Richard Feynman

Chapter 1 · The Difference Between Knowing the Name and Knowing the Thing

A father's teaching in Queens

1918 – 1942 · Far Rockaway, New York · MIT · Princeton

Richard Feynman was born on 11 May 1918 in Queens, New York, to a Jewish family that was not religious. His father Melville sold uniforms and had wanted to be a scientist. He taught his son a habit that shaped everything: when Richard asked about a bird, his father said that you can know the name of that bird in every language and still know nothing whatever about it — what matters is watching what it does.

Melville also taught him to distrust the trappings of authority, pointing out that a uniform makes the wearer no different underneath. Feynman's lifelong contempt for pomposity started there.

He fixed radios in the neighbourhood as a boy, working out faults by reasoning about circuits rather than by trial and error. At Far Rockaway High School he won the New York University Math Championship. His sister Joan, nine years younger, was told by their mother that women's brains were unsuited to science; Richard encouraged her, and she became a distinguished astrophysicist.

At MIT he switched from mathematics to physics, and at Princeton, under John Archibald Wheeler, he scored perfect marks in the physics entrance examinations — with poor marks in history and English.

He married Arline Greenbaum in 1942. She had tuberculosis and both knew she was dying; his family objected, and he married her anyway, in a ceremony on the way to a hospital on Staten Island.

Why this matters

Feynman's father gave him the distinction between naming something and understanding it — the principle behind his teaching and his suspicion of formalism dressed up as insight.

You have met the boy taught to look rather than label. What would you ask him?

Ask Feynman

• “What did your father mean about knowing the name of a bird?”
• “How did fixing radios teach you physics?”
• “Why did you encourage your sister when your mother did not?”
• “Why did you marry Arline knowing she was dying?”
• “Why did you dislike ceremony and authority so much?”

Chapter 2 · Los Alamos

Safecracking, computation, and a telegram

1943 – 1945 · Los Alamos · Albuquerque · Trinity site

At twenty-four Feynman went to Los Alamos as a junior theorist and ended up running the group doing the numerical computations for weapon design. He organised human computers — many of them the scientists' wives — into a parallel assembly line with punched-card machines, working out how to run several calculations simultaneously through the same equipment. It was, in effect, early computational project management.

He also made a study of the site's security by breaking into filing cabinets and safes containing the project's most sensitive documents, leaving notes inside. He argued he was demonstrating that the locks were inadequate; officials found it less amusing than he did.

Arline was in a sanatorium in Albuquerque, and he hitchhiked to see her at weekends. They wrote constantly, sometimes in code, which alarmed the censors. She died in June 1945, a month before the test. He recorded feeling almost nothing at the time, and broke down months later in front of a department-store window displaying a dress he thought she would have liked. Sixteen months after her death he wrote her a letter, sealed it, and it was found among his papers when he died.

At the Trinity test on 16 July 1945 he watched through a truck windscreen with welding glass, reasoning that the glass blocked the ultraviolet and the windscreen would stop the rest — probably the only person to see the first nuclear explosion with something close to the naked eye.

His reaction afterwards was complicated. He described the elation and drumming in the streets, and then sitting in a New York restaurant calculating how far the blast radius would reach and thinking it was all pointless because it would soon be destroyed.

Why this matters

Feynman's Los Alamos work is a case study in the moral position of the technical specialist: he solved the problems in front of him and did his reckoning with what they meant afterwards.

You have the bomb project. What would you ask him?

Ask Feynman

• “How did you organise human computers to work in parallel?”
• “Why did you break into the project's safes?”
• “What did you feel when Arline died?”
• “What did you think while watching the Trinity test?”
• “Did you reconsider the project after Hiroshima?”

Chapter 3 · Diagrams and the Nobel Prize

Making the infinities go away

1946 – 1965 · Cornell · Caltech · Stockholm

After the war Feynman went to Cornell in a state of depression, unable to work, and recovered by deciding to play with physics for its own amusement. Watching a student spinning a plate in the cafeteria, he worked out the relationship between its wobble and its spin for no reason at all, and the thinking led him back into the problem that made his name.

Quantum electrodynamics — the theory of how light and matter interact — produced infinite answers to reasonable questions. Feynman, and independently Julian Schwinger and Sin-Itiro Tomonaga, found a consistent way to handle the infinities, a procedure called renormalisation.

His approach was distinctive. Building on the path integral formulation from his doctoral work, he treated a particle as taking every possible path between two points, with the observed behaviour emerging from the sum over all of them. To calculate, he invented a pictorial notation: simple line diagrams representing particles interacting, each of which corresponds to a precise mathematical term.

Feynman diagrams were initially met with suspicion — Freeman Dyson's work showing they were equivalent to Schwinger's formalism helped persuade physicists — and are now the standard working language of particle physics. QED became the most accurately tested theory in science, matching experiment to around ten decimal places.

He shared the 1965 Nobel Prize with Schwinger and Tomonaga. He also worked out the theory of superfluid helium, contributed the parton model that helped establish quarks, and co-developed with Murray Gell-Mann the theory of the weak interaction — and in 1959 gave a lecture, 'There's Plenty of Room at the Bottom', anticipating nanotechnology decades early.

“I think I can safely say that nobody understands quantum mechanics.”

— Richard Feynman, The Character of Physical Law, 1965

Why this matters

Feynman diagrams turned an intractable calculation into something a physicist can sketch on a napkin — one of the clearest examples of a notation changing what a field can do.

You have the physics that won the prize. What would you ask him?

Ask Feynman

• “What problem were the infinities in quantum electrodynamics?”
• “What does a Feynman diagram actually represent?”
• “How can a particle take every possible path?”
• “Did the spinning plate really restart your career?”
• “What did you mean that nobody understands quantum mechanics?”

Chapter 4 · The Teacher

The Lectures, Brazil, and the trouble with cargo cults

1950 – 1985 · Caltech · Rio de Janeiro

Feynman moved to Caltech in 1950 and stayed. Between 1961 and 1963 he redesigned the introductory physics course, and the transcripts became *The Feynman Lectures on Physics* — a set of books that has been in print ever since. He judged the course a failure by his own measure, because he did not think he had reached the weakest students, but generations of physicists have learned from them.

He taught by insisting on understanding rather than manipulation. His test was whether you could explain something to a first-year student; if you could not, you did not understand it.

A year teaching in Brazil in 1951 produced his sharpest critique of education. He found students who could recite definitions perfectly and could not answer a question about the same phenomenon in the world outside the textbook. He told a conference of Brazilian education officials, with the minister present, that no science was being taught at all — only words to be repeated.

He extended the idea in a 1974 Caltech commencement address about cargo cult science: work with the form of science — the apparatus, the statistics, the publications — but missing the essential thing, which is a determined effort not to fool yourself, and the reporting of everything that might make your result wrong.

His 1985 memoir *Surely You're Joking, Mr. Feynman!* made him famous outside physics. It also contains accounts of his conduct toward women — including a period of deliberately treating women in bars with contempt as a technique — that many readers now find objectionable, and that colleagues at the time criticised as well. Both the teaching and this belong in an honest picture.

Why this matters

Feynman's 'cargo cult science' address is one of the most quoted statements of scientific integrity: that the first principle is not to fool yourself, and you are the easiest person to fool.

You have the teacher and the memoirs. What would you ask him?

Ask Feynman

• “How do you know when you really understand something?”
• “What was wrong with how the Brazilian students had been taught?”
• “What is cargo cult science?”
• “How do you respond to criticism of how you wrote about women?”
• “Why did you consider your own lecture course a failure?”

Chapter 5 · A Glass of Ice Water

The Challenger inquiry and a last lesson

1986 – 1988 and after · Washington · Pasadena

On 28 January 1986 the space shuttle *Challenger* broke apart seventy-three seconds after launch, killing all seven crew. Feynman, already seriously ill with cancer, was persuaded to join the presidential commission.

He refused to work through official briefings and went to talk to engineers directly. What he found was a gap: working engineers estimated the chance of catastrophic failure at roughly one in a hundred, while NASA management was quoting one in a hundred thousand.

The physical cause was a rubber O-ring seal in a solid rocket booster that lost resilience in cold weather; the launch morning had been unusually cold, and engineers at the manufacturer had objected to launching and been overruled.

At a televised hearing Feynman asked for a glass of ice water, took a sample of the O-ring material clamped in a small C-clamp, dipped it in, removed it and showed that it did not spring back. The demonstration took less than a minute and made the finding impossible to bury.

He insisted on including his own appendix to the commission's report, describing the divergence between management and engineering estimates as a serious failure of organisational honesty and ending with a sentence that has become the standard warning in engineering ethics: that for a successful technology, reality must take precedence over public relations, because nature cannot be fooled.

He died on 15 February 1988 of rare abdominal cancers, aged sixty-nine. His last recorded words were that he would hate to die twice, because it is so boring. The blackboard in his office read: what I cannot create, I do not understand.

Why this matters

The Challenger inquiry is the standard case study in how organisational pressure distorts risk assessment — and how a single well-designed demonstration can settle a public argument.

You have the last public act. What would you ask him?

Ask Feynman

• “Why did you go and talk to the engineers directly?”
• “Why did the ice water demonstration work so well?”
• “How could management and engineers differ by a factor of a thousand?”
• “What did you mean that nature cannot be fooled?”
• “What does 'what I cannot create, I do not understand' mean?”

What Feynman changed

Feynman's reformulation of quantum electrodynamics and his diagrams became the working language of particle physics, and QED remains the most precisely tested theory in science. His lectures reshaped how physics is taught, his 1959 nanotechnology talk anticipated a field by decades, and his Challenger appendix is a standard text in engineering ethics.

A debate that continues

Readers and physicists continue to weigh Feynman's scientific contribution against the conduct described in his own memoirs, and to discuss how far his cultivated showmanship shaped and distorted his public reputation.

Keep exploring — ask Feynman

• “How do you tell the difference between understanding and memorising?”
• “What would you have wanted to work on that nobody was doing?”
• “How do you stop yourself believing something because it is convenient?”

Related lives

• J. Robert Oppenheimer — Father of the Atomic Bomb
• Albert Einstein — Nobel Laureate · Author of Relativity
• Niels Bohr — Architect of the Quantum Atom

Related themes

Quantum physics · Nuclear weapons and ethics · Scientific method and integrity