In 1922, Compton discovered that radiation (high-energy X-ray photons) could collide with electrons, exchanging energy with them as they were scattered. This was early evidence for the wave-particle duality of matter and radiation. He was awarded the Nobel Prize in Physics in 1927 for this "Compton effect," the year that Werner Heisenberg discovered quantum indeterminacy.

Later he championed the idea of human freedom based on quantum indeterminacy and invented the notion of amplification of microscopic quantum events to bring chance into the macroscopic world.