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Who really said it

Shut up and calculate!

Not Richard Feynman — actually N. David Mermin N. David Mermin b. 30 March 1935 · Horace White Professor of Physics Emeritus, Cornell University
Disputed In copyright

The line is Cornell physicist N. David Mermin’s, written in his Physics Today “Reference Frame” column for April 1989: if he had to sum up the Copenhagen interpretation in one sentence, it would be “Shut up and calculate!” Feynman had died in February 1988, more than a year before the column ran, and when Mermin went looking in 2004 for the Feynman source everyone cited, he found that not one of the sites crediting Feynman named a source ↗.

Last verified 10 Aug 2026 · how we verify · spot an error?

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Disputed credit — copy with the correction

“Shut up and calculate!” Shut up and calculate! — N. David Mermin, "What's Wrong with this Pillow?", Physics Today 42, no. 4 (April 1989): 9. Widely misattributed to Richard Feynman, who died in February 1988, more than a year before the line was published. Via Quotle.info · Verbatim: “If I were forced to sum up in one sentence what the Copenhagen interpretation says to me, it would be "Shut up and calculate!"”

The slide-ready mistake: crediting this to Richard Feynman. Use the credit shown above instead.

Can you use it?

Still under copyright (rights held by N. David Mermin and the American Institute of Physics (Physics Today)). A short, credited quote is generally fine for talks, teaching, and internal decks; for commercial, published, or large-scale reuse, get permission.

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In context

Evoking the world of N. David Mermin — American solid-state physicist · Cornell University. Theme: "Shut up and calculate!". Atmospheric and restrained, cinematic directional light, a muted period-appropriate palette, fine grain and texture. Compose with generous empty space for the quote and a small credit line. No lettering in the image itself.

Minimalist

Minimalist editorial slide for the quote "Shut up and calculate!". Clean background, a single muted accent color, generous negative space, subtle paper or linen texture, no literal illustration — let the words carry it. Reserve clear space for a serif quote and a small credit line. No lettering in the image itself.

Provenance

The source

Work
“What’s Wrong with this Pillow?”
Author
N. David Mermin
Published
Physics Today 42, no. 4 (1 April 1989), p. 9 — “Reference Frame” column
Misattributed to
Richard Feynman (1918–1988)

If I were forced to sum up in one sentence what the Copenhagen interpretation says to me, it would be “Shut up and calculate!” Physics Today, April 1989

Mermin’s sentence from his April 1989 column, as he re-quoted it in his May 2004 Physics Today column while investigating why everyone was crediting Feynman.

Physics Today column, full text
Read Mermin’s “Could Feynman Have Said This?”
Physics Today: “What’s Wrong with this Pillow?” (1 April 1989)

How the credit went wrong

In copyright

The sentence was first published in Physics Today in April 1989 — far later than the pre-1931 line for US public domain — so the column it comes from is in copyright, held by Mermin and his publisher; it was reprinted in his 2016 Cambridge collection Why Quark Rhymes with Pork. The four-word catchphrase circulates freely as a slogan, but the essay around it is not public domain.

Rights status is our research, not legal advice — and copyright varies by country and edition. For commercial or published use, confirm with the rightsholder. See terms.

Fact-check

Who it gets pinned on

This is one of the cleanest misattributions in physics: a living author, a dated publication, and a credited man who was already dead when the line appeared.

Richard Feynman Misattributed

Feynman is credited on countless sites, T-shirts and even in the physics literature — Mermin first noticed the problem when a preprint called the view “Feynman’s famous dictum”. When he searched in 2004, Google returned more than 130 pages mentioning both Feynman and the phrase — about a dozen of which actually credited him — and not one of those cited a source or hinted at the circumstances ↗. Feynman died on 15 February 1988; the phrase was published in April 1989.

Richard Feynman Conflated

Feynman does have a famous line about the unintelligibility of quantum mechanics, and it gets blurred into this one: “I think I can safely say that nobody understands quantum mechanics” — The Character of Physical Law (1965), ch. 6, p. 129 ↗. That is an admission of bafflement, close to the opposite of an instruction to stop asking.

Bohr and the Copenhagen school Not their words

The phrase is often quoted as if it were Copenhagen’s own motto. It is not: it is Mermin’s outsider caricature of what Copenhagen said to him ↗, written by a physicist dissatisfied with that interpretation — and who later said he had come to hold a milder view of it.

The author is N. David Mermin, in “What’s Wrong with this Pillow?”, Physics Today, 1 April 1989 ↗ — and he only discovered the line was famous when he saw the credit going to somebody else.

Context

Why it stuck to the wrong man

“Shut up and calculate!” is the four-word caricature of the Copenhagen interpretation of quantum mechanics: stop asking what the wavefunction means, run the numbers, the numbers work. It is a real attitude with a real history — historian David Kaiser traces the pragmatic turn to wartime physics ↗ — but the slogan itself has a single, datable author, and he is not the man on the T-shirts.

Mermin coined it in April 1989 as self-deprecating shorthand for the advice his Harvard professors gave him when he asked awkward conceptual questions as a graduate student: stop being distracted by frivolities and produce some results. Fifteen years later he read a preprint describing the “shut up and calculate” view as Feynman’s famous dictum, briefly panicked that he had unconsciously plagiarised Feynman, went hunting for the source — and found there wasn’t one.

Nobody ever needed to tell Feynman to calculate.

The Matthew effect, and why Feynman is the last person who would have said it

Mermin diagnosed his own case using sociologist Robert K. Merton’s Matthew effect: scientific credit drifts to the most eminent plausible candidate. Asked who among the famous could have said something that irreverent, almost everyone lands on Feynman — Einstein, Schrödinger and Bohr are all obviously wrong for it. Being the only plausible candidate is not the same as being the author.

Mermin’s substantive objection is better than the missing citation. Feynman said he had always had great difficulty understanding the world view quantum mechanics represents, and that it still made him nervous — hardly the outlook of a man who tells the perplexed to stop asking. And nobody, Mermin noted, ever had cause to tell the best human calculator in physics to get on with the arithmetic.

Mermin has since distanced himself from the sentiment as well as reclaiming the words, describing his 1989 formulation as a brusque dismissal of a subtle position and saying he had come to hold a milder, more nuanced view of the Copenhagen interpretation.

Explore

Filed under

More provenance-checked quotes on the same theme, each with its reuse status.

Work Simplicity Knowledge

Go further

Dig deeper

Trusted places to keep pulling the thread — primary archives, fact-checks, and scholarship. We show how we used each one before you leave.

Could Feynman Have Said This? (full text)physicstoday.aip.org

Mermin’s May 2004 Physics Today column — the primary investigation, in which he quotes his own 1989 sentence, documents the sourceless Feynman attributions online, and argues the phrase was his.
What’s Wrong with this Pillow? (1989 column)physicstoday.aip.org

Publisher record for the April 1989 Reference Frame column where the phrase first appeared: byline N. David Mermin, 1 April 1989 (full text in PDF, subscription).
Wikiquote: David Merminen.wikiquote.org

Sourced entry giving the full sentence and its citation — Physics Today, April 1989, page 9 — with a note that the line is frequently attributed to Feynman via the Matthew effect.
Wikipedia: N. David Merminen.wikipedia.org

Biography of the true author; states he coined “Shut up and calculate” and that it is often misattributed to Richard Feynman.
Wikiquote: Shut up and calculateen.wikiquote.org

Page for the phrase itself, collecting later commentary including David Kaiser’s Nature (2014) history and Hardy and Spekkens’ counter-slogan.
Wikiquote: Richard Feynmanen.wikiquote.org

What Feynman actually said about quantum mechanics — including the genuine, sourced line from The Character of Physical Law (1965) that is routinely confused with this one.
Why Quark Rhymes with Pork — contentsmermin.lassp.cornell.edu

Mermin’s own Cornell page listing his collected Reference Frame columns, including “What’s wrong with this pillow, April 1989” and “Could Feynman have said this?, May 2004”.

The real author

About N. David Mermin

N. David Mermin

b. 1935 · American solid-state physicist · Cornell University

N. David Mermin (born 30 March 1935 in New Haven, Connecticut) is Horace White Professor of Physics Emeritus at Cornell, where he joined the faculty in 1964. He is best known to students as half of Solid State Physics, the Ashcroft & Mermin textbook, and to physicists for the Hohenberg–Mermin–Wagner theorem and for importing the word boojum from Lewis Carroll into condensed-matter physics. He also wrote thirty “Reference Frame” columns for Physics Today between 1988 and 2009 — one of which produced the most famous sentence about quantum mechanics he never gets credit for.

For writers & researchers

Cite this

Chicago

N. David Mermin, “What’s Wrong with this Pillow?” Physics Today 42, no. 4 (April 1989): 9. Mermin set out the case that the phrase was his own, not Feynman’s, in “Could Feynman Have Said This?” Physics Today 57, no. 5 (May 2004): 10.

This verification page

Quotle.info. “Who really said ‘Shut up and calculate!’?” Last verified 10 Aug 2026. https://quotle.info/who-said/shut-up-and-calculate/

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