Murray Gell-Mann - Henry Margenau's physics class (11/200)
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New York-born physicist Murray Gell-Mann (1929-2019) was a theoretical physicist. His considerable contributions to physics include the theory of quantum chromodynamics. He was awarded the 1969 Nobel Prize in Physics for his work on the theory of elementary particles. [Listener: Geoffrey West; date recorded: 1997]
TRANSCRIPT: Good teachers are so very rare that it's worth mentioning. This was Henry Margenau, who died only very recently. He lived to be 97 or something like that. And he was a very good teacher. He taught a course that was called something like Philosophical Foundations of Physics or something of that sort, I forget the exact name, but... through calling it philosophy he was able to present very advanced material, which otherwise might not have been considered suitable for sophomores or juniors or whatever.
[GW] Was that… he wrote this book Nature of Physical Reality...
Well, that was later... this was Margenau and Murphy… no, was it? Wait a minute, was it..?
[GW] Margenau and Murphy was the Mathematical...
No, that was Mathematical Method, so it wasn't that...
[GW] But he had written this book later and I wondered if that…
Maybe it was Margenau…
[GW]… that sort of was the text...?
…maybe it was Margenau. I really can't remember whether it was by him alone or by him and Murphy, but either way what happened… the way the course went was the following: he would say, ‘Now, we’re going to do… right at the beginning… we're going to do Lagrangian and Hamiltonian mechanics. Now, you all know the calculus of variations, don't you?’ And everybody looked blank. And he said, ‘Well, they haven't taught you the calculus of variations? What do they do in your math classes? They must waste your time with epsilons and deltas. Why don't they teach you the calculus of variations? I can't understand’.
[GW] He is a man after our own hearts!
Of course, exactly, exactly. ‘Can't understand why they would waste your time with that stuff instead of teaching you the calculus of variations. Well’, he said, ‘It's not a problem. On Tuesday we will learn the calculus of variations, and on Thursday we will begin Lagrangian and Hamiltonian mechanics, and we'll do it on Thursday, Saturday and the following Tuesday’. Something like that, and that was plenty. And he did discuss the philosophical foundations. For example, he showed us how the principles - the principle of least time, the principle of least action, and so on - were… appeared to be teleological, the physical laws appeared to be teleological, they appeared to be heading toward the objective of satisfying the principle of least action and so on. But, he said, since they're mathematically equivalent to Newton's differential equations, now there is no problem. They're not teleological, they are in fact just progression from one instant of time to the next. And by bringing in these very simple philosophical lessons he stuck to the promise of the course while actually telling us a lot of very interesting material about actual physics. Then he went on to the next subject, which was… well, I don't know, he covered many subjects, but one of them was special relativity which took, I think, two days, and then general relativity. And when he got to general relativity, he asked the same question, he said, ‘You all know tensor analysis, I assume’. We said, no, we don't. He said, ‘Well, what do they do in those math classes? Why don't they teach you tensor analysis instead of all those stupid epsilons and deltas?’ And he said, ‘Well, that’s not a problem. Tuesday and Thursday we'll do tensor analysis and then we'll do general relativity’. And that's exactly the way it worked, and general relativity took only a few days, and he made some wise philosophical remarks about general relativity as well, while teaching us the actual stuff, the actual equations. And then he went on to quantum mechanics and he did the same thing with quantum mechanics. He said, ‘I assume you know Sturm-Liouville theory?’ We said no. He said, ‘Well, what do they teach you in those math classes?’ Then he said, ‘No problem, we'll do Sturm-Liousville theory, and then we'll do vector spaces and then we'll do quantum mechanics’. And that's what he did, and he showed us wave mechanics and matrix mechanics and how they're equivalent and so on, which was very nice.
[GW] So he gave… he gave a complete survey basically, of all the...
… of the advanced ideas of modern physics…
[GW]…modern physics..?
…of the advanced ideas of… well, he didn't do quantum field theory or, and he didn't cover peculiar particles like the neutrino, anti-matter. Those were the things I read about in science fiction stories...
Read the full transcript at www.webofstori...
Love it when the interviewer knows his sh*t. This is probably the reason why Gellmann could take these interviews seriously. And we got some wonderful footage out of it.
'And when he got to general relativity, he asked the same question, he said, ‘You all know tensor analysis, I assume’. We said, no, we don't. He said, ‘Well, what do they do in those math classes? Why don't they teach you tensor analysis instead of all those stupid epsilons and deltas?’'
Hah, reminds me of my grad physics days. Trying to learn GR without knowing tensors. Professor said the same thing :P
so true, about real analysis.
He is so clear in his ideas
Apparently the listener(Geoffrey West) is a respected theoretical physicist too. How are they getting all these people?
RIP Professor Gell-Mann
As a graduate student I got a B in a Mathematical Methods course that used the text by Margenau & Murphy.
Lindsay & Marganau (sp?) was published by Dover
Damn the epsilons and deltas!
This channel is ❤️
I like him very much. He is a brilliant memory and all does it so "very light". Brilliant mind with fair judgements
Murray is a very entertaining raconteur
"... but of course yale was a backwater" And cut! 😆
Every year or so, TH-cam recommends this clip to me. Hearing that statement has eternally reminded me of how Gell-Mann unapologetically called things the way they were.
Gell-Mann praises excellence where it is merited and he excoriates anything less with measured bluntness. He is neither as gracious as Dyson nor as abrasive as Oppenheimer.
who is interviewing murray here
Geoffrey West, a Staff Member, Fellow, and Program Manager for High Energy Physics at Los Alamos National Laboratory. He is also a member of The Santa Fe Institute. He is a native of England and was educated at Cambridge University (B.A. 1961). He received his Ph.D. from Stanford University in 1966 followed by post-doctoral appointments at Cornell and Harvard Universities. He returned to Stanford as a faculty member in 1970. He left to build and lead the Theoretical High Energy Physics Group at Los Alamos. He has numerous scientific publications including the editing of three books. His primary interest has been in fundamental questions in Physics, especially those concerning the elementary particles and their interactions. His long-term fascination in general scaling phenomena grew out of his work on scaling in quantum chromodynamics and the unification of all forces of nature. In 1996 this evolved into the highly productive collaboration with James Brown and Brian Enquist on the origin of allometric scaling laws in biology and the development of realistic quantitative models that analyse the influence of size on the structural and functional design of organisms.
Every physics teacher is like that
RIP!
Well neutrinos and antimatter had only been postulated like 15-20 years before his time, in the late 40's early 50's so I wouldn't be unreasonable for the teacher not to teach about them.
5 years is plenty of time. Yale was a backwater.
@@Achrononmaster a bitter pill to swallow for the Bull Dog blue crowd
uhm would they see a real course of calculus of variations, like Sobolev spaces, BV functions, weak compactness, calibrations, gamma convergence..., I guess they'd miss those stupid epsilons&deltas! :D
I think that deep down inside Gell.Mann is a grouch.
Epsilons and deltas are only done by mathematicians.
Learned calculus of variations many times... still don't remember it lol
what are they teaching you in all those classes?!?!