The Anthropic Principle
Posted by aogMonday, 09 August 2004 at 15:37 TrackBack Ping URL

Via The Brothers Judd is an article about the fact that the fabric of reality seems tuned for life. This natural leads to the anthropic principle. There are two major forms of this, the weak and the strong versions.

Weak:The fabric of reality must be such that it is possible for intelligent life to evolve. Strong:The fabric of reality must be such that intelligent life will evolve.

Obviously the weak form is true for any intelligent observer, since the observer exists. The strong version is far more debatable.

One of the objections to the anthropic principle is:

the whole idea is roundly trashed by Lee Smolin, a renowned quantum-gravity theorist at the Perimeter Institute in Waterloo, Canada. Smolin asserts, in a preprinted paper on Arxiv1, that the anthropic principle is not a scientific theory at all, because it lacks the basic requirement of falsifiability. It is impossible to prove the anthropic principle wrong, hence it is outside the remit of science.

I disagree strongly with this view. For the weak version, it’s a truism. One can argue about how useful it is. It is, however, not really science since science doesn’t deal with truisms. In this sense it’s more akin (as one of the commentors notes) to the “elegance” principle, which is that more elegant theories are more likely to be correct (and this is itself a form of Occam’s Razor).

The strong form, however, is capable of being proved or falsified. Some proponents of the strong form argue that there is only one consistent set of physical laws, which of course is the set we have (because inconsistent sets cannot exist). If this could be shown, or more properly if it could be shown that other sets of laws are possible that do not lead to the evolution of intelligent life, then this would constitute falsification. While the anthropic principle in either form is hardly a panacea, it’s not a worthless bit of sophistry either.