Richard Garwin Oral History

Authors(s):Interviewed by W. Patrick McCray Publication:American Institute of Physics Oral Histories Publication Date:June 7, 2001 Publisher: American Institute of Physics Citation:Interview of Richard Garwin by W. Patrick McCray on 2001 June 7, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, Link:

Focused interview deals with Garwin's childhood and schooling at Case and University of Chicago; his time at Chicago and interaction with Fermi. Majority of interview is on Garwin's work in designing the H-bomb and consulting work at Los Alamos in 1950-51. Recollections interspersed with technical details of design and apparatus. Discussion of recent 'discovery' of interview with Edward Teller in 1979 by George Keyworth that gives credit for H-bomb design to Garwin; Teller and Ulam's relation. Last part of the interview deals with Garwin's work in conjunction with Leon Lederman to confirm the non-conservation of parity in late 1956-early 1957.

Of course I would go to the seminars at Columbia, whatever they were. When Lee and Yang gave a seminar probably in August or whenever about non-conservation of parity and that they had studied the literature. Really there was no evidence for the conservation of parity in the weak interactions! In that paper they have two experiments proposed. One is a polarization of nuclei looking at asymmetric beta emission, and the other is the pi-mu-e [pion-muon-electron] decay asymmetry. The electron asymmetry was expected to be a lot smaller, because if parity is violated only a little bit, it's violated in the pi-mu-e decay so the muons are only slightly polarized; and then if it's violated only a little bit in the pi-mu-e decay, then the new electron is only slightly asymmetric. If parity violation were 5% effect, then it would be a 5% squared or one part in 400 effect. And so that isn't what you want. People started in photographic emulsion tracking muons and seeing, but there're all kinds of scanning bias there. All kinds of people did those experiments.

So Miss Wu (Chien-Shiung Wu), knowing I was in low temperature physics, asked me I think in September  Miss Wu came to me and she said, "I'd like to do this cobalt-60 experiment. Do you have a demagnetization cooling set-up?" I said, "Well, funny you should ask. I'm working on one that is to be much better than anybody else's, but it's going to go slowly because I've recently created a superconducting computer project at IBM. Not only at our laboratory, but also at Poughkeepsie. (This was in 1956.) And I've got 100 people working for me at various places and I had this responsibility. I can tell you how to do it and I can tell you how we would do it and I would be very happy to do so, but my advice is for you to go to where they have an operating demagnetization refrigerator. You should go to the Bureau of Standards." She did, but she would come back and talk about her work and her problems.

Then at Christmastime more or less, she came back and at a Chinese lunch she said, "We have these warming curves after we cool the cobalt 60 in a magnetic field and demagnetize. We do seem to have an asymmetry, depending whether we have the spins up or the spins down, and that's a clear evidence of parity violation. Now we've got to track down all kinds of dirt effects."