Our Amazing World
Edge to Edge
by Joe Selzler
How big is the universe around us? Has anyone ever counted the number of stars, galaxies, comets, planets and the like? Do we know where the edge of the Universe is, or for that matter, where the centre is? You may think the scientific community has come up with the answers to these many questions, but it has not. Every day astronomers make startling discoveries that challenge our understanding of the universe we inhabit. Discoveries such as the "Great Wall" of galaxies (a large sheet-like structure of galaxies that measures 200 million light years by 600 million light years and 20 million light years thick) call into question some of the theories on which modern astronomy is based.1
Where is the edge of our universe? Considering the number of stars that may exist in space it is hard to know for sure where to find it. If we take our galaxy, the "Milky Way", to be an average one then we can say that the average galaxy contains about 100 billion stars. The estimated number of galaxies in the visible universe is from 100 billion to 240 billion. (Some put the estimate higher _ about 500 billion.)2 Simple multiplication puts the number of stars at from 1022 to 2522 or 10 billion trillion to 25 billion trillion. Therefore, for each of the 6 billion persons alive on earth today there are more 1½ trillion stars.
We live in a world of ever increasing knowledge where the edges of science are pushed continually beyond what we ever imagined. Everyday we seem to discover things that push the boundaries of space and even time further and further away from us. Recently NASA crashed a probe into a comet to study its makeup and to learn new things about the beginning of our own solar system. Scientists believe that comets are made up of material left over from the formation of our sun and other planets.3 Indeed for clues to the origin of our universe scientists want to look deep into space so that they can capture the moment in time when the Big Bang occurred.4 It is believed by most in the field of Astronomy and physics that the universe was created by a massive, rapid expansion of some material at the beginning of time. What that material was and where it came from no one seems to conclusively explain.5
Once upon a time, back in 1916, when Einstein was developing his Theory of Relativity, the universe was thought to be in a static state, not moving. Indeed the belief that this was the case was so strong that he introduced a cosmological constant into his theory in order to preserve the idea of a universe in a state of rest. However, in 1929 Edwin Hubble discovered that galaxies further away from ours were red shifted. That is, the light we are seeing from them is shifted towards the red end of the spectrum. This indicates that they are moving away from us and that the universe is expanding. Surprisingly, we can't even see the substance that may be responsible for this effect . It is referred to as dark matter. Therefore, since the universe is moving apart and at an ever-increasing rate6, can we ever find the edge of the universe and know its entirety?
How many times have you been given that answer when you asked how long something would take? We use this phrase whenever we want to let someone know that they have asked a question to which the obvious answer is that we have no way of telling. One of the biggest problems in physics today is trying to unify the Theory of General Relativity, developed by Albert Einstein and Quantum Theory. It seems that these two theories are the basis for all of our current knowledge of physics; that is they each describe some feature of the physical world around us. However, they do not describe the same features. Relativity seems to describe the behaviour of the large-scale world while Quantum Theory describes the behaviour of the small-scale world.
For many years physicists have tried to unify the two theories into one grand, unified theory, often called the Theory of Everything. Indeed, Einstein tried for the last 30 years of his life to find this theory, without success. Physicists, however, are reluctant to give up and have been working on several answers. The one many see as the most promising is the Superstring Theory. It describes all of the quantum particles in nature as notes that sit on a vibrating string, sort of like a violin string. The notes themselves are of less importance than the string, which is fundamental. It says that a particle, such as an electron, is actually a string vibrating in a certain mode. This string is so small that it appears to us to be a point particle, that is, just a point. If we shake the string so that it vibrates in a different mode the electron can become a different particle. The theory says that there is a collective set of vibrations corresponding to all of the known particles in the universe.
Many scientists have begun to look beyond the theory of the Big Bang to try to answer the ultimate question of the beginning of it all. They realize that it requires more that just a theory that says that what we see around us started as some speck somewhere, because the obvious question is, "Where did the speck come from?" Men of no less reputation than Stephen Hawking have postulated about the beginning of the universe and time. He says in his book, A Brief History of Time, "the quantum theory of gravity has opened up a new possibility, in which there would be no boundary to space-time and so there would be no need to specify the behaviour at the boundary. There would be no singularities at which the laws of science broke down and no edge of space-time at which one would have to appeal to God or some new law to set the boundary conditions for space-time. One could say: `The boundary condition of the universe is that it has no boundary.' The universe would be completely self-contained and not affected by anything outside itself. It would neither be created nor destroyed. It would just BE.7
But other scientists of equal reputation would disagree with Hawking. The physicist Charles Townes, inventor of the laser writes: "I do not understand how the scientific approach alone, as separated from a religious approach, can explain an origin of all things. It is true that physicists hope to look behind the `big bang,' and possibly to explain the origin of our universe as, for example, a type of fluctuation. But then, of what is it a fluctuation and how did this in turn begin to exist? In my view, the question of origin seems always left unanswered if we explore from a scientific view alone."7
Do not the words of the Psalmist sum up the existence of our universe in a more compelling manner:
In all of our attempts to obtain the complete knowledge of our surroundings and our universe we seem to find more questions than answers. And as our universe expands our questions expand with it. We may come up with a theory to explain everything, but fail to realize that the theory just adds one more question: "Where did the string come from?" We may try to do as Stephen Hawking and insist that the universe could exist eternally apart from a creator. But then we would be left with an eternity of questions. Because even if the universe just "IS", it would always be just what we see now, a series of mysterious physical phenomena, which we would always be trying understand.
We may indeed make some progress in physics as we study the world around us, but many of us wonder if more knowledge of the physical world will answer the problem of the human heart. Perhaps our best hope lies in the sublime language of the Psalmist.
1. http://groups.msn.com/KosmicPlenum/greatwallofgalaxies.msnw The Great Wall. See also:
2. Estimate of stars:
3. Genesis 1: 1-19
4. Seeing back in time:
5. The Big Bang:
6. Dark Matter accelerating the universe:
7. Theories beyond the Big Bang:
i. See footnotes 2 & 4
8 Psalms 8
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