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."

Comments

All Things Considered

[EReidJ]

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.

Sky and Telescope also has an explanation

[Leeji]

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.

Steven Weinberg

[polyphemus-blinder]

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.