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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...
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
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.
It's all going according to
While there's a superficial resemblence, there's a huge difference between the old oscillatory models and this one.
In the old models, the universe collapsed from many billions of light years across (or even larger - we really have no idea of how big the universe is) back to the singularity of the big bang.
In this model, the universes (plural) only have to move a few millimeters. The big bang occurs when the branes separate (we're in one brane, the other universe is in another), and the big crunch occurs when they collapse again. The point of intersection can even travel faster than the speed of light without violating relativity - it's okin to the scan of a lighthouse beam against a wall a very long distance away.
For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken