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Cyclic Universe a Possibility
An Anonymous Coward writes "Spacedaily has a post(from Science) about a new theory at odds with the big bang theory. The researchers claim that this theory of an oscillating energy field could be experimentally tested in the coming years."
On April 25, All Things Considered on NPR did a five-minute story on this new Science article. Highly recommended, gives some good background not only on how this theory fits better with some of the current data that we are collecting, but also talks about how difficult it is for a new theory to gain acceptance in the scientific community when it flies in the face of a long-established theory.
modern choral music...
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I sig, therefore I was.
The latest versions of the big bang theory, with the addition of dark energy or whatever, of an extra repulsive force, predict, basically, the entropic death of everything - the universe as we know it today, with hot stars and habitable planets and the like, exists for some finite period and then disperses forever.
There is certainly a desire - I feel it, myself - that the universe not be that way. It is far more pleasant to think that it will regenerate itself and that complex phenomena like life could re-emerge in some subsequent cycle. However, it is important, as scientists, that we not give in to wishful thinking of that sort.
While these branes are a cute idea in a number of respects - not just because a parallel plane full of dark matter is 100% cool old school science fiction - it strikes me that they answer "how can we match our observations to what we want to be true?" rather than "how can we match our explanations to what we observe?"
Which is not to say that it isn't an excellent theory - merely that there is extreme intellectual danger associated this sort of speculation.
Let me say also - Entropy is a thorough bitch. Whatever the laws of physics turn out to be, and whatever cycles they may allow, if subsequent phenomena depend in any way on previous phenomena (phenomena being the most general term I can manage), there will be a tendency for the whole shebang to degenerate, to move into a more likely state. It is possible that the most likely state for the whole universe involves repeated regeneration of galaxy-rich explosions like the one we all inhabit, but it is also possible that subsequent big bangs would be smaller and smaller in size, eventually dwindling below some critical threshold to generate stars and the like.
The good and new comes from no quarter where it is looked for, and is always something different from what is expected.
Sky and Telescope also covered this story, but didn't obscure it with piss-poor scientific writing like this other source did.
As an aside, the other source over simplifies things, and leaves you with the feeling that you learned nothing but marketing hype. It's target is obviously non-astronomers (or we would have read the original paper in an original journal.) Because of that, they should have explained "branes" (and other terms) with more than sound-bytes from involved physicists. Think diagrams, break-out boxes, etc.
It all goes downhill from first post
The big bang or any other theory of the universe does not contradict the existance of God, it only contradicts their narrow-minded view of God.
Okay, a lot of people have been saying that an infinite cycle of exands and contracts would NOT generate infinite heat. Here's what Steven Weinberg has to say:
"Some cosmologists are philosophically attracted to the oscillating model, especially because, like the steady-state model, it nicely avoids the problem of Genesis. It does, however, face one severe theoretical difficulty. In each cycle the ratio of photons to nuclear particles (entropy per nuclear particle) is slightly increased by a kind of friction (known as "bulk viscosity") as the universe expands and contracts. As far as we know, the universe would then start each new cycle with a new, slightly larger ratio of photons to nuclear particles. Right now this ratio is large, but not infinite, so it is hard to see how the universe could have previously experienced an infinite number of cycles."
Pysicist Sidney A. Bludman says:
"Our Universe cannot bounce in the future. Closed Friedman universes were once called oscillatory universes. We now appreciate that, because of the huge entropy genereated in our Universe, far from oscillating, a closed universe can only go through one cycle of expansion and contraction. Whether closed or open, reversing or monotonically expanding, the severely irreversible phase transitions give the Universe a definite beginning, middle and end."
If any of you have counter-quotations from equally famous physicists, I would love to read them. This is all I have found on the matter so far.
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