Bøger af Otto Robert Frisch

The elementary building bricks of matter have long been known: the elec­ tron (1897), the proton (1911) and the neutron (1932); in addition, there was the quantum of radiation, the photon (1905), known to have a double nature with both wave and particle features. The bold idea (L. de Broglie, 1924) that streams of ordinary particles such as electrons should possess a similar double nature led to the development of wave mechanics; moreover, diffraction phenomena were found with beams of electrons, atoms and even molecules. Pauli's Exclusion Principle causes us to distinguish between fermions which obey the Exclusion Principle ("no two equal particles in the same quantum state"), and bosons which do not. Another distinction is that all fermions possess a spin of h/4n, which is indestructible because in quantum theory the spin of a system can change only by whole multiples of h/2n. In 1928 Dirac showed that the spin is a consequence of describing the electron by the simplest linear wave equation that is relativistically invar­ iant. A further consequence of his theory was the existence of positive elec­ trons, which were indeed soon observed. After that it was expected that to any fermion there should exist an anti-particle, and this has been fully con­ firmed in recent years.

Otto Frisch took part in some of the most momentous developments in modern physics, notably the discovery of nuclear fission (a term which he coined). His work on the first atom bomb, which he saw explode in the desert 'like the light of a thousand suns', brought him into contact with figures such as Robert Oppenheimer, Edward Teller, Richard Feynman and the father of electronic computers, John von Neumann. He also encountered the physicists who had made the great discoveries of recent generations: Einstein, Rutherford and Niels Bohr. This characterful book of reminiscences sheds an engagingly personal light on the people and events behind some of the greatest scientific discoveries of this century, illustrated with a series of fascinating photographs and witty sketches by the author himself.