jlg@lanl-a.UUCP (06/10/83)
A steady state universe is not consistent with the general theory of relativity. The general theory predicts that the usiverse will be gravitationally unstable and will therefore either expand or contract. It was this prediction which caused Einstein to introduce a cosmological term in the theory in order to permit a steady state theory to work. When Hubble (and others) showed that the galaxies receeded at rates proportional to their distances (so the universe is expanding) Einstein retracted his cosmological terms and said that they should not have been introduced at all. The general theory has no prediction about continued expansion (open universe) or eventual contraction (closed). It also does not require a finite universe. The Big Bang theory also does not require a finite universe, an infinite extent, very dense beginning is consistent.
gwyn%brl-vld@sri-unix.UUCP (06/12/83)
From: Doug Gwyn VLD/VMB <gwyn@brl-vld> You state the popular view of cosmology based on 1915 general relativity. There are some not-so-well known problems that are seldom considered but are nonetheless relevant: Nobody has demonstrated that distant galaxies recede from us at a rate proportional to their distance from us. What HAS been shown is that their light is red-shifted proportionally the farther away they are. This is not at all the same thing, as light can be red-shifted for reasons other than Doppler effect. Indeed, long ago E. Milne came up with a cosmology that obeyed the "perfect cosmological principle" (that globally things are similar everywhere and everywhen), used special relativity only, and had light red-shifted in spite of the steady state. Any relativistic steady-state cosmology is likely to have the same feature. Here is the story of the "cosmological constant". As you state, it was introduced __ad ___hoc by Einstein in the early years of general relativity because he felt a closed universe was necessary and couldn't figure out one with the original field laws. After Friedmann was able to come up with closed cosmological models consistent with the original equations, Einstein withdrew the "cosmological constant" term (effectively setting the constant back to zero) and admitted HIS PROCEDURE had been a great blunder. Einstein never considered his general theory complete, and he spent the rest of his life investigating ways to complete it. Most of this work on a unified field theory was spent on generalizing the theory of general relativity, principally through considering generalizations of differential geometry (connections on fiber bundles, etc.). Einstein never again introduced an __ad ___hoc constant into his work. By 1950 Schr"odinger had completed his program to investigate all possibilities for a unified field theory along Einstein's general lines and made the remarkable discovery that the simplest, most natural generalization of general relativity AUTOMATICALLY produced equations that generalized the original field laws WITH cosmological term! The cosmological constant appeared spontaneously as a definitely non-zero quantity in this development. Those of you who received copies of my Master's thesis can follow this theory therein. Recent fads such as "black holes" and "big bang" cosmology are usually based on extending 1915 general relativity into domains where it was clear to earlier workers such as Einstein and Schrodinger that the approximations of the theory were no longer valid. A correct treatment of such matters would require a different theory, perhaps Schr"odinger's and perhaps something rather different like one of the modern supersymmetry theories.
laura@utcsstat.UUCP (06/16/83)
When I was a child I stumbled on the Steady State theory of cosmology long before the Big Bang. I found it a rather emotionally satisfying theory. Later, alas, I was told that it was obselete, and was horribly disappointed. Much later, I discovered that the people who told me that Big Bang was definitely it (such as high school physics teachers) were oversimplifying. When I finally went out and hit the physics textbooks myself, I find a lot of contradictions. I also keep having to look up the names of physicists to see what else they were doing and whether they changed their minds about some of the theories they used to advance Big Bang or Steady State throughout their lives. As if this were not bad enough, I learned that the maths were hideously complicated and you could spend weeks and months looking at one equation not understanding it at all. Now I have a problem. I would dearly love to believe in Steady State for personal reasons, but I am not going to adopt it if it is generally thought false by physicists who know far, far better than I. On the other hand, if there is about equal strength to either hypothesis, one only being currently "popular" among the general public, then I can go back to believing Steady State, cant I? What I need is the names of current books and articles written by the proponents of both theories so I can better understand each view. I would be especially greatful if only Undergraduate level math was required to understand the views as well. you can reach me at utzoo!utcsstat!laura. Utzoo talks to many sites including linus, allegra and ihnp4. In desperation you can try the decvax!utzoo link, but it has not been very reliable lately. Thank you very much, Laura Creighton utzoo!utcsstat!laura now, if you could only restore my belief in Santa Claus....
gwyn%brl-vld@sri-unix.UUCP (06/18/83)
From: Doug Gwyn (VLD/VMB) <gwyn@brl-vld> First, you need to realize that physicists are human beings with their own prejudices and politics; the latter is aggravated by the almost total reliance on government funding. Therefore there are many fads and camp followers... It really shouldn't matter what theory feels comfortable; one should arrange his value system so that the truth is emotionally satisfying. However, the truth is definitely not identical with the ideas a majority of professionals happen to believe at any given moment. The history of science bears this out. A majority of physicists in a position where they should know currently believe in the Big Bang cosmology, although there are others who think the evidence is inconclusive. Astronomy in general is based on extrapolation, since it is impossible to perform controlled laboratory experiments on the subject matter. Extrapolation is a risky business! In the case of cosmology, the red shift of distant objects is observable, but its significance is a matter of conjecture; the common conjecture is that it is a Doppler effect, and many cosmological models take this for granted although alternative causes are possible. Just because a technical paper was published some time ago does not make it worthless (it does, however, tend to isolate it from current fads). The best discussion of cosmology I ever saw was a little book "Expanding Universes" by Erwin Schr"odinger. It is eminently readable but a little hard to find. (If anyone with access to this book is willing to run me off a copy, I would gladly cover expenses!)