## Saturday, October 27, 2012

### Anniversaries: Meitner, van Vleck, Mills, Bohm

If you're a famous physicist, you should be careful today: October 27th is a day when many famous physicists die. This very date turned out to be fatal for Lise Meitner in 1968, John Hasbrouck van Vleck in 1980, David Bohm in 1992 (twenty years ago), and Robert Mills in 1999.

They're known for the co-discovery of the nuclear fission; the van Vleck transformations, determinant, paramagnetism, and other insights about quantum mechanics applied to solids; Aharonov-Bohm effect and the revival of the misguided pilot wave theory by Louis de Broglie; and Yang-Mills theory, respectively.

You may see it's way too many people and way too many topics to discuss.

I already wrote a similar, perhaps complementary, text about her in 2008 but because the lady had such trustworthy initials :-), let me offer you another one so that you may compare.

Lise Meitner was born to a Jewish family in Vienna on November 7th, 1878 (her birthday would later be known as the Great October Socialist Revolution anniversary, proving that leftists prefer communist assholes such as Lenin over great scientists such as Meitner).

In Spring 2011, I watched a program on her fascinating life when I was a jury member at the Academic Film Festival in Olomouc. She faced all kinds of difficulties that would be enough for a strong man. At the same moment, even this very movie convinced me that most of the harassment she has experienced throughout her life had very little to do with her being a woman.

It was mostly about her being Jewish, her bad luck – but she was lucky in many other respects. Not everyone lives for 90 years, for example (that's true despite her heart attack that occurred in 1964). The Jewish girl converted to (Lutheran) Christianity as an adult which is kind of cute but the Nazis didn't pay much attention to this fact even though Meitner herself apparently considered herself a loyal citizen of Germany and perhaps a Christian role model, too. And she actually inherited her detachment from the Jewish identity from her ancestors: it has had quite some roots in her family.

Ludwig Boltzmann, a great statistical mechanic and a forefather of quantum mechanics, was her teacher. She got a PhD in 1905 for "Heat conduction by inhomogenous bodies" (in German) and she was actually not the first woman but the second woman who got a physics PhD over there. Women would be officially discouraged from studying such things a century ago. At the same moment, it seems to me that almost every woman who got the desire as well as talent to become a physicist managed to find a loophole or exception of a sort.

Off-topic: I usually embed this snowy music video on TRF when the first snow of the second half of each year arrives to Pilsen. It's usually but not always at the end of the October and 2012 confirms the approximate rule: the snow is here again. ;-) See a photo gallery.

She rejected an offer to work in a factory and, with some financial backing, boldly went to Berlin and attended Max Planck's lectures – the first woman who was allowed to be there which may sound bad but on the other hand, it also shows that there were no unbreakable barriers imposed by leaders of physics such as Boltzmann and Planck.

Meitner would become Planck's assistant and work with Otto Hahn on radioactive isotopes and beta-decay. She got some medals in Berlin, earned her own lab by 1917, and independently discovered the Auger effect (it is a bit surprising that it still hasn't been renamed as Auger-Meitner effect). In 1926, she became a full professor, and did work that was essential for the discovery of the nuclear fission in 1939.

At that time, however, this "Marie Curie of Germany" as Einstein called her was already in emigration so she wasn't physically present during the final moments of the discovery of nuclear fission. I guess that many people would agree that this fact itself was a sufficient explanation why she didn't share the 1944 Chemistry Nobel Prize for nuclear fission. In some sense, I am more surprised that in 1944, they would still count such nuclear physics things as "chemistry". It sounds stupid.

In 1933, when Hitler came to power, she was actually a director. As a Jew, she was under a clear threat that she denied in front of herself, despite the terror against her fellow Jewish physicists. She continued to work, being partly protected by her Austrian citizenship. This citizenship became worthless with the Anschluss – when Austria was annexed – and she managed to change her identity and escape Germany with 10 marks in her wallet and a diamond ring ready to be paid to border guards (which wasn't necessary).

From the Netherlands, she was able to escape to Sweden and she was able to quickly become the boss of a physics lab in Stockholm. Despite all the comments about "prejudices against women" that were everywhere, I think it is extremely hard to find some tangible evidence of these claims in the actual events that were directing her career.

She continued to communicate with Otto Hahn and she was also meeting Niels Bohr. She was actually the first person in the world to realize the concept of "chain reaction", the reason why $$E=mc^2$$ explained the energy released by the reactions, the main contributor to the discovery of transuranium elements, and so on. I have no doubts that from a broader perspective, she's been a stellar physicist who deserved a Nobel prize. However, she's far from being the only one in this category who wasn't given one, for various reasons: there are tons of men in this category, too. So when I evaluate her life, I would say that there was almost no genuine substantial "discrimination" against women even a century ago.

John Hasbrouck Van Vleck who shared the 1977 Physics Nobel Prize with Phil Anderson and Nevill Francis Mott was born in Connecticut in 1899. His father and grandfather were a mathematician and astronomer, respectively. He studied in Wisconsin, at Harvard, worked in Minnesota, and then at Harvard again.

He is considered the father of modern magnetism as he pioneered the quantum mechanical description of magnetism, especially paramagnetism, as well as the chemical bonding in metal complexes and crystals. He worked on radars during the Second World War and he would understand lots of things about the absorption of centimeter-or-so microwaves by molecules. That was important not only for the military but also for the later birth of radioastronomy. During the Manhattan project, he would help to reduce the size of the Little Boy's firing gun.

The van Vleck determinant is known to theorists as the determinant of an infinitely large matrix, the operator $$\omega^2+U''$$, whose power appears as a normalization prefactor if you're trying to solve various quantum mechanical problems exactly (e.g. the harmonic oscillator in the path integral language).

I wrote a long text about David Bohm in 2007. It was followed by lots of texts explaining why his "interpretation" is based on a deep misunderstanding of how the quantum mechanical phenomena work.

Robert Mills of the Yang-Mills fame was born in New Jersey in 1927. He studied at Columbia from 1944 and won the Putnam Competition in 1948. He earned a degree in Cambridge, spent some time at the IAS, and worked in Ohio.

Of course, the 1954 discovery of the Yang-Mills equations – when these men shared an office in Brookhaven – is his most famous achievement but he actually also studied many-body theory and the theory of alloys. I would say that Oskar Klein knew a "large part" of the spirit behind the Yang-Mills theories back in the 1930s.

Even though the Yang-Mills equations were a bit isolated "superhit" of Robert Mills, all these people were ahead of time, however. Only in the mid 1960s or so, it became meaningful to build realistic models of particle physics that depended on non-Abelian gauge theories. At that time, people wouldn't study proposed theories too carefully unless they were confident that they described the actual Universe around us. We're no longer this narrow-minded today – it's hard to find the experimental evidence revealing some completely new phenomena which is why theorists inevitably have to think about models well before their effects manifests themselves empirically – so it's somewhat unlikely that the right and relevant equations would remain unnoticed and understudied for many decades. But maybe it could happen again.

He died in 1999.

1. what is the probability of four physicists having the same anniversary?

everywhere, I think it is extremely hard to find some tangible evidence
of these claims in the actual events that were directing her career."

"I would say that there was almost no genuine substantial "discrimination" against women even a century ago."

What is evident to me is that there was no discrimination as a woman against her. But that cannot be generalized for all females. During the centuries before, discrimination started from the cradle and the expectations of the family which deprived of good education the female part of the species and channeled it mostly to "kinder kuche kirche".

Once women by serendipity (father enlightened, good teacher at gradeschool recognized mathematical abilities and rewarded them, etc.) got on their feet their colleagues were mostly supportive as they are now. It is seldom that a woman is discriminated against just because she is a woman, in physics studies. Actually I do not know a case during graduate and postgraduate work. The opposite might be true, getting extra advantages using female wiles :) .
It is later in the academic career where there could be discrimination in tough posts. It is hard though to separate that from the biological burden of having and raising a family, which necessarily is a type of handicap for advancement.

But at her time women did not come into touch with physics and mathematics at all, so as to aspire for a career there. They were not expected to have careers.

2. Bohm's formalism is not dead at all: In the field of quantum chaos, the Bohmian trajectories are used to investigate semiclassical behavior of systems that are chaotic in their classical limits. The benefit is: There are phase space trajectories of the test particles which allow to definee.g. Lyapunov exponents, something impossible with the orthodox wavefunction. In the classical limit (if it exists), the quantum potential simply vanishes and the entire formalism turns into classical mechanics. Hence, the Bohmian formalism, thanks to its similarity to the classical Hamilton-Jacoby formalism, delivers insights into semiclassical systems and helps to answer important questions like how to reach classical limits of quantum mechanical systems.

Cheers,
Holger,

3. Dear Holger, fine, in some context, you may use some trajectories that happen to obey the same equations as the Bohmian trajectories. But it's just an overlap of mathematical tools; it doesn't contain any evidence that the Bohmian trajectories are "real" and relevant for the foundations of quantum mechanics. Indeed, there is overwhelming evidence that the answer to the latter question is No, the Bohmian mechanics with its "objective Bohmian trajectories" can't replace proper probabilistic quantum mechanics, a point that becomes totally obvious when spin or other features of quantum field theory are to be added.

Jacobi is spelled with an "I".

4. I mostly agree, Anna. Except for your universal condemnation of the role of expectations.

Expectations - including your Kinder Kuche Kirche - often have very good reasons. And general expectations from an individual are always being adjusted once the other people learn details about the particular person. But some expectations have to exist even before one learns lots of details about the person. There is nothing wrong about expectations; they're the primordial basic term in the knowledge and the foundation for rudimentary strategies to approach the reality. The societies and individuals couldn't properly operate if they never had any "expectations".

Incidentally, there is nothing "anti-female" about expectations. Men were and are also expected to do certain things, things that are usually equally anti-intellectual as your Kinder Kuche Kirche. It's Fucke, Bier Drinke, und Geld Verdienen. ;-)

5. I had no intent to condemn expectations in general. I was trying to explain why there were so few women physicists at the time. Of course our parents and society have expectations from all of us and that is the framework we develop in.

Just that expectations have now changed so that more women can go into careers and science. And the wide spread educational system catches the talented ones, boys and girls, much more efficiently than in olden times.

6. I agree with you Anna. having said that I do feel that some women are willingly leaving it all to the men -when I say "all" it is from earning a living to politics, from science to home decisions-. A lot of women prefer to do that because they are lazy and stupid. They are too happy to use the conventions to do nothing and especially to limit the use of their narrow brain to their family (trapped by them). These women think the world orbits around them (perfect example : muslim women, but some christian ones too.. who could happily belong to harem).

7. "I was trying to explain why there were so few women physicists at the time."

Right, that's exactly what I consider wrong about your comment. Expectations don't explain or "cause" an underrepresentation of a group in another group. Expectations are, on the contrary, a consequence of the previous observations of similar representation of one group within another group. So your mechanism just can't work. Moreover, as I said, the "negative role expectations" holds exactly as well for men, I could tell you quite something about it.

Just in the case of men, it's not a tradition to use any correlation or any observation as a reason to whine how discriminated the men are.

I am actually not sure whether the current system is better in catching talented boys and girls than the system 100 or 300 years ago. I would agree with a statement that is different and "almost" opposite to yours: The current system is surely "better" in catching - and often insanely promoting - many untalented ones.

8. isn't Meitner the one that liked Heisenberg and he did not like her and he treated her wrong?
from what i know she did not face discrimination in how up she could go but she faced discrimination in everyday interactions. so noone tried to stop her from doing physics or stop her career wise but some people were not nice to her because she was a woman.
like other women she would probably be less famous if she was a man, because since she was a woman she stands out.

9. Dear George, I've never heard of a romantic relationship between Meitner and Heisenberg if you meant one. I know that Heisenberg gave a talk in Copenhagen in 1941 that promoted some Third Reich interpretations of social questions and that pissed Meitner off but I don't know of any other interaction between them. She also wanted Heisenberg to have seen all the concentration camps etc.

But if your comment were right, how do you exactly determine that Heisenberg would be the "bad one" in the romantic relationship? Doesn't a man have the right to refuse a woman who is interested in him? Note that if the exact opposite situation took place, the man could be accused of harassment. Sorry, without any detailed data, I would wisely remain neutral in both situations. They're completely symmetric.

10. anna v somehow got me to see and be surprised about that I have not yet heard of a woman who made her fame in the field of anatomical physics! %-o

11. i think i should have said Otto Hahn. in the book E=mc^2: A Biography of the World's Most Famous Equation there are details about it. it also talks about the discrimination she faced because she was the only female from a group of students. it has been 10 years since i read it...so it probably talks about her and Hahn and not Heisenberg. it does not mention that she was stopped from doing physics but that she had a teacher-supervisor that was not nice to her and this had to do with her being female. i don't remember the details. of course one person or more not being nice to you is different than being stopped from your potential or not getting recognition for what you did. she did all she could and got all the recognition any male physicist would have.

12. wasn't it Heisenberg that came close to being executed because he collaborated with Jews and talked about their theories and his life was sparred because his mother knew Himler's mother or something like that?