Father Georges-Henri Lema?tre (July 17, 1894 每 June 20, 1966) was a Belgian
Roman Catholic priest, honorary prelate, professor of physics and astronomer.
Monsignor Georges-Henri Lema?tre, priest and scientist (1894 - 1966).
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Monsignor Georges-Henri Lema?tre, priest and scientist (1894 - 1966).
Fr. or Msgr. Lema?tre proposed what became known as the Big Bang theory
of the origin of the Universe, although he called it his 'hypothesis of
the primeval atom'. He based his theory, first broached in the pages of
Nature in 1931, on the laws of relativity set forth by Einstein, among others,
although at the time Einstein believed in an eternal universe and had previously
expressed his skepticism about Lemaitre's original 1927 paper. A similar
solution to Einstein's equations, suggesting a changing radius to the size
of the universe, had been proposed in 1922 by Alexander Alexandrovich Friedman,
as Einstein informed Fr. Lema?tre when he approached him with the theory
at the 1927 Solvay Conference (Friedman had also been criticized by Einstein)
, but it is Fr. Lema?tre that made the theory famous with his widely read
papers and media appeal. Fr. Lema?tre also proposed the theory at an opportune
time since Edwin Hubble would soon release his red shift observations that
strongly supported an expanding universe and, consequently, the Big Bang
theory. In fact, Lema?tre derived what became known as Hubble's Law in his
1927 paper, two years before Hubble.
Contents
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* 1 Biography
* 2 Personality
* 3 See also
* 4 External links
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Biography
After studying humanities at a Jesuit school (Saint Michel), Lema?tre entered
the civil engineering school of the Catholic University of Leuven at the
age of seventeen. In 1914, at the beginning of World War I, he paused his
studies to engage as a volunteer in the Belgian army. At the end of hostilities,
he received the Military Cross with palms.
After the war, he undertook studies in physics and mathematics and began
to prepare for priesthood. He obtained his doctorate in 1920 with a thesis
entitled l'Approximation des fonctions de plusieurs variables r谷elles (Approximation
of functions of several real variables), written under the direction of
Charles de la Vall谷e-Poussin.
The tragedy of the war in which he took part deeply marked him, although
there is no evidence to suggest the reason he became a priest was due to
traumas he suffered in combat; Lema?tre had made it clear to his parents
at an early age that he was interested in a vocation: he entered the Mechelen
seminary and was ordained as a priest in 1923. Neither the war nor his studies
nor his vocation dried up his curiosity: since 1920, he had learnt the theory
of relativity and perfectly mastered it.
In 1923, he became a graduate student in astronomy at the University of
Cambridge, spending one year at St Edmund's House (now St Edmund's College,
Cambridge). He worked with the astronomer Arthur Eddington who initiated
him into modern cosmology, stellar astronomy and numerical analysis. He
spent the following year at Harvard College Observatory in Cambridge, Massachusetts
with Harlow Shapley, who had just gained a name for his work on nebulae,
and to the Massachusetts Institute of Technology, where he registered for
the doctorate in sciences.
In 1925, on his return to Belgium, he became a part-time lecturer at the
University of Leuven. He then began the report which would bring him international
notoriety and which was published in 1927 in the Annales de la Soci谷t谷
Scientifique de Bruxelles (Annals of the Scientific Society of Brussels),
under the title Un Univers homog豕ne de masse constante et de rayon croissant
rendant compte de la vitesse radiale des n谷buleuses extragalactiques (A
homogeneous Universe of constant mass and growing radius accounting for
the radial velocity of extragalactic nebulae). In this report, he presented
the new idea of an expanding Universe.
At this time, Einstein, whilst approving of the mathematics of Fr. Lema?tre's
theory, refused to accept the idea of an expanding Universe. The same year,
Lema?tre returned to MIT to present his doctoral thesis on The gravitational
field in a fluid sphere of uniform invariant density according to the theory
of relativity. He obtained a PhD and was then named ordinary Professor at
the University of Leuven.
In 1930, Eddington published an English translation of the 1927 article
with a long commentary. Fr. Lema?tre was then invited to London in order
to take part in a meeting of the British Association on the relation between
the physical Universe and spirituality. It is there that he proposed an
expanding Universe which started with an initial singularity, and the idea
of the Primeval Atom which he developed in a report published in the Monthly
Notices of the Royal Astronomical Society. Fr. Lema?tre himself liked to
describe his theory as "the Cosmic Egg exploding at the moment of the creation"
, which was later to be coined by his critics as the Big Bang theory.
This proposal met skepticism from his fellow scientists at the time. Eddington
found Fr. Lema?tre's notion unpleasant. As for Einstein, he found it suspect,
because, according to him, it was too strongly reminiscent of the Christian
dogma of creation and was unjustifiable from a physical point of view. On
the other hand, Einstein encouraged Lema?tre to look into the possibility
of non-isotropic expansion models, so it's clear he was not dismissive of
the concept altogether. He also appreciated Lema?tre's argument that a static-
Einstein model of the universe could not be sustained indefinitely into
the past.
In January 1933, Fr. Lema?tre and Einstein, who had met on several occasions
- in 1927 in Brussels, at the time of a Solvay congress, in 1932 in Belgium,
at the time of a cycle of conferences in Brussels and lastly in 1935 at
Princeton - traveled together to California for a series of seminars. After
the Belgian detailed his theory, Einstein stood up, applauded, and is supposed
to have said, "This is the most beautiful and satisfactory explanation of
creation to which I have ever listened". However there is disagreement over
the reporting of this quote in the newspapers of the time and it is likely
that Einstein was not actually referring to the theory as a whole--but in
fact to Lema?tre's proposal that cosmic rays might in fact be the left over
artifacts of the initial 'explosion'. Later research on cosmic rays by Millikan
would undercut his proposal, however.
In 1933, when he resumed his theory of the expanding Universe and published
a more detailed version in the Annals of the Scientific Society of Brussels,
Fr. Lema?tre would achieve his greatest glory. The American newspapers called
him a famous Belgian scientist and described him as the leader of the new
cosmological physics.
On March 17, 1934, Fr. Lema?tre received the Francqui Prize, the highest
Belgian scientific distinction, from King L谷opold III. His proposers were
Albert Einstein, Charles de la Vall谷e-Poussin and Alexandre de Hemptinne.
The members of the international jury were Eddington, Langevin and Th谷ophile
de Donder. Another distinction that the Belgian government reserves for
exceptional scientists was allotted to him in 1950: the decennial prize
for applied sciences for the period 1933-1942.
In 1936, he was elected member of the Pontifical Academy of Sciences. He
took an active role there, became the president in March 1960 and remaining
so until his death. At the outset of the Second Vatican Council, he was
bemused to find himself appointed by the Pope to sit on a commission investigating
the subject of birth control. He was also named prelate (Monsignor) in 1960
by Pope John XXIII.
In 1941, he was elected member of the Royal Academy of Sciences and Arts
of Belgium.
In 1946, he published his book on L'Hypoth豕se de l'Atome Primitif (The
Primeval Atom Hypothesis), a book which would be translated into Spanish
in the same year and into English in 1950.
In 1953 he was given the very first Eddington Medal award of the Royal Astronomical
Society.
During the 1950s, he gradually gave up part of his teaching workload, ending
it completely with his 谷m谷ritat in 1964.
At the end of his life, he was devoted more and more to numerical calculation.
He was in fact a remarkable algebraicist and arithmetical calculator. Since
1930, he used the most powerful calculating machines of the time like the
Mercedes. In 1958, he introduced at the University a Burroughs E 101, the
University's first electronic computer. Fr. Lema?tre kept a strong interest
in the development of computers and, even more, in the problems of language
and programming. With age, this interest grew until it absorbed him almost
completely.
He died on June 20, 1966 shortly after having learned of the discovery of
cosmic microwave background radiation, proof of his intuitions about the
birth of the Universe.
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Personality
Sociable, devoted to his students and collaborators, he remained, however,
an isolated researcher, and one finds only few correspondences and scientific
exchanges with his peers.
If this undeniable co-founder of modern cosmology remains in the shade of
the great names of the 20th century (Einstein, Eddington, Hubble and Gamow
in particular), it may be due to the fact that scientists themselves are
often remiss in keeping up with the history of their own discipline. It
has been suggested that Lema?tre's obscurity may have been due to anti-clerical
bias. But the evidence for this is scant. Fred Hoyle, who coined the term
Big Bang, in fact got along quite well with Lema?tre and they enjoyed each
other's company and respected each other's scientific work.