Advent Calendar #13: A Postdoc's Nightmare

Pascual Jordan was, along with Werner Heisenberg, Paul Dirac, and Wolfgang Pauli, one of the Wunderkinder contributing to the development of quantum mechanics. He had obtained his Ph.D. in 1924, at the age of 22. In the following year, together with his Ph.D. advisor Max Born and with Heisenberg, he created the matrix formulation of quantum mechanics, formulating the canonical commutation relations between position and momentum. Jordan kicked off quantum field theory, and found the anti-commutation relation for creation and annihilation operators of particles with spin 1/2. These particles, now known as fermions, actually could be linked directly to Jordan, were it not for a case of extremely bad luck. As Max Born remembers:

In December of 1925 I went to America to give lectures at MIT. I was editor of the Zeitschrift für Physik, and Jordan gave me a paper to be published in the journal. I didn't find time to read it and put it in my suitcase. I forgot about it, and when I returned half a year later and unpacked, I found the paper at the bottom of the suitcase. It contained the Fermi-Dirac statistics. Meanwhile both Fermi and Dirac had discovered it. But Jordan was the first.

The Max Born quote, and more about Jordan, can be found in Engelbert Schuckings reminescences "Jordan, Pauli, Politics, Brecht... and a Variable Gravitational Constant" (in On Einstein's path: Essays in Honor of Engelbert Schucking).

Advent calendar #12: All of astronomy

In 1904, Max Born, a German born physicist who would win the Nobel prize in 1954, went to Göttingen to study mathematics and physics. He soon made friends with Professor Karl Schwarzschild, who taught astronomy, and at that time was not much older than his students. Schwarzschild's name might be familiar to you from the Schwarzschild-metric - the first known exact solution to Einstein's field equations that he would derive about a decade later.

In their book "Der Luxus des Gewissens" (The Luxury of Conscience) by Max Born and his wife Hedwig, Born recalls that he used to play tennis with Schwarzschild. Max Born (who was called "Maxel" by his friends) liked Schwarzschild's astronomy class, but did not feel very inspired by the lectures on geometry, held by the great mathematician Felix Klein, namegiver of the Klein bottle:

"Die geometrischen Vorlesungen... waren aber nicht nach meinem Geschmack, und ich besuchte sie nicht sehr regelmäßig... Mein Reinfall im müdlichen Examen, das in nur sechs Monaten bevorstand, schien unvermeidlich."

"The lectures in geometry... were not to my taste and I did not attend them on a regular basis. That I would flop at the oral exam, to which there were only six months to go, seemed unavoidable."

Maxel asked his friend Schwarzschild for advice. Schwarzschild suggested to instead take the exam in astronomy:

"[E]r sagte, ein halbes Jahr sei reichlich Zeit, die ganze Astronomie zu lernen."

"He said, half a year is more than enough time to learn all of astronomy."

Max passed the oral exam in astronomy, even though he answered the question "What do you do when you see a falling star?" with "I make a wish!" and only after Schwarzschild's further inquiry remembered to add "I note down the time and location, the direction and the length of the visible trace."

Advent calendar #11: Prescient Einstein

From Bertram Kostant (Professor Emeritus of Mathematics at MIT) via Garrett Lisi @ Physics Forums comes the following anecdote:

"I was a visiting member of Princeton's Institute for Advanced Study in 1955. It was a Good Friday in April and Einstein was looking for the Institute bus to take him back home to 112 Mercer Street. Being Good Friday, the driver was on holiday amd I offered to drive him home. We had a wonderful conversation and at one point he asked me what I was working on. I told him Lie groups. He then remarked, wagging his finger, that that will be very important. Actually, I was quite surprised that he knew who Lie was. About a week later Einstein was dead."

Advent calendar #10: It sounds Greek to me!

Of course we cannot allow Richard Feynman to be missing when we tell physics anecdotes. He told his anecdotes well himself, and they have been captured by Ralph Leighton in the book "Surely You're Joking, Mr. Feynman!" One of my favorites is this story:

I don't know why, but I'm always very careless, when I go on a trip, about the address or telephone number or anything of the people who invited me. I figure I'll be met, or somebody else will know where we're going; it'll get straightened out somehow.

One time, in 1957, I went to a gravity conference at the University of North Carolina. I was supposed to be an expert in a different field who looks at gravity. I landed at the airport a day late for the conference (I couldn't make it the first day), and I went out to where the taxis were. I said to the dispatcher, "I'd like to go to the University of North Carolina."

"Which do you mean," he said, "the State University of North Carolina at Raleigh, or the University of North Carolina at Chapel Hill?"

Needless to say, I hadn't the slightest idea. "Where are they?" I asked, figuring that one must be near the other.

"One's north of here, and the other is south of here, about the same distance."

I had nothing with me that showed which one it was, and there was nobody else going to the conference a day late like I was.

That gave me an idea. "Listen," I said to the dispatcher. "The main meeting began yesterday, so there were a whole lot of guys going to the meeting who must have come through here yesterday. Let me describe them to you: They would have their heads kind of in the air, and they would be talking to each other, not paying attention to where they were going, saying things to each other, like 'Gmunu.Gmunu.'"

His face lit up. "Ah, yes," he said. "You mean Chapel Hill!" He called the next taxi waiting in line. "Take this man to the university at Chapel Hill."

"Thank you," I said, and I went to the conference.

Advent calender #9: Prof. Jolly's advice

When Max Planck had finished high school in 1874, he was unsure which career path to chose. He had many different talents and interests, and pondered becoming a concert pianist, or study classical philology, or maybe mathematics and physics. Planck's father, a professor of law, mediated an appointment with his colleague, physicist Philipp von Jolly, for Max to get some advice. Prof. Jolly was a bit gloomy about the prospects of physics, and didn't want to raise false hopes in the young man. As Max Planck remembered,

Als ich meine physikalischen Studien begann und bei meinem ehrwürdigen Lehrer Philipp von Jolly wegen der Bedingungen und Aussichten meines Studiums mir Rat erholte, schilderte mir dieser die Physik als eine hochentwickelte, nahezu voll ausgereifte Wissenschaft, die nunmehr, nachdem ihr durch die Entdeckung des Prinzips der Erhaltung der Energie gewissermassen die Krone aufgesetzt sei, wohl bald ihre endgültige stabile Form angenommen haben würde. Wohl gäbe es vielleicht in einem oder dem anderen Winkel noch ein Stäubchen oder ein Bläschen zu prüfen und einzuordnen, aber das System als Ganzes stehe ziemlich gesichert da, und die theoretische Physik nähere sich merklich demjenigen Grade der Vollendung, wie ihn etwa die Geometrie schon seit Jahrhunderten besitze. (Max Planck, Wege zur physikalischen Erkenntnis, S. Hirzel, 1933, p. 128)

Philipp von Jolly described physics as a highly developed, almost fully matured science, which was about to reach a final form, now that the principle of conservation of energy had been discovered. He thought that there may be a speck or a vesicle left to be studied and classified in one or the other angle of the field, but that as a whole, the system had a fairly safe standing, and that theoretical physics was approaching the same degree of perfection reached by geometry already centuries ago.

Max Planck did not let himself be dissuaded from studying physics by this assessment, and the rest is history.

Advent calendar #8: Einstein's old envelopes

When Herr Professor Doktor Einstein and his wife visited Mr and Mrs Hubble at Mt Wilson, at one stage the two ladies were left alone to swap confidences. Mrs Hubble pointed at the great telescope and explained that her husband used it “to study the nature of the universe” whereupon Frau Einstein retorted that “my husband does that on the back of an old envelope!”

Submitted by Cormac O' Raifeartaigh. This anecdote is mentioned for example in “The Day We Found the Universe” by Marcia Bartusiak.

Advent calendar #7: Bullshit with equations

“In [high energy] quantum physics, to observe something, you have to create it. Now this sounds scarily close to bullshit. But if it is bullshit, then at least it's bullshit with equations.”

~Frank Wilczek, public lecture at Perimeter Institute

(Recycled from November 2008)

Advent calendar #6: The dissolved Nobel Prizes

This is the most wondrous story in our advent calendar.

The two German physicists Max von Laue and James Franck won the Nobel Prize in 1914 and 1925 respectively. When the Nazis grew strong in Germany von Laue and Franck sent their medals, made of 23-karat gold, to Niels Bohr in Copenhagen. During these troublesome times many people were hiding or burying their family jewelry or anything of timeless value that they wanted to keep out of the Gestapo's hands, though it was illegal to send valuables out of country.

Unfortunately, by 1940 the Nazis made it to Copenhagen. Bohr was now in possession of two large gold pieces that carried von Laue's and Franck's names and clearly left Germany unapproved. Bohr had to get rid of the Nobel medals, and quickly so. It was Georgy de Hevesy, a colleague and friend from the department of chemistry, who came up with a ingeneous solution, quite literally: he would dissolve the medals.

Now gold is a precious metal and what makes it so precious is that it is slow to react with anything. It takes a mixture of acids known as aqua regia and time to dissolve gold, but at the end of a seemingly endless afternoon the medals were gone and left was a glass with a bright orange solution that didn't catch the interest of the Nazis.

But that wasn't the end of the story. After the war, de Hevesy returned to his lab and found the orange solution undisturbed in his shelf. He precipitated out the gold and sent it back to the Nobel Foundation in Stockholm. They recast the medals and gave them back to von Laue and Franck.

De Hevesy won the Nobel price for chemistry in 1943.

This story can be found in many books. It was recently told in some more details at NPR blogs: Dissolve my Nobel Prize! Fast!.

Advent calendar #5: Share the love

In 1933, Erwin Schrödinger moved to Oxford. The physicist Arthur March, best known for his (failed) attempt to give physical meaning to a Lorentz-invariant minimal length scale, was not only Schrödinger's colleague but also a close friend. Due to Schrödinger's initiative, March too got a position in Oxford. Summer 1933, on a vacation in Tyrol, Schrödinger went on a bike excursion with Arthur March's wife Hilde. Nine months later Hilde gave birth to Schrödinger's daughter. Arthur March did not seem to mind much, but Schrödinger's wife went on to have an affair with the mathematician Hermann Weyl, while Weyl's wife in return found comfort with the physicist Paul Scherrer.

This and other details of Schrödinger's illustrious life can be found in Walter Moore's biography Schrödinger: Life and Thought.

Advent calendar #4: Einstein's haircut

In Stefan's bookshelf I found a little book "Einstein privat" by Friedrich Herneck who, on the book cover, is described as "one of today's leading Einstein researchers." Herneck interviewed Einstein's former household aid, Herta W., about everything from Einstein's smoking habits, over nicknames used in the family to how often Einstein fed the goldfish. Herta W. had the following to say about Einstein's haircut which, next to going sockless, has become trademark of the ingenious theoretical physicist:

"Wenn seine Haare zu lang waren, wenn es gar zu schlimm geworden war, dann hat [seine Frau Elsa] ihm das Haar mit der Schere abgeschnitten. Das hat er sich dann auch machen lassen. Da Frau Professor aber sehr kurzsichtig war und beim Haarschneiden ihre Lorgnette, ihre Stielbrille, nicht ständig benutzen konnte... Aber Herr Professor war eben nicht zu bewegen, zu einem Berufsfrisör zu gehen."

"When his hair grew too long, when it got really intolerable, then [his wife Elsa] cut his hair off with a scissor. He let her do that. But since Frau Professor was very shortsighted and, during cutting, could not always use her Lorgnette... But Herr Professor could not be bothered to see a professional barber."

"Frau Professor" is (here) the form of address for the professor's wife and a lorgnette are old-fahioned glasses that have to be held on a handle in front of one's eyes. Later in the interview there's more talk about Frau Professor's shortsightedness and it seems it was indeed serious. She was however too vain to permanently wear thick glasses.

Advent calendar #3: Details are missing

In 1958, Pauli and Heisenberg were working an a unified theory which is today still the holy grail of particle physicists. Heisenberg gave a talk about their recent results, appearing confident that they had found a unified theory, only technical details were missing. An eager journalist who sat in the audience spread the news about the "world-equation," very much to Pauli's dismay. In a 1958 letter to George Gamov, Pauli commented on Heisenberg's radio announcement: "This is to show the world that I can paint like Titian. Only technical details are missing," illustrated by an empty rectangle.



This alleged all-explaining world equation came about before Yang and Mill's contribution to physics became appreciated. Looking at the Lagrangian in question today, it doesn't seem to be gauge invariant and with a four-fermion coupling won't fare well in terms of renormalizability.

Pauli's letter can be found in the CERN archive.

Advent calendar #2: Pauli and the anomalous Zeeman effect

The Zeeman effect is the splitting of spectral lines in an external magnetic field, first observed by Pieter Zeeman in the late 19th century. The magnetic field removes a degeneracy between electron shells with different magnetic quantum number. By 1920 that was fairly well understood, unfortunately most of the observed atoms showed much more complicated spectra than expected. This became known as the "anomalous Zeeman effect" and caused the theoretical physicists of the time quite some headache. We know today that the additional splitting is due to the electron spin, but it was still a decade till Dirac would write down the equation for spin 1/2 particles that is now named after him. Recalling the time in 1946, Wolfgang Pauli wrote:

“A colleague who met me strolling rather aimlessly in the beautiful streets of Copenhagen said to me in a friendly manner, “You look very unhappy,” whereupon I answered fiercely, “How can one look happy when he is thinking about the anomalous Zeeman effect?””

Call to readers: Send us your favorite physics anecdote!

Reminded by a recent comment, Stefan and I noticed that time has come to open the first door on the advent calendar. This year, we will have a daily anecdote from the lives and works of well-known physicists. These are all quotations or stories that many of you will be familiar with from your physics lectures, but I hope for the rest of our readers it will be a little daily entertainment one the way to the holidays. We also have a few anecdotes that while widely known I learned are actually fabricated.

Unfortunately, Stefan's and my brainstorming only brought up 19 items! So we need you to help us out: Send us your favorite physics anecdote or quotation (if possible with source), or we'll run out of stories a week before Christmas. To save an element of surprise for our readers, please do not post it in the comments here, but send an email to hossi[@]nordita.org (remove brackets), subject: physics anecdote. Don't be shy, I won't tell anybody you're reading blogs ;o)

We start today with the 1st anecdote. It's one of my favorites and, I guess, probably also among the best known ones. A journalist who goes under the name Roundy, interviews Paul Dirac. The interview appeared in the Wisconsin State Journal in April 1929 and its complete version can be found on this website.

"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 Poincaré 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.