Jeffrey LewisThe Thing Is Superb Physics

“Laßt mich in Ruhe mit euren Gewissensbissen, das ist doch so schöne Physik!”

–Enrico Fermi, arguing with his colleagues on the Manhattan Project about the ethical implications of developing the atomic bomb.

What?  I thought Enrico Fermi was Italian!  And why were they arguing in German at Los Alamos?  Didn’t the security people freak out?

Actually, this is the original version of the famous quote attributed to Enrico Fermi — commonly rendered in English as “Don’t bother me with your conscientious scruples, the thing is superb physics!”

The quote was first attributed to Fermi by Robert Jungk, in his book Heller als tausend Sonnen (1956), which as I am sure you can guess, was originally written in German.  The book was translated into English in 1958, by James Cleugh, who gave us the wonderful version that is so often cited.  Pearl Buck helped popularize the attribution, by having Fermi also say it in her fictional account of the Manhattan Project, Command the Morning (1959).

This remark probably would be the most famous thing Enrico Fermi ever said, had he said it.  But I have my doubts.

I’ve had a vicious case of writers block for a couple of months now and this damned quote is one reason why.  It won Michael Krepon’s contest for Best Quips About the Bomb, but it just didn’t strike me as right.  I didn’t think Fermi said it.

Then, I started to obsess.  I bought lots of books.  I contacted research librarians and archivists.  And my doubts grew.

Let’s go through this in order. Here is the original passage from the 1958 English language edition of Brighter Than A Thousand Suns.

Even so cool and matter-of-fact a person as Enrico Fermi received a profound shock, in spite of the retort he had made to all the objections of his colleagues to the bomb during the discussions of the past few weeks.  He had always said: “Don’t bother me with you conscientious scruples! After all, the thing’s superb physics!”  Never before had he allowed anyone else to drive his car.  But on this occasion he confessed that he did not feel capable of sitting at the wheel and asked a friend to take it for him on the road back to Los Alamos.  He told his wife, the morning after his return, that it had seemed to him as if the car were jumping from curve to curve, skipping the straight stretches in between.

The German is a bit more dense, but the translation is pretty accurate — particularly the idea that Fermi had repeated the line several times over the weeks preceding Trinity. (I actually picked up a first edition in German, in case anyone wants to see the original text.)

Jungk doesn’t provide a citation for the quote.  Actually, he doesn’t provide any citations. More on Jungk in a moment.

This leads us to our first major observation — the English language quotation is the work of the a translator named James Cleugh.  I asked archivists at the University of Reading to look through Cleugh’s papers.  There is a small amount of correspondence related to his translation of Brighter Than a Thousand Suns, which seems to have been a rather hasty affair.  Cleugh’s method seems to have been to work very quickly preparing a draft from the German manuscript, then sending it to a physicist (selected almost at random) to check the technical information.  Significantly, in the last few weeks, Cleugh attempted to acquire origingal English-language copies of the Bohr Memorandum and the Franck Report, which had appeared as appendices to the German edition.  It is clear that Cleugh was working without access to Jungk’s source material.

That would suggest that Cleugh did not have the original wording of the quotation in English as attributed to Fermi.  Cleugh simply rendered Jungk’s German phrase in faithful English. It seems likely that whatever Fermi might have said, it was rendered in German, than back again in English.

So if Fermi didn’t say those precise words, might he have said something similar?

Here, too, I have my doubts. Fermi died in November 1954, more than a year before Jungk released Heller als tausend Sonnen. Unfortunately, Fermi never had a chance to comment on the accuracy of the attribution.

I looked through several books written by those closest to Fermi — including Atoms in the Family (1954) by his wife, Laura, and Enrico Fermi, Physicist by Emilio Segre, probably his closest collaborator and friend.  (Here is a picture of Fermi and Segre at the beach, with Enrico Persico.)

Jungk borrows the story about the car from Laura Fermi’s book, but she does not mention any comments by Fermi in advance of Trinity.  (Nor, I suppose could she have been privy to any, given wartime secrecy.)  What really caught my attention, however, was that Segre explained that he never really know how Fermi felt about about the bomb:

Fermi was not vocal, and even his close friends did not always fully know his viewpoint.  His scrupulous regard for security regulations undoubtedly contributed to his reticence. My impression is that he was much less radical than Szilard and more liberal than Compton, Oppenheimer, or Lawrence.


Fermi was as thoughtful for the future as anyone else, but he recognized the difference between technical decisions, in which he was supremely competent, and political choices, in which he was a normal man well aware of his fallibility.  His anchors were his analytical power. confidence in his brain, and his integrity, but he did not like to pass judgment on problems that could not be compassed by his habitual methods of thought. When confronted by such problems, he preferred not to express himself, especially publicly.

That would seem to cast quite a bit of doubt on Jungk’s story.  If Segre — Fermi’s lifelong friend and colleague — did not know Fermi’s opinion during their time together at Los Alamos, than I doubt Jungk’s attribution of  the quote to Fermi.  It is certainly unlikely that Fermi had made such a statement repeatedly in the weeks leading up to Trinity.  Segre would have known better than anyone.

(As a side note, there were only a few public meetings at Los Alamos on the political or ethical issues relating to the development of the atomic bomb, and I can find no evidence that Fermi attended any of them.  I identified three such meetings — the famous one at the cyclotron laboratory or Building X called “The Impact of the Gadget on Civilization” as well as one meeting in the old theater and another in a small wooden chapel.  I met Kai Bird for the first time last week and began rambling incoherently about the sourcing in his biography of Oppenheimer, American Prometheus, for the meeting in the old theater.  The look of sheer terror in Bird’s eyes convinced me it was time to move on with my life.  Just to recap, I can’t find any recollection of Fermi at any of these meetings, let alone a first person account of comments by Fermi. And neither Bird nor his co-author, Martin Sherwin, need seek a restraining order.  Really, I am moving on.)

Segre goes on to note that “I sometimes thought Fermi believed that when the noise and excitement of the hour had long been forgotten, only physics would last and assert its perennial value.”  That is consistent with the remark attributed to Fermi, but it is important to note that Segre is clear that he thinks, but does not know.

It seems more likely, then, that Jungk either mistakenly attributed a comment by someone else to Fermi or incorrectly represented what someone, perhaps Segre, merely believed to be Fermi’s opinion.

Brighter Than A Thousand Suns is rather famous for its many errors of fact in matters like this.  E.U. Condon called it “a thoroughly bad book” and claimed that “there is a serious error in nearly every one of the anecdotes about incidents of which I have personal knowledge.”  Robert Wilson — who was at Los Alamos with Fermi and organized the meeting at the cyclotron building — took a more mischievous approach in his review of Jungk’s book for Scientific American:

In view of Jungk’s profound errors of judgment, it is perhaps pedantic to add that he has mangled the names of many minor characters of his epic, and that he has a positively abandoned manner with dates.  He has not been able to copy with any degree of accuracy a simple table from Atomic Energy for Military Purposes, the classic history of the Manhattan Project.   He indicates that liquor was banned at Los Almaos, when in fact the only fluid in short supply there was water. (When Klaus Fuchs was arrested, many of us not only asked ourselves “Why did he do it?” but also, “How did he dare drink so much at Los Alamos?”) Oppenheimer was not educated at the Los Alamos Ranch School for Boys.  It is simply not true that “barely a dozen physicists on the bomb project had an over-all view.”  Robert Serber did not collect the pool money for the most accurate prediction of the energy released by the first atomic explosion, nor was he a “visitor” to Los Alamos.  I. I. Rabi won the pool, and Serber was a regular member of the Los Alamos staff.  The Wilsons lived across the hall from the Serbers, and often said: “The Serbers are our nerbers.” The Serbers now live across the hall from the Rabis in New York.  The world of nuclear physics is rather chummy, and anyone who confuses Robert Serber and I. I. Rabi has not studied that world very carefully.

All this is not, of course, particularly important.  It suggests, however, that even Jungk’s anecdotal history is weak. What is more to the point, the factual errors do indicate a lighthearted and uncritical approach toward his material which becomes serious when he attacks men and interprets events.  The book lacks the documentation one expects of a historian; one never knows whether Jungk obtained some particular fact from someone’s lips or from an unpublished paper or from his own vivid imagination.

It is tempting to imagine that Wilson is thinking, at least in part, of his meeting at Building X and the implication by Jungk that Fermi spoke there.  But if he was, Wilson did not say so.  (I asked the archivists to look through Wilson’s papers at Cornell, but he doesn’t seem to have corresponded with others in preparation for his review.)

There is one last detail.   As I mentioned at the outset, the quotation became famous not merely because of Brighter Than A Thousand Suns, but also because the author Pearl Buck used it a year later in her 1959 fictional account Command the Morning.  Buck had met the Fermis in 1938 a the Nobel Prize ceremony — Buck was awarded the prize for literature; Fermi, the prize for physics. Buck’s biographer, Nora Stirling, wrote to Laura Fermi in 1977 to ask whether Buck had been in contact with Fermi for technical advice on Command the Morning.  (I obtained copies of their correspondence from the Nora Stirling collection at Randolph College).

Mrs. Fermi responded by noting that neither she not seen Buck after the Nobel Prize ceremony nor, to the best of her knowledge, had her husband.  Then she added this tantalizing observation:

Her book came out several years after my husband’s death.  I remember reading it and thinking that although she seemed technically accurate (but I am no judge) she made scientists talk in a way that didn’t seem right to me.  I had never heard any of my friends talk that way.

Again, so close!  How can Laura Fermi not be thinking of the her husband’s remark?  Yet, if she was, she did not say so explicitly. (In a second letter, Laura Fermi mentions one of Fermi’s students, Leona Marshall, by name as someone with an inaccurate literary alter ego.)

In the end, it seems to me the balance of evidence is clearly against Fermi having, in the weeks before Trinity,  repeatedly said “Don’t bother me with your conscientious scruples, the thing is superb physics!”  Those are the words are those of a translator.  Fermi may have felt the bomb was “superb physics,” but was reticent enough that even Segre was not certain of his actual opinion.  Our only source for the attribution, Robert Jungk, is notoriously unreliable when it comes to details like this.  And then there is Mrs. Fermi’s comment about Command the Morning, which seems to suggest that the pep in Cleugh’s rendering was not very Fermi-like.

Not quite “case closed” but good enough for me.


  1. bradley laing (History)

    —Do more research into the authors german. For example, In the real world, people often say things in “double negatives,” but everyone hears the certainty in the persons voice, and everyone in the room understands what is being said.

    —Secondly, Itally in the 1920s had a lot of language variations. Find Fermi’s region, and ask how many variations on italian he learned in the course of his life.

    —I heard a Scotsmen in the 1990s say “the Cats Whiskers.” In the U.S., the best known variation would be “The Cat’s Meow,” and that was long out of style in the U.S.

  2. bradley laing (History)

    —As this article points out, there are two seperate names for the same ammunition “.32 Smith and Wesson Long,” which it’s rival marketed under the name “.32 Colt New Police.”

    —Both the German language author, and Fermi himself, might have used very different phrases for the same concept. If so much variation can be found in an english-language description of an identifical *object,* then regional variations on langauge to describe *concepts* could be even further apart.

  3. Nick Russell (History)

    You know, that quote has always bothered me as well. It doesn’t square with the general impression I get of the Los Alamos scientists’ feelings about the project – that while the bomb’s engineering was an exciting challenge, the physics, at least by 1944 or 45, was comparatively known and boring.

    It’s one thing for Oppenheimer to talk about how the bomb was scientifically inevitable, or for Feynman to describe the pleasure and excitement of hard work on the project. It’s another for Fermi, unquestionably one of the leading scientific minds of the entire era, to gush about the physics of “the thing.” Particularly as a justification for its existence, or even possibly its use. That just seems… out of character.

    Thanks for pouring so much energy into this research. You’ve convinced me not to use the quote, at least unless more evidence comes to light.

  4. Daniel N. (History)

    In case you guys want I can check translations if you provide the german originals (german mothertongue here).

  5. krepon (History)


  6. Alex W. (History)

    Very nicely done.

    One might also note that Fermi was among the most concerned with “conscientious scruples” when it came to the H-bomb debate. His minority annex (with I.I. Rabi) to the 1949 GAC Report on the Superbomb is the one which invoked “fundamental ethical principles” against the building of the H-bomb, and declared it “necessarily an evil thing considered in any light.” (This does not, of course, imply that Fermi’s opinions on these things in 1949 would have been the same as his opinions pre-Hiroshima/Nagasaki.)

    Jungk’s poor reporting of Heisenberg’s position on the atomic bomb was partially behind the later (1950s-60s) dust up between Heisenberg and Bohr, which led to the play “Copenhagen.” If you compare Heisenberg’s letters to Jungk to what Jungk reproduces in his book, one can see that Jungk’s excerpts were highly misleading. Cathryn Carson discusses this in depth in her recent book on Heisenberg.

    Aside from Jungk’s book, the other major Manhattan Project history that contains copious dubious and unsourced anecdotes (which nonetheless are repeated verbatim again and again) is Stéphane Groueff’s _ Manhattan Project: The Untold Story of the Atomic Bomb_ (1967).

    Lastly (though I think I may have posted in this in the comments once before), on the question of famous Los Alamos quotes, I tracked down Bainbridge’s famous post-Trinity, “Now we’re all sons of bitches,” remark to Lansing Lamont’s _Day of Trinity_ (1965). In the Bainbridge papers at Harvard, there is a letter from Bainbridge to Oppenheimer from 1966 about the quote: “The reasons for my statement were complex but two predominated. I was saying in effect that we had all worked hard to complete a weapon which would shorten the war but posterity would not consider that phase of it and would judge the effort as the creation of an unspeakable weapon by unfeeling people. I was also saying that the weapon was terrible and those who contributed to its development must share in any condemnation of it. Those who object to the language certainly could not have lived at Trinity for any length of time.” There is in the same folder a response from Oppenheimer to Bainbridge: “When Lamont’s book on Trinity came, I first showed it to Kitty; and a moment later I heard her in the most unseemly laughter. She had found the preposterous piece about the ‘obscure lines from a sonnet of Baudelaire.’ But despite this, and all else that was wrong with it, the book was worth something to me because it recalled your words. I had not remembered them, but I did and do recall them. We do not have to explain them to anyone.”

    • Carey Sublette (History)

      Isn’t Wyden’s “Day One” also a well known vehicle for unsourced and unverified quotations?

  7. A Complete Stranger (History)

    There is much exaggeration about what happened and what was said during the Manhattan Project. My favorite exaggeration is the story about how worried they were that the atmosphere would ignite if they set off a nuclear explosive. Many stories overstate this and say that the physicists devoted months to trying to figure out if all life would be wiped off the Earth by an out of control thermonuclear reaction. It turns out that my old Physics Professor Emil Konopinski (who is described in at least one book as “pink cheeked Konopinski”) was the one who was asked to look into this. He told me that it was the work of an afternoon to show the impossibility of such an event. Unfortunately, it is becoming impossible to go back and check any of these stories with the principals.

    • A Complete Stranger (History)

      I’m glad to be able to relate this story about Prof. Konopinski who was an excellent and devoted teacher as well as a brilliant physicist.

    • beebop (History)

      Of course this comes to mind…

    • Carey Sublette (History)

      Although what you say about Konopinski and the ease with which a case against atmosphere ignition can be made is no doubt correct, there is good evidence that there was more life to the issue than that.

      I don’t recall reading anywhere about a claim that it occupied months of time to determine the answer – but it did cause Oppenheimer to bring this to the attention of Compton, and led to Konopinski, Marvin and Teller to write a 20 page report on the issue (LA-602).

    • A Complete Stranger (History)

      The fact that LA-602 is dated 1946 should tell you its story. No one wants to let a brilliant insight disappear without writing it down. But surely the memo had no effect on the use of the bomb so I dont understand your remarks about it having “more life” other than to prove my point about how people continue to exaggerate the extend of the worries Los Alamos might (but did not) have.

    • Carey Sublette (History)

      “…so I dont understand your remarks about it having “more life” ..”

      Well, just read the report. It would seem to represent significantly more analysis of the issue than just an afternoon of work by Konopinksi.

      Consider Compton’s account in Atomic Quest (p. 127) in which he relates Oppenheimer coming out to see him specifically to discuss this issue.

      Teller recounts (p. 209-210 in his Memoirs) doing additional work on this question in 1945 (note his name on the 1946 report) ahead of the Trinity test (I think Marvin may have been part of Teller’s group).

      Certainly many accounts have overstated this (I am reminded of a preposterous article in The Bulletin back in the 1970s claiming a non-zero probability of it occurring), but nonetheless you are understating it.

  8. FSB (History)

    Many physicists (including me) find “the thing” beautiful physics, because it is. It is also an awful device when used on people.

    Dr. Strangelove was named for a reason: it is a strange love for the physics — see George Dyson’s article for the mindset that likely produced the quote:

    • FSB (History)

      I agree the first ““Don’t bother me with your conscientious scruples'” part may be in doubt, but any physicist who does not think that the physics is beautiful is a chemist, or worse.

    • Alex W. (History)

      Of course, the most famous expression of this sentiment — and more careful than the alleged Fermi quote — is from Oppenheimer, at his 1954 security hearing: “When you see something that is technically sweet, you go ahead and do it and argue about what to do about it only after you’ve had your technical success. That is the way it was with the atomic bomb.”

  9. nick black (History)

    surely among Fermi’s most famous quips must be included “then where are they?” regarding seemingly-inevitable alien civilizations.

    also, his baiting of Edward Teller with, “ahhh edward-a, ah how come-a the Hungarians have never invented anything?”

  10. Jens (History)

    There is a very small mistake in the translation of Jungk’s book. The title is “Heller als tausend Sonnen” 😀

    ps.: I LOVE this blog!