Feynman and the Trinity test

February 22, 2011

in Bombs and rockets, Books and literature, Geek stuff, Science, Writing

This post have been revamped in response to a perceptive comment. The old version is available here.

In Surely You’re Joking, Mr. Feynman, American physicist Richard Feynman speculates that he may have been the only person who watched the Trinity Test relatively directly, using a windshield to exclude ultraviolet light. Everyone else, he claims, was looking through something akin to welding goggles.

This claim is contradicted in chapter 18 of Richard Rhodes’ The Making of the Atomic Bomb, in which Rhodes claims that Ernest Lawrence considered watching the test through a windshield, but decided to step out of the car and watch it directly, and that Robert Serber also watched with unprotected eyes.

Feynman does come up a few times in Rhodes’ Pulitzer Prize-winning book. He is quoted on the limitations of human understanding (p.32-33 paperback), the boundaries of science (35), and the status of Seth Neddermeyer‘s plutonium implosion setup in 1943 (479). The book also describes Feynman coining of the term ‘tickling the dragon’s tail’ to describe Otto Robert Frisch‘s dangerous criticality experiment (611), and fixing a shortwave radio being used during the Trinity test itself (668). In one of his books, Feynman describes how he began fixing neighbourhood radios as a small boy.

Quite possibly, people other than Feynman did watch the test without welding goggles and he never found out about it, or at least learned of it after the wrote the speculative comment in his book.

Report a typo or inaccuracy

{ 23 comments… read them below or add one }

EK February 22, 2011 at 12:11 pm

This book sounds great – you keep mentioning it and each time I bump it higher on my to-read list. I will grab it ASAP, especially since I’m studying the Manhattan Project soon in my history of science core class.

R.K. February 22, 2011 at 12:33 pm

I think you mean ‘whose’ account. Also, there is faulty parallelism in the list of page references.

Matt February 22, 2011 at 2:28 pm

Also, there is faulty parallelism in the list of page references.

And I thought I could be pedantic!

Milan February 22, 2011 at 9:55 pm

Grammar corrected! I really do appreciate any and all free editing services. After all, I don’t want people scoffing at my errors when they find these posts via Google.

Michael A. Gottlieb February 23, 2011 at 8:32 am

Dear Mr. Ilnyckyj,

You write, “In several of his writings, American physicist Richard Feynman claims that he was the only person who watched the Trinity Test relatively directly, using a windshield to exclude ultraviolet light.” I do not think that is true. In “Surely You’re Joking, Mr. Feynman” (which is, surely, Mr. Feynman’s most popular work) he says, “I am about the only guy who actually looked at the damn thing–the first Trinity test. Everybody else had dark glasses, and the people at six miles couldn’t see it because they were all told to lie on the floor. I’m probably the only guy who saw it with the human eye.” (You can also find this quoted verbatim in Mehra’s biography.) Feynman does not positively state that he was the only person who saw the event with naked eyes, as you claim that he does “in several of his writings.” It seems clear that he did not know if he was the only one or not, and only supposed that he probably was. “Probably” does not mean “definitely,” particularly to a physicist, and particularly in an informal conversation (which this statement came from – Feynman never wrote it at all – he was tape recorded, telling his stories in an informal setting, and the recordings were later transcribed and edited by Ralph Leighton). In the letter that Feynman wrote to his mother the day after the A-bomb was dropped on Hiroshima, in which he describes the Trinity test (published in Michelle Feynman’s collection of her father’s correspondence), Feynman mentions the welder’s glasses and the fact that he viewed (or tried to view) the blast through a windshield instead, but he says nothing at all about what other people were doing (I suppose, at the time, he was not paying careful attention to other people, but rather, to the events of the day!). The same story is told in Gleick’s biography, without Feynman making any claims to exclusivity in viewing the Trinity test without dark glasses. In fact, I can not find nor remember anywhere that Feynman ever made such a claim (despite the fact that I have read most of the works written by or about him, and much of his unpublished writings as well). So, in my opinion, your claim about Feynman is unjustified, which, ironically, makes your conclusion about Feynman and his stories seems more applicable to you and your story about Feynman, that “there is sometimes something a bit over-polished … and the details don’t always seem to fully accord … Perhaps that can be put down to the subjectivity of memory, but it also suggests that this famous prankster may not always have been a completely reliable narrator.”

Best regards,
Mike Gottlieb
Editor, The Feynman Lectures on Physics

Milan February 23, 2011 at 8:59 am

Thank you for your detailed and informative comment.

I may well be wrong about exactly what Feynman claimed. I will check my collection of Feynman books and see if I can find a stronger claim in any of them.

Michael A. Gottlieb February 27, 2011 at 3:04 pm

Thanks for the correction, though I still do not agree with what you wrote, that “Everyone else, [Feynman] claims, was looking through something akin to welding goggles” because what Feynman says (in Surely You’re Joking, Mr. Feynman) is only that, “Everybody else had dark glasses,” (so did he), not that everybody else was wearing them when the bomb exploded. Nor do I agree with you that Feynman’s “claim is contradicted in chapter 18 of Richard Rhodes’ The Making of the Atomic Bomb,” for the same reason: he never made the claim that you claim he made.

Milan February 27, 2011 at 3:34 pm

You’re the one who quoted him saying: “I’m probably the only guy who saw it with the human eye.”

Does that not mean that – in his view – he saw the test in a less obstructed way than anybody else he knew about?

Michael A. Gottlieb February 27, 2011 at 3:41 pm

“I’m probably the only guy who saw it with the human eye,” means that in Feynman’s view, he _probably_ was the only one who saw it with the human eye, not that he definitely did.

Milan February 27, 2011 at 4:30 pm

If either Lawrence or Serber actually saw the blast without goggles, and if Feynman found out about it before writing the book, then his claim could be called misleading.

That said, it is possible that Rhodes is wrong and neither Lawrence nor Serber saw the blast with bare eyes. It is also possible that Rhodes is right, but Feynman never knew about what Lawrence or Serber saw. He could also have found out after publication.

Milan February 27, 2011 at 4:31 pm

If Feynman knew full well that someone else had seen the blast with their bare eye, to say that he was ‘probably’ the only person who saw it that way would be as misleading as to say he was definitely the only one.

Michael A. Gottlieb February 27, 2011 at 4:42 pm

I am not aware of any evidence that ” Feynman found out about … before writing [Surely You're Joking, Mr. Feynman]” that ” Lawrence or Serber actually saw the blast without goggles”, nor am I aware of any evidence that “Feynman knew full well that someone else had seen the blast with their bare eye.” Are you aware of any such evidence? If not, why would you suppose it is true (which you imply with your statement that Feynman’s “claim” was contradicted). Why would you even _suppose_ it might be true? Knowing what I do of Richard Feynman, it is my opinion that he would not say “I’m probably the only guy who saw it with the human eye” if he knew for a fact otherwise.

Milan February 27, 2011 at 4:47 pm

Don’t get me wrong. I think Feynman is great. I have written positive reviews of four of his books and mentioned him frequently, almost always in a positive light.

I just find it hard to believe that he wouldn’t learn who else watched the bomb with bare eyes. The reason the story is so good is that it is an act of bravado. He was so confident in his own guess of how bright the bomb would be that he was willing to bet his vision on it.

There probably weren’t many scientists who chose to make that bet. If there were others aside from Feynman, telling the same story (which is an excellent one), it seems he would have heard of it.

I admit, that is all speculation on my part.

Milan February 27, 2011 at 4:53 pm

Rhodes’ book also won the Pulitzer Prize, so it seems safe to consider it a fairly reputable source of information.

. February 27, 2011 at 4:55 pm

Praised by both historians and former Los Alamos weapon scientists alike, the book is considered a general authority on early nuclear weapons history, as well as the development of modern physics in general, during the first half of the twentieth century. Nobel Laureate I. I. Rabi, one of the prime participants in the dawn of the atomic age, called the book “an epic worthy of Milton. Nowhere else have I seen the whole story put down with such elegance and gusto and in such revealing detail and simple language which carries the reader through wonderful and profound scientific discoveries and their application.”

Milan February 27, 2011 at 5:06 pm

There are a number of factual possibilities here.

Either Lawrence and Serber did not watch the blast with bare eyes or they did watch it with bare eyes

Call those possibilities ‘WATCHED’ and ‘DIDN’T WATCH’.

Then there is whether Feynman knew about it or not.

Call those ‘KNEW’ and ‘DIDN’T KNOW’.

In a world where ‘DIDN’T WATCH’ is true, and ‘DIDN’T KNOW’ is the claim, it is possible that Feynman spoke accurately and that Richard Rhodes is wrong. He may not have spoken with full confidence, though, because he may not have observed what Lawrence and Serber did for certain.

A world where ‘DIDN’T WATCH’ is true and ‘KNEW’ is true, then Feynman would also be being honest and Rhodes inaccurate. This would be a world where Feynman positively saw for himself that Lawrence and Serber either didn’t watch the blast or watched it with goggles, or at the very least that he heard them claim otherwise to him.

In a world where ‘WATCHED’ is true, it is still possible that ‘DIDN’T KNOW’ is true. In that world, Feynman would be speaking honestly but incorrectly.

In a world where ‘WATCHED’ is true and ‘KNEW’ is true, Feynman knowingly spoke untruthfully.

. February 27, 2011 at 5:16 pm

At 4:45 am, a crucial weather report came in favorably, and, at 5:10 am, the twenty-minute countdown began. Most top-level scientists and military officers were observing from a base camp ten miles (16 km) southwest of the test tower. Many other observers were around twenty miles (32 km) away, and some others were scattered at different distances, some in more informal situations (physicist Richard Feynman claimed to be the only person to see the explosion without the dark glasses provided, relying on a truck windshield to screen out harmful ultraviolet wavelengths). The final countdown was read by physicist Samuel K. Allison.

Milan February 27, 2011 at 5:24 pm

Oh, and Surely You’re Joking, Mr. Feynman isn’t the only source of the claim:

“For people who were far away like we were – others were closer, six miles away – they gave out dark glasses that you could watch it with. Dark glasses!! Twenty miles away from the damn thing, you get dark glasses – you couldn’t see a damn thing through dark glasses. So then I figures the only thing that could really hurt your eyes – bright light can never hurt your eyes – it’s ultaviolet light that does. So I got behind a truck windshield, so the ultraviolet can’t go through glass, so that would be safe, and so I could see the damn thing.

It was a series from bright to dark and I had seen it. I am about the only guy that actually looked at the damn thing, the first Trinity Test. Everybody else had dark glasses… The guys up where I was all had dark glasses. I’m the only guy who saw it with the human eye.”

Feynman, Richard. The Pleasure of Finding Things Out. 1999.

That “bright light can never hurt your eyes” claim also seems a bit dubious. A laser the emitted visible light and which was sufficiently powerful could hurt your eyes.

Milan February 27, 2011 at 5:27 pm

Of course, the essay in the 1999 anthology – entitled “Los Alamos from Below” – was written well before 1999. I am making an effort to find out when Feynman originally wrote it.

. February 27, 2011 at 6:33 pm
Michael A. Gottlieb February 28, 2011 at 9:01 am

Feynman did not write “Los Alamos From Below,” (just like he did not write “Surely You’re Joking Mr. Feynman,” nor any of his other books) – it was recorded, transcribed and edited from a talk he gave at UCSB in 1976, and in it (according to the Caltech transcript you point to, above) he said “I’m probably the only guy who saw it with the human eye. ” Again, “probably,” not definitely. The chapter “Los Alamos from Below” in the book “The Pleasure of Finding Things Out” is supposed to be an edited transcript of the same speech (if you compare the Caltech transcript with the book, you will see they are almost identical) but in it we find Feynman saying, “I’m the only guy who saw it with the human eye.” (No “probably” this time.) Which is right? Here is a snippet of (I believe) the original speech: http://www.feynmanlectures.info/cds/LosAlamosFromBelowPreview.mp3 . In it Feynman does NOT say “probably.” But you know how it is when you are giving a talk – it’s not like writing – it’s less precise. Is it surprising that Feynman might make a mistake sometimes? (He’s human.) In any case, in _most_ of the places you see this story reproduced Feynman says “probably” and if he failed to say “probably” once, I would not read anything into it, beyond a slip of the tongue. Feynman was not the kind of man to take credit for something that was not his due – not even something small, like this. He had incredible integrity, which is one of the reasons he is so admired. It’s only a shame that some people seem to feel compelled to hold Feynman to some kind of superhuman standard, and belittle him at the least opportunity. That’s all I have to say on this subject.

Milan February 28, 2011 at 9:48 am

Do you think Rhodes’ account is wrong? I am curious about exactly what happened, as well as why both Rhodes and Feynman ended up with the perspective they did.

Michael A. Gottlieb February 28, 2011 at 10:24 am

I don’t have any reason, offhand, to suspect Rhodes’ account is wrong… though I have not tried to verify it (and don’t plan to, for lack of time).

Regarding Feynman’s perspective – I’m not sure what you mean, exactly.

In closing, I might add that in 1991, 2 years after Feynman died, his secretary Helen Tuck received a concerned letter, to Feynman, from an ophthalmologist, regarding Feynman’s statement (in SYJ), “So I figured the only thing that could hurt your eyes (bright light can never hurt your eyes) is ultraviolet light.” To this the doctor responded: “WRONG! From even the low level of science available to an average ophthalmologist, and more specifically from personal experience in military research projects dealing specifically with the effects of nuclear explosions on the eye, this statement is false. There is a perfectly good reason, in addition to a measure of good fortune, that you didn’t suffer serious damage in the situation you describe, but your analysis is flawed, seriously. My Q clearance has long since lapsed and I am not comfortable dealing with what might still be “classified material,” but please be assured that your statement is wrong and probably potentially dangerous to promulgate in a lay book.”

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