The Anthropic Principle argues, in brief, that because we're here we can draw certain logical conclusions about the universe. The cosmos has to be old enough to permit evolution of intelligent life (or else we wouldn't be here). The Sun has to be a reasonably stable star (or else we wouldn't be here). The laws of chemistry have to allow complex self-reproducing molecules (or else...). Nuclear binding energies have to accommodate elements beyond hydrogen and helium (...). And so forth. Serious people use the Anthropic Principle to deduce limits on the possible values of the natural constants --- the strength of gravity, the speed of light, the charge of the electron, etc.
Well, maybe! For starters, there isn't really a single Anthropic Principle --- there are many. They range from the loose premise that "the universe has to permit intelligent life" to the strict "natural law must be able to result in humanity as we know it today". And there's no reason not to argue even more strongly that "the world must be so arranged as to make me, as I am right now, with absolute precision". (After all, here I am, eh?!) Contrariwise, what's so horrible about a universe that doesn't contain intelligence (whatever that word means)? How can one plausibly pick a single Anthropic Principle from this wide spectrum of equally-good candidates?
Even worse, there's a embarrassing lack of imagination hiding behind the classic Anthropic Principle. Who's to say, for example, that a cosmos with only hydrogen atoms in it couldn't evolve brilliant creatures, with their thinking based on nuclear spin-flips or other subtle non-chemical interactions? Sure, we carbon-based critters wouldn't be around to pat ourselves on the back, but so what? (In the smart-hydrogen-spin world, no doubt philosophers would argue cogently that humanoids were inconceivable.) So how can one contend that a completely different set of physical laws won't work?
And how solid is this after-the-fact retrospective "logic" anyway? OK, things are the way that they are (barring observer error) --- but does that imply anything unavoidable about the past? Couldn't we have arrived here via other routes? And couldn't the here-and-now just as easily be somewhat different than what we see? People often have the hubris to deduce that others deserve their inferior position because of past sins, mistakes, or misfortunes. (Funny, hardly anybody deduces that they themselves belong in the cellar ... it always seems to go the other direction.) But "is" doesn't necessarily imply "ought" or "must" or "should".
Maybe the best escape from narrow anthropocentrism is radical open-mindedness. The "Many-Worlds" interpretation of quantum mechanics is one example; see the 24 October 1999 ^zhurnal entry (ManyWorldsDemystified).
Friday, May 26, 2000 at 05:55:30 (EDT) = Datetag20000526