The Story of The Universe

Introduction

According to the Boshongo people of central Africa, in the beginning there was only darkness, water, and the great god Bumba. 

One day Bumba, in pain from a stomachache, vomited up the sun. The sun dried up some of the water, leaving land. Still in pain, Bumba vomited up the moon, the stars, and then some animals: the leopard, the crocodile, the turtle, and, finally some men, of which only one of them named Yoko Lima was white like Bumba.

This creation myth, like many others, tries to answer the questions we all ask. Why are we here? Where did we come from? Most people would find that myth of our creation rather ridiculous, but why do we think we know better? What do we know about the universe, and how do we know it? Where did the universe come from, and where is it going? Did the universe have a beginning, and if so, what happened before then? What is the nature of time? Will it ever come to an end? Can we go back in time?

Recent breakthroughs in physics, made possible to suggest answers some of these longstanding questions. Someday these answers may seem as obvious to us as the earth not being flat, or maybe as ridiculous as Bumba vomiting up everything. Only time (whatever that may be) will tell.

The Elevation of Thought

The Greek philosopher Aristotle, in his book On the Heavens, was able to put forward a good argument for believing that the earth was a round sphere rather than a flat plate. First, he realized that eclipses of the moon were caused by the earth coming between the sun and the moon. The earth’s shadow on the moon was always round, which would be true only if the earth was a sphere. If the earth had been a flat disk, the shadow would not have always been round unless the sun was directly under the center of the disk.

The Greeks even had an argument that the earth must be round as well, therefore one first see the sails of a ship coming over the horizon, and only later see the hull.

Aristotle thought the earth was stationary and that the sun, the moon, the planets, and the stars moved in circular orbits about the earth. Ptolemy elaborated this idea in the second century AD into a complete cosmological model. The earth stood at the center, surrounded by eight spheres that carried the moon, the sun, the

stars, and the five planets known at the time, Mercury, Venus, Mars, Jupiter, and Saturn.

The outermost sphere carried the so-called fixed stars, which always stay in the same positions relative to each other but which rotate together across the sky. What lay beyond the last sphere was never made very clear, but it certainly was not part of mankind’s observable universe.

It was adopted by the Christian church as the picture of the universe that was in accordance with Scripture, for it had the great advantage that it left lots of room outside the sphere of fixed stars for heaven and hell.

However, in 1514 a Polish priest, Nicholas Copernicus, proposed a simpler model. At first, perhaps for fear of being branded a heretic by his church, Copernicus circulated his model anonymously. His idea was that the sun was stationary at the center and that the earth and the planets moved in circular orbits around the sun. Nearly a century passed before this idea was taken seriously.

Then two astronomers the German, Johannes Kepler, and the Italian, Galileo Galilei started publicly to support the Copernican theory,

despite the fact that the orbits it predicted did not quite match the ones observed. The deathblow to the Aristotelian/Ptolemaic theory came in 1609. When the telescope was newly invented Galileo used it to observe the night sky, he noticed; the planet Jupiter was accompanied by several small satellites or moons that orbited around it. Which implied that everything did not have to orbit directly around the earth, as Aristotle and Ptolemy had thought.

At the same time, Johannes Kepler had modified Copernicus’s theory, suggesting that the planets moved not in circles but in ellipses. As far as Kepler was concerned, elliptical orbits were merely an ad hoc hypothesis, because he could not reconcile them with his idea that the planets were made to orbit the sun by magnetic forces.

The Role of Modern Science

1687, Sir Isaac Newton published his Philosophiae Naturalis Principia Mathematica, probably the most important single work ever published in the physical sciences. In it Newton suggested a law of universal gravitation according to which each body in the universe was attracted toward every other body by a force that was stronger the more massive the bodies and the closer they were to each other. It was this same force that caused the apple to fall to the ground. In addition he put forward a theory of how bodies move in space and time, he also developed the complicated mathematics needed to analyze those motions.

However, according to Newton’s law, gravity causes the moon to move in an elliptical orbit around the earth and causes the earth and the planets to follow elliptical paths around the sun. But it also suggested something new and controversial; could the universe be static with all the gravitational forces of stars, shouldn’t stars attract each other? Or would they stay motionless, if they even were essentially?

It is an interesting to observe the general climate of thought before the twentieth century that no one had suggested that the universe was expanding or contracting. It was generally accepted that either the universe had existed forever in its unchanging state, or that it had been created at a finite time in the past more or less as we observe it at the time. Even those who realized that Newton’s theory of gravity showed that the universe could not be static did not think to suggest that it might be expanding. Instead, they

attempted to modify the theory by making the gravitational force repulsive at very large distances by achieving a certain distribution of stars to remain in equilibrium with the attractive forces between nearby stars balanced by the repulsive forces from those that were farther away. However, it is now believed such an equilibrium would be unstable.

Heinrich Olbers, a German philosopher who also objected about the static universe theory in 1823. In his article Olbers discussed that in a static universe every line of sight would end at the surface of a star, which will eventually lead to a sky as bright as the surface of the sun even at night. Olbers argument was that the light coming from distant stars would be dimmed by absorption of matter. However, if that was the case intervening matter would heat up and glow as the stars. Thus, the only way to avoid that conclusion is to dismiss the idea that the stars has been shining forever but existed in a finite time in the past. Therefore the absorbing matter might not have heated up to that point or maybe the light from the start has not reached us yet. But this of course raises a new question; what could have caused the stars to shine in the first place?

Among all the answers we have reached to that question or any similar one like “how did it all start?” There was still not a single response that gives a clear answer of course excluding beliefs that rely on divine intervention; even these answers do not perfectly match.

The Expanding Universe

In 1929, Edwin Hubble’s observation showed that distant galaxies are rapidly moving away from us, which can only means that the universe is expanding. There for it is only logical that in earlier times objects have been closer to each other. In other words, sum thousand million years ago everything was exactly at the same place.

This landmark discovery considered that there was a time called the big bang at which, the universe was extremely small and infinitely dense. If there were events earlier than this time, then they could not affect what happens at the present time. Their existence can be ignored because it would have no observational consequences. One may say that time had a beginning at the big bang, in the sense that earlier times simply would not be defined.

Any physical theory is always a subject to conformation, in the sense that it is only a hypothesis: one can never prove it. No matter how many times the results of experiments agree with some theory, you can never be sure that the next time the result will not contradict the theory. On the other hand, you can disprove a theory

by finding even a single observation that disagrees with the predictions of the theory. Each time new experiments are observed to agree with the predictions the theory survives, and our confidence in it is increased; but if ever a new observation is found to disagree, we have to abandon or modify the theory.

In practice, what often happens is that a new theory is devised that is really an extension of the previous theory. For example, very accurate observations of the planet Mercury revealed a small difference between its motion and the predictions of Newton’s theory of gravity. Einstein’s general theory of relativity predicted a slightly different motion from Newton’s theory. The fact that Einstein’s predictions matched what was seen, while Newton’s did not, was one of the crucial confirmations of the new theory. However, we still use Newton’s theory for all practical purposes because the difference between its predictions and those of general relativity is very small in the situations that we normally deal with.

The eventual goal of science is to provide a single theory that describes the whole universe. However, it turns out to be very difficult to devise a theory to describe the universe all in one go. Instead, the problem is broken up into bits and devises a number of partial theories.

Today scientists describe the universe in terms of two basic partial theories – the general theory of relativity and quantum mechanics.

The general theory of relativity describes the force of gravity and the large-scale structure of the universe, that is, the structure on scales from only a few miles to as large as a million million million million (1 with twenty-four zeros after it) miles, the size of the observable universe. Quantum mechanics, on the other hand, deals with phenomena on extremely small scales, such as a millionth of a millionth of an inch. Unfortunately, however, these two theories are known to be inconsistent with each other – they cannot both be correct.

However, scientists today are trying to develop a theory that will incorporate both theories – a quantum theory of gravity. Such theory does not yet exist and it might be a long way before it does, but still one of the goals of this research is to study many of the properties, which are known that such theory must have.

Many scientists were still unhappy with the universe having a beginning because it seemed to imply that physics broke down. One would have to invoke an outside agency, which for convenience, one can call God, to determine how the universe began. They therefore advanced theories in which the universe was expanding at

the present time, but didn't have a beginning. Tough I will not go through them because of complicated physics that is eventually irrelevant, since none of these theories got anywhere.

The Big Bang

October 1965, Stephen hawking and Roger Penrose depending on the Einstein’s General Theory of Relativity, came to the conclusion that there would be a singularity, a point of infinite density and spacetime curvature, where time has a beginning. They discovered upon their observation that there was a faint background of microwaves throughout space. These microwaves are similar to the ones we are familiar with in microwaves oven, but very much less powerful.

One can actually observe these microwaves using a TV. Set your television to an empty channel. A few percent of the snow you see on the screen will be caused by this background of microwaves. The only reasonable interpretation of the background is that it is radiation left over from an early very hot and dense state. As the universe expanded, the radiation would have cooled until it is just the faint remnant we observe today. 

Although the singularity theorems of Penrose and Hawking, predicted that the universe had a beginning, they didn't say how it had begun. The equations of General Relativity would break down at the singularity. Thus Einstein's theory cannot predict how the universe will begin, but only how it will evolve once it has begun.

There are two attitudes one can take to the results of Singularity. One is to that God chose how the universe began for reasons we could not understand. This was the view of Pope John Paul. At a conference on cosmology in the Vatican, the Pope told the delegates that it was OK to study the universe after it began, but they should not inquire into the beginning itself, because that was the moment of creation, and the work of God.

The other interpretation, which is favored by most scientists, is that it indicates that the General Theory of Relativity breaks down in the very strong gravitational fields in the early universe. It has to be replaced by a more complete theory. One would expect this anyway, because General Relativity does not take account of the small-scale structure of matter, which is governed by quantum theory. This does not matter normally, because the scale of the universe is enormous compared to the microscopic scales of quantum theory. But when the universe is extremely small, the two scales are the same, and quantum theory has to be taken into account. 

The best way to combine the General Theory of Relativity with quantum theory is to use Richard Feynman idea of a sum of histories. He proposed that a system of got from a state A, to a state B, by every possible path of history. Each path of history has certain amplitude or intensity; the probability for a state of universe at the present time is given by adding up the amplitudes for all histories that end with that state. But this does not answer the question of how did the histories start?

Einstein's General Theory of Relativity unified time and space as spacetime, but time was still different from space and was like a corridor, which either had a beginning and end, or went on forever. However, when one combines General Relativity with Quantum Theory, Jim Hartle and Stephen Hawking realized that time can behave like another direction in space under extreme conditions.

Suppose the beginning of the universe was like the North Pole of the earth, with degrees of latitude playing the role of time. The universe would start as a point at the North Pole. As one moves south, the circles of constant latitude, representing the size of the universe, would expand. To ask what happened before the beginning of the universe would become a meaningless question, because there is nothing north of the North Pole.

Time, as measured in degrees of latitude, would have a beginning at the North Pole, but the North Pole is much like any other point. The same laws of Nature hold at the North Pole as in other places. This would remove the age-old objection to the universe having a beginning; that it would be a place where the normal laws broke down. The laws of science would govern the beginning of the universe. The picture Hartle and Hawking developed of the spontaneous quantum creation of the universe would be a bit like the formation of bubbles of steam in boiling water. 

The idea is that the most probable histories of the universe would be like the surfaces of the bubbles. Many small bubbles would appear, and then disappear again. These would correspond to mini universes that would expand but would collapse again while still of microscopic size. One can think of theses bubbles as possible alternative universes but they are not of much interest since they do not last long enough to develop galaxies and stars, let alone intelligent life. A few of the little bubbles, however, grow to a certain size at which they are safe from re-collapse. They will continue to expand at an ever-increasing rate, and will form the bubbles we see. They will correspond to universes that would start off expanding at an ever-increasing rate. This is called inflation.

So I will try to make it simple by avoiding complicated physics, according to Hawking, if we follow the clues and we will deduce that very long time ago the universe burst into existence. As it was a very small and ultra-hot extremely dense fog of energy the universe expanded with a tremendous flash of radiation. From smaller than an atom to about the size of a tennis ball in a trillionth of a second. Getting bigger and cooler with every passing moment. Within 100 seconds, it was as big as our solar system, trillions of miles across meanwhile the pure energy of the cosmos began to cool and create matter in the form of countless subatomic particles, in other words; the first stuff their ever was.

Half these particles were made of matter, the rest were made of the opposite of matter, which is called antimatter. When the two meet, they destroy each other in a flash of energy. Fortunately, there was just a bit more matter than antimatter. Which was lucky for us, because that residue is what our present day universe is made of.

By the time the universe was 10 minutes old, it was already thousands of light-years in diameter. Everything spread out and cooled for about 330,000 years.

Imperfection

Here came the biggest role gravity ever played. Right after the big bang the universe was just gas, almost perfectly spread out throughout space. Over the next 200 million years, gravity began to pull gas back together to produce the very first structures, from which every thing else would grow. It nearly never happened if it were not for a stroke of cosmic luck. Simply, because if the particles of the thin gas were spread out evenly across the vast universe. Gravity would have pulled each particle evenly in all direction, causing it to stay still.

Fortunately, one of the basic rules of the universe; is that nothing’s perfect. Therefore, the early universe had a tiny unevenness in the density of gas. Which allows gravity to clump together the denser areas of the sea of gas. Hydrogen, the gas that filled the young universe is the simplest of gases. But hydrogen has a special property; it’s a tremendous source of power. When it’s heated to 10 million degrees it begins to produce the energy that makes the stars shine, and supplies the universe with warmth and light.

However, when hydrogen compacts due to gravity, the atoms of gas start bouncing off each other, and the temperature begins to rise. When the hydrogen reaches the critical 10 million degrees a process called nuclear fusion begins, in which, the hydrogen atoms starts to fuse together making a new heavier material; Helium. Keep in mind, it’s not the only outcome, during the process some matter gets converted into pure energy.

Basically, that process happened for the first time on a huge scale. Gravity compressed the hydrogen gas clouds over millions of years, until deep in the center, the hydrogen became hot enough for fusion to occur. The first star burst into life pouring its energy into the vast universe, a product of laws of nature, and the raw materials left over from the big bang. It was almost 1,000 times bigger than our own sun, and burned a deep blue. Soon enough that star had company; the stars were turning on.

The same process happened in our sun, which is where we get the energy we need to live. But there was still a long way to go to get from this to where we are today. It’s uncanny to build a world like

ours from simple gases such as hydrogen and helium. All sorts of other elements are essential in such process, like oxygen and carbon and iron and many more. Here where luck stroke again, because the very same process that causes the stars to shine also just happens to make materials. In that regard you can consider stars as giant factories.

As noted above, the stars originally burst from hydrogen clouds being compressed and resulting in hydrogen atoms fusing together, creating helium, which produces the star’s energy. But helium is slightly heavier than hydrogen, so it sinks to the center of the star. And now helium atoms start to fuse together producing even more energy and form yet another new element, Carbon, a vital building block in all living things.

Eventually the process repeats itself over and over, producing more energy and creating new elements, until the star is finally layered like an onion. The closer you get to the center, the heavier the elements, like neon, oxygen, and in the end iron.

However, iron does not produce energy as it fuses, so now things change because you can say that the star is running out of fuel. More and more iron builds up in the core until all the remaining furl runs out. Gravity takes over and squashes the star in on itself, and as its core gets more compressed its temperature increases rapidly above the usual level, until it’s over 100 times hotter than the core of our sun. Finally the star collapses and explodes.

Supernova: the death of a star and the birth of something new. A massive shock wave that passes through the star to cause a beautiful blast, so powerful that it forces some of the iron to fuse into even heavier elements. Such as gold, platinum or lead.

Color-composite image of E0102-72.3 – a supernova remnant in the Small Magellanic Cloud. The Chandra X-ray image (blue) shows gas that has been

heated to millions of degrees Celsius by a shock wave moving into matter ejected by the supernova. The radio image (red) made with the Australia Telescope Compact Array, traces the outward motion of a shock wave due to the motion of high-energy electrons. The optical image (green) made with the Hubble Space Telescope, shows dense clumps of oxygen gas that have cooled to about 30,000°C.

But as magical as the star is, there are even more fascinating and powerful things. Around 300 million years after the big bang the early stars began to form galaxies, which slowly took on a huge variety of shapes and sizes. Our galaxy the Milky Way is thought to be one of the oldest, having started to assemble itself some 13 billion years ago. It’s roughly 6,000 billion miles in diameter and contains something like 200 billion individual stars. Nobody is quit sure how many since they cannot be all seen from earth, but what we know that they were all assembled by gravity.

Black Holes

So one can say that gravity is the hero of the universe by turning meaningless clouds of gas into something so magnificent and powerful as the stars. But as we all know each hero has a dark side. In the center of our galaxy there’s an example of what happens when the gravity rules unchallenged, a black hole.

A black hole forms when a large star, maybe 20 times the mass of our sun, comes to the end of its life. And that point the star would become unstable, convulsing violently as it dies. Finally, it runs out of fuel and begins to shrink, getting denser and hotter, but with a star the massive there’s no force in the universe capable of stopping the collapse. The core is so heavy that it keeps on falling in on itself. The unstoppable gravitational force crushes the star in a matter of seconds from millions of miles in diameter to as little as twelve miles in diameter. Though, all the mass of the star is still there, it’s own weight keeps in forcing it down smaller and smaller. The temperature of the core reaches 100 billion degrees. The outer layers are blasted away in a massive supernova, but deep in the center, the core falls down what is called a gravitational well. A black hole is born; nothing nearby can escape its pull, not even light. Since light is made of waves and particles, the particles mass would be dragged into the black hole.

However, a black hole cannot be perfectly black. For the same reason the early universe could not have been perfectly spread out. Black holes must give off radiation. The smaller the black hole the greater the radiation, and eventually shine. Usually, in outer space, small black holes are four times the mass of our sun, around 15 miles in diameter. Others are much larger, reaching the mass of thousands of suns. And there are even bigger ones; super massive black holes, that exist at the center of galaxies like our own. The one in the center of the Milky Way is thought to have the mass of

four million suns, and a diameter of 11 million miles. One can consider such black hole as the stabilizer that gives the galaxy its form and shape.

How did we get here? “The Hero”

So, 8 billion years after the big bang, after a remarkable luck streak, we have stars and galaxies rotating slowly around giant black holes. Now everything is set for the formation of our sun, the earth and ultimately us.

Our solar system lies about 26,000 light-years from the center of our galaxy, it is estimated that it took 6 billion years to form. Long story short, it all started when and ancient star exploded, spreading through space all the materials it had made while it lived, and the heavier metals it created as it died. Until this day, similar fields of dust exist in space they are called nebulae, every nebula is different, and in our case, the clouds contained nitrogen and oxygen and iron and silica and many other stuff needed to build a world like ours. Then the tireless force of gravity started to pill everything back together, where the heavy engineering that produces planets began. Vast swirls of dust began to form, and the center of one of them, a rocky planet called earth started to take shape. Built of stardust and assembled by gravity. After millions of years it became a giant ball, sweeping up billions of tons of celestial debris. But if it were not for one more event, one more expression of the forces of nature, the earth wouldn’t be anything more that a giant ball of rock and metals and minerals forever. 93 miles away, at the heart of the giant nebula, the pressure and temperature of a ball of hydrogen gas was becoming greater and greater and the atoms began to fuse. Our sun was coming to life, and as it ignited it gave off a huge blast of solar wind, a radioactive gust of energy, which blew all the remaining dust and gas that was left over from the nebula out to the edge of the solar system, which is why everything is neat and orderly today. Hence, the sun is 865,000 miles in diameter, just the right size to burn consistently for around 8 billion years. Long enough to allow the next development to take place, life.

Life is one of the strangest phenomena known. The mostly like explanation is probably that it was an accident. Just by chance, some molecules bumped into each other at random until finally, one formed that could copy itself. Then began the slow process of evolution that led to all extraordinary diversity of life on earth. Life seems to be simply what matter does, given the right conditions and enough time. I would not be surprise if life was quite common trough out the universe.

As life developed, it changed the planet on which it was born, altering the very fabric of the earth. After almost 5 billion years, the human race arrived to the scene.

People might have a hard time accepting such story, that the thing they cherish the most “Life” was the result of a series of coincidences. If you rewind all the previous events that got us here you must believe that there has to be a grand designer that aliened all this good fortune. Well not necessarily. What if there were other universes, ones not as luck as ours? Each of these universes has come from its own big bang, with different laws of physics and different conditions. In some, gravity might not exist, and there could be no life. In others hydrogen might not fuse, so there would be no stars and, again, no life. So for no matter how many numbers of reasons universes could have come and gone without producing anything at all, just like the bubbles in the boiling pot example – mentioned above.

So maybe we should not be too surprised to find ourselves in a perfect universe, orbiting a perfect sun, on a perfect planet. Because such perfect places are the only ones where life like us can exist. Still we are one of the many products of the universe, the result of an ancient mechanism. But even this remarkable discovery, is only a part of what physics can tell us. Its possible to predict what mankind will face in the distant future, and ultimately, we might discover the fate of the universe itself.

The Future

History can tell us that the map of the earth that we are all familiar with today, wasn’t exactly the same. The continents of our plant were and still are drifting. If we fast-forward 75 million years they will be all clustered towards the South Pole. No one knows if the earth will still be habitable then, but the truth is that we may not last long enough to find out. Apparently, as cosmologists study our universe the came to conclude that it turned out to be a pretty dangerous place. If we just considered the our galaxy the Milky Way, it’s littered with billions of asteroids, leftovers from the process that built our solar system and others like it. Thus, the possibility of and asteroid wiping us out is not just a matter of fiction, the threat is real.

Apophis is an asteroid named after a mythical Egyptian evil god, discovered in June 19th, 2004. Apophis’ length was estimated at 450

meters and weighs about 20 million tons. Speeding through space at 28,000 Mph, it carries more energy than the most powerful nuclear weapon. Yet, its precise path is not fully known but on April 13th, 2029, it’s likely to pass so close to the planet’s surface it would be visible to the naked eye. Luckily, there is a very little chance that it would actually hit us, but the problem is that in space, there’s always a bigger rock.

It’s believed that asteroids much bigger than Apophis sometimes over 10 miles long hits the earth every 100 million years or so. The last one struck the earth 65 million years ago and it was mostly responsible for the extinction of the dinosaurs. If an asteroid like that would hit the earth in the future, it could sterilize the planet and put an end to long story of life on earth. That is of course if humans themselves destroyed everything with pollution and nuclear wars. “I believe intelligence is probably overrated. It’s not a necessarily a good thing for a species’ survival. Bacteria have managed without it for over 3 billion years.” Stephen Hawking.

Asteroids are one of many surprises the universe has in store for us. As the asteroid may push the reset button of civilization, others could destroy the earth. In 1967 during the cold war, U.S. military satellites picked up a massive burst of gamma radiation, which is the most dangerous type of radiations. At first it was thought to be a new soviet weapon, but after careful analysis it was discovered that the gamma rays were coming from outer space. It’s now believed that gamma ray bursts are caused by one of two possible reasons. Either it’s caused by a special kind of supernova, or by the collision of two neutron stars. However, the focused beams of radiation that will be produced are capable of stripping the ozone from the atmosphere, allowing deadly radiations from the sun to strike the earth.

Let alone galaxies collisions, which our galaxy is destined to merge with its nearest neighbor, the Andromeda galaxy, in around 3 billion years. A slow motion collision that will take place over 2 billion years.

The point is the spread of life in other parts to other parts of the universe is something should be taken into consideration. Thankfully, it is. And yet it has already begun by the launch of Apollo 11, and the robot missions to mars, which are the first stepping-stones in humans journey to the stars. Though mars lacks most of the fundamental elements to host life, such as sufficient gravity to hold on to an atmosphere. Given the time needed I think

that technology would allow us to alter what it lacks or maybe what we need in order to live. But still if we look further enough into the future we will see that our solar system itself will cease to exist as countless solar systems before it.

Right now our sun is at the middle of its life cycle, it’s getting gradually hotter and brighter all the time. In about 5 billion years the sun’s temperature will have grown to the point where the earth will be an unrecognizable ball of molten rock. It’s our planet unavoidable destiny. As the sun transforms into a red giant it will change from being the object that gave us life, to the one that annihilates it.

But as the universe continue to evolve at its own relentless pace; new opportunities will present themselves to us. Gliese 581d, a large, rocky and earth-like planet discovered in 2007, it’s seven times bigger than the earth. It orbits a star smaller and redder than ours, but its stands just at the right distance to allow water to exist on the surface. Gliese 581d is the nearest known of its kind. It is possible that this planet or at least one like it could in the future become the home of human race. Still there’s a big problem, Gliese is very far away from earth, more than 20 light-years. Which is equal to 120 trillion miles.

However, I believe that with the pace of the technology evolution, we might have a chance to be a lasting part of the ever-changing universe. Many cosmologists believe so as well, and they think that developing faster means of space transportation is essential for our survival. Present-day engineers have already begun thinking about the principals of building such ships. But even with really fast space ships journeys would still take hundreds of years and maybe they will never come back to earth, hence the goal if such missions is colonize other planets. So the problem is who’s going to pilot such ships and for how long? Will elder generations last long enough for their successors to be ready to be passed the torch? Well the only

solution that might come to mind is that to find a way to increase the human life span. Genetic engineering is aiming to achieve in the future. By giving us longer life span and greater intelligence, maybe even modifying our genes so our skin could protect us from radiation, and the ability to breathe in alien atmospheres. And eventually, resistance to infections.

The Villain

Gravity has been driving the cosmic clockwork since the big bang. But will it go on forever? The answer lies back in the beginning. If we could one day answer what caused the big bang, we will also learn the fate of our universe. The key to it all is something called the dark energy, a mysterious form of energy that punches space itself apart, even as gravity is making matter cluster together. It seems like the kick that inflated the universe, still no one knows how.

However, what is certain is that the fate of the universe depends on how the dark energy behaves. If the dark energy weakens, then gravity could get the upper hand, and the universe would go into reverse and everything will go back to whence it came. This theory is known as the big crunch. In the end if the theory is right 30 billion years from now all the matter of the universe would be sucked into a single black hole. The entire universe would exist as one tiny point, much as it was at the instance of the big bang.

But there is a second probability, what if the dark energy drove the expansion of the universe forever. Ultimately, everything will just keep spreading out until the universe is so cold and dark, and everything will be so far apart that even gravity will be defeated. And we will face something called the big chill.

All things considered, I believe evolution is a natural phenomenon. We, as humans should embrace the fact that our species is the most developed creation of the universe in terms of knowledge. And despite how small we are compared to the vast size of the cosmos, we were able to wrap our minds around the universe as a whole, and understand many of its secrets with new, groundbreaking discoveries on the horizon. This leads me to believe that we are somehow on the right path to revealing it all. Perhaps there is a grand designer after all; perhaps he had greater things in mind for us than what religion would dare to explain. It seems unlikely, but an idea worth exploring anyways.

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