As I began to think about it, I realized that, contrary to popular view, scientists don’t really care that much about facts. We recognize that facts are the most unreliable part of the whole operation. They don’t last, they’re always under revision. Whatever fact you seemed to have uncovered is likely to be revised by the next generation. That’s the difference between science and many other endeavors. Science revels in revision. For science, revision is a victory. In religion, or astrology, or any other belief system, revision is a kind of defeat. You were supposed to have known the answer to this. But the joy of science is that it’s about revision.