"L. L. Whyte, in a short but prophetic essay, Archimedes or the Future of Physics, pointed out that in each of the two great new physical theories of this century the fundamental role was played by a particular constant of nature: in Relativity by c, the velocity of light in vacuo, and in Quantum Theory by h, Plank's constant. He suggested that the next great advance in our understanding of nature would be associated with a new fundamental constant, and he prophesied that this would be concerned with the flow of time."