About 15 years ago, Smolin's name became among the most talked-about in science, for an idea that's a cosmic version of Darwin. Modern physics is troubled by the anthropocentric character of the universe. For instance, had gravity been only a teensy bit stronger or weaker, planets and stars could not have formed. So, does the fortuitous value of gravity for planets and stars show that a higher power is manipulating physical law? Some theorists have responded to this quandary by supposing that our 60-billion-galaxy universe is but a slice of a far larger "multiverse" with a cornucopia of different realities, each operating under its own physics. By chance one section of the multiverse got physical laws that favor us, and chance was all that was involved. Smolin countered with his theory of cosmic natural selection. The theory goes like this: Black holes cause Big Bangs. Any universe whose physical laws do not result in black holes thus will hit a cosmic dead end and fail to "reproduce." The set of physical laws that result in stars and planets also results in black holes, allowing universes like ours to copy themselves. Over eons, the firmament would become dominated by universes possessing the kind of laws we observe, because universes with such laws "reproduce." Therefore it is not weird that our cosmos has stars and planets; it is exactly what we should expect.

Today if a professor at Princeton claims there are 11 unobservable dimensions about which he can speak with great confidence despite an utter lack of supporting evidence, that professor is praised for incredible sophistication. If another person in the same place asserted there exists one unobservable dimension, the plane of the spirit, he would be hooted down as a superstitious crank.