Sunday, September 7, 2008

More demolition teams trying to blow up the Big Bang

Recently, I was looking at non-Big Bang theories, and here Discover Magazine (March 25, 2008) offers three of them, including cyclic universe, the multiverse, and the non-existence of time.

This gives you a sense of it:
It is almost as if our universe were fine-tuned to start out far from equilibrium so it could possess an arrow of time. But to a physicist, invoking fine-tuning is akin to saying “a miracle occurred.” For Carroll, the challenge was finding a process that would explain the universe’s low entropy naturally, without any appeal to incredible coincidence or (worse) to a miracle.
But, if ony by coincidence,
For each of the alternatives to the Big Bang, it is easier to demonstrate the appeal of the idea than to prove that it is correct. Steinhardt and Turok’s cyclic cosmology can account for critical pieces of evidence usually cited to support the Big Bang, but the experiments that could put it over the top are decades away. Carroll’s model of the multiverse depends on a speculative interpretation of inflationary cosmology, which is itself only loosely verified.

Barbour stands at the farthest extreme. He has no way to test his concept of Platonia. The power of his ideas rests heavily on the beauty of their formulation and on their capacity to unify physics. “What we are working out now is simple and coherent,” Barbour says, “and because of that I believe it is showing us something fundamental.”

The payoff that Barbour offers is not just a mathematical solution but a philosophical one. In place of all the conflicting notions about the Big Bang and what came before, he offers a way out. He proposes letting go of the past—of the whole idea of the past—and living fully, happily, in the Now.

In one model, each round of existence stretches a trillion years. By that reckoning, our universe is still in its infancy.
Oh well, then ... plenty of time for new theories - assuming time really exists (but some theorists say it doesn't, right?).

See also:

"Big Bang exploded? Seriously, is there room for reasonable skepticism about the Big Bang?"

"Hello, God: This is the Big Bang. Okay, look, I done it. What do I do NOW?"