Sunday, January 30, 2011

Has Our Universe Won the Cosmic Jackpot?

By Steve Paulson / Source:

Forget science fiction. If you want to hear some really crazy ideas about the universe, just listen to our leading theoretical physicists. Wish you could travel back in time? You can, according to some interpretations of quantum mechanics. Could there be an infinite number of parallel worlds? Nobel Prize-winning physicist Steven Weinberg considers this a real possibility.

Even the big bang, which for decades has been the standard explanation for how the universe started, is getting a second look. Now, many cosmologists speculate that we live in a "multiverse," with big bangs exploding all over the cosmos, each creating its own bubble universe with its own laws of physics. And lucky for us, our bubble turned out to be life-friendly.

But if you really want to start an argument, ask a room full of physicists this question: Are the laws of physics fine-tuned to support life? Many scientists hate this idea -- what's often called "the anthropic principle." They suspect it's a trick to argue for a designer God.

But more and more physicists point to various laws of nature that have to be calibrated just right for stars and planets to form and for life to appear. For instance, if gravity were just slightly stronger, the universe would have collapsed long before life evolved. But if gravity were a tiny bit weaker, no galaxies or stars could have formed. If the strong nuclear force had been slightly different, red giant stars would never produce the fusion needed to form heavier atoms like carbon, and the universe would be a vast, lifeless desert.

Are these just happy coincidences? The late cosmologist Fred Hoyle called the universe "a put-up job." Princeton physicist Freeman Dyson has suggested that the universe, in some sense, "knew we were coming."


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