The sojourn to man's universe begins with an examination of what is beyond man's reach, physically and intellectually-the far reaches of the universe.
The Realm of the Universe
Let there be time. GOD. (15,000,000,000 BC.)
It all began, give or take a billion or two, about 15 billion years ago with a big bang that created the universe and time. The ancient Chinese thought portrays the beings having risen from nothing; prehistoric myths depict genesis in biological terms: the primeval god transforming himself into an egg. In the Judeo-Christian tradition, creation involved the order arising from chaos and light from darkness: in the beginning God created the heaven and earth and the earth was without form and void and dark; the spirit of God moved upon the face of the water and God said, "Let there be light.
The concept of big bang as the point of creation of our universe does not tell us anything about God; it only tells us about the time when this event took place; or, at least that's how it appears to us. The problem of conceiving existence of any thing before the big bang is now resolved by the assertion that the space and time itself were created with the big bang. Nothing existed before. The Aristotelian arguments (340 BC) that the universe has no beginning and has always existed is rejected because the time about which Aristotle speaks was also created at the big bang. Asked of St. Augustine, "What was God doing before He created the universe," he answered: "He was preparing Hell for those who ask such questions."
The shape of our Universe as it appears to us has been a matter of curiosity for man since man began to think and thus wonder. Given the sensory apparatus of man, he was soon able to decipher the physical dimensions of things around him. It all began with debating about the shape of the planet of his abode. Many theories were proposed but Aristotle is credited with the idea that earth is a round sphere. He concluded this from the appearance of the sails of the ships before the ships are seen. Ptolemy (200 AD) proposed that earth is stationary while sun and other planets revolve around it. Copernicus (1514 AD) refuted Ptolemy and suggested that sun is stationary and earth and other stars revolve around it. This was later confirmed by Galileo (1609 AD), who barely escaped death sentence for his belief. Until this time, nothing more could be said about the universe until the findings of Roemer (1676 AD) about the speed of light became known and also when Newton (1687 AD) proposed his theory of gravity that all bodies attract each other. This helped explained the elliptical orbits of planets under the force of gravitation. (Note: Newton was never hit by an apple; he just thought of apples falling.)
More recent discoveries about the nature of light (Maxwell, 1865 AD) and the observation that light travels with same speed regardless of the direction and the speed of observer (Michelson and Morley, 1887 AD) afforded Einstein (1905 AD) the opportunity to propose his famous theory of relativity.
Einstein suggested that nothing can travel faster than the speed of light. Even time slows down as we speed up or pass near massive bodies. Two clocks one at the top of a tower and the other at the bottom show different times because of gravitational force. Einstein combined the concept of space with time to propose what is now called space-time coordinate and also suggested that space can warp. It is the warping of space under sun's gravitational space that makes earth appear going in circles; it is actually traveling in a straight line path.
Today, thanks to our space travel ventures, we know a great deal more about our universe or at least what appears to us as our universe (See below, Do We Really Exist?). We know that we live in a major spiral galaxy, the milky way; it is home to the sun and a few billion other stars. The galaxy belongs in turn to a cluster of galaxies, the astronomers call it the local group, which is a part of the Virgo supercluster, an archipelago of galaxies stretching across one hundred million light years of space which is continually expanding.
How big is our universe? It is difficult to comprehend for the human mind. From the viewpoint of its mass, our galaxy has about ten billion stars (sun is just one such star with its planets including earth as part of the solar system); there are over 10 billion such galaxies. The current size of the universe is about a billion trillion miles. The light reflected from stars created at the time of big bang is still reaching us as we routinely discover stars never seen before. Surely, we have not seen them all yet. Given the speed of light of 186,000 miles per second and the time of about 15 billion years it has taken to reach us will allow calculation of the distance of these newly found stars. (186,000 miles/second x 15,000,000,000 years x 365 days x 24 hours x 60 minutes x 60 seconds = 8,798,544,000,000,000,000,000 miles). The continuous expansion of the universe was confirmed in 1929 by Hubble, who used his famous telescope to confirm the Newtonian gravitational theory and initiated the concept of big bang. More recently, Penzias and Wilson confirmed in 1965 that the universe is expanding in all directions around the earth because the microwaves are coming from all direction. Microwaves are created by objects running away from us. So it is not a unidirectional but an all-directional expansion.
(Note: This is called Doppler Effect. An application of this is found in radar guns which police use to detect speed of a moving car; waves bounced-off an object moving away are reflected back as longer wave lengths. The faster the speed, the longer the wave length shift of the bounced-off radiation.)
The concept of the universe expansion is often difficult to grasp because of the limited meaning of the word expansion. Expansion of the universe involves expansion of space as well. It connotes dots on a balloon. As you inflate a balloon, selecting any dot as the reference point, all other dots get away from it with every dot appearing as a center. In three dimensions, that's how the universe expands; there is no center to the universe because the space itself is created with expansion. Collapsing a balloon will merge all spots into one; the universe collapses into a unitythe beginning of the universe.
The boundaries of the universe, some say there are none, are expanding at a rate just below the speed of light. We know this because nothing can move faster than the speed of light (at 186,000 miles per second); at the speed of light, the mass (call it weight) of all bodies becomes infinite, halting their movement and time. Can the universe go on expanding forever?; the answer clearly is no because the energy endowed at its creation is continuously been used up and as a result, it must retract, like a yo-yo, to the ultimate Armageddon so often recited in religious teachings; science now confirms this probability.
What Armageddon would be like is seen from the phenomenon of black holes. Like an unending trip, stars collapse onto themselves making them so dense that the planet earth would concentrate on the head of a pin. At this stage the gravity is so strong that even light does not escape it and the collapsing stars "appear" in the universe as black holesthe intense gravity holes. They are called black holes because they cannot be visualized though they do emit energy waves that can be recorded. When would the process of Armageddon begin? Probably not for a very long time since the universe is still in the phase of expansion; it would at least take same time it has been expanding to contract completely. Unfortunately, we do not know of the present state of the boundary of the universe; it may well have started to contract. We can however make a safe bet that the universe will be around at least for a few billion years. Whether our planet will survive for that long a time is questionable; chances are earth will vanish long before the universe does.
All of these scenarios appear to be operated under what we have come to conclude as the operating principles of the universe Universal Principles.
Science incorporates the idea that the universe really is universal, a singular system ruled by a single set of laws; science acquired this concept from the Judeo-Christian-Muslim belief in one God. There may have been millions of creations and armageddons of the universes before our time and likely there may be many more after this universe vanishes; in all probability, each creation producing different creatures, animate or inanimate based on the principles innate to the universe. Our present thinking does not preclude the possibility that other universes could not have been governed by entirely different "universal" principles.
However, limitations of our physical visualization prevent us from expounding on the nature of the universes different from ours. We are only able to model other universes based on the principles indigenous to this universe. For example, the contention that a universe must operate on the basis of some "universal principles" is a prodigy of the ideas of this universe and thus it cannot be applied to other universes.
Even accepting that other universes may have different "universal" principles is not correct because the theory itself that two things can be different is also based on the "universal" principles of the current universe.
The universality of principles, if any, is probably created with the universe itself and dies with it also. Man will never know what other universes might have been like or would possibly be in the future because man has been situated in a position where he can see from inside out and not from outside in. It is difficult for man to even know enough about his own universe. Support to this thesis comes from many recent scientific discoveries. A major disappointment to the scientists who thought they could know all about the universe came from the discovery of Heisenberg in 1926. According to the Heisenberg's Principle of Uncertainty, it is not possible to measure the speed and location of any object simultaneously. Measuring location involves interrupting path that causes alterations of speed. A theoretical extension of this theory is that when look at the moon, we alter its course. This discovery just about eliminates the possibility of ever finding the exact dimensions of the universe.