New York-born physicist Murray Gell-Mann is known for his creation of the eightfold way, an ordering system for subatomic particles, comparable to the periodic table. His discovery of the omega-minus particle filled a gap in the system, brought the theory wide acceptance and led to Gell-Mann's winning the Nobel Prize in Physics in 1969.
Hans Bethe first of all calculated the Lamb Shift with a cut-off at the electron mass, right away, right after the Shelter Island meeting, within a day. And then Viki and his graduate student, Bruce French, Kroll and Lamb himself, and two of the people who were working on the new relativistic methods, Dick Feynman and Julian Schwinger all started to calculate the relativistic Lamb Shift using mass renormalization and the cancellation of the infinities in the vertex and the propagator, for the electron. French and Weisskopf actually won the race, they got the right answer first, but because Feynman and Schwinger using the relativistic methods got different answers at that moment, they were - Weisskopf was discouraged.
French was not, he knew he was right, but Viki Weisskopf insisted on waiting and so Kroll and Lamb using old-fashioned methods were actually the first ones to publish the correct calculation. It could have been French and Weisskopf if they hadn't been put off by Feynman and Schwinger. Dick Feynman in his paper manipulated his footnotes with stars and daggers and so on, so that the footnote referring to this was numbered thirteen. And then he wrote 'I had some difficulty,' he wrote, 'in reconciling the relativistic method with the non-relativistic cut-off of Bethe, and therefore I made a mistake at that point. French and Weisskopf were discouraged by that, and I'm sorry. This footnote is appropriately numbered.' Something like that. Schwinger of course never said he was sorry. So that - quantum field theory - was okay. Then the pion was discovered by Lattes, Giuseppe Occhialini, Cecil Powell and that was all fine too them. In the meantime, just before the pion was discovered...
That was fine because we now understood Yukawa?
Right, but just before that, Marshak had suggested that there were two different particles: they are what we now call the pi, which was Yukawa's particle, more or less; and the muon, which was more like the electron. It was he who suggested the actual properties of the pi and the muon, and within a few months they were confirmed. So suddenly theory wasn't so bad. The two crippling contradictions were both removed and it was in that atmosphere that I arrived at MIT.
Title: The state of physics at MIT (Part 2); calculating the Lamb shift
Listeners:
Geoffrey West
Geoffrey West is 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.
Tags:
Shelter Island Conference, Victor Weisskopf, Hans Bethe, Bruce French, Norman Kroll, Willis Lamb, Richard Feynman, Julian Schwinger, César Lattes, Giuseppe Occhialini, Cecil Powell, Hideki Yukawa, Robert Marshak
Duration:
2 minutes, 53 seconds
Date story recorded/uploaded:
October 1997
Date story went live:
24 January 2008
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