Ettore Majorana {1906-2006}
Art Neuendorffer
rank, who do their best, but do not go very far. There are also people
of first class, who make great discoveries, fundamental for the
development of science. But then there are the geniuses, like Galilei
and Newton. Well, Ettore Majorana was one of them" - Enrico Fermi
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http://everything2.com/index.pl?node_id=1826017
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<<Ettore Majorana was born on the 5th of August in the year 1906 in
Catania, Sicily, and was, or maybe still is, an italian quantum
physicist. His teacher was Enrico Fermi. He is well known for his
proposal that the neutrino is not a massless particle, which seems to
be confirmed by current experiments. He also proposed that the neutrino
and its anti-particle, the antineutrino, are the same particle (at
least regarding many of their properties, like charge). This is
reflected in the Majorana equation which includes charge unlike the
Dirac equation.
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After many travels where he met Heisenberg and Niels Bohr, he returned
to Rome in 1933, earning a scholarship in 1937 in Naples, till his
disappearance in 1938.
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Before his disappearance in 1938, where he is listed as a passenger
aboard a postal vessel, he sent out letters indicating both that he was
willing to commit suicide that and that he was not, much like in the
experiment of Schrodinger's cat.>>
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>From Wikipedia
<<Ettore Majorana (Catania, Sicily, 05 August 1906 - Tyrrhenian Sea,
27 March 1938 (presumed)) was an Italian theoretical physicist who
began promising work on neutrino masses. He disappeared suddenly in
mysterious circumstances.
Majorana was mathematically extremely gifted, and was very young when
he joined Enrico Fermi's team in Rome as one of the "Via Panisperna
boys", who took their name from the street address of their laboratory.
His first papers dealt with problems in atomic spectroscopy. His first
paper, published in 1928, was written when he was an undergraduate and
was coauthored by Giovanni Gentile Jr., a junior professor in the
Institute of Physics in Rome. This work was an early quantitative
application to atomic spectroscopy of Fermi's statistical model of
atomic structure (now known as the Thomas-Fermi model, due to its
contemporaneous description by Llewellyn Thomas). In this paper,
Majorana and Gentile performed first-principles calculations within the
context of this model that gave a good account of experimentally
observed core electron energies of gadolinium and uranium, and of the
fine structure splitting of cesium lines observed in optical spectra.
In 1931, Majorana published the first paper describing the phenomenon
of autoionization in atomic spectra, designated by him as "spontaneous
ionization"; an independent paper in the same year, published by Arthur
Shenstone of Princeton University, first used the term
"auto-ionization", which has since become conventional, without the
hyphen. An important paper (1932) in the field of atomic spectroscopy
concerned the behaviour of aligned atoms in time-varying magnetic
fields. This problem, also studied by I. I. Rabi and others, led to an
important sub-branch of atomic physics, that of radio-frequency
spectroscopy. Also in 1932, Majorana published his paper on a
relativistic theory of particles with arbitrary intrinsic momentum, in
which he developed and applied infinite dimensional representations of
the Lorentz group, and gave a theoretical basis for the mass spectrum
of elementary particles. Like most of Majorana's papers in Italian,
this paper languished in relative obscurity for several decades. (It is
discussed in detail by D. M. Fradkin, Amer. J. Phys., vol. 34,
pp.314-318 (1966)). Subsequently, he studied with Heisenberg in Leipzig
and worked on a theory of the nucleus (published in German in 1933)
which, in its treatment of exchange forces, represented a further
development of Heisenberg's theory of the nucleus. Majorana's
last-published paper, in 1937, again in Italian, concerned his
elaboration of a symmetrical theory of electrons and positrons.
Majorana did prescient theoretical work on neutrino masses, a currently
active subject of research. He also worked on an idea that mass may
exert a small shielding effect on gravitational waves, which did not
gain much traction.
His uncle Quirino Majorana was also a physicist.
The year 2006 marks Majorana's centenary, and a book of his (nine)
collected papers, with commentary and English translations, is
scheduled to be published by the Italian Physical Society.
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Disappearance
Majorana disappeared in unknown circumstances during a boat trip from
Palermo to Naples. Despite several investigations, the truth about his
fate is still uncertain. His body has not been found.
Hypotheses include that
He could have committed suicide. (He left two letters which contained a
sort of farewell.)
He could have been kidnapped by foreign powers.
He could have voluntarily disappeared, changed his identity and
possibly left Italy.
.
Some argue for this latter hypothesis, conjecturing that after having
envisioned the destructive power of atomic energy, Majorana did not
want to contribute to its deployment in a fascist state. There have
been sporadic rumors that he may have been sighted in South America in
the 1950's. Also in Italy a story appeared in the news when a man
living on the street claimed that he once was a famous physicist.
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The Italian writer Leonardo Sciascia has summarized some of the results
of these investigations and these hypotheses in his passionate book "La
Scomparsa di Majorana (Einaudi, 1975)" (English translation: "The Moro
Affair and The Mystery of Majorana," Carcanet (1987), ISBN
0-85635-700-6). However, some of Sciascia's conclusions were refuted by
certain of Majorana's former colleagues, including E. Amaldi and E.
Segrè. The various hypotheses on Majorana's disappearance have been
extensively discussed by Erasmo Recami in his book "Il caso Majorana:
Lettere, testimonianze, documenti" (Di Renzo Editore, Roma, 2000) and
in a journal article (E. Recami, I nuovi documenti sulla scomparsa del
fisico Ettore Majorana, Scientia, vol. 110, pp.577-588 (1975); English
version titled "New Evidence on the Disappearance of the Physicist
Ettore Majorana", Scientia, vol. 110, p.589ff. (1975)). In the
above-mentioned book and article, Recami discusses critically the
various rival explanations concerning Majorana's disapparance,
including those advanced by Sciascia in his short book, and presents
highly suggestive evidence to the effect that Majorana absconded to
Argentina.>>
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Art Neuendorffer