Interesting anecdotes in the history of physics?

In summary, the history of physics is filled with intriguing anecdotes, such as Galileo’s use of a pendulum to time events, which led to advancements in mechanics; Isaac Newton's unexpected discovery of gravity when an apple fell; and Albert Einstein's thought experiments that challenged conventional understanding of space and time. These stories not only highlight the creativity and curiosity of physicists but also illustrate how seemingly simple observations can lead to groundbreaking theories.
  • #176
Hornbein said:
They say Lev Landau and Richard Feynman looked quite alike.

Neils Bohr had a horseshoe over his door. When asked whether he believed it brought good luck he said no. "But they say," he continued, "that it works whether or not you believe in it."
I think this is inaccurate. The story is that Bohr said that people that criticise QM are like the person who puts a horse shoe over his door and doesn't believe it brings good luck, but puts it there anyway because it works even if you don't believe in it.
 
Science news on Phys.org
  • #177
Gunslinger effect
Following up on Bohr stories, here is an anecdote about his psychological hypothesis.
In the evening, when a handful of Bohr's students were "working" in the Paa Blegdamsvejen Institute, discussing the latest problems of the quantum theory, or playing ping-pong on the library table with coffee cups placed on it to make the game more difficult, Bohr would appear, complaining that he was very tired, and would like to "do something." To "do something" inevitably meant to go to the movies, and the only movies Bohr liked were those called The Gun Fight at the Lazy Gee Ranch or The Lone Ranger and a Sioux Girl. But it was hard to go with Bohr to the movies. He could not follow the plot, and was constantly asking us, to the great annoyance of the rest of the audience, questions like this:
Is that the sister of that cowboy who shot the Indian who tried to steal a herd of cattle belonging to her brother-in-law?

The same slowness of reaction was apparent at scientific meetings. Many a time, a visiting young physicist (most physicists visiting Copenhagen were young) would deliver a brilliant talk about his recent calculations on some intricate problem of the quantum theory. Everybody in the audience would understand the argument quite clearly, but Bohr wouldn't. So everybody would start to explain to Bohr the simple point he had missed, and in the resulting turmoil everybody would stop understanding anything. Finally, after a considerable period of time, Bohr would begin to understand, and it would turn out that what he understood about the problem presented by the visitor was quite different from what the visitor meant, and was correct, while the visitor's interpretation was wrong.

Bohr's addiction to Western movies resulted in a theory which is unknown to all but his movie companions of the period. Everybody knows that in all Western movies (Hollywood style at least) the scoundrel always draws first, but the hero is faster and always shoots down the scoundrel. Niels Bohr ascribed that phenomenon to the difference between willful and conditioned actions. The scoundrel has to decide when to grab for the gun, which slows his actions, while the hero acts faster because he acts without thinking when he sees the scoundrel reach for the gun. We all disagreed with that theory, and the next morning the author went to a toy shop to buy a pair of cowboy guns. We shot it out with Bohr, he playing the hero, and he killed us all.
From: G. Gamow, Biography of Physics

The effect has even a Wiki entry with experimental evidence: Gunslinger effect
 
Last edited:
  • #178
Hilbert also tended to be the only one who didn't understand a lecture.
 
  • #179

An interview with Dirac​

Professor Michael Keissling, a faculty member in the Rutgers Department of Mathematics whose field of study is mathematical physics, kindly sent me a transcript of an actual interview with Dirac which appeared in the Wisconsin State Journal of April, 1929.


ROUNDY INTERVIEWS PROFESSOR DIRAC​

An Enjoyable Time Is Had By All​

By Roundy
I been hearing about a fellow they have up at the U. this spring --- a mathematical physicist, or something, they call him --- who is pushing Sir Isaac Newton, Einstein and all the others off the front page. So I thought I better go up and interview him for the benefit of State Journal readers, same as I do all other top notchers. His name is Dirac and he is an Englishman. He has been giving lectures for the intelligentsia of math and physics departments --- and a few other guys who got in by mistake.

So the other afternoon I knocks at the door of Dr. Dirac's office in Sterling Hall and a pleasant voice says "Come in." And I want to say here and now that this sentence "come in" was about the longest one emitted by the doctor during our interview. He sure is all for efficiency in conversation. It suits me. I hate a talkative guy. I found the doctor a tall youngish-looking man, and the minute I seen the twinkle in his eye I knew I was going to like him. His friends at the U. say he is a real fellow too and a good company on a hike --- if you can keep him in sight, that is.

The thing that hit me in the eye about him was that he did not seem to be at all busy. Why if I went to interview an American scientist of his class --- supposing I could find one --- I would have to stick around an hour first. Then he would blow in carrying a big briefcase, and while he talked he would be pulling lecture notes, proof, reprints, books, manuscript, or what have you out of his bag. But Dirac is different. He seems to have all the time there is in the world and his heaviest work is looking out the window. If he is a typical Englishman it's me for England on my next vacation!

Then we sat down and the interview began.

"Professor," says I, "I notice you have quite a few letters in front of your last name. Do they stand for anything in particular?"

"No," says he.

"You mean I can write my own ticket?"

"Yes," says he.

"Will it be all right if I say that P.A.M. stands for Poincare' Aloysius Mussolini?"

"Yes," says he.

"Fine," says I, "We are getting along great! Now doctor will you give me in a few words the low-down on all your investigations?"

"No," says he.

"Good," says I. "Will it be all right if I put it this way --- `Professor Dirac solves all the problems of mathematical physics, but is unable to find a better way of figuring out Babe Ruth's batting average'?"

"Yes," says he.

"What do you like best in America?", says I.

"Potatoes," says he.

"Same here," says I. "What is your favorite sport?"

"Chinese chess," says he.

That knocked me cold! It was sure a new one on me! Then I went on: "Do you go to the movies?"

"Yes," says he.

"When?", says I.

"In 1920 --- perhaps also in 1930," says he.

"Do you like to read the Sunday comics?"

"Yes," says he, warming up a bit more than usual.

"This is the most important thing yet, doctor," says I. "It shows that me and you are more alike than I thought. And now I want to ask you something more: They tell me that you and Einstein are the only two real sure-enough high-brows and the only ones who can really understand each other. I wont ask you if this is straight stuff for I know you are too modest to admit it. But I want to know this --- Do you ever run across a fellow that even you can't understand?"

"Yes," says he.

"This well make a great reading for the boys down at the office," says I. "Do you mind releasing to me who he is?"

"Weyl," says he.

The interview came to a sudden end just then, for the doctor pulled out his watch and I dodged and jumped for the door. But he let loose a smile as we parted and I knew that all the time he had been talking to me he was solving some problem that no one else could touch.

But if that fellow Professor Weyl ever lectures in this town again I sure am going to take a try at understanding him! A fellow ought to test his intelligence once in a while.
 
  • Like
  • Haha
  • Love
Likes sbrothy, dextercioby, Astranut and 3 others
  • #180
Great find!
pinball1970 said:
"Will it be all right if I say that P.A.M. stands for Poincare' Aloysius Mussolini?"
This is how I will call him from now on.
pinball1970 said:
"Same here," says I. "What is your favorite sport?"

"Chinese chess," says he.
That's not something you hear often...
pinball1970 said:
"This is the most important thing yet, doctor," says I. "It shows that me and you are more alike than I thought. And now I want to ask you something more: They tell me that you and Einstein are the only two real sure-enough high-brows and the only ones who can really understand each other. I wont ask you if this is straight stuff for I know you are too modest to admit it. But I want to know this --- Do you ever run across a fellow that even you can't understand?"

"Yes," says he.

"This well make a great reading for the boys down at the office," says I. "Do you mind releasing to me who he is?"

"Weyl," says he.
We need more Weyl anecdotes.
 
  • Like
Likes pinball1970
  • #181
pines-demon said:
We need more Weyl anecdotes.

I’ll look around. But…
It may take a while.
 
  • Haha
Likes pines-demon and BillTre
  • #182
Weinberg: distraction is human
I found this article about Steven Weinberg that describes how he used to work. It is an interesting case:
Yet Weinberg is not your stereotypical lost-in-his-work genius who locks himself away for long periods to work on a problem. His best ideas don’t come to him while he’s working at all. He recalls one day he came out of the shower and exclaimed to his wife that he had figured out why the cosmological constant is so small (at a time before he had started thinking about anthropic explanations).
Then the next day I came out and I said [deep voice] ‘no’! So ideas come to you all the time and most of them are no good, and every once in a while you find one that is good and you have fun working at your desk. Getting good ideas isn’t something you get by trying hard, but by thinking a lot about what problems bother you. But that doesn’t always work either – just think of my ruined summer in 1972!
He never works in his office. His research work has always been done at home, where he and his wife [Louise Weinberg] have separate offices down the hall from one another and interrupt one another frequently.
I’m not hard to interrupt. I have a television set on my desk which I keep on while I work, typically watching an old movie, because I find work in theoretical physics so far removed from normal affairs.
Doesn’t it distract him?
But I need the distraction to keep at my desk because the actual work is so, well…it’s so chillingly non-human. I need to feel that I am still part of the human race while I’m doing it.
From M. Chalmers, Model Physicist, CERN Courier (October 2017)
 
  • Informative
Likes pinball1970
  • #183
pinball1970 said:

An interview with Dirac​

Professor Michael Keissling, a faculty member in the Rutgers Department of Mathematics whose field of study is mathematical physics, kindly sent me a transcript of an actual interview with Dirac which appeared in the Wisconsin State Journal of April, 1929.


ROUNDY INTERVIEWS PROFESSOR DIRAC​

An Enjoyable Time Is Had By All​

By Roundy
I been hearing about a fellow they have up at the U. this spring --- a mathematical physicist, or something, they call him --- who is pushing Sir Isaac Newton, Einstein and all the others off the front page. So I thought I better go up and interview him for the benefit of State Journal readers, same as I do all other top notchers. His name is Dirac and he is an Englishman. He has been giving lectures for the intelligentsia of math and physics departments --- and a few other guys who got in by mistake.

So the other afternoon I knocks at the door of Dr. Dirac's office in Sterling Hall and a pleasant voice says "Come in." And I want to say here and now that this sentence "come in" was about the longest one emitted by the doctor during our interview. He sure is all for efficiency in conversation. It suits me. I hate a talkative guy. I found the doctor a tall youngish-looking man, and the minute I seen the twinkle in his eye I knew I was going to like him. His friends at the U. say he is a real fellow too and a good company on a hike --- if you can keep him in sight, that is.

The thing that hit me in the eye about him was that he did not seem to be at all busy. Why if I went to interview an American scientist of his class --- supposing I could find one --- I would have to stick around an hour first. Then he would blow in carrying a big briefcase, and while he talked he would be pulling lecture notes, proof, reprints, books, manuscript, or what have you out of his bag. But Dirac is different. He seems to have all the time there is in the world and his heaviest work is looking out the window. If he is a typical Englishman it's me for England on my next vacation!

Then we sat down and the interview began.

"Professor," says I, "I notice you have quite a few letters in front of your last name. Do they stand for anything in particular?"

"No," says he.

"You mean I can write my own ticket?"

"Yes," says he.

"Will it be all right if I say that P.A.M. stands for Poincare' Aloysius Mussolini?"

"Yes," says he.

"Fine," says I, "We are getting along great! Now doctor will you give me in a few words the low-down on all your investigations?"

"No," says he.

"Good," says I. "Will it be all right if I put it this way --- `Professor Dirac solves all the problems of mathematical physics, but is unable to find a better way of figuring out Babe Ruth's batting average'?"

"Yes," says he.

"What do you like best in America?", says I.

"Potatoes," says he.

"Same here," says I. "What is your favorite sport?"

"Chinese chess," says he.

That knocked me cold! It was sure a new one on me! Then I went on: "Do you go to the movies?"

"Yes," says he.

"When?", says I.

"In 1920 --- perhaps also in 1930," says he.

"Do you like to read the Sunday comics?"

"Yes," says he, warming up a bit more than usual.

"This is the most important thing yet, doctor," says I. "It shows that me and you are more alike than I thought. And now I want to ask you something more: They tell me that you and Einstein are the only two real sure-enough high-brows and the only ones who can really understand each other. I wont ask you if this is straight stuff for I know you are too modest to admit it. But I want to know this --- Do you ever run across a fellow that even you can't understand?"

"Yes," says he.

"This well make a great reading for the boys down at the office," says I. "Do you mind releasing to me who he is?"

"Weyl," says he.

The interview came to a sudden end just then, for the doctor pulled out his watch and I dodged and jumped for the door. But he let loose a smile as we parted and I knew that all the time he had been talking to me he was solving some problem that no one else could touch.

But if that fellow Professor Weyl ever lectures in this town again I sure am going to take a try at understanding him! A fellow ought to test his intelligence once in a while.
It appeared on April 31st in the paper.
 
  • Haha
Likes phinds and sbrothy
  • #184
haushofer said:
It appeared on April 31st in the paper.
It's fake? All of it or Newspaper embellishments?
 
  • #185
pinball1970 said:
It's fake? All of it or Newspaper embellishments?
It's not entirely certain, but I'd say it's a complete fake, yes. I recently translated this interview for an upcoming popular science book, and consulted Graham Farmelo's "The Strangest Man" for it. The interview never appeared in any newspaper, is not to be found in any archive, and Farmelo hypothesizes that the interview was a prank, maybe used for his leave at the university of Wisconsin-Madison. This "Roundy" was also well-known for his "quirky humor".

But who knows; maybe it has a grain of truth in it ;)
 
  • Informative
Likes pines-demon and pinball1970
  • #186
haushofer said:
It's not entirely certain, but I'd say it's a complete fake, yes. I recently translated this interview for an upcoming popular science book, and consulted Graham Farmelo's "The Strangest Man" for it. The interview never appeared in any newspaper, is not to be found in any archive, and Farmelo hypothesizes that the interview was a prank, maybe used for his leave at the university of Wisconsin-Madison. This "Roundy" was also well-known for his "quirky humor".

But who knows; maybe it has a grain of truth in it ;)
What a shame. I got the story from the strangest man originally then found that transcript.
 
  • #187
THE Oppenheimer
After having directed the famous post-war Shelter Island Conference (1947), Oppenheimer rented a plane to go back Harvard to hear a conference of George C. Marshall on the plans of economic revitalization of post-war Europe. Oppenheimer invited some of the people of the conference with him, Victor Weisskopf remembers this:
We took off over the ocean on a beautiful, clear day, but as we approached Boston, the weather grew threatening. The pilot, worried about flying into the storm, decided to land at the seaplane airport in New London, Connecticut. Unfortunately, this was a navy airport. The tower at New London informed our pilot in the strongest terms that civilian planes were forbidden to land there, but the pilot felt he had no other choice. As he came closer and closer to the landing site, we could see a fat, red-faced man waving and shouting at us, obviously signaling that we were not allowed to land. The pilot expressed his anxiety to us about the whole affair.

Oppenheimer patted him on the shoulder and said,
You just land the plane and let me handle this.
When we touched down, the fat man, who turned out to be a captain, was furious with us. Sputtering and shouting, he told us we were breaking the law and described the penalties for what we had done. Oppenheimer came out of the plane first.
My name is Oppenheimer
he announced, and then he explained our reasons for trying to land. The captain gasped and asked,
Are you the Oppenheimer?
Oppie replied,
I am an Oppenheimer.
Then the captain realized with whom he was dealing. Instantly the mood changed from rage to veneration, and suddenly the captain couldn't have been more polite and cordial. He was terribly impressed that Oppenheimer, the great hero, had honored him by dropping in on his little field. Ceremoniously he led us to the command office, where we were given tea and cookies and put on a navy bus that took us to Boston. None of us was ever quite that famous again.
Source: Weisskopf, The Joy of Insight: Passions of a Physicist.
 
  • Like
Likes phinds
  • #188
I'm not sure if the story is apocryphal or not but there seems to be a lot of references saying that Oppenheimer (I think after Operation Paperclip) had difficulties shaking hands with Fritz Haber the inventor of the WW1 battlefield poison gas.

OK, yes, an atomic bomb might be used for something constructive, but in reality that's not what we've been seeing (personally I was a teenager in the 80s so when todays youth complain about PTSD in relation to climate-anxiety I am just a little sceptic.). If the stories about Oppenheimer's behaviour is true is strikes me as just a wee bit hypocritical.
 
Last edited:
  • #189
sbrothy said:
I'm not sure if the story is apocryphal or not but there seems to be a lot of references saying that Oppenheimer (I think after Operation Paperclip) had difficulties shaking hands with Fritz Haber the inventor of the WW1 battlefield poison gas.
I could not find anything about it on the web...
 
  • #190
pines-demon said:
I could not find anything about it on the web...
It was Ernest Rutherford, not Oppenheimer.
Max Born, like Haber a Nobel Prize winner, but at the end of his life very thoughtful and almost hopeless, mentioned that Rutherford, one of the first and greatest nuclear physicists, refused “to accept an invitation to my house together with Haber because he did not want to shake hands with the inventor of gas warfare”.
Hans Lenk, Zur Verantwortungsfrage in den Naturwissenschaften
https://publikationen.bibliothek.kit.edu/1000024963/24288706
 
  • Like
  • Informative
Likes pinball1970, sbrothy and pines-demon
  • #191
Freeman Dyson on Wittgenstein

This is more a story about the philosopher Ludwig Wittgenstein than about Dyson but it is an interesting encounter, here it goes.
Dyson had recently entered at University of Cambridge as a fellow. He had read Wittgenstein and had incredible respect for him. However the encounter was not as expected. From a 1998 interview with Sam Schweber [SS] taken from Web of Stories:
[SS] And eat at High Table?

Even if I wanted to, I didn't eat much at High Table because it wasn't my kind of food. It was too elegant for me. I needed calories and at that time food was pretty scarce in England, it was still rationed, and I found I could do better with the food ration, cooking it myself, than they did at the High Table. So that's what I did, and next door to me there was Wittgenstein, who lived on the same staircase, and he always cooked for himself too, and so I used to cook my supper with the smell of fish from Wittgenstein's room next door.

[SS] And you got to get to know him?

A little bit. Of course, Wittgenstein was a man who loved to torture people and so he invited me into his rooms one day - this was the closest contact I ever had with him, in fact. I mean, we passed each other very often on the stairs without speaking, but once he suddenly invited me into his rooms and said,
Would you like to come and have a cup of coffee?
So I was thrilled, I said,
Yes, I'll certainly come.
So I came in there and there was one chair, and he invited me to sit down in it, and it was a canvas deck chair which meant I was practically lying horizontally on this canvas chair, and he was standing uncomfortably waiting for me to say something, and so I found it acutely embarrassing, but in any case, I'd come in and so I thought I might as well try, and so eventually I decided I would start a conversation. So I said to him,
Well, you know, I read the Tractatus and I'd be interested to know whether you still believe the things you said in the Tractatus or have you changed you mind?
And so Wittgenstein looked at me in a very, very hostile fashion and he said,
Tell me please, which newspaper do you represent?
That was the end of the conversation. So there was another long silence, and then I drank the coffee and left.

So I didn't get much out of Wittgenstein. I had the impression he was simply a charlatan. He loved to torture people and he was of course always extremely insulting to women. He couldn't tolerate women coming to his lectures, and he would just simply be so rude that they had to leave. So a thoroughly disagreeable character, and apart from the Tractatus I never read any of his stuff, so I shouldn't judge him but - I think I consider him anyway overrated as a philosopher.
In "What can you really know?" The New York Review of Books (2012), Dyson adds
Fifty years later, walking through a churchyard on the outskirts of Cambridge on a sunny morning in winter, I came by chance upon his tombstone, a massive block of stone lightly covered with fresh snow. On the stone was written the single word, "WITTGENSTEIN." To my surprise, I found that the old hatred was gone, replaced by a deeper understanding. He was at peace, and I was at peace too, in the white silence. He was no longer an ill-tempered charlatan. He was a tortured soul, the last survivor of a family with a tragic history, living a lonely life among strangers, trying until the end to express the inexpressible.
 
  • #192
pines-demon said:
This is more a story about the philosopher Ludwig Wittgenstein than about Dyson but it is an interesting encounter, here it goes.
That seems to be a notorious encounter: physicist versus philosopher. I have a translation of Popper's book "The Logic of Scientific Discovery" that contains facsimiles of his exchange (through letters) with Einstein who criticized Popper's book.
 
  • Like
  • Informative
Likes pinball1970 and pines-demon
  • #193
The sad history of N-Rays was told to us at Uni as an object lesson...

Just after the the discovery of X-Rays, a French scientist thought he'd found an analogous phenomenon, which he named as 'N-Rays. They could be refracted, diffracted etc. Truly, fun stuff !!
However, Reproducibility proved as hard as eg our recent 'near-ambient superconductors'' claims...

Finally, a group of scientists was sent to the central lab to figure what was going on. An investigator covertly displaced the essential aluminium 'prism' at the core of one apparatus, but the demonstration still worked...
Game Over.

Seems, like many seeing 'Martian Canals' and, later, hapless Prof Laithwaite enthralled by gyroscopes' math, the French scientist' had simply lost the plot'...

https://en.wikipedia.org/wiki/N-ray

Due Care, Please ??
 
  • #194
fresh_42 said:
It was Ernest Rutherford, not Oppenheimer.

Hans Lenk, Zur Verantwortungsfrage in den Naturwissenschaften
https://publikationen.bibliothek.kit.edu/1000024963/24288706
That explains why I couldn't find anything to back up my claim. I was barking up the wrong tree. Thanks for setting that straight.
 
  • Like
Likes fresh_42
  • #195
sbrothy said:
That explains why I couldn't find anything to back up my claim. I was barking up the wrong tree. Thanks for setting that straight.
It is an interesting article "On the question of responsibility in the natural sciences" with a list of references that isn't less interesting, e.g. Born's article "The destruction of ethics by the natural sciences. Reflections of a physicist." Harsh words! It's too bad my Google Translate trick with Chrome does not work with pdf.
 
  • #196
pines-demon said:
Gunslinger effect
Following up on Bohr stories, here is an anecdote about his psychological hypothesis.

From: G. Gamow, Biography of Physics

The effect has even a Wiki entry with experimental evidence: Gunslinger effect
Fast draw is one of the fastest sports in the world. Every time is measured under one second, from the signal to draw to when the timer is stopped. The current World Fast Draw Association (WFDA) record for Open Class Fast Draw in an event called Standing Balloons is .208 seconds - and that includes the time it takes to react, draw, fire and pop a balloon target at eight feet away. A world class competitor can draw and fire a shot in under half a second. Given that the average human reaction time is around 0.2 to 0.25 seconds, the round is over before most people can react. The reaction times of the best fast draw shooters is 0.145 seconds, which means that the gun is cocked, drawn, aimed (from the hip), and fired in just over 0.06 seconds. To establish a World Fast Draw Association record, a second shot must be fired in the same competition that is no more than 0.30 seconds slower than the first; this is intended to prevent a shot that anticipates the start signal from setting a record. In competitions where two rounds must be fired, at separate targets, less than 0.10 seconds separate the shots.

----https://en.wikipedia.org/wiki/Fast_draw

(Bold added)

EDIT: Quite a difference really. Had a discussion on this very topic today.

EDIT2: Not gonna add more noise. Just wanted to share this particular clip: Fast Draw from Concealment.
 
Last edited:
  • Like
Likes phinds and BillTre
  • #197
Cabrera's romantic monopole

On the night of St. Valentine (14th February) of 1984, Blas Cabrera Navarro (grandson of Spanish experimental physicist Blas Cabrera) from Stanford, recorded an event which had the signature of a magnetic monopole with a single Dirac magnetic charge. A year later, Cabrera received a Valentine's card from Sheldon Glashow, which read:
Roses are red,
violets are blue.
The time has come for monopole two!
We are still waiting.

Source: AIP Oral History with Blas Cabrera Navarro, 2021
 
Last edited:
  • #198
pines-demon said:
Cabrera's romantic monopole

On the night of St. Valentine (14th February) of 1984, Blas Cabrera Navarro (grandson of Spanish experimental physicist Blas Cabrera) from Stanford, recorded an event which had the signature of a magnetic monopole with a single Dirac magnetic charge. A year later, Cabrera received a Valentine's card from Sheldon Glashow, which read:

We are still waiting.

Source: AIP Oral History with Blas Cabrera Navarro, 2021
Actually this interview is interesting, various important physicists are named.

Blas Cabrera, grandfather of Cabrera Navarro was a famous physicist in the realm of magnetism. He appears in one of the pictures from the 1930 Solvay Conference. In one instance during a conference, Cabrera Navarro (who never met his grandfather), asked Paul Dirac if he remembered him. Dirac just said:
Yes, there was a Spaniard there [in Solvay]
 
  • #199
The Experiment that Confirmed Quantum Mechanics:
Some good insights into how the Stern-Gerlach story came to pass.


 
Last edited:
  • #200
Swamp Thing said:
The Experiment that Confirmed Quantum Mechanics:
Fascinating insights into how the Stern-Gerlach story came to pass.
If you are interested in the Stern–Gerlach experiment, see also comment #86
 
Last edited:
  • #201
Swamp Thing said:
The Experiment that Confirmed Quantum Mechanics:
Fascinating insights into how the Stern-Gerlach story came to pass.



Interesting. Although it belongs more in "my" thread than in "yours" :-p

But heavens I've seldom seen so horrific subtitles! I'm a very visual person so I can't help but read them, even though they are in some obscure language I don't even remotely understand (I even read Russian subtitles because I had that language in what I guess you would call high school, although I pretty much only learned the Cyrillic alphabet itself!). I once resorted to putting tape on the bottom of my TV because I was binging English westerns on a Polish channel and it annoyed me to no end!
 
  • #202

Gödel's constitutional loophole​

In 1947, Kurt Gödel, Albert Einstein, and Oskar Morgenstern drove from Princeton to Trenton in Morgenstern’s car. The three men, who’d fled Nazi Europe and become close friends at the Institute for Advanced Study, were on their way to a courthouse where Gödel, an Austrian exile, was scheduled to take the U.S.-citizenship exam, something his two friends had done already. Morgenstern had founded game theory, Einstein had founded the theory of relativity, and Gödel, the greatest logician since Aristotle, had revolutionized mathematics and philosophy with his incompleteness theorems. Morgenstern drove. Gödel sat in the back. Einstein, up front with Morgenstern, turned around and said, teasing,
Now, Gödel, are you really well prepared for this examination?
Gödel looked stricken.

To prepare for his citizenship test, knowing that he’d be asked questions about the U.S. Constitution, Gödel had dedicated himself to the study of American history and constitutional law. Time and again, he’d phoned Morgenstern with rising panic about the exam. (Gödel, a paranoid recluse who later died of starvation, used the telephone to speak with people even when they were in the same room.) Morgenstern reassured him that
at most they might ask what sort of government we have.
But Gödel only grew more upset. Eventually, as Morgenstern later recalled,
he rather excitedly told me that in looking at the Constitution, to his distress, he had found some inner contradictions and that he could show how in a perfectly legal manner it would be possible for somebody to become a dictator and set up a Fascist regime, never intended by those who drew up the Constitution.
He’d found a logical flaw.

Morgenstern told Einstein about Gödel’s theory; both of them told Gödel not to bring it up during the exam. When they got to the courtroom, the three men sat before a judge, who asked Gödel about the Austrian government.
It was a republic, but the constitution was such that it finally was changed into a dictatorship,
Gödel said.
That is very bad,
the judge replied
this could not happen in this country.
Morgenstern and Einstein must have exchanged anxious glances. Gödel could not be stopped.
Oh, yes, I can prove it.
the judge said,
Oh, God, let’s not go into this,
and ended the examination.
Neither Gödel nor his friends ever explained what the theory, which has since come to be called Gödel’s Loophole, was. For some people, conjecturing about Gödel’s Loophole is as alluring as conjecturing about Fermat’s Last Theorem.
Despite all of that Gödel did get the US nationality.

From: J. Lepore, "When Constitutions Took Over the World", The New Yorker (2021)
 
  • Like
Likes dextercioby and sbrothy
  • #203
There are quite a few anecdotes in this new paper:

Cross-post
 
  • #204
Mattress.jpg
Brian Josephson the physicist who predicted the Josephson effect in superconductors, left physics to work on consciousness. In 2014 he apparently sent a draft for a paper titled "Group Theory and the Art of Mattress Turning" describing
the order-4 symmetry group of a mattress, and how an alternating sequence of the two easiest non-trivial group operations…takes you in sequence through all four mattress orientations, thereby preserving as much as possible the symmetry of the mattress under perturbations by sleepers [and] enhancing its lifetime
Details:
The paper goes on to observe that the symmetry group of a mattress (that is, the collection of all transformations under which it is mathematically invariant) contains four elements. The first element is the identity transformation, which leaves the mattress’ orientation unchanged. The other three elements are rotations about the mattress’ axes of symmetry. Listed “in order of increasing physical effort required to perform”, these rotations are:

  • V, rotation by π (180 degrees) about a vertical axis (that is, keeping the mattress flat and spinning it around so that the erstwhile head area is at the feet)
  • L, rotation by π about the longer axis of symmetry (that is, flipping the mattress from the side of the bed, such that the head and foot ends remain in the same position relative to the bed, but the mattress is now upside down)
  • S, rotation by π about the shorter axis of symmetry (that is, flipping the mattress from the end of the bed, such that the head and foot ends swap places while the mattress is simultaneously turned upside down)
Ideally, S should be avoided in order to minimize effort”, the paper continues. Fortunately, there is a solution: “It is easily seen that alternate applications of V and L will cause the mattress to go through all ‘proper’ orientations relative to the bed, in a cycle of order 4. The following algorithm will achieve this in practice: Odd months, rotate about the lOng axis. eVen months, rotate about the Vertical axis.” In case this isn’t memorable enough, the paper advises that “potential users of this algorithm may find it helpful to write it down on a piece of paper which should be slipped under the mattress for retrieval later when it may have been forgotten.
The paper contains a single citation: Volker Heines “Theory of Compliant Mattress Group lecture notes on applications of group theory"

And acknowledgments to his wife “for bringing this challenging problem to my attention.”

He keeps the draft under his bed (photo).

Source: Margaret Harris, How to rotate your mattress like a physics Nobel prizewinner, Physics World (2024)
 
  • Haha
Likes WernerQH
  • #205
This one is a today-I-learned item, but it belongs more in this thread, perhaps.

So TIL that Cavendish didn't actually design or build the torsional balance that he used to measure G. He did this work on a setup that had been built by John Michell, who died before he could complete his own work.

https://en.wikipedia.org/wiki/John_Michell
Michell devised a torsion balance for measuring the mass of the Earth, but died before he could use it. His instrument passed into the hands of his lifelong friend Henry Cavendish, who first performed in 1798 the experiment now known as the Cavendish Experiment. Placing two 1-kg lead balls at the ends of a six-foot rod, he suspended the rod horizontally by a fibre attached to its centre. Then he placed a massive lead ball beside each of the small ones, causing a gravitational attraction that led the rod to turn clockwise. By measuring the rod's movement, Cavendish was able to calculate the force exerted by each of the large balls on the 1-kg balls. From these calculations, he was able to provide an accurate estimate of the gravitational constant and of the mass and average density of the Earth. Cavendish gave Michell full credit for his accomplishment.

And TI-also-L that
Michell was the first to propose the existence of celestial bodies similar to black holes. Having accepted Newton's corpuscular theory of light, which posited that light consists of minuscule particles, he reasoned that such particles, when emanated by a star, would be slowed down by its gravitational pull, and that it might therefore be possible to determine the star's mass based on the reduction in speed. This insight led in turn to the recognition that a star's gravitational pull might be so strong that the escape velocity would exceed the speed of light. Michell calculated that this would be the case with a star more than 500 times the size of the Sun. Since light would not be able to escape such a star, it would be invisible.
 
Last edited:
  • Like
Likes pines-demon and Hornbein
  • #206
Landau get-out-of-jail-free-theory
I have posted many stories about Lev Landau and Pyotr Kapitsa but I still missing some of the classics. Here is about the time that Landau was in prison.

In 1938, Landau seems to have been very pissed with the Soviet regime, he and his friend Moisey Korets campaigned against it by distributing leaflets during May Day parade (under the name of a non-existing "Antifascist Worker’s Party"). This event happened during Stalin's Great Purge, where many intellectuals were put into prison, or worse were executed (including physicists and friends of Landau like Lev Shubnikov). Part of the leaflet read something along the lines of:
The great cause of the October Revolution is being despicably betrayed. The country is inundated with torrents of blood and filth. Millions of innocent people are being thrown into prisons and no-one can tell when his own turn will come. It is clear, comrades, that the Stalinist clique has carried out a fascist coup. Socialism has remained only on the pages of the habitually lying newspapers. In his rabid hatred of genuine socialism, Stalin is not different from Hitler and Mussolini.

No surprises, Landau was also imprisoned for being "a German spy", along other promising physicists like Vladimir Fock. Landau was first sent Lubyanka Prison and threatened to be sent to Letforvo Prison, one of the worst of Soviet prisons. Landau was also forced to sign a confession:
At the beginning of 1937, we came to the conclusion that the Party had degenerated and that the Soviet government no longer acted in the interests of workers but in the interests of a small ruling group, that the interests of the country demanded the overthrow of the existing government, and creation in the U.S.S.R. of a state that would preserve the kolkhozes and State property for industry, but build upon the principles of bourgeois-democratic state.
Of course this was written under coercion or torture.

Scientists asked for the liberation of Landau. Niels Bohr wrote to Stalin and Kapitsa wrote to Molotov the following:
In my recent studies on liquid helium close to the absolute zero, I have succeeded in discovering a number of new phenomena... I am planning to publish part of this work... but to do this I need theoretical help. In the Soviet Union it is Landau who has the most perfect command of the theoretical field I need, but unfortunately he has been in custody for a whole year. [...]
It is said that Kapitsa was brought to a tribunal and later Landau was released in 1939 under the condition that he would develop the theory superfluidity in the upcoming years. Kapitsa would be held responsible of any actions that Landau would take afterwards. Landau seminal paper on superfluidity appeared just two years later. Individual Nobel Prizes for Landau and Kapitsa were awarded afterwards.

Additional details
After the death of Kapitsa, many of his correspondence with Soviet leaders was found including 45 letters to Stalin, 71 to Molotov, 63 to Malenkov, and 26 to Nikita Khrushchev. Kapitsa also helped to release Fock from prison.

Landau is said to have "graphophobia", he only wrote short sentences. There are two jokes here, first the Landau-Lifshitzs books are said contain "not a word of Landau and not a thought of Lifshitz". The second joke is that the confession in prison is the longest piece of handwriting Landau accomplished in his life.

About his imprisonment, Landau wrote later:
I spent a year in prison and it was clear that I would be unable to live for even another half year.

Korets was sentenced to 20 years in the gulag.

Sources: many, including
  • MacTutor
  • G. Gorelik, "The Top-Secret Life of Lev Landau", Scientific American (1997)
  • S. Balibar, "Superfluidity: How quantum mechanics became visible", in History of Artificial Cold, Scientific, Technological and Cultural Issues (2013), Springer
  • L. R. Graham, Moscow Stories, 2006
 
Last edited:
  • Like
Likes dextercioby
  • #207
Ghostly steady-state universe
Here is a short one:
There is a charming story, not taken seriously by all historians, about how steady state theory began. The idea came in 1947, [Fred] Hoyle claimed, when he and his fellow scientists Hermann Bondi and Tommy Gold went to a movie. The three knew each other from shared research on radar during World War II. Hoyle was versatile, undisciplined and intuitive; Bondi had a sharp and orderly mathematical mind; Gold's daring physical imagination opened new perspectives. The movie was a ghost story that ended the same way it started. This got the three scientists thinking about a universe that was unchanging yet dynamic. According to Hoyle,
One tends to think of unchanging situations as being necessarily static. What the ghost-story film did sharply for all three of us was to remove this wrong notion. One can have unchanging situations that are dynamic, as for instance a smoothly flowing river.
I will be nice to find the movie. Bonus cartoon of Fred Hoyle:
bigbang-hoyle-cake-lg.jpg


Source: Big Bang or steady-state ?, American Institute of Physics,
 
  • Like
Likes sbrothy
  • #208
Un-intuitive, but still true. The principle of a dynamical steady-state course, not the steady state theory itself. :smile:

Although short I must admit I haven't read it but it promises anecdotes:

My Firend Alex Müller

and a little bonus:

Communicating With Anecdotes
 
  • #209
pines-demon said:
I will be nice to find the movie.
According to another source, Hoyle said:
a ghost-story film, which had four separate parts linked ingeniously together in such a way that the film became circular, its end the same as the beginning. I have not been able to trace the name of the film but, drawing on a remote corner of my memory. I think it was called The Dead of Night. Tommy Gold was much taken with it and later that evening he remarked:
How if the universe is constructed like that?
It refers to Dead of Night (1945) a British horror film.

Source: H. Kragh, Cosmology and Controversy (2021)
See also: Papers of Woodruff T. Sullivan III, “Interview with Fred Hoyle on 22 May 1988” NRAO/AUI Archives
 
Last edited:
  • #210
Newton anonymous letter

This Veritasium video is quite interesting on the history of action principles:


Here is the excerpt from the anecdote of Johann Bernoulli related to Isaac Newton:

Nearly 60 years later, in June of 1696, Johann Bernoulli set this [brachistochrone] problem as a challenge to the best mathematicians in the world.

Steven Strogatz: Mainly because he's a big show off and he wants to show that he's better than all of them.

He gave everyone six months to come up with solutions, but none were submitted. So Gottfried Leibniz, a friend of Bernoulli's, persuaded him to extend the deadline to give foreigners a chance.

S. Strogatz: And I think Newton was probably the intended target because everybody thought of him as the best, and so Johann would've wanted to show that he was better than Newton. He was no longer a really active mathematician or physicist. He was working as the Warden of the Mint, like a big high government position.

And on the 29th of January, 1697, Newton returned home after a long day at work to find Bernoulli's challenge in the mail. Irritated, he wrote,
I do not love to be dunned and teased by foreigners about mathematical things.
But the problem was too enticing, so Newton spent the rest of the day and night on it, and by 4:00 a.m. he had come up with a solution, something that took Bernoulli two weeks! Newton submitted his solution to the journal Philosophical Transactions.

S. Strogatz: he sent his solution there but didn't sign it. And Johann Bernoulli, after seeing the solution, is alleged to have said,
I recognize the lion by his claw.
S. Strogatz: You know, that, "Okay, you don't need to sign it, Newton. I can tell who you are. Who else could give such a solution"
 

Similar threads

Replies
2
Views
1K
Replies
1
Views
2K
Replies
19
Views
2K
Replies
4
Views
911
Replies
2
Views
3K
Replies
21
Views
3K
Back
Top