--- Leonard Susskind, physicist
Source: Because we're here, Interview with Leonard Susskind, New Scientist 17 Dec 2005. Quote in context:
Q. Steven Weinberg recently said that this is one of the great sea changes in fundamental science since Einstein, that it changes the nature of science itself. Is it such a radical change?
A. In a way it is very radical but in another way it isn't. The great ambition of physicists like myself was to explain why the laws of nature are just what they are. Why is the proton just about 1800 times heavier than the electron? Why do neutrinos exist? The great hope was that some deep mathematical principle would determine all the constants of nature, like Newton's constant. But it seems increasingly likely that the constants of nature are more like the temperature of the Earth - properties of our local environment that vary from place to place. Like the temperature, many of the constants have to be just so if intelligent life is to exist. So we live where life is possible.
For some physicists this idea is an incredible disappointment. Personally, I don't see it that way. I find it exciting to think that the universe may be much bigger, richer and full of variety than we ever expected. And it doesn't seem so incredibly philosophically radical to think that some things may be environmental.