According to Steinhardt and Turok, today's universe is part of an endless cycle of big bangs and big crunches, with each cycle lasting about a trillion years. At every big bang, the amount of matter and radiation in the universe is reset, but the cosmological constant is not. Instead, the cosmological constant gradually diminishes over many cycles to the small value observed today.
The physicists' calculations show that the cosmological constant decreases in steps, through a series of quantum transitions. Crucially, the higher the value of the constant, the more rapid the transitions, says Turok. But as the constant reaches lower levels, it changes more slowly, lingering on the lowest positive value for an extremely long time. That means that today's universe is most likely to have a small cosmological constant, just as we currently observe, says Turok.
(Via KurzweilAI.net.)
This model makes intuitive sense. It compliments how I've come to feel about the perennial ebb and flow of life and order from my vantage-point as an individual confined to an average planet in an average solar system in an average galaxy. That doesn't, of course, make it true; to many, the idea that the Sun revolves around the Earth instills a sense of harmony.
I wonder -- will the cosmological constant ever decline so markedly that "Big Crunch"-style contraction becomes impossible? If so, what if we're living in that ultimate end state, confronted with endless expansion and the eventual exhaustion of energy resources as stars fade and the galaxies cease glowing like unplugged Christmas decorations? What are the odds that we've been saddled with the futility of a terminally ill Cosmos?
And do I have a right to feel a tinge of despair, a pang of envy?
9 comments:
Envy? For whom?
Envy for the beings in previous universes in which they could look forward to a Big Crunch instead of facing long, lingering thermodynamic oblivion...
I dunno; I kinda like the idea of seeing the End of All Things :D
What are the odds that we've been saddled with the futility of a terminally ill Cosmos?
One more damn thing to worry about!
Think about it Mac, if we don't blow up ourselves... we could see the end of it all.
That's amazing. To me it is... the last witnesses to our universe.
Jon
One could argue that this is further evidence that we inhabit a computer simulation. Again -- what are the odds?
(Sometimes I'm drawn to the idea that the universe is some sort of existential stress test.)
Then again, the anthropic principle suggests that the universe we find ourselves living in is as we observe it because, if it were any different, we wouldn't be here to observe it in the first place.
On that note, I'm going to bed.
I've always considered the anthropic principle an immensely arrogant standpoint. It's a self-justifying circular argument that ignores the fact that the universe came first.
The simulation hypothesis is less annoying and probably far more plausible.
The anthropic principle arrogant? It depends on which version you subscribe to.
The one I think makes the most sense is vastly humbling; the one Frank Tipler believes in is downright anthropocentric.
The one I think makes the most sense is vastly humbling
Ahh, now you've gotten me curious. Which version would that be?