

Another way to understand starlife is from the point of view of its role in galaxies. Galaxies are emergent systems, each made of billions of stars. Stars are the “particles” that constitute galaxies, and the entropy of a galaxy – meaning the degree of disorder of the constituent stars – increases in forward time according to the general second law (randomization of particles in forward time). Thus, like the stars, galaxies decrease entropy and are life systems in reverse time. In reverse time, a galaxy is analogous to a plant and the stars are analogous to the plant’s cells, which perform photosynthesis. In this conceptualization, the stars themselves are living “cells” within galaxies, which are “organisms” with structures reminiscent of some life forms on earth (see figure below).



Figure 23. Photographs of organisms in the universe. Four of the

photographs are jellyfish, and the other 18 are Hubble Space Telescope photographs of galaxy “organisms” made of photosynthesizing stellar “cells.”

As a group, the galaxies, in reverse time, are converging on our big bang. If you run universal expansion backward, the galaxies are all on the precisely correct “glide paths,” with the correct directions and speeds, to meet, all at the same time, at the big bang. This conceptualization is simply Hubble’s law and is in fact the logic used to argue for the big bang. The only idea added here, if any, is that the reverse time contraction of the universe is viewed as just as “real” or “valid” as the forward time expansion of the universe. In backward time, all galaxies are on course to meet in 14 billion years, at "our" big bang, at which time the entropy of the universe "will" be at its minimum.

Interestingly, the current ΛCDM model has a surprising result – the rate of expansion of the universe appears to be accelerating. The universe is expanding faster with time. So not only is the universe expanding against the attraction of gravity, and not only is the expansion not decelerating due to the pull of gravity, but instead the rate of expansion is increasing. This inexplicable result has led to suggestions of matter that travels at speeds above the speed of light



and of a universe that expands forever. “Dark energy” has been invoked to accelerate the galaxies.

However, this acceleration may also be explained by considering the situation in reverse time. As discussed, the universal contraction in reverse time can be conceptualized as a coordinated migration of living galaxies to meet at our big bang. If the universal expansion is accelerating in the future direction of time, then universal contraction is decelerating in the past direction of time. The galaxies may be slowing to coordinate an organized meeting at the big bang, or more precisely at the hydrogen cloud from whence they came in forward time, as part of the process to create the highly ordered big bang state. Thus, in reverse time, stars perform photosynthesis, are organized into galactic organisms, and as a group are evolving to their “future” (our past) big bang state. These processes can be collectively referred to as “starlife.”



17. ENERGY SOURCE AND LIFECYCLE OF STARLIFE

The process by which stars convert free photons (starlight) into matter in reverse time (fusion in reverse) is nuclear photosynthesis, which is the same process as chemical photosynthesis in plants, but at a different scale (chemical vs. nuclear). Plants use starlight to organize water and carbon dioxide into biomass, and stars use starlight (in reverse time) to organize heavier elements, such as helium, into lighter elements, such as hydrogen (fusion in reverse) into “biomass.” In both cases, the free photons (starlight) combine with the existing matter to create new particle bonds and thus more organized, higher free energy particles. The fact that nuclear and chemical photosynthesis are central to life on earth and starlife is a life process common to both life systems.

Nuclear photosynthesis is the nonlife process of “nucleosynthesis” considered in the opposite direction of time. Nucleosynthesis is the process of creating atomic nuclei, which has produced the variety of elements on the periodic chart from subatomic particles. According to the standard ΛCDM model of the big bang, nucleosynthesis occurred in two phases to create the matter currently in the universe. The first phase is primordial nucleosynthesis, in which protons and neutrons formed the low mass number atoms hydrogen (with a proton and neutron in the nucleus), helium, and lithium. Much more hydrogen was created than helium and lithium. The second phase of nucleosynthesis was and continues to be nuclear fusion in heavy stars and supernovae explosions. In all cases, nucleosynthesis is a spontaneous, entropy-increasing process that produces disordering of the universe according to the second law. Thus, nuclear photosynthesis – the starlife process – is the second phase of nucleosynthesis (stellar nucleosynthesis) considered in reverse time.

Nuclear photosynthesis is an entropy-decreasing process, like chemical photosynthesis (plants), distinct from and in fact the opposite process from the entropy-increasing process of nucleosynthesis. Nuclear photosynthesis and nucleosynthesis are the same process, just described



in opposite directions of time, just as chemical photosynthesis (plants) and burning (of plants) are the same process, just described in opposite directions of time. Nucleosynthesis is fusion, which results in heavier nuclei and emission of starlight. Nuclear photosynthesis results in lighter nuclei and absorption of starlight (see figure below).

Figure 24. Nucleosynthesis and nuclear photosynthesis are the same process

considered in opposite directions of time (H=hydrogen, He= helium).

In both directions of time, plants perform the same functions as stars, except that, first, plants perform these functions at the chemical scale rather than at the nuclear scale, and second, plants perform these functions in the opposite direction of time from stars. In forward time, plants are alive and use water, carbon dioxide, and starlight from the sun to form new, more complex hydrocarbon molecules and oxygen. The basic photosynthetic reaction generates glucose according to 6CO2 + 6H2O + starlight C6H12O6 + 6O2. Any organic molecule, such as a protein or DNA, can be made from glucose. This process is chemical photosynthesis, the molecular-scale analog to nuclear photosynthesis. In reverse time, plants are not alive. Instead, plants spontaneously burn hydrocarbon molecules by addition of oxygen and emission of starlight, according to C6H12O6 + 6O2 6CO2 + 6H2O + starlight (reverse photosynthesis). The emitted starlight travels to the sun, in reverse time, and the living sun uses the photons to perform nuclear photosynthesis. In reverse time, plants are nonlife “chemical stars” that contribute a small amount of the starlight used by the sun in reverse time.

Obviously, plants provide only a miniscule fraction of the photons used by stars in reverse time, so the next question is the source of the rest of the starlight that is drawn toward the stars from our future to use in nuclear photosynthesis. In other words, the hypothesis that starlife draws



starlight toward itself to make matter requires that a source of starlight is available to it. The stars cannot obtain the starlight from themselves, because in reverse time stars are not emitting starlight, but rather are absorbing starlight. Additionally, the starlight must be emitted in the future in order to be absorbed today by the star in reverse time. The only viable candidate for the stars that emit this starlight in reverse time is future starlife, which is predicted to evolve from “our” A life system (see figure below).

Figure 25. Exchange of photons within a big bang cycle.

Some of the photons emitted by a star in forward time, the sun for example, falls incidentally on plants, which use the energy to organize atoms. The rest of the photons continue into the universe, incidentally falling onto celestial bodies and warming those bodies or reflecting off those bodies. Some starlight is captured by black holes. But much or most of the starlight wanders the universe at speed c, continuing to increase entropy and expand the universe. This starlight is gathered back in order to have a future big bang, just as the current starlife in reverse time gathers starlight from the future in order to have the past big bang (see figure above). Again, because this can be a bit confusing, the future A system starlife is, in reverse time emitting starlight. These future stars “shine” only in reverse time; in forward time they absorb light for photosynthesis. This reverse time “shining” starlight is emitted in reverse time and is



absorbed in reverse time by today’s reverse-time, photosynthesizing starlife. Thus, the future A system stars are the source of the vast majority of the energy used by reverse-time starlife.

The process by which starlife draws starlight toward itself to organize the starlight into matter is unclear, but one constraint on this process is that it uses starlight but not other photons, specifically the CMB radiation. The CMB radiation is photons that were emitted soon after the big bang and permeate the entire universe, but has no source such as a star or galaxy. This radiation is not drawn to stars and is not used by starlife to create order and matter in reverse time. In other words, a living star in reverse time is surrounded by and is incidentally impacted by photons of the CMB radiation, but the process of nuclear photosynthesis uses only the starlight and leaves the background radiation. If stars were using CMB radiation in reverse time, then they would be emitting CMB radiation in forward time, which is not the case. Thus, starlife uses the directional starlight, which is organized into beams of light with lower entropy than the random photons that constitute the CMB radiation.

One way to view the concept of starlife is to consider a model of the universe that does not include “life as we know it,” including ourselves. As scientific observers, we have all our observations of the nonlife universe, we just haven’t observed earth life or any other life. In this universe with no life, the increasing entropy defines spacetime. The universe is a network of line-particles that are more ordered toward the big bang and less ordered away from the big bang. The system decreases mass (nuclear decay) and increases entropy, primarily by stellar processes of fusion and expansion, in one direction of time (away from the big bang). The universe is smaller and more organized near the big bang and is larger and less organized near heat death. We name the directions of time “past” (toward the big bang) and “future” (toward heat death). We observe processes that define an entropy gradient. The processes as viewed in the past direction of time are very interesting as various scales of order are created from disorder. These processes include nuclear photosynthesis, increasingly organized galaxies, and a migration of billions of galaxies toward one another. The other direction time is less interesting, with order being continuously lost as the universe equilibrates.

This view of the universe is the reconciliation of directional time and block time and we could stop there. We have a universe with a single entropy gradient that extends from the big bang to heat death, which form the boundaries of our model and thus the “ends” of time.



Then we add to this model the life system as more than just another entropy-increasing, emergent system. Specifically, life on earth has decreased specific entropy and increased mass over a period of time greater than 3.5 billion years. No other system in the universe does that, except in reverse time. Thus, life on earth provides a cosmologically reciprocal entropy-gradient system to the rest of the universe. The interesting photosynthesis and other complex behaviors exhibited by the rest of the universe in reverse time are exhibited on a much smaller scale by earth life in forward time. Earth life would be identified as a temporally backward system. From this point of view, reverse-time starlife is the main evidence for “life” in the universe, and our life system provides the hint that the universe includes a second entropy gradient system. In a sense, stars in reverse time represent a very viable and powerful life process, whereas life on earth is less energetic and more primitive.

* * *

Each star has a “lifecycle” that depends on the mass of the star, and the interpretation of stars as reverse-time life forms predicts that a reverse-time stellar “lifecycle” is an actual lifecycle. Stellar lifetimes range from only a few million years for the most massive stars to trillions of years (much greater than the age of the universe) for the least massive. A stellar lifecycle in forward time begins with the gravitational collapse of part of a “giant molecular cloud” of up to 6 million solar masses. Molecular clouds are composed primarily of primordial hydrogen, and also include primordial helium and lithium, and heavier elements from exploded stars. As part of the cloud collapses under the mutual gravitational attraction of the hydrogen (and other matter), the cloud condenses and releases heat. As its temperature and pressure increase, it condenses into a rotating sphere of superhot gas, a protostar.”

Protostars are emergent structures, and they develop to various sizes depending on small perturbations in the initial rotational organization of the protostar. In this respect, protostars are very much like hurricanes; in both situations, a small differences in the starting conditions of a highly unstable system produces large differences in the size of the resulting rotational flow. Protostars with masses less than roughly 0.08 solar masses never reach temperatures high enough for fusion of hydrogen; these protostars become brown dwarfs. For more massive protostars, the temperature eventually becomes sufficiently hot to ignite hydrogen fusion to deuterium and then



to helium, and stars larger than the sun fuse helium to create larger atoms, including carbon and all the rest of the 92 naturally occurring elements on the periodic chart (nucleosynthesis).

The onset of nuclear fusion leads relatively quickly to a hydrostatic equilibrium in which energy released by the core balances the gravitational weight of the star's matter, preventing further gravitational collapse. The star thus evolves rapidly to a stable state, beginning the “main sequence” phase of its evolution. Again, the type of fusion that occurs in a star depends on its mass. Small, relatively cold red and brown dwarfs burn hydrogen slowly and remain on the main sequence for hundreds of billions of years, while massive, hot supergiants burn quickly and leave the main sequence after just a few million years. A mid-sized star like the sun remains on the main sequence for about 10 billion years.

Larger stars become red giants or supernovae that create the heavier elements. Depending again on mass, medium and large stars become stellar remnants such as white dwarfs, neutron stars, and black holes. Stellar remnants are depleted of free energy available to do work and represent the high entropy “ash” remaining from the “burning” of primordial hydrogen. The lifecycles of low mass stars are much longer than the age of the universe and they continue to burn slowly.

Stars are dissipative, emergent structures. They reflect the process of dissipating the energy contained in light atoms, primarily hydrogen, that dominated the universe from primordial nucleosynthesis. Stars are chaotic structures, very sensitive to the initial strength of the protostar, which dictates the star’s mass and its lifespan. Most importantly, a star decreases its mass by orders of magnitude during its lifecycle; the mass is converted to starlight by fusion reactions, which produces higher entropy mass and free photons (starlight) that leave the star.

The “birth” of a star in forward time by gravitational coagulation of hydrogen gas is its “death” in reverse time. Because stars are alive in reverse time, the death of all stars is the same. The death of a star results in dispersal of the huge quantities of hydrogen created by nuclear photosynthesis during the star’s reverse time lifecycle. In other worlds, the “purpose” of starlife is to create the primordial hydrogen (and lesser helium and lithium) state of the universe. This creation of high energy, low entropy hydrogen is the observed role of starlife in decreasing entropy toward the minimum entropy big bang state.



18. LIGHT AND DARK LIFE

We have identified photon exchange between plants and stars as a defining life process in both directions of time. Plants and stars use starlight to synthesize matter and, in the reverse direction of time, burn matter to emit starlight. The burning of matter increases entropy and is nonlife, and the same process in reverse time is photosynthetic life. This exchange of photons accounts for much of the work performed in the universe, including all stellar and life processes. The remaining matter in the universe does not exchange photons, except via absorption of light that heats the matter. Matter that is not actively photosynthesizing/burning will be called “dark matter” herein, although this definition may not align exactly with other definitions of “dark matter” and is different from “cold dark matter.” The term “dark matter” as used here includes cold dark matter (CDM). Astrophysical measurements indicate that there is more gravity in the universe than can be explained by observed matter-energy in the universe. This extra gravity is attributed to CDM, which cannot be observed except via the effects of its gravity on observed celestial bodies. The nature of CDM is unknown, but other dark matter is known. Brown dwarfs are “dark matter,” as used herein, as are planets and cosmic dust, all of which are observable, unlike CDM.

The matter in the universe can be subdivided into light matter that is involved in photosynthesis and dark matter that is not. Dark matter is either near equilibrium or, if it is far from equilibrium, has not overcome the activation energy to ignite. Light matter is involved in photosynthesis (chemical or nuclear) and is part of a life system in one direction of time or the other. The difference between light and dark matter, as used herein, boils down to the manner in which photons interact with the matter. Consider light shining onto some matter. A photon striking the matter interacts with the matter in one of three ways. First, the photon may be absorbed and warm the matter; in this case, the photon becomes thermal energy and increases the temperature of the matter or changes the phase of the matter at constant temperature. An example of the latter is sunlight shining on and warming melting ice. Second, the photon may be absorbed and used to create order and mass (E mc2). This process is photosynthesis (life), and some of the



absorbed photons are stored in a chemical or nuclear bond rather than dissipating. Third and last, the photon may be reflected and travel at speed c through spacetime indefinitely or until it encounters another material object and faces the same three possible futures. All materials absorb and reflect some fraction of the incident light, and materials that additionally perform photosynthesis are “light matter.” The reverse-time process of burning, including stellar nucleosynthesis, is also light matter.

We have defined life as a system that decreases specific entropy and increases mass, but we have not specified that life must be involved in photosynthesis. Thus, dark matter, like light matter, is modeled as being alive in one direction of time or the other. In a given direction of time, all matter in the current life system (A or B) can be subdivided into “light life” and “dark life.” Light life is easy to visualize as plants and, hopefully by now, as stars in reverse time, but dark life is not as easy to visualize. For example, is a rock on the ground alive? Isn’t it just a rock in either direction of time?

The common feature of all life is decreasing specific entropy and increasing mass, and a rock fits this description in reverse time. Again, because rocks and all nonlife objects increase specific entropy and decrease mass in forward time, they do the reverse in reverse time. For a rock on the ground, the nonlife process is slow disintegration (weathering) in forward time, and the life process is slow integration in reverse time. More generally, reverse time dark life is what we normally think of as “inanimate objects,” that is, objects that are not alive in forward time and thus increase entropy in forward time. Planets, including the physical earth around us, are entropy-increasing, nonlife systems in forward time and thus are entropy-decreasing, dark life systems in reverse time.

The earth, excluding our life system but including the solid earth, hydrosphere, and atmosphere, is dark life in reverse time. The inexorable randomization of earth particles in forward time is an inexorable organization of particles in reverse time. To the extent that the earth obeys the second law of thermodynamics in forward time, the earth decreases specific entropy in reverse time and its processes in reverse time thus reflect dark life. Dark life, like all life and nonlife, both emits and absorbs photons to various extents, but the photons do not photosynthesize the matter in dark life. The important point is that the earth and all “inanimate” objects in the universe, other than stars, are dark life in reverse time.



Dark life also exists in forward time with at least two examples. The first example of forward-time dark life is “prokaryotes.” Prokaryotes are anaerobic bacteria whose genetic material is not contained in the nucleus of the cell. They are the oldest known and most primitive forms of life on earth, with fossil remains in rocks older than 3.5 billion years. These earliest known life forms did not perform photosynthesis; rather, they absorbed carbon dioxide to obtain energy, and much later some evolutionary lines of prokaryotes developed photosynthesis. Today’s prokaryotic bacteria include types that absorb inorganic and organic molecules and types that perform photosynthesis. Non-photosynthesizing prokaryotes are thus dark life. However, although “dark” prokaryotes were present on earth prior to any photosynthesizing life, these early prokaryotes evolved into photosynthesizing life and thus are part of the life system that includes light life.

The second example of forward-time dark life is life that consumes photosynthesizing plants. The plant eaters, and the carnivores that eat the plant eaters (including ourselves), do not photosynthesize but are alive in forward time. However, these organisms are completely dependent on light life and evolved from a common ancestor. Therefore, non-photosynthesizing prokaryotes, plant eaters, and carnivores are dark life, and all share an evolutionary tree with photosynthesizing plants. Dark life and light life on earth are parts of a single life system (evolutionary bifurcation tree), and constitute the only known example of a forward-time life system in the present universe. Additionally, life on earth includes a fundamental evolutionary advance from dark life to light life, that is, from non-photosynthesizing prokaryotes to photosynthesizing prokaryotes.

In reverse time, the life system (B system) displays the same fundamental evolutionary advance as the earth-life system, from dark life to light life, that is, from non-photosynthesizing life to photosynthesizing life. This evolutionary advance is “stellar evolution” considered in reverse time. As discussed previously, all stars, in reverse time, photosynthesize lighter elements from heavier elements (nucleosynthesis in reverse), ultimately creating a huge mass of hydrogen and smaller amounts of other light elements (see figure below).



Figure 26. Reverse-time evolution of “primitive” dark life to

photosynthesizing light life to a hydrogen cloud.

Consider the above figure in forward time, from right to left. The “hydrogen cloud” in the figure is the light elements from the primordial nucleosynthesis event, which expanded through the photon epoch and dark ages until conditions allowed local gravitational collapse into protostars. The basic steps in stellar evolution in forward time, beginning with a hydrogen cloud (giant molecular cloud), are indicated in the figure. First, protostars of various masses form, with the size of the protostars – like the sizes of hurricanes – depending on small variations in the initial gravitational rotations that grow to become the stars. Large stars burn quickly (millions to tens of millions of years); therefore, many generations of large stars have already burned out and reformed. The remnants of the burned out large stars exist today as heavy elements in planets, moons, comets, neutron stars, black holes, and other celestial objects. Medium stars burn out over periods of billions of years, like our sun. Medium stars become white dwarfs over time, so the universe is old enough that white dwarfs can be observed currently. By contrast, small stars burn slowly over tens to hundreds of billions of years, so the universe is not old enough that mature red dwarfs can be observed. Regardless of size, all stars ultimately burn out and become dark (non-fusing) matter (left side of the above figure). Again, this stellar evolution of protostars



of various masses, as shown on the above figure from right to left, is a very basic summary of the standard model of stellar evolution.

Now let’s consider the above figure in reverse time, from left to right and labeled “starlife evolution.” The arrows that point from left to right indicate the direction in which of starlife decreases specific entropy and increases mass via nuclear photosynthesis and thus is alive. As can be seen in the figure, the dark matter stellar remnants on the left side of the figure evolve toward the right into photosynthesizing stars. This evolution of starlife, which is simply the burning of stars considered in reverse time, means that dark starlife evolves into photosynthesizing light starlife. This parallelism with forward time life, in which non-photosynthesizing prokaryotes evolved into photosynthesizing life forms, supports the concept of stars being evolving life forms in reverse time. Additionally, in reverse time, the nonlife earth (solid earth, hydrosphere, and atmosphere) is a primitive (non-photosynthesizing) life system that currently lives alongside more advanced photosynthesizing life forms (stars), just as today’s primitive (non-photosynthesizing) prokaryotic bacteria live on earth with photosynthesizing life forms (plants). The above figure shows the location in spacetime of the evolutionary transition from dark to light (non-photosynthesizing to photosynthesizing) starlife.

One of the forms of dark life, according this conceptualization, is black holes. Black holes are remnants of the most massive stars, after their fusion fuel is depleted. The resulting gravity is so great that light cannot escape a black hole; the speed of light is not fast enough to achieve “escape velocity” from a black hole. Black holes cannot emit or reflect photons and thus are “black,” and non-emission/reflection of photons is the only difference between back holes and other celestial objects. All celestial objects have gravity and accelerate nearby real particles (matter and free photons). Expressed in terms of general relativity, real line-particles (worldlines) are curved in the vicinity of massive celestial objects. Some line-particles are only deflected from their original courses by the gravitational field, but other particles actually encounter the massive object and remain gravitationally bound to the object (for example, meteorite impacts). Photons are either absorbed or reflected by the massive object, except that black holes only absorb photons (no reflected photons).

The fact that black holes increase mass in forward time does not mean that they are alive in forward time. The masses of all celestial bodies increase with time due to gravitational



coagulation, but supernovae and other processes sometimes disperse massive celestial bodies. In forward time, all celestial bodies increase specific entropy, and black holes are no exception. Stephen Hawking has shown that a black hole has “Hawking radiation” that indicates increasing entropy, the “Bekenstein-Hawking entropy,” at the event horizon of the black hole. Therefore, black holes decrease specific entropy in reverse time and are reverse-time dark life, like the earth and other planets. In reverse time black holes evolve into large, photosynthesizing stars and ultimately to primordial hydrogen, just like other dark life in reverse time.

* * *

Our life system is the only observable forward time life system in the universe. Therefore, our life system is the only observable reverse time nonlife system in the universe. All the other matter in the in the universe – the B system – is nonlife in forward time. Our life system fits the definition of nonlife in reverse time – our life system increases specific entropy and decreases mass to zero in reverse time. The reverse time increase in specific entropy is evolution in reverse, and the decrease in mass to zero is the origin of life – spontaneous generation – in reverse. In reverse time as in forward time, this nonlife system is an emergent system. The specific processes of this emergent system are strange at first blush, but actually parallel the processes of dark and light nonlife in forward time (stars, dark matter).

First, let’s examine the reverse time increase in specific entropy of “our” nonlife system, which is evolution in reverse. This nonlife system includes both dark and light nonlife. In reverse time, the A system is an emergent system that becomes less complex with time, changing from mammals to reptiles to crustaceans to trilobites to bacteria to carbon dioxide and water. In reverse time, the A system tree of evolution is followed down the tree, down the bifurcation diagram of the life system toward equilibrium (see following figure).



Figure 27. The major branches of the bifurcation diagram of the earth life system, showing reverse time converging branches of the tree of evolution

(entropy increasing nonlife system).

In reverse time (left to right in above figure), the increase in the specific entropy of the A nonlife system is manifested by more primitive life forms and ultimately to organic and inorganic molecules and the proto-earth. Photosynthesis evolved more than once in earth history, so light and dark life evolved together ever since the first photosynthesizing prokaryotes. The reverse-time decrease in the mass of the A life system is manifested by the retreat of life system to fewer niches, for example the retreat of land life back into the oceans, and ultimately to the disappearance of the life dissipative system (origin of life in reverse). The increasing specific entropy and decreasing mass of A system in reverse time fits the definition of a nonlife entropy-gradient system, as manifested by the forward-time B system, and our life system is the only observable reverse-time nonlife system in the universe.

This is the big picture of the A life system as whole in reverse time, the direction in which we and other life forms are not alive. Now let’s look at individual life systems (e.g. cells and organisms). Individual life systems in reverse time are nonlife, dissipative, emergent structures. Together, these individual systems reflect the reverse-time increase in specific entropy and decrease in mass of the only observable, reverse-time nonlife system. In reverse time, each cell



or organism performs the life process in reverse. The “starting materials” are the carbon dioxide, water, and other matter that were in system when it died and subsequently dispersed into the surroundings. In reverse time, this dispersed matter organizes to the point of being a fresh corpse (decay in reverse). Continuing in reverse time, the fresh corpse suddenly begins performing work; this work is the life-process work in reverse. These reverse time processes result in a net loss of mass and increase in specific entropy carbon dioxide, water, and other matter is lost from the life system to the surroundings until the mass of the system is again zero (reproduction in reverse).

During the reverse-time nonlife process, work is performed to increase the specific entropy of the cell or organism, which is a nonlife dissipative/emergent system. This work decreases the entropy of the universe (second law in reverse). In reverse time, dark life that depends on plants for food (such as ourselves) discharge the food, which becomes a photosynthesizing plant. Then, in reverse time, the photosynthesizing plant is a chemical star that emits photons in the form of starlight (sunlight in reverse) as the plant absorbs oxygen and burns (see figure below).

Figure 28. The earth life system in reverse time is nonlife.

This nonlife A system is an emergent system and is unlike any other emergent system, just like its forward-time life system. The uniqueness of the A system owes to the fact that it is the only



observable system in the universe that has an entropy gradient opposite to that of the rest of universe. The unique A system entropy gradient is manifest in both directions of time. The forward time “miracle” of life is completely unpredictable, and the reverse time nonlife processes that rise from the dead and grow younger are just as unpredictable.



19. THE BIG BANG STATE

The big bang state is the minimum specific entropy state of the universe and, to the extent that universe is an isolated system, the “big bang state” is the minimum entropy state of the universe. The minimum entropy big bang state has been called the “past state” in the philosophical literature. The minimum entropy past state is characterized as either a cosmological boundary condition or law of nature, but in either case cannot be explained, it is simply observed. The conceptual model of big bang lifecycles presented herein envisions the big bang state in terms of opposing entropy gradients of the A and B systems, which predict extreme ordering of all or almost all the matter-energy in the universe at the big bang state of the universe. The big bang state is the minimum specific entropy, maximum mass state of system A or B, and the high mass of the low entropy system means that the total entropy of the universe is a minimum at the past (big bang) state.

The ΛCDM model provides a detailed account of the big bang, beginning less than a second from the singularity to the present time. And let’s recall here what the “singularity means conceptually. The singularity is the reverse-time extrapolation of our forward-time expanding universe backward in time to the point in spacetime at which the volume of the universe would be zero if the universe did indeed appear from nothing. The early part of the big bang scenario envisioned in the ΛCDM model, from the first second to about 3 minutes after the singularity, is based on physical laws, especially general relativity and particle physics. Thus, the ΛCDM timeline from the singularity to 3 minutes after the singularity includes extreme gravity and temperature, and the particles that are stable under these conditions such as leptons and quarks. However, there are no astrophysical data from this period to test the model.

Recall, the “four pillars” of the big bang theory are empirical observations. The earliest-formed of these observations are the observed abundances of light elements formed during primordial nucleosynthesis, which occurred during the interval from 3 to 20 minutes after the singularity. The other pillars of the big bang occurred later in the ΛCDM big bang timeline. Thus, the observed abundances of light elements are the oldest “cosmological fossils.” The natural history of the pre-primordial nucleosynthesis universe is constrained by – but not predicted by – the



current ΛCDM model, and it is possible that the real universe never got any closer to the singularity than the primordial nucleosynthesis event. In other words, the “fossil record” of the universe extends to within 3 minutes of the theoretically oldest possible “beginning” of the universe, the singularity. The actual “beginning” of the universe, the actual big bang state, is chronologically bracketed between the singularity and the primordial nucleosynthesis state.

The primordial nucleosynthesis state is the lowest entropy state of the universe for which we have hard evidence. In this state of the universe, the low specific entropy exists primarily as high free energy hydrogen nuclei, and at this point in spacetime the amount of hydrogen in the universe is huge. Recall, this hydrogen subsequently fuels all the stars in the universe. At the time of the primordial nucleosynthesis, all the matter currently in the universe and almost all the photons – including all the photons that currently exist as starlight – were in hydrogen nuclei. Other than the CMB radiation and some helium and lithium nuclei, virtually all the matter-energy in the universe was in hydrogen. The big bang model does not “need” to explain the universe prior to primordial nucleosynthesis to explain the cosmological data set, so the primordial nucleosynthesis event could be the big bang state. In this model, the laws of physics continue through the big bang, with protostars forming in both directions of time away from the primordial hydrogen cloud (see figure below).



Figure 29. Conceptualization of limiting case in which the big bang state is

the primordial nucleosynthesis event.

Remnants of the primordial hydrogen cloud are observable today and are still making stars (see figure below).



Figure 30. Hubble Space Telescope photographs of protostars forming from

hydrogen clouds. In reverse time, the hydrogen forms by nuclear photosynthesis in stars and disperses into hydrogen clouds toward the big

bang.

To be clear, there is no direct evidence that the hydrogen cloud is the actual big bang state. Rather, the point is that the actual big bang state could be anywhere between the singularity and 3 minutes after the singularity, and there is a viable conceptual model of the limiting case in which the big bang state is the primordial nucleosynthesis state. Furthermore, a primordial hydrogen cloud big bang is the simplest model consistent with the data. If our observations of the cosmos find no trace of the universe from earlier than 3 minutes after the singularity, then our model does not “need” to explain the universe prior to primordial nucleosynthesis. Until that evidence for an earlier universe is found, the simplest model consistent with the current data set is that the big bang state is all the matter-energy in the universe configured as hydrogen (and lesser helium and lithium) nuclei and random photons (the CMB radiation). This conceptual model avoids the singularity, allows the line-particles of the universe to continue through big bangs, allows the universe to remain an isolated system (rather than losing all its matter-energy to unspecified surroundings by vanishing), and allows the laws of physics to continue through big bangs. A conceptual big bang cycle based on this vision of the big bang state is summarized in the figure below.



Figure 31. Conceptual model of a big bang cycle, with big bangs at the

primordial nucleosynthesis event.

All matter in the universe, both life and nonlife, came from the primordial hydrogen cloud. Recall, life on earth began as prokaryotic bacteria that organized earth materials, particularly carbon and hydrogen in carbon dioxide, water, and organic molecules. The carbon originated – at the earliest – about 150 million years after the big bang, from the first burned out large stars (stellar nucleosynthesis). Observations of “giant molecular clouds” from which stars and solar systems form today contain, in addition to hydrogen and other primordial elements, contain organic compounds such as methane, formaldehyde, and methanol. Thus, “our” ancestry can be traced back directly to the primordial hydrogen cloud via nucleosynthesis of hydrogen to carbon in large stars, bonding of carbon with primordial hydrogen, and use of the hydrocarbon molecules to form and sustain a system that decreases specific entropy (life).

The evolutionary “missing link” in this model is the transition from our life system to starlife, indicated by a “?” in the above figure. This region of spacetime is the high-entropy middle ground between adjacent big bangs, for which we have little information because of our vantage point in spacetime – the “current” time. The strength of the model, of course, is that this



maximum-entropy middle ground is not heat death. The opposing entropy gradient provided by two-entropy-gradient systems provides a mechanism to decrease the entropy of the universe to the “next” big bang state (see specific entropy curves in above figure).



20. THE UNIVERSE AS A PHOTON

The conceptualization of a big bang state that retains the laws of physics is a simple model that explains the defining characteristics of the big bang in terms of familiar processes of physics, life, and death. Life (as we know it) and “starlife” (stars in reverse time) share the characteristic of converting starlight into lower entropy matter. Starlife is an advanced form of life that, from “its point of view” as a life system, is looking “forward” to a big bang in 14 billion years (“our” big bang). Starlife thus provides a future point for interpolation, rather than extrapolation, of our life system into the future.

Using starlife as a model future data point for our life system (the A system; all forward-time life in the universe), let’s run through the evolution of “our” universal life system, beginning back at the big bang. The matter-energy that would become today’s living system existed as hydrogen from the primordial nucleosynthesis state. Sometime in the interval 150 million to 9 billion years after the big bang, some of the hydrogen coagulated into large stars that fused helium to carbon and other heavier elements. The stars exploded (supernovae), the dust mixed with primordial hydrogen, and around 9 billion years after the big bang, some of that dust formed a protostar (the sun). Some of the heavy elements in the rotating disk of the protostar gravitationally coagulated into planets, including the earth, where hydrogen and heavy elements existed as organic molecules, water, carbon dioxide, and other inorganic molecules. Some of the organic molecules joined to form more complex, lower specific entropy molecules. The molecules utilized the energy contained in molecular bonds to replicate (increase mass) and evolve (decrease entropy), with an evolutionary milestone – the development of the cell – about 11 billion years after the big bang (prokaryotes). Subsequent evolutionary milestones that occurred as the life system decreased specific entropy include the capacity to utilize starlight for energy to decrease specific entropy and increase mass (photosynthesis) and the organization of and specialization of cells in multi-cellular organisms. At the present time, 14 billion years after the big bang, the same life system – with a continuous ancestry – is increasing mass and decreasing entropy at an accelerating rate, including an unprecedented expansion of technology (manipulation of the earth by life processes) and mass production.



The future of life interpolated between the current life system and future starlife requires the universal life system to increase its mass and decrease its specific entropy in the future direction of time. The life system that evolves to starlife may or may not be the earth life system, and may or may not have already started (spontaneously generated from nonlife). At a point mid-way between big bangs, the masses and specific entropies of the life and nonlife systems are equal, and further in the future the life mass exceeds the nonlife mass. At that point, the total entropy of the universe is dominated by the life system and the total entropy of the universe starts to decrease. At a point in spacetime beyond the mid-point, the universe looks like the current state, in terms of specific entropy gradients of the A and B systems, but the A system is evolved to starlife, gathering up starlight of the universe and organizing it into matter. The starlight used by the A system stars for nuclear photosynthesis is the starlight emitted by today’s stars. The future A system starlife stars are on a course to organize all the starlife into a denser and more organized system, the “next” big bang, which is the minimum entropy state of the universe.

The A and B entropy-gradient systems are mirror images in terms of specific entropy gradients, but the actual processes and evolutions that constitute these gradients may be very different. The reason for these differences is the intrinsic unpredictability of real processes, as visualized using the bifurcation diagrams of the A and B systems (see figure below).



Figure 32. The evolutions of the two universal entropy-gradient systems A

and B through spacetime (heavy green and red lines) are two among an unlimited number of possible evolutions for each system, as represented by

the opposing bifurcation diagrams (thin lines).

The bifurcation diagram for each system A and B represents schematically just a few of the unlimited number of possible evolutions of states of each system, and the “route” indicated for each system represents the actual states of each system during this particular big bang cycle. The actual dissipative structures formed in each system depend on which route is followed, which is unpredictable, and each big bang represents the minimum-entropy state of one or the other of the two systems. In the above figure, the plants, people, and galaxies represent levels of organization (specific entropy). Thus, the people and plants in system A are our system and are people and plants, at least on earth, and the B system at the same time as our earth life (right side of figure) are today’s galaxies. However, the plants, people, and galaxies on the left side of the figure may be much different structures, as long as they have the same specific entropies and masses as plants, people, and galaxies.



The possible evolutions of all big bang cycles can be represented in principle by two bifurcation diagrams, one for each of the two cosmological systems A and B. In the bifurcation diagrams for each of these two systems, each "route" on each tree represents a possible evolution for that system. Each universe (big bang cycle) uses a different "route" and thus has a unique evolution.

The concept of big bang lifecycles envisions real line-particles that continue through big bangs. As a group, the line-particles display opposing entropy gradients that define big bang cycles. This process can continue indefinitely in cyclic big bangs (see figure below).

Figure 33. Conceptual model of mass (matter-energy) distribution between

the two universal entropy-gradient systems A and B.

In a given direction of time, the two cosmological systems A and B alternate between increasing specific entropy (nonlife) and decreasing specific entropy (life) modes at big bangs. At alternate big bangs, one system or the other is the low specific entropy system that dies and becomes the entropy-increasing nonlife system, the other is consumed and plays a passive role in the big bang process.

Through big bangs, matter functions as a storehouse for free energy that is transferred back and forth between the cosmological systems A and B in alternate big bang cycles. The storage process is life and the stored energy at any given time is manifested by the organization of the life system, including technology, at that time. Big bangs are cosmological nodes in spacetime,



where the direction of net mass-energy transfer changes direction between the two systems. The mass-energy transfer creates temporally opposite entropy gradient systems (A and B). The total entropy of the universe at a big bang is the entropy of the system (A or B) that is the high mass, low specific entropy system at that big bang. The total free energy of the universe is commensurately high at big bangs (see figure below).

Figure 34. Total entropy and free energy of the universe through big bang

cycles.

This conceptual model of the universe explains how the big bang “attained” its low entropy state within the constraints of relativistic block time, and at the same time explaining the role of life in the universe, avoiding heat death, and explaining the “next” big bang. Time directionality is the entropy (free energy) gradients of the systems A and B. The sign of the entropy gradient of each system changes at each big bang, so time directionality is a property of the universe only at scales smaller than the big bang interval. At the scale of several big bang intervals, the universe



is time symmetric, because the entropy gradients of the two universal systems are equal and opposite (note that the above figure has no time directionality).

* * *

The universe consists only of line-photons, which are of unlimited length and continue through big bangs. Each line-photon is in one or the other of two states along its entire unlimited length: as a free photon that travels through space at speed c, or organized into matter that cannot travel at speed c. The total number of photons that are organized into matter increases toward big bangs, and the maximum amount of matter occurs at big bangs. Away from big bangs in both directions of time, both the number of free photons and the total entropy of the universe increase. Overall, the universe goes through cycles defined by exchange of photons (as light and as matter) between two universal systems. The net direction of transfer of photons is consistent in one direction of time, from system A to B or visa versa, through a given big bang cycle. The receiving system organizes the photons into matter, thus “storing” energy in nuclear and chemical bonds (free energy) via photosynthesis. The organization of matter that occurs during this energy storage process, considered in the direction of time in which the specific free energy increases (specific entropy decreases), is life. The matter-energy donor system decreases specific free energy (increases specific entropy) as it gives up its matter-energy to the life system by performing entropy-increasing work. Of course, this same process can be considered in either direction of time and the two systems change roles reciprocally. The net result is a waveform in the total free energy (and total entropy) of the universe, which is invariant to the direction of time in which the matter-energy exchange between the A and B systems is considered (see figure below).



Figure 35. Waveform of the universe, which reflects the change of direction of

matter-energy transfer between the A and B systems at big bangs.

The net physical effect is a time-symmetric waveform in the total entropy and total free energy of the universe. The free energy of the universe is at a maximum at big bangs and at a minimum midway between big bangs. At big bangs, the total free energy of the universe is dominated by the high mass and high specific free energy of the A or B system at alternating big bangs. The frequency (ν) of the waveform is the reciprocal of the time between big bangs. The time from one big bang to the next in our universe is greater than 28 billion years, but an upper limit for the frequency is not obvious and depends on the amount of time over which “our” life system evolves to stars. The big bang frequency ν has units of cycles (big bangs) per unit time and for our universe is less than 3.6 x 10-8 per year (1/28 billion years)(see figure below).



Figure 36. Frequency of big bangs is less than 1 per 28 billion years (b.y) by

an unknown amount (? b.y.).

We have assumed that all big bang cycles for our universe are the same duration, which is the simplest model consistent with the data. Additionally, although the duration of a big bang cycle is unknown (other than being greater than 28 billion years), the matter-energy transfer between the A and B systems may control the duration of a big bang cycle. The idea that all big bang cycles are of equal length for our universe is consistent with the universe modeled an isolated system, which means that each cycle should be energetically identical.

The free energy of the universe is a characteristic of our universe, and if the universe were of higher energy, it may have shorter big bang cycles. If so, conceptually, the energy (E) of the universe may be proportional to the frequency of its associated big bang cycle (ν) via a “Planck-like” constant (h), such that E = hν. The real Planck constant h relates the energy and frequency of a photon. Note, however, that the Planck-like constant h for the universe could not have the same value as the real Planck constant h, which pertains to photons. Additionally, the uncertainties in the total free energy of the universe and in the frequency of the universe



(duration of big bang cycles) make an obvious calculation of h beyond the scope of the current model. Nonetheless, the universe is starting to look a bit like a photon.

* * *

We have no evidence for anything “outside” the universe. The “universe” is by definition all of reality that is available for observation, and as far as we can tell the universe is an isolated system that remains contiguous with time. In other words, the universe stays together rather than fragmenting into smaller universes. There is no evidence that pieces of the universe “break off” from the rest of the universe, and there is no evidence for a “surroundings” in which universal fragments can exist separate from one another. However, we can characterize some aspects of the overall structure of the universe.

Because the universe remains contiguous with time and is extended indefinitely in the temporal dimension, the universe has the structure of a line-particle. The universe is finite in all but one dimension, the temporal dimension. In the other three dimensions, the line-particles become more then less organized and commensurately expand and contract. The unlimited extent of the universe through big bang cycles is a direct reflection of the unlimited temporal extent of its constituent line-photons. Again, the underlying structure is the linear structure of photons and thus of all real particles (worldlines). The continuity of the universe as a system is the big bang cycle, in which all the constituent photons of the universe are organized, disorganized, and reorganized through big bang cycles and at several scales of organization (atomic scale, galactic scale, etc). Thus, the universe has the linear (particle) structure and the waveform of a real particle.

Let’s consider three possibilities as to the type of particle the universe may be. First and most simply, the universe could be a photon. The universe has four basic properties: its energy, its waveform (which is possibly related to its energy via a Planck-like constant), its line-particle structure, and its gravitational attraction (general relativity). These same four properties are the main properties of a photon. The second possibility is that the universe is a matter particle, which would require that the universe be made of subatomic particles that could potentially fragment. The universe could not be an isolated system if it were a matter particle, and we’d need to be able to interpret galaxies, stars, and black holes as sub-atomic structures. This



interpretation is not obvious. Third and last, the universe could be a particle that doesn’t exist in our universe, which is possible but is more complex without explaining the data any better. The photon hypothesis is very simple because it means we live in a universe that at once is a photon and is itself made of photons. The waveform, energy, line-particle structure, and gravitational property of the universe are consistent with the universe being a photon, with a frequency that is the reciprocal of the time of one big bang cycle and a total energy equal to the net energy exchanged between systems A and B in a big bang cycle.



21. TESTING THE CONCEPTUAL MODEL

The conceptual model presented herein describes a universe of big bang lifecycles that is simple, consistent with existing mainstream physics, and testable in many ways. Big bang lifecycles reflect entropy gradients, which are manifested by time directionality and all life and nonlife processes in the universe. The universe consists only of photons, which are linear structures. The relative orientations of these line-particles in 4-space are controlled by the physical properties of photons, specifically the strong, weak, and electromagnetic forces that organize photons into matter (atoms), and the gravitational force that organizes the atoms into celestial bodies. These forces keep the line-photons together throughout their lengths, so the universe has the structure of a cable made of many strands (line-photons), not of separate strands strewn about randomly. This linear structure of the universe reflects the linear structure of its constituent photons and is the factor that distinguishes the time dimension from the 3 space dimensions. Cross sections of the “cable” universe are 3 dimensional spatial volumes, not 2 dimensional planes.

At any given time (location along the “cable”), some of the photon line-particles in the universe are organized into matter particles instead of being free photons at speed c. The matter particles – atomic and subatomic particles at less than speed c – are partitioned between two cosmological-scale systems called A and B. These systems are defined by opposing entropy gradients that reflect a continuous transfer of matter and energy from one system to the other. With respect to a given direction of time, the system that is losing matter-energy – the “donor” system or “nonlife” system – increases specific entropy as its mass decreases. Commensurately, the growing mass of the “receptor” system – “life” – decreases its specific entropy and stores free energy by organizing its constituent matter particles. The “donor” and “receptor” systems are defined only in terms of a given time direction, and the roles are reversed if the system is described in the opposite direction of time. Additionally, the roles of the A and B systems, as donor and receptor, switch at each big bang.

When the mass of the universal donor system (A or B) decreases such that it can no longer supply the matter-energy needed to sustain the decreasing entropy of the receptor system, the life



processes of the receptor system cease and the system begins to degrade. This “death” of the receptor (life) system is manifested as a big bang, which commences a cycle of “spontaneous” (nonlife) disorganization of the huge mass of low entropy matter. This low entropy matter is likely primordial hydrogen (and lesser helium and lithium). Thus, in both directions of time away from a big bang, this primordial hydrogen combines with new heavy elements, formed quickly (about 200 million years from the big bang state) in large stars, to form more complex molecules. These complex molecules developed cell structures, replication, and photosynthesis, all of which are natural processes that reflect decreasing specific entropy of an increasing amount of matter (life). Alternating big bangs represent the deaths of the A and B systems.

The two systems A and B are mirror images, not with respect to actual processes but rather with respect to the entropy gradients produced by the actual processes. Entropy gradients define time asymmetry, and the entropy gradients of the systems A and B are modeled as equal and opposite. However, the universe overall, like any individual particle, has no time directionality. Time directionality is a property only within individual big bang cycles, which are symmetric at scales greater than a big bang lifecycle. The temporal asymmetry within big bang cycles can be visualized as a waveform in which the slopes of individual waves are asymmetric but several wavelengths are symmetric. Our perception that the network of line-photons progresses in one direction of time, from past to future, is a function only of the fact that we are alive in that direction of time and thus make memories of the universe in that direction of time. This model provides conceptually understandable time directionality, block time, life processes, and big bang cycles. The model is simple in that the universe is an organization of photons and is itself a photon, and allows the laws of physics to continue through big bangs.

Now let’s step back and evaluate this model relative to the currently accepted standard ΛCDM model of the big bang. First and foremost, the big bang lifecycle model presented herein is consistent with and, it is hoped, builds upon the ΛCDM model of the big bang. The standard big bang conceptual model is based on cosmological observations, the four pillars of the big bang, which include the abundances of light elements, the CMB radiation, the observed expanding universe (Hubble’s law), and the structure and distribution of galaxies. The ΛCDM numerical model makes quantitative predictions that are confirmed by the astrophysical data and provides a quantitative timeline of stable states of the matter-energy of the universe to within less than a second of the singularity. The ΛCDM model is based on a non-equilibrium, isolated system



universe, but the model does not explain how the universe is not at equilibrium. In other words, the standard model is not designed to explain how the universe creates disequilibrium. Why is the universe not a dispersed, equilibrium system that has “always” been at heat death? The standard model does not explain entropy gradients and thus does not explain the origin or physical role of big bangs. The ΛCDM model confirms the big bang concept and places quantitative constraints on past and future states of the universe, but is not designed to predict the chaotic subsystems and emergent systems that define real processes and the cosmological entropy gradient. The standard ΛCDM model leaves the singularity and heat death in the realm of philosophy and does not address these “ends” of spacetime.

The conceptual model of big bang lifecycles extends the knowable universe beyond the singularity and heat death by making a conceptual connection between the entropy gradient and life. Specifically, the suggestion is that life on earth is more than just another dissipative system. Rather, the suggestion is that life on earth defines a cosmologically significant entropy-gradient system with a polarity opposite to that of the rest of the observable universe. Furthermore, life has the same entropy gradient polarity that the rest of the universe has in reverse time. Because the universe is heading toward a big bang in reverse time, life has the potential to evolve to the “next” big bang in forward time. That potential opens up the knowable universe to spacetime beyond heat death.

The connection between life and reverse time processes is based on the opposing specific entropy gradients and is supported by the similarities of the natural processes that define the entropy gradients in opposite directions of time. The evidence for opposing entropy gradients is that the earth life system displays evolution, which reflects decreasing specific entropy in the forward direction of time. One might argue that other dissipative systems create local order too, such as the cyclonic flow of a hurricane to dissipate solar energy, and from that point of view life is an emergent system like any other. However, hurricanes do not evolve. The specific entropy of hurricanes always has been and always will be the same. No emergent system other than life decreases specific entropy in forward time, and life on earth has already continuously decreased entropy for a period of time greater than a quarter of the age of the universe. Thus, life reflects an entropy gradient opposite to the entropy gradient of the rest of the universe, and the entropy gradients of both systems define directional time. Specifically, the biological arrows of time, such as the biological evolution arrow of time biomass arrow of time, reflect the decreasing



specific entropy and increasing mass of the earth life system (and any extraterrestrial forward-time life that may exist and thus be part of system A). By contrast, the nonlife arrows of time, such as the expanding universe and stellar fusion, reflect the increasing specific entropy and decreasing mass of the rest of the universe.

The key natural process shared by the universal life systems – earth life and starlife – is photosynthesis. In opposite directions of time, plants and stars store the energy of starlight in matter. The resulting matter particles contain higher specific free energy (and commensurately lower specific entropy) than the parent matter. In the case of starlife, heavy atoms are the parent matter that transforms into lighter atoms, for example the transformation of helium to hydrogen, as the sun absorbs starlight in reverse time. In the case of plants, earth materials are the parent matter that transform into biomass, specifically the transformation of atmospheric carbon dioxide and hydrospheric water to glucose as the plant absorbs starlight in forward time. The exponentially decreasing specific entropy (evolution) and exponentially increasing mass (over-reproduction) of life systems provide a conceptual unification of time directionality, life, and big bang cycles.

This conceptual unification provides a mechanism to extend the worldlines of real particles beyond the big bang and heat death. In the standard ΛCDM model, heat death allows the worldlines of real particles to continue indefinitely into the future, but the big bang singularity means that worldlines end at the singularity and the universe vanishes. If the universe vanishes, then from a particle point of view, our universe may be a “virtual” particle. Virtual particles appear and disappear due to “quantum fluctuations,” and current research on the nature of the singularity focuses on the quest for “quantum gravity.” Instead of the universe being a real particle – a photon as suggested herein – the universe could be a virtual particle that transmits a fundamental force. These alternative hypotheses for the fundamental nature of the universe warrant further testing.

* * *

Based on the current ΛCDM model parameters, the universe is expanding at an accelerating rate. This acceleration creates physical problems, such as matter that travels faster than the speed of light. The accelerating expansion is attributed to dark energy, the “Λ” in ΛCDM, which is a



cosmological constant with no conceptual interpretation except as the equivalent amount of real energy required to cause the observed acceleration. Thus, to the extent that dark energy is responsible for the acceleration of the expansion of the universe in forward time, dark energy is equally responsible for the deceleration of the contraction of the universe in reverse time. As mentioned previously, this deceleration in reverse time can be interpreted as a coordinated meeting of all parts of the universe at “the” big bang. Furthermore, to the extent that the expansion of the universe is one of many natural processes that reflect an underlying randomization of particles in forward time (Boltzmann’s statistical time directionality and arrows of time), dark energy may be responsible for, or a manifestation of, all particle randomization in forward time. This interpretation means that the entropy gradients of the A and B systems and dark energy are the same things, and that dark energy equally reflects particle organization in reverse time.

Recall, time directionality and all arrows of time, including the expanding universe, are emergent manifestations of the overall randomization of particles in the future direction of time. This randomization of particles, or equivalently the ordering of particles in reverse time, defines a gradient of specific entropy. However, the reason particles are more ordered in one direction of time and less ordered in the other is unexplained. Perhaps dark energy, which is envisioned to permeate all spacetime, is the ordering/randomization of particles along the entropy gradients of the A and B systems. In other words, dark energy may randomize particles at all scales, with expansion of the galaxies being just the largest scale manifestation of the randomization. If dark energy is associated with randomization in one direction of time, then dark energy is equally well described as being associated with ordering in the other direction of time. Dark energy would thus be the “force” that organizes matter-energy in life systems. This interpretation predicts that dark energy “operates” in opposing directions in the A and B entropy gradient systems, so the A system (earth life) may have dark energy of opposite temporal polarity from the rest of the observable universe (B system).

An alternative way to view dark energy is that it reflects an unpredictable, non-equilibrium process. The possibility, described above, that the forward-time acceleration of expansion is a life process in reverse time, specifically a coordinated reverse-time deceleration of the starlife galactic “organisms” as they approach the big bang, could be an unpredictable, non-equilibrium process. Other non-equilibrium conceptualizations of reverse-time deceleration are possible,



such as deceleration of the galaxies as part of the death of the B system in reverse time. In this scenario, in reverse time, the “current” time is within the big bang process, because the reverse-time “death” of stars as they dissipate into primordial hydrogen – which occurs today – is the big bang process. The point here is that the forward-time acceleration of expansion of galaxies could be a temporary, emergent process – in both directions of time – rather than part of the physics of the universe.

Thus, the big bang lifecycle model provides at least two ways to model the acceleration of the expansion of the universe: first, that dark energy underlies the cosmological entropy gradient and thus underlies all natural processes, and second, that dark energy doesn’t exist, and the acceleration is just another temporary, unpredictable, emergent process within the overall entropy gradient. Further evaluation of these possibilities may shed light the dark energy question and the big bang process.

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Physics provides no explanation of photons. Among the conceptual breakthroughs of special relativity was the idea that photons are the most fundamental real particle and as such are a “given;” all other real particles (matter) are made of photons (E=mc2). If the universe is an isolated system, the number of photons in the universe is a constant; photons can be incorporated in matter, but cannot be created or destroyed. The properties of photons control their interactions and are manifested as the fundamental forces – the weak, strong, electromagnetic, and gravitational – but the substructure of photons remains unclear. The possibility that the universe is itself a photon, as proposed herein, predicts that the wave properties of photons are a direct result of the exchange of energy-matter between entropy-gradient systems within those photons.

Photons in our universe may themselves be composed of photons. Specifically, “our” photons may be composed of smaller scale line-photons that are each organized into two entropy gradient systems, just like A and B. These smaller scale line-photons are predicted to organize and disorganize during cyclic exchange of free energy between entropy gradient systems. The cyclic exchange defines a frequency ν, which is related to the free energy exchange between the A and B systems E via the (real) Planck constant h, where E = hν. This conceptual model may be tested at the cosmological scale by relating estimates of the frequency of big bangs and the total



energy exchange during big bang cycles to arrive at a universal “Planck-like constant,” and at the microscopic scale by evaluating the (real) Planck constant from the point of view of the proposed substructure of photons (entropy gradient subsystems).

Additionally, the presence of A and B entropy gradient systems within photons could be related to the property of magnetism. Specifically, if the A and B systems in photons are different in any way, the resulting asymmetry would be polar, so based on symmetry arguments could generate the “magnetic” in “electromagnetic” energy (photon). This possibility offers another approach to test the photon model of the universe and further define the substructure of photons.

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Further evaluation of the history of the pre-primordial nucleosynthesis universe will be an interesting test and refinement of the conceptual model of big bang lifecycles. Specifically, the ΛCDM model for the earliest part of the universe, from the singularity to 3 minutes after the singularity, is based on reverse-time extrapolation beyond the earliest time for which we have astrophysical evidence of the existence of the universe. The extrapolation is based on stable states of matter-energy at high energies, as determined from particle accelerators. If our observations of the cosmos find no trace of an earlier universe, then our model does not “need” to explain the universe prior to primordial nucleosynthesis. For example, the ΛCDM model predicts that at approximately 1 second after the singularity, neutrinos decouple and begin traveling freely through space. This event should produce a difficult-to-detect, and not-yet-detected, cosmic neutrino background radiation, which is analogous to the later CMB radiation. Observation of this cosmic neutrino background radiation would be evidence that the universe gets closer to the singularity than 3 minutes. Until that evidence is detected, the simplest model consistent with current data set is that the “big bang state” – the minimum entropy, minimum volume, maximum mass, and maximum free energy state of the universe – is hydrogen nuclei and photons.

If the big bang state of the universe is hydrogen nuclei and photons, then the primordial nucleosynthesis event may be neither “nucleosynthesis” nor an “event.” Within the context of the big bang lifecycle model, the interpretation of the hydrogen-photon state of the universe is that it is the “corpse” of the A or B life system at alternate big bangs. In reverse time,



photosynthesizing stars become hydrogen clouds, which are dark (non-photosynthesizing) matter. The hydrogen-photon universe becomes stars in both directions of time away from the big bang, so the hydrogen-photon state of the universe is the only state of the universe known to exist “prior” to star formation (photon epoch and dark ages in the standard big bang model). In this view of the universe, primordial hydrogen does not evolve from earlier, higher energy particles, and does not require nucleosynthesis of hydrogen from more fundamental particles. In this regard, it should be noted that the physics of the hydrogen-photon state does not require nucleosynthesis from more fundamental matter particles. Rather, standard model is based on the fact that the hydrogen-photon state is the stable state of matter-energy at the temperatures of the universe that exist 3 to 20 minutes after the singularity. The hydrogen-photon state of the universe does not “need” an earlier universe. Further evaluation of these two working hypotheses – the “particle physics” predictions of the first 3 minutes of the universe versus the hydrogen-photon big bang state suggested here – will test and possibly refine our conceptual model of the early universe.

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The idea of physical memory is the appearance that systems contain information about, or are a product of, the past but not of the future. In other words, systems seem to be the result of their histories – “cause-and-effect” – but do not seem to be the result of their futures. This challenge to the idea of block time can be reconciled by first separating the objective universe from our subjective memory making process. Subjective memory is our capacity to remember some of our past “experiences,” that is, sensory input, but we cannot remember future experiences. This asymmetry is interpreted herein as a function of being alive only in the future direction of time and the subjective vantage point of “now.”

With regard to objective memory in the universe, there are two scales of physical memory. The larger scale memory can be called “big bang memory.” The standard big bang model includes primordial nucleosynthesis, which is a state of the universe in which the matter-energy of the universe was in light elements and photons. The universe contains a physical memory of this state in the relative abundances of light elements and the CMB radiation. The entropy of the universe in this state was lower than at any subsequent time. This low entropy state was preceded by one of two processes. The standard big bang model has the universe decrease in



size and entropy in reverse time until the universe vanishes at a singularity; in forward time, the subatomic particles stable under these extreme conditions form hydrogen and the light elements by primordial nucleosynthesis as the universe cools. The big bang lifecycle model presented here has the universe as a life system “prior” to the big bang. The life process is the starlife of the “previous” big bang cycle, which forms hydrogen and the light elements by nuclear photosynthesis in stars before they “die” at the big bang, leaving the hydrogen-photon “corpse.”

The current data set is consistent with both these models because no physical memory (evidence) of events prior to primordial nucleosynthesis has been recognized. Thus, regardless of the origin of the primordial nucleosynthesis state of the universe, the entire evolution of the universe since the big bang (except life) is completely explained by the randomization of the light elements over a period of 14 billion years. Because of this, the physical memory of the big bang state was at a maximum during primordial nucleosynthesis and has been continuously lost since then. Big bang memory decreases in the forward direction of time as the total entropy of the universe increases. In other words, contrary to intuition, the total memory of the universe decreases in forward time. If heat death were to be attained – actual equilibrium – then all physical memory of earlier states of the universe would be completely lost.

The smaller scale memory can be called “emergent structure memory.” The universe equilibrates in forward time via stellar fusion and other processes of increasing entropy. All these processes are emergent systems, material structures formed as part of the universal equilibration processes. All emergent systems have a lifecycle, which is a life process in one direction of time and a nonlife process in the other direction of time. All emergent systems have finite lifecycles defined, in both directions of time, by the organization then disorganization of the constituent particles. Emergent systems define all processes in the universe and include people, planets, the rings of Saturn, or any feature of the universe one can identify.

As has been pointed out in the philosophical literature, probability alone predicts that a given system should be more random before it is observed as well as after it is observed, and this is true for individual systems. Time directionality is defined by the overall randomization of the big bang state, that is, the increase in the entropy of the universe with time, not by the comings and goings of individual emergent systems that accommodate the overall randomization. For example, an individual hurricane is an emergent system that accommodates equilibration



(increasing entropy) of thermal gradients. The hurricane organizes air and water molecules, but then its organization dissipates. The overall result of the process is an increase in the entropy of the universe in one direction of time and a decrease in the entropy of the universe in the other direction of time. In the example of a hurricane, the thermal gradient itself – like all current forward-time processes – is a manifestation of the randomization of the big bang state. The hurricane dissipated the thermal gradient that was a result of solar heating, which itself is randomization of primordial hydrogen by fusion in the sun.

Thus, the question of physical memory boils down to the fact that when we observe emergent structures at some “now” during the lifecycle of that structure, we are able to know some aspects of its past but not of its future. For example, at a given “now” during the lifecycle of a hurricane, we can know its past path with certainty but not its future path. This knowledge asymmetry is obviously due to our vantage point in spacetime. If we “move” to a different vantage point in spacetime, say a month later, after the hurricane has dissipated, then we can know the entire path of the hurricane with certainty. Furthermore, we can know the entire path of the hurricane only after it is fully dissipated, which means the physical memory of the hurricane has vanished, except for its effects, which also will dissipate with time. The same is true of physical memory of which we have no actual (psychological) memory, for example the trilobite fossil exposed in the cliff face. The fossil is an emergent structure that formed half a billion years ago and has been dissipating ever since. We observe it before it fully dissipates, and from that subjective vantage point (now) we can tell more about its past then about its future. In both cases – the hurricane and the trilobite -- there is no objective aspect of any emergent structure that can be interpreted as being a memory of its past but not of its future. Any real process is an emergent system -- a temporary organization of moving particles -- and from the vantage point of any time during the lifecycle of the emergent system, we know with certainty that the system will completely dissipate in both directions of time.

The big bang lifecycle model presented here suggests ways interpret memory and information. The standard big bang model involves an initial low entropy state (big bang) and a final high entropy state (heat death). The big bang state contains the most information about the universe and the heat death state contains the least. According to the standard model -- without big bang lifecycles -- heat death is the theoretical equilibrium state of the universe, and any possible evolution of the universe leads to that state. Therefore, in theory, the heat death state contains no



information about its past (or future). By contrast, the big bang state and all subsequent states contain all the information that exists in the universe, and the information content of the universe increases in reverse time toward the big bang state. Again, this physical memory of the big bang state dissipates away from the big bang state via stellar fusion (nucleosynthesis) and all other natural processes. Thus, contrary to our intuitive notion that the amount of physical memory in the universe increases with time, because the “amount of history” increases with time, the amount of memory in the universe actually decreases with time as memory of the big bang state is irreversibly lost. In the limiting case, if the universe were to completely equilibrate to free photons, there would be no evidence that the universe ever contained hydrogen or any matter. Conversely, in reverse time, the amount of memory in the universe increases, which is a direct reflection of the universe (except our life system) being alive in reverse time. Further evaluation of physical memory, and of the possibility that stars have memory of the future (their past), will clarify the role of memory in time asymmetry and test the big bang lifecycle model.

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In our big bang lifecycle, starlife (the current B system) evolves in reverse time to the same primordial hydrogen cloud from which our life system evolved (in forward time). Therefore, the simplest model of the big bang state of the universe – its minimum entropy state – is a hydrogen cloud and photons. The high specific entropy system (A) – our life system – may go to zero mass at the big bang. Obviously, if the mass goes to zero, which means that in reverse time our A nonlife system is completely consumed by the B life system, then its entropy is undefined at the big bang. An entropy gradient system (A or B) whose mass goes to zero at the big bang creates a problem for the big bang lifecycle model.

If the A (or B) system mass goes to zero, then the system loses its identity across the big bang. Clearly, the entropy gradient that defines the A system vanishes if the system contains no particles (zero mass). If the A system vanishes at the big bang, then, in forward time, the decreasing specific entropy gradient that defines the A system spontaneously appears in particles of the B system. This is the spontaneous generation model for the origin of A life on earth, but that spontaneous generation occurred 10 billion years after the big bang and required carbon, which was not available at the big bang. Thus, if earth life is the only life in the universe, then all the particles in the universe were in the B system for the 10 billion years from the big bang



until the appearance of life on earth, and the A system did not exist for this 10 billion year period (Scenario 1 in the figure below).

Figure 37. If the A life system exists only on earth, the entropy gradient

would be discontinuous (Scenario 1). Life systems other than the earth life system must exist for the A (or B) system to persist through big bangs and

contribute to a continuous entropy gradient (Scenario 2).

Nonexistence of the A (or B) system at the big bang (Senario 1 above) is inconsistent with the conceptual model, because the A life system is predicted to originate by decreasing the high entropy remnant of the “pre-big bang” A nonlife system. However, if the A system mass goes to zero at the big bang, the minimum mass, maximum specific entropy state of the A system does not exist at the big bang. This problem is avoided if earth life is not the only forward time life in the universe (Scenario 2 above). Specifically, the persistence of the A and B entropy gradient systems through big bangs is viable if other forward time life systems exist, including some form of life at the big bang. Of course, such life could not organize carbon atoms, which did not exist until stellar nucleosynthesis (fusion) created a supernovae to produce the heavier elements. Carbon-based life could have existed as early as about 200 million years after the big bang, but



any form of life that existed prior to stellar fusion would have organized hydrogen, helium, and/or lithium atoms.

According to this reasoning, the big bang lifecycle model predicts that forward-time life exists outside the earth, in both space and time. Additionally, the model predicts that a life form that organized light elements and possibly subatomic particles existed at the big bang state of the universe. These life forms, like all life forms and all emergent structures, emerge and disspate, as shown in the above figure. These earliest life forms persist until about 200 million years after the big bang and possibly beyond, when stellar nucleosynthesis started forming heavier elements. These heavier elements include the first carbon in the universe, which makes carbon based life -- and any other organizations of heavier elements -- possible. Thus, the model can be tested by searching for extraterrestrial life and by evaluating heterogeneities in the universe in light of the possibility that they represent “fossils” of early life in the universe. Unfortunately, experiments designed to test for extraterrestrial life seem to stand a low probability of yielding positive results. However, further evaluation of heterogeneities in the universe may provide clues to the early A system life forms – our life system – prior to stellar nucleosynthesis. Such life forms would have organized the light elements that constituted the early universe, and the observed large-scale heterogeneities of galaxies and galaxy clusters could be the dissipating organization of these early life forms. In other words, galactic heterogeneities could be “fossils” of pre-stellar life, analogous to the disintegrating trilobite fossil in the cliff face.

Another possibility for avoiding the vanishing (zero mass) high entropy system at the big bang is that the CMB radiation is the high entropy system at the big bang. This possibility is attractive because the CBM radiation is the highest entropy state of matter-energy. Recall, free photons are in a higher entropy state than the same photons organized into matter particles, and CMB radiation is less organized than later-produced photons in our universe, i.e. starlight. Therefore, the CMB radiation certainly qualifies as being of high specific entropy, but it is difficult to see how the CMB radiation could have evolved into our life system. Specifically, our life system does not organize CMB radiation, and the B reverse time life system (starlife) does not organize CMB radiation. If evidence can be found to the contrary, that is, evidence that CBM radiation participates in the A and B entropy gradient systems, then the CMB radiation may be the low mass, high specific entropy system at the big bang.



Thus, the model of big bang lifecycles predicts that a low mass-high specific entropy system exists at the big bang, and that state of the A or B system could be attained if life exists at other locations in spacetime, including at the big bang, or if the CBM radiation is organized by life processes. The proposition that life exists at other locations in spacetime alleviates the need for our life system, or any life system, to be indestructible. In other words, if earth life is the only life in the universe, then the destruction of earth life, for example by a major comet impact or burning out of the sun, would mean the disruption of the A entropy gradient system and thus of the big bang lifecycle. If the universe is a photon and has limitless big bang lifecycles, it does not seem possible that each big bang lifecycle depends on the survival of life on one planet. Unfortunately, it does not seem likely that we will detect extraterrestrial life in any foreseeable future to confirm this prediction and, more to the point, there is no foreseeable, viable experimental design to test for extraterrestrial life.

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The concept of big bang lifecycles envisions disequilibrium in the universe as existing only at the scale of less than one big bang cycle. The overall structure of the universe through multiple big bang cycles does not contain disequilibrium, nor does it contain equilibrium or time directionality. The universe line-particle is envisioned to extend indefinitely in both directions of time and overall displays neither time directionality nor equilibrium-disequilibrium. One may ask whether such a universe constitutes a “perpetual motion machine.” After all, work is performed during each big bang cycle and the model proposes that this work goes on indefinitely; does this mean the universe has an unlimited rather than finite energy content? The answer is clearly “no,” the energy is the finite total energy of all the photons (including matter) in the universe.

However, this still does not answer how a universe with finite energy – an isolated system – can contain disequilibrium. Why is the universe not at equilibrium? This question is the same question as why there are big bangs and why entropy gradients exist and define the waveform of the universe. One approach to this question is that, to the extent that the universe is a photon, this question is the same question as how light travels indefinitely at speed c. Free photons exist at speed c, but are not perpetual motion machines. If the universe is a photon, then big bang cycles are simply the “microscopic” substructure of the wave property of the universe line-



particle (worldline of the universe). The light speed c is a natural constant that is observed but cannot be derived from other laws or data. This universal constant c controls the wavelength-frequency relationship in photons according to c = νλ, where ν is the frequency and λ the wavelength of the photon. By analogy to the universe, the universe has a wavelength and a frequency, the product of which is some constant “speed of the universe.” The value of this natural constant – the speed of the universe – is unknown, but whatever is, the conceptual model predicts that this constant exists. Therefore, by analogy to c, the “speed of the universe” is a natural law that cannot be explained in terms of other laws of physics, but it can explain other processes. Specifically, the disequilibrium in the universe – which is manifested as time directionality and all natural processes in the universe – is the substructure of the speed of the universe, just as each wave (νλ) of a photon is the substructure of c. In other words, the big bang lifecycle model conceptually explains directional and block time, the role of life in the universe, big bangs, and all processes in the universe in terms of one fundamental property of photons, that property being their intrinsic speed. When free photons are organized into matter, the speed c is “converted” to the properties of matter but the waveform remains as particle vibration (temperature). Further testing of the model could shed light on all natural, disequilibrium processes in terms of the underlying entropy gradients and the natural constant (c) that they reflect.

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