Newton's third law is more restrictive than Anonymous' reformulation. Anon claims that makes the reformulation better.

Next up, restating the principles of relativity to allow for faster-than-light travel of one of a pair of interacting particles as long as their center of mass travels slower than the speed of light.

Or redefining the uncertainty principle to allow perfect determination of both position and momentum of one particle as long as another particle that interacts with it has twice the uncertainty.

C'mon, Anon, you need to do better than that!

Fred Bortz -- Science and technology books for young readers (www.fredbortz.com) and Science book reviews (www.scienceshelf.com)