The Astronomy Quarterly. Vol. 7, pp. 87-94, 1990 Printed in the USA. All rights reserved.

0364-9229/90 $3.00+.00 Copyright (c) 1990 Pergamon Press plc

THE BIG BANG IN CONVERSATION: WDERSTANDING THE BIG BANG

JAMES C. LOPBESTO ’

INTRODUCTION

Perhaps one of the most difficult set of concepts to convey to astronomy enthusiasts, who are not physics-oriented, involve the latest ideas concerning the “Big Bang” or the creation of the Universe. Since this theory combines three great areas of physics (namely: relativity, quantum theory, and particle physics), speaking about its details can be intimidating mathematically and difficult at best. Another problem is that since the subject matter is so abstract and esoteric, there is a tendency on the part of the layman to ask questions that are too anthropomorphic. The abstract and esoteric ideas come from the seemingly strange aspects of relativity and quantum physics that, unfortunately, seem to disobey common sense. For example, the question of “what came before the Big Bang?” can be criticized by saying, “time had not started yet; it, like space and matter, is a creation of the Big Bang”.

Beginning students also ask: 1. What is created in the Big Bang? 2. At what time was it created? 3. Where was it created?

These same students are often surprised to hear that the answers are: 1. Everything! 2. The beginning of time! 3. Everywhere!

METHOD

How does one explain this fascinating subject and convey the enthusiasm, the xeal and the excitement without also including fear, confusion, and perhaps even boredom?

’ Dr. J.C. LoPresto is an astronomy professor in the Department of Physics at the Edinboro University of Pennsylvania, in Edinboro, PA 16444.

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The “begimier” has the natural tendency not to separate science from theology. The subject should be approached with the sensitivity and understanding that many readers may have strong religious convictions. These convictions need not be attacked, if one attempts to separate the disciplines of science and theology with regard to how they are practiced. Some preliminary discussion informing the student that a hypothesis will fail as an acceptable scientific theory unless confirmed by experiment and observation is essential. This might be enough to separate science from theology to the reader’s satisfaction.

At the same time, it is important to convey how impressively successful the theoretical work on unification theories (theories that attempting to explain all the four forces in nature -- the strong and weak nuclear forces, electromagnetism, and gravitation -- as one combined superforce) appear to be. It seems that many ideas about unification of the forces in nature have the potential of evolving into a viable verifiable theory.

Many theories of particle physics and cosmology appear whimsical and without basis, but that is certainly not the case. Astronomers and physicists enjoy using whimsical names and making associations with other intellectual endeavors such as literature and art. A good example is the use of the term “quark” by Murray Gellman for the fundamental makeup of sub-atomic particles. Gellman obtained the Nobel Prize for the Quark Theory of fundamental particles. He borrowed the term quark from the novel by James Joyce entitled Finnegans Wake. Another example concerns particles which appear out of nothing and are called “virtual particles”, an invention of Richard Feynman. Feynman used this concept in his “Theory of Quantum Electrodynamics” for which he also received the Nobel Prize. Particles “appearing out of nothing” is now well established in particle physics; these same ghostly particles have been both directly and indirectly detected with use of some of the great particle accelerators. The reader might consider these ideas as temporary suspensions of such classical concepts as conservation of mass and energy within the limited time restrictions of quantum physics. However, at the beginning of time, a major violation of conservation of energy and matter seems to be unavoidable. But since time came into existence at the Big Bang, is the creation of all the energy in the Universe really a violation?

The historical aspects of the developments of Big Bang ideas can aid in understanding the theory. At any time, various fields of science have a

Understanding the Big Bang 89

given status among the scientists themselves. This status is to some extent a sort of fashion. Fashion determines what areas of science are more likely to be productive and in turn will be funded by grant monies. Big Bang physics is now very fashionable. This was not the case only a few decades ago. Big Bang physics has risen from “on the fringe” to center-stage in only a half a century. To a large extent this change of fashion was brought on by experimental and observational developments in both astronomy and physics.

Among these developments are the discovery of the different types of neutrinos by the physicists Lederman, Schwartz, and Steinberger. This monumental particle accelerator project (for which they, too, received the Nobel Prize in 1988) has given experimental verification to some aspects of standard cosmological models based on quarks, leptons, and exchange particles (called gluons, photons, vector bosom, and gruvitom). The different kinds of quarks are distinguished from one another by properties called up, down, charm, strange, top, and bottom, which in turn have other properties identified by the colors red, green and blue. Recent theoretical developments for unification theories, such as GUTS (Grand Unified Theories combining the Nuclear, Weak and Electromagnetic forces) and SUPERGUTs (a unification of all the forces in nature, including gravity), along with inflation theories, have provided more and more impetus to push onward. Hubble’s discovery of the expansion of the Universe from the observations, first made in the 1920’s, of the spectral red-shifts of galaxies, and the discovery of the cosmic background microwave radiation by Penzias and Wilson, in the late 1%0’s, are the main astronomical observations. Still, with all of this apparently under our control, a serious armchair astronomer must work hard to acquire any sense of “under-standing”. In my mind, two conditions must be met to give some initial understanding to the non-scientist. It should be done, first, without a great investment in time; second, without the need of advanced education in physics.

A few of my students and I sat down and discussed this dilemma one Saturday afternoon. After a lengthy discussion, debate, argument and several good laughs, the conversation turned to a new Time-Life Publication, Voyage i%rough the Universe: i’?re Cosmos. We noticed that the introductory paragraph in this wonderful volume provided the seed to

J.C. LoPresto

accomplishing the task cited above. Namely, how does one convey the Big Bang easily, understandably, convincingly and yet interestingly?

With a great deal of computer power available at our disposal in the observatory, we set out to investigate how to simply convey ideas about the “Big Bang”. We used a popular personal computer, with a commonly-used word-processing program and a generally-not-too-commonly-used electronic theS&UlNS. We read this introductory paragraph to one another and reconstmcted it in our minds and repeated phases from it over and over again. We constantly changed words and word order and argued back and forth in favor of using less or more dramatic language. However, we stuck to the flow and sense of the paragraph and tried not to change what it conveyed. In any case, we found the experience to be a great deal of fun and perhaps more importantly very instructive.

The introductory paragraph (Time-Life Pds. 1989, p. 12) goes as follows:

“First there is nothing - not time, not space, not even emptiness, since there is no space to be empty. Then, from this void, this utter nothingness so complete that no work can make it imaginable, springs . . . a universe, suddenly there but far smaller than the smallest dust mote. The seed for everything that will ever be, it contains all of creation. For now, however, chaos reigns; the universe is so tiny, hot, and dense that none of the familiar laws of physics hold. The dimensions of space and time are tom and snarled by discontinuities. The concepts here and there have no meaning, nor do now and then. ‘Ihere is no matter, no force such as gravity or electromagnetism, only a node of pure energy. ” One could convincingly argue that we probably cannot improve much

on this well-worded paragraph. It contains many of the elements we desire to convey the ideas of the Big Bang. However, we felt strongly, and this is not being critical, that certain ideas need expansion and others needed to be stated more dramatically and perhaps with more scientific precession. For example, the idea of “small” is very misleading. Certain types of Universes can be created already infinite in extent. What is at issue is how much is observed by a given observer at a given time in its evolution. What is observable may be small, but not necessarily the Universe itself. The non-scientist can be mislead by thinking of something starting out as small, since they will generally imagine “the small thing” within an already existing and perhaps infinite space. It’s important to promote the concept

Understanding the Big Bang 91

“events take place, is created. Finally, we decided that an outline in one-liner forms would best fit our

goal. We also gave headings or main section titles to help convey what was being said in the one-liners. The following scenario is what we came up with.

OUTLINE INTRODUCTION

The reader might find that his/her understanding of the Big Bang might be easier, if he/she ask of him/her-self these simple but profound questions.

1. What is created in the Big Bang? 2. When does the Big Bang occur? 3. Where does the Big Bang happen?

Upon reflection, the answers to these questions are: 1. Everything: space (with its geometrical properties), time, matter and energy. This means that the Universe can have no boundary, since that would imply that there is something on the other side of the boundary and by definition, the Universe is everything.

2. The beginning of time: time started at the first event known as “Creation”. There can be no time before anything existed.

3. Everywhere: whatever type of Universe is created by the Big Bang, it acquires its properties, inftite size or finite size or what have you, upon its creation ! According to modern science the Universe came into existence about 15 billion years ago in a series of events known as the BIG BANG. All of time from this beginning until now can be divided up into six major phases, which are:

i. Creation of the rules (the laws of physics) ii. Making the raw materials (limda-mental particles) iii. Rearrangement (formation of galaxies and clusters) iv. Gathering of material to make-up local details C&nets, people) v. Mm observes the Universe vi. Man makes models of the Big Bang

92 J.C. LoPresto

vi. Man makes models of the Big Bang The first two phases occur in a matter of about 1 second~f-time. The

third phase occurs after one billion years or so and the last three phases occur over the range of the last 14 billion years or so. In the first two phases, one can point out distinct events such as the singularity at time zero, the Plan& time at 10J) seconds, the Hadronic era at lo6 seconds, the leptonic era at about 1 second, the radiation era at about 1 minute and the matter era after 10 years. The series of events in these phases are described in greater detail below.

CREATION

First there is nothing!

No time, no space, not even emptiness, since there is no space to be empty!

From this utter nothingness a Universe convulsively bolts into existence!

Matter crea&d out of nothing is a prediction of modern quantum physics.

Upon creation, the dimensions of space and time are tom, twisted and snarled in a jumble of disarray, disorder and chaos.

l%is is caused by extreme curvature of space over very tiny dimensions.

Here and there, now and then have no meaning!

There is no matter, no force such as gravity or electromagnetism.

The first existence is a PURE, INTANGIBLE, INCORPOREAL, INDISCERNIBLE, ETHEREAL FORM OF ENERGY.

At the instant of its creation the infant Universe begins to expand (create its own space) and cool rapidly from an unimaginably high temperature -- jum- bled space and time starts to disentangle.

Expansion is the creation of space!

Understanding the Big Bang 93

EXPANSION

Suddenly, within the fleetest flash of an impulsive instant the cooling allows gravity to congeal from the undifferentiated energy.

Before this all the fourforces in nature are one supe$orce and now gravity jkeezes out.

The constraint of gravity slows the rapidity of expansion.

Pairs of virtual particles that can only exist in the extreme conditions of this newborn epoch dance instantaneously into existence.

Jammed and crushed together and zooming through space, the newly created particles of matter crash together in a pandemonium of violent and rupturing collisions.

Usually they annihilate one-another, vanishing in detonating streaks of quantized energy.

Every so often they recreate a deluge of new particles, all rushing to their individual fierce demise.

INFLATION

Due to a symmetrical homogeneous (homogeneous means uniformly spread out) and isotropic (isotropic means the same in all directions as viewed from any point) geometry in the newly formed Universe, gravity in a grotesque like-fashion, behaves repulsively rather than attractively.

Instead of hindering the expansion, gravity triggers the Universe into a swelling stampeding frenzy of bubble like blistering.

Before the Universe is one second old its searing contents have become familiar forms of matter springing and equally rapidly decaying in and out of existence into forms called protons, neutrons, electrons which in turn

94 J.C. LoPresto

of existence into forms called protons, neutrons, electrons which in turn combine to form atoms.

As the expansion continues, it has the effect of spreading the particles further and further apart from one-another.

These fundamental building blocks need now only accumulate into the molds of stars, galaxies, planets and ultimately life forms.

These latter happenings will take great stretches of time but the necessary ingredients have been prepared.

WEAREHERE!

THE MYTH CALLED CREATION HAS BECOME REALITY; WE EXIST AND WE GO ABOUT OUR BUSINESS -- WE WERE MOLDED IN THE FIRST SLIVER OF AN INSTANT ESTIMATED AS: 0.000,000,000,000,000,000,000,000,000,000,1 SECONDS.

WHAT WAS CREATED? THE LAWS OF PHYSICS!

Eventually man appears in the Universe and creates theories of the Big Bang and conveys these ideas to his fellow human beings.

After reading this outline, one does not understand, by any means, a great deal more about the physics of cosmology or the Big Bang; but, perhaps the reader might acquire the excitement to push forward and learn much more since he/she perhaps may now feel that it is understandable.

Do you think we are right?

REFERENCES

Joyce, J. 1939, Finnegans Wake (New York: Viking Press).

The Editors of Time-Life Books, 1989, Voyage Through the Universe: Ihe Cosmos (Alexandria, VA: Time-Life Publications).