Action in Physics: The Old Quantum Theory
Some of Bohr's results had actually been foreshadowed by Arnold Johannes Wilhelm Sommerfeld (1868 – 1951). Here was a man totally committed to science. Just prior to the appearance of Einstein's paper on Special Relativity, he had finished some outstanding work on the electrodynamics of electrons in motion. He had even considered electrons moving at speeds greater than light. When Einstein's paper on special relativity appeared and showed that such motion was not possible for electrons in empty space, Sommerfeld abandoned his work and turned to relativity…