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Richard Feynman
1948· Person
ProvenTested many times; part of working physics.
Richard Feynman (1918-1988), American physicist, Nobel laureate and teacher, co-creator of QED and inventor of Feynman diagrams.
See it on the Science map →How it works
Feynman worked on the Manhattan Project, then at Cornell and Caltech. He pictured particle interactions as simple stick-figure diagrams, each standing for a calculation, turning pages of algebra into bookkeeping. He reformulated quantum mechanics as a sum over every possible path a particle could take. He insisted on testing ideas against nature, and on the 1986 Challenger commission showed with ice water how a rubber seal failed in cold.
Why it matters
Feynman diagrams are now the everyday tool of particle physics. His lectures and books taught generations, and in 1981 he proposed quantum computers.
How the work held up
QED's predictions, computed with his methods, match experiments to better than a part in a billion. Nobel Prize 1965, shared with Schwinger and Tomonaga.
Still a mystery
He remained uneasy with renormalization as a mathematical trick, and his attempts at quantum gravity and a theory of turbulence did not succeed.
Connections (2)
▸Richard Feynman proposed Quantum computingWell supported
The relationship
Feynman pointed out that simulating quantum systems on ordinary computers becomes impossibly slow as the system grows, because the possibilities multiply exponentially. His proposed fix: build a computer that itself runs on quantum rules, so it could mimic nature naturally. That idea is the root of quantum computing.
How the link was found
Feynman's 1981 talk at an MIT conference, published in 1982 as 'Simulating Physics with Computers'. Yuri Manin and Paul Benioff had related ideas around 1980.
Is it proven?
Quantum computers now exist in labs. Google reported in 2019 a task beyond ordinary supercomputers and in 2024 showed improving error correction. Practical, useful machines are not yet here.
Open questions and mysteries
Whether large, error-free quantum computers can be built economically is still open.
▸Richard Feynman co-created QED: the theory of light and electronsProven
The relationship
Feynman drew each possible particle interaction as a simple diagram: lines for electrons and photons, joints where they meet. Each diagram stands for a term in the calculation, so adding up diagrams gives the answer. Combined with renormalization, this turned QED from an infinity-plagued theory into a practical, precise tool.
How the link was found
Feynman, at Cornell, presented the method in 1948 and published it in 1949. Freeman Dyson showed in 1949 it was equivalent to the methods of Schwinger and Tomonaga.
Why it's proven
Calculations using his diagrams match the electron's magnetism to better than a part in a billion. Nobel Prize 1965.
Open questions and mysteries
Why renormalization works so well is now understood better, but the sum of all diagrams may not strictly converge.