Markus Pössel (User name: Mapos) · CC BY-SA 3.0

Spent four decades at Harvard working out why laser light and the light from a bulb are fundamentally different kinds of light, publishing the theory of optical coherence in 1963 and picking up half the 2005 Nobel Prize in Physics for it decades later. The same year he also laid early groundwork on the stochastic dynamics of the Ising model, a foundation for later work on phase transitions. He later served on the National Advisory Board of the Center for Arms Control and Non-Proliferation.