As physicists, we have been educated to share a common conception of a law of nature. A law, such as one of Newton’s laws of motion or the Schrödinger or Einstein equation, is a general statement that tells how large classes of systems change in time. Laws themselves don’t change; they apply everywhere in space and for all time. According to the common conception, if a putative law changed, it wouldn’t be a law. What changes is everything else—particles and fields—according to laws that never change.
The notion of unchanging natural laws is very old. It goes back to the atomism of the ancient Greeks, which says, in brief, that the world consists of atoms with unchanging properties that move in an unchanging space in a manner governed by unchanging laws. All that changes are the positions and motions of the atoms. Atomism is, more or less, physicists’ modern picture...
