Feynman, Richard (1918-1988)

American physicist

Richard Feynman's career spanned some of the greatest discoveries of twentieth century physics , from developing the atomic bomb and studying quantum electrodynamics (QED ) to solving the riddle of the space shuttle Challenger disaster.

Feynman received the 1965 Nobel Prize for his work regarding the interaction of light and matter, which he shared with Shin'ichio Tomonaga and Julian Schwinger. Other honors he received include the Albert Einstein Award (1954), the Niels Bohr International Gold Medal (1973) and membership in the National Academy of Sciences (1954).

Richard Phillips Feynman was born in Queens, New York. His parents were Lucille Phillips and Melville Feynman, a clothing salesman originally from Minsk. Feynman was interested in science from an early age, when he tinkered with crystal radio sets. His father had predicted that his first child, if a boy, would be a scientist; Mr. Feynman got more than he bargained for, for Richard's younger sister Joan also became a physicist

Feynman attended New York public schools, and after high school graduation went on to study physics at the Massachusetts Institute of Technology. After receiving his bachelor's degree in 1939, he went on to do his doctoral work at Princeton, where he served as a research assistant to John A. Wheeler, a Nobel-Prize-winning physicist. As a graduate student under Wheeler, he concerned himself with the knotty problem of how electrons interact, a question that would occupy him for years.

During the 1920s, Paul Dirac had introduced the theory that described the behavior of electrons in such a way that satisfied both quantum mechanics and Albert Einstein's theory of relativity. However, many problems arose with Dirac's equation when the known principles governing electromagnetic interactions were brought to bear on it; then Dirac's equation involved dividing by zero, which resulted in infinite answers, which were for all practical purposes useless.

Feynman—who from his undergraduate days had a well-deserved reputation for finding better ways to complete calculations—found a way to circumvent these useless answers. By "renormalizing" or redefining, the existing value of the electron's mass and charge, he was able to make irrelevant the parts of Dirac's theory that led to the troublesome answers.

But Feynman's work did more than just clean up some messy mathematics. It also provided physicists a new way to work with electrons. It opened the way for a new examination and description of the hydrogen atom . It gave scientists a look at what really happens when electrons, anti-electrons (or positrons) and photons (light particles) collide.

After receiving his doctorate, Feynman and his wife, Arlene Greenbaum, moved to Los Alamos, N.M., where he went to work with the Manhattan Project. There he worked, and held his intellectual own, with noted scientists such as Enrico Fermi and Hans Bethe, who headed Feynman's division. Feynman's wife Arlene, who had been his high-school sweetheart, died in 1945 after battling lymphatic tuberculosis. Less than a month after Arlene's death, Feynman became one of the first people in the world to witness the explosion of an atomic bomb.

After World War II, Bethe offered Feynman a position at Cornell University. While teaching physics, he also studied the question of the interaction of light and matter. In his description of the problem, he discarded the effect of the electromagnetic field and concentrated on the interactions of the particles themselves, as ruled by least action. In 1945, he also created a visual way to keep track of the interactions of the particles within time and space . Read from the bottom up (which indicates the passage of time), the diagrams show incoming particles (electrons) as straight lines. Their interactions (when they meet) are illustrated with wavy lines, indicating photons, which transmit the interactions. The straight lines then resume, indicating the departing particles after the interaction. Known as Feynman diagrams, they are still in use by theoretical physicists in such diverse areas as acoustooptics, QED, and studies of electroweak interactions.

Feynman left Cornell in 1950 to join the California Institute of Technology, or CalTech, with which he would be affiliated for the rest of his life. During his time at CalTech he turned his prodigious mind and imagination to a staggering variety of problems, including the superfluidity of helium, superconductivity, and quark theory.

He married again in 1952, to Mary Louise Bell; they divorced four years later. In 1960, he married again, for the last time, to Gweneth Howarth; the couple had two children.

In 1979, Feynman was diagnosed with cancer, which he would battle for the next decade, before his death at age 69. During his last decade, Feynman became one of the world's most popular scientists, with the publication of two autobiographies, "Surely You're Joking, Mr. Feynman!" Adventures of a Curious Character (1984) and "What Do You Care What Other People Think?" Further Adventures of a Curious Character (1988). He also published QED: The Strange Theory of Light and Matter in 1985. During the 1960s, he published Quantum Electrodynamics (1961), The Character of Physical Law (1965), and The Feynman Lectures, three volumes of transcribed physics lectures he gave at CalTech that beautifully explain everything from the fall of water to QED.

Feynman was part of the group that investigated the explosion of the space shuttle Challenger in 1986. Feynman memorably demonstrated the failure of the shuttle's O-ring gaskets by placing a piece of gasket in a clamp and dropping it into ice water. The material became brittle, and the simple demonstration showed that the gaskets' failure had caused the explosion.

See also Bohr Model; Electromagnetic spectrum; Quantum theory and mechanics