Developer of Quantum Electrodynamics
Born in New York City on May 11, 1918, the son of Jewish immigrants, Feynman studied physics at the Massachusetts Institute of Technology and Princeton University, where he received his doctorate in 1942. During World War II he worked on the atomic bomb project at Princeton University and then at the government’s secret facility in Los Alamos, New Mexico, from 1943 to 1945. Feynman was the youngest of the section leaders in the project, heading a group of scientists using mechanical addingmachinetype calculators, slide rules, and paper to perform the vast numbers of calculations required to design and build the bomb. In his spare time at Los Alamos, he enjoyed figuring out how to crack the military officers’ safes and mailing coded nonsense messages to his wife to pester the security police that checked all the mail.
After the war Feynman taught at Cornell University from 1945 to 1950; he became professor of theoretical physics at California Institute of Technology (Caltech) in 1950, and remained there for the rest of his career. He shared the Nobel Prize for Physics in 1965 for his work on quantum electrodynamics, the theory of the interaction between light and matter; the two scientists he shared the prize with, Julian S. Schwinger and Tomonaga Shin’ichiro, developed similar theories, which ultimately were not as farreaching as Feynman’s. In the nineteenthcentury theory of electromagnetism formulated by JAMES CLERK MAXWELL, one charged particle affected another some distance away through the action of electric and magnetic fields. That theory works well for larger objects, such as two socks tumbling in a clothes dryer, or even two pieces of lint. It does not work well, though, for atoms or the particles within them. To Feynman, electromagnetic forces were not attributable to mysterious action at a distance but to the exchange of particles of light, the quanta of the electric field. Feynman’s quantum electrodynamics explained the interaction between charged particles as a result of the exchange of forcecarrying particles, called bosons.
That the theory is nicknamed QED is part of Feynman’s sense of humor. Those letters are the first letters of three Latin words that together could be construed as meaning “Thus ends the demonstration.” Medieval scholars would write QED at the bottom of a page of a mathematical or logical proof. Calling his theory QED suggests, in a joking way, that the theory is the ultimate end of all physics theories.
Feynman perfected the mathematics of QED and improved it by introducing simple drawings, now called Feynman diagrams, to keep track of the interactions between particles in the theory. He could solve the most difficult mathematical problems of a theory and also explain a theory in a simple model— few scientists could work at both extremes with such ease.
Feynman served as part of the Presidential Commission to investigate the explosion of the Challenger space shuttle in 1986. He will be remembered for dipping a rubber Oring into his glass of ice water to demonstrate how low temperatures on the day of the launch may have affected rubber seals in the booster rockets. On February 15, 1988, Feynman died of cancer in Los Angeles, California.
Richard Feynman‘s Legacy
Feynman’s development of quantum electrodynamics was one of the most important advances in quantum mechanics, the system that explains how subatomic waves and particles behave.
Feynman’s approach in QED has been used to unravel the operation of other forces in nature. Other theoreticians have applied Feynman’s ideas to the strong nuclear force that binds quarks together to form protons and neutrons. That situation is more complex but the theory, called quantum chromodynamics (QCD), has been completely successful in explaining the strong force. Another similar application of the theory explains the operation of the weak nuclear force involved in radioactivity and nuclear reactions as attributable to the exchange of other particles.
Feynman was a brilliant lecturer and a superb teacher who could teach a lesson equally well with the full power of calculus or with no mathematics at all. His lectures at Caltech from 1961 to 1963 were recorded, edited, and published as The Feynman Lectures on Physics. They are widely read even today for Feynman’s dear explanations and witty presentations.
Richard Feynman – 1918-1988