Niels Bohr

Niels Bohr resisted Einstein's light particles for years, and in 1924 he, Hendrik Kramers and John Slater proposed a theory that gave them up at the cost of energy being conserved only on average. Experiments by Walther Bothe and Hans Geiger, and by Arthur Compton and Alfred Simon, showed in 1925 that energy is conserved in each collision. Bohr promptly accepted the result and abandoned the theory.