The man I married, physicist Daryl Reagan, was a skeptic. It gave him an endearing humility. He loved explaining physics to me. When he used his brakes, which produced heat by friction, he explained entropy. He told how eventually all energy would be dull heat energy, a heat death of the universe.
Physics at its base was a reductionist enterprise, breaking things into smaller and smaller pieces to examine and understand. Daryl’s work...