H. David Politzer

From a Jewish family in New York, Politzer discovered asymptotic freedom in 1973 while a graduate student at Harvard — the surprising property that the strong force between quarks weakens as they come closer together, which explained why quarks behave almost freely inside protons. The insight underpins quantum chromodynamics, the theory of the strong interaction. He shared the 2004 Nobel Prize in Physics with David Gross and Frank Wilczek.