Bengt Oberger · CC BY-SA 4.0

John Polanyi won the 1986 Nobel Prize in Chemistry for founding the field of chemical reaction dynamics, using infrared light emitted by reacting molecules to observe, for the first time, the intermediate states a chemical reaction passes through as bonds break and form. Born in Berlin to a prominent Hungarian Jewish family who emigrated to Britain in 1933, he built his career at the University of Toronto from 1956 onward. Beyond the lab, he has been an outspoken voice in public debates over science policy and nuclear weapons.