| 1930: Conference on disarmament on sea in
London | Der blaue Engel with Marlene Dietrich | First model of a cyclotron |
Clyde Tombaugh discovers planet Pluto |Airship on rails | Perm in
hairdressing |
| Deutsch |
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The Neutrino |
Wolfgang Pauli's name is inseparable from his pioneering hypothesis
of the existence of the neutrino, which was confirmed by experiment only after
25 years. The starting point for Pauli was the continuous energy spectrum of
beta rays, which could not be interpreted theoretically. Niels Bohr attempted
it with the hypothesis of the restricted validity of the principle of energy
conservation, which Pauli could not accept because the principle of the
conservation of energy had proved itself in all fields of physics and its
proposition seemed to be plausible. In this critical situation Pauli hit on a
desperate way out: he developed the idea that during beta decay, apart from the
electron a further, but electrically neutral particle is emitted in such a way
that the sum of the energies of both particles is constant.
On 4th December
1930, Pauli wrote his famous letter to the "Dear Radioactive Ladies and
Gentlemen" who had gathered in Tübingen. In it, he sketched out his idea
and inquired how things stood with the experimental proof. But he considered
his idea to be too immature to be published. |
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Participants of the Congress of Solvay in Bruxelles, 1933 |
The Italian nuclear physicist Enrico Fermi took up Pauli's idea and on its basis
developed a theory of beta decay. Fermi also coined the term "neutrino", after
Pauli had spoken of "neutron", but the latter designation was reserved for the
heavy component of the atomic nucleus discovered in 1932.
Not until October
1933 at the 7th Solvay Conference in Brussels did Pauli dare to present his
hypothesis in public. It then took a further 23 years before the experimental
proof of the existence of the neutrino succeeded. |
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