Saturday, 21 April 2007

cosmic jackpot?

Photo: NASA

I have long been a fan of physicist and author Paul Davies. Books like "About Time" and "The Mind of God" are excellent scientific reading from a well credentialled theoretical physicist and cosmologist which also touch on bigger questions like "how and why does the universe exist?" and "is there any objective meaning to our lives?".

Davies has written several books on the "anthropic principle", the scientific observation that the fundamental laws and values of the universe appear to have been "fine-tuned" to support life. If such fundamentals as the force which binds protons and neutrons together in the nucleus of the atom, the strength of the gravitational force, or the relative masses of protons, electrons and neutrons, were varied by sometimes extremely small amounts, life, planets, stars and even the universe itself would not exist. Thus the odds against this fine-tuning occurring by chance are unbelievably enormous.

This has led some people to suggest that the universe was deliberately designed by a god, a conclusion Davies himself came close to endorsing in "The Mind of God" (1993). Now Davies has just released a new book on a similar subject, "Cosmic Jackpot: Why Our Universe Is Just Right for Life", and based on reviews, he seems to have weakened in his support for "the god explanation". He does still tend to believe in an undefined "life principle" in the cosmos, but admits that this "is something I feel more in my heart than in my head." And his main emphasis is on finding an explanation for the universe from within the universe.

Some people just say that the laws and values had to take on some values, and why question it? But if the fine-tuned design is accepted, there seem to be four main scientific hypotheses for this:

  • There is some underlying fundamental reason for these values that we just don't know yet.
  • The multiverse: if there was not one universe but absolutely zillions of them, the odds of one of them being just right for life may not be so high. But there is no evidence for the multiverse and it seems somewhat far-fetched to believe in zillions of universes. Davies rejects this option, because in his view it raises more problems than it solves.
  • If there are advanced cultures somewhere in the universe with advanced computer technology, they could develop a simulation of the universe (sort of like "the Matrix" writ huge). Since the universe is so huge, it is likely this may have occurred, and therefore quite likely we are all virtual people in a virtual universe. Fanciful (to say the least) as this hypothesis may seem, some people are postulating it, and Davies touches on it too. But it seems to me that this option isn't useful, because it still doesn't explain the origin of the "real" universe where this advanced civilisation is supposed to exist.
  • A fourth option is that the fundamental laws and values of the universe are not fixed as commonly thought, but somehow "evolved" in a way that allowed life to begin. The mechanisms of biological evolution (mutation and natural selection) will not be relevant here, but Davies speculates another mechanism. He suggests that just as quantum physics seems to allow backwards causation in time (things in the present cause things in the past), contrary to normal reason, so the same may have occurred in the universe. Way back not long after the big bang, life in the future caused the laws to evolve in ways that would lead towards that life. It may come as no surprise that critics say this idea is even more wild, speculative and unjustified (perhaps even unjustifiable) than the alternatives.

I find all this quite fascinating, but I can't help feeling that if the multiverse, a "Matrix" universe, or backwards causation, are the best scientific theories around, the god hypothesis doesn't look so wild at all.

Check out reviews of Davies' new book at Amazon and on the "Reality Conditions", the "Uncertain Principles" or the "Reference Frame" blogs. Read about the Multiverse, the "Matrix universe" and time in quantum physics. Or check out Paul Davies' home page or the April/May 2007 issue of Cosmos which includes an article by Davies on this topic.

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