August 11, 2005

Evolution for Universes

Since I don't know all that much about evolution, relatively—hey, they never even broached the subject in my tenth grade class (this was upstate New York)—I picked up Richard Dawkins' The Ancestor's Tale and started reading. Good stuff so far, but I thought I'd quote a fun bit from the beginning, when he goes through the possible theories as to why our universe just happens to be so fine-tuned that it can support life:
The theoretical physicist Lee Smolin added an ingenious Darwinian spin which reduces the statistical improbability of our existence. In Smolin's model, universes give birth to daughter universes, which vary in their laws and constants. Daughter universes are born in black holes produced by a parent universe, and they inherit its laws and constants but with some possibility of small random change—'mutation'. Those daughter universes that have what it takes to reproduce (last long enough to make black holes, for instance) are, of course, the universes that pass on their laws and constants to their daughters. Stars are precursors to black holes which, in the Smolin model, are the birth events. So universes that have what it takes to make stars are favoured in this cosmic Darwinism. The properties that furnish this gift to the future are the self-same properties that incidentally lead to the manufacture of large atoms, including vital carbon atoms. Successive generations of universes progressively evolve to become increasingly the sort of universe that, as a by-product, is capable of producing life.
That brings to mind, by the way, one of my favorite Scientific American articles of all time, which runs through the variety of theories on parallel and possible universes. Fun, fun.
-- Brad Plumer 2:15 PM || ||