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How to observe a neutrino


Condensation of K-minus mesons
Hans Bethe Scientist
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Gerry Brown, together with other collaborators found that at high density another phenomenon happens, namely a condensation of K-minus Mesons, and K-minus mesons can condense and thereby lose their... thier normal mass so that their mass becomes smaller then... or let me say their MC2 becomes smaller than the Fermi Energy of Electrons which would exist at the center of a neutron star. And so there is good reason to believe that when the density at the center of a... of as neutron star gets higher than, maybe, three, four times nuclear density, there is this K-minus condensation and the neutrons near the center again convert, not into protons plus electrons, but into protons plus K-minus mesons. And thereby the limiting mass of a neutron star is reduced from something like twice the mass of the sun to something like one-and-a-half times. And it is very believable from Jim Wilson's calculations, it is very believable that supernova 1987A had more than that mass and therefore would collapse to a black hole. As I said, not everybody believes this, but it is a very interesting theory, and it is very interesting how the very small varies the, and very high energy the K-minus mesons, how that connects again to astrophysics. This is, as I said, mostly the work of Gerry Brown and my only contribution was about the mass of the neutron star which first forms inside supernova 1987A.

The late German-American physicist Hans Bethe once described himself as the H-bomb's midwife. He left Nazi Germany in 1933, after which he helped develop the first atomic bomb, won the Nobel Prize in Physics in 1967 for his contribution to the theory of nuclear reactions, advocated tighter controls over nuclear weapons and campaigned vigorously for the peaceful use of nuclear energy.

Listeners: Sam Schweber

Silvan Sam Schweber is the Koret Professor of the History of Ideas and Professor of Physics at Brandeis University, and a Faculty Associate in the Department of the History of Science at Harvard University. He is the author of a history of the development of quantum electro mechanics, "QED and the men who made it", and has recently completed a biography of Hans Bethe and the history of nuclear weapons development, "In the Shadow of the Bomb: Oppenheimer, Bethe, and the Moral Responsibility of the Scientist" (Princeton University Press, 2000).

Tags: James Wilson, Gerald Brown

Duration: 3 minutes

Date story recorded: December 1996

Date story went live: 24 January 2008