A hundred years ago, it became clear that most events at the level of the subatomic are random, uncaused, indeterministic quantum events—merely matters of probability. Locate an electron on one side of a steel barrier it doesn't have the energy to penetrate. There is some probability that the next time you detect it, the electron will be on the other side of the barrier it can't penetrate. But there are no facts about the electron that explain why sometimes it does this and sometimes it doesn't. At the basement level of reality, there are just probabilities.

What we know of physical and biological science makes existence of God less probable than the existence of Santa Claus. And the parts of physics that rule out God are not themselves open to much doubt. There is no chance that they will be revised by anything yet to be discovered. To be sure, there will be revolutionary developments in science. Superstring theory may give way to quantum-loop gravity; exceptions to the genetic code may be discovered; some unique function of consciousness may be identified. But there are some things that won't happen. Purposes and designs will never have a role in physics and biology. Perpetual motion machines and other violations of the laws of thermodynamics won't arise, not even if there turns out to be such a thing as cold fusion.