Jean Baptiste Perrin (30 September 1870 – 17 April 1942) was a French physicist who, in his studies of the

Brownian motion Brownian motion, or pedesis (from grc, πήδησις "leaping"), is the random motion of particles suspended in a medium (a liquid or a gas). This pattern of motion typically consists of random fluctuations in a particle's position insi ...

of minute particles suspended in liquids ( sedimentation equilibrium), verified

Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...

’s explanation of this phenomenon and thereby confirmed the atomic nature of

matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic part ...

. For this achievement he was honoured with the

Nobel Prize for Physics ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...

in 1926.

Biography

Early years

Born in

Lille Lille ( , ; nl, Rijsel ; pcd, Lile; vls, Rysel) is a city in the northern part of France, in French Flanders. On the river Deûle, near France's border with Belgium, it is the capital of the Hauts-de-France region, the prefecture of the N ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

, Perrin attended the

École Normale Supérieure École may refer to: * an elementary school in the French educational stages normally followed by secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing in région Île-de-France * École, S ...

, the elite

grande école A ''grande école'' () is a specialised university that is separate from, but parallel and often connected to, the main framework of the French public university system. The grandes écoles offer teaching, research and professional training in s ...

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), ma ...

. He became an assistant at the school during the period of 1894–97 when he began the study of

cathode rays Cathode rays or electron beam (e-beam) are streams of electrons observed in discharge tubes. If an evacuated glass tube is equipped with two electrodes and a voltage is applied, glass behind the positive electrode is observed to glow, due to el ...

and

X-rays An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nbs ...

. He was awarded the degree of ''docteur ès sciences'' (beyond PhD) in 1897. In the same year he was appointed as a lecturer in

physical chemistry Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistica ...

at the

Sorbonne Sorbonne may refer to: * Sorbonne (building), historic building in Paris, which housed the University of Paris and is now shared among multiple universities. *the University of Paris (c. 1150 – 1970) *one of its components or linked institution, ...

. He became a professor at the University in 1910, holding this post until the German occupation of France during World War II.

Research and achievements

In 1895, Perrin showed that cathode rays were of negative electric charge in nature. He determined Avogadro's number (now known as the

Avogadro constant The Avogadro constant, commonly denoted or , is the proportionality factor that relates the number of constituent particles (usually molecules, atoms or ions) in a sample with the amount of substance in that sample. It is an SI defining c ...

) by several methods. He explained solar energy as due to the

thermonuclear Thermonuclear fusion is the process of atomic nuclei combining or “fusing” using high temperatures to drive them close enough together for this to become possible. There are two forms of thermonuclear fusion: ''uncontrolled'', in which the re ...

reactions of

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

. After

published (1905) his theoretical explanation of

in terms of

atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, ...

s, Perrin did the experimental work to test and verify Einstein's predictions, thereby settling the century-long dispute about John Dalton's

atomic theory Atomic theory is the scientific theory that matter is composed of particles called atoms. Atomic theory traces its origins to an ancient philosophical tradition known as atomism. According to this idea, if one were to take a lump of matter ...

Carl Benedicks Carl Axel Fredrik Benedicks (27 May 1875 – 16 July 1958) was a Swedish physicist whose work included geology, mineralogy, chemistry, physics, astronomy and mathematics. Biography Carl Benedicks was born 27 May 1875 in Stockholm, Sweden to Edwa ...

argued Perrin should receive the

Nobel Prize in Physics ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...

; Perrin received the award in 1926 for this and other work on the discontinuous structure of matter, which put a definite end to the long struggle regarding the question of the physical reality of molecules. Perrin was the author of a number of books and dissertations. Most notable of his publications were: "Rayons cathodiques et rayons X"; "Les Principes"; "Electrisation de contact"; "Réalité moléculaire"; "Matière et Lumière"; "Lumière et Reaction chimique". Perrin was also the recipient of numerous prestigious awards including the Joule Prize of the Royal Society in 1896 and the La Caze Prize of the French Academy of Sciences. He was twice appointed a member of the Solvay Committee at Brussels in 1911 and in 1921. He also held memberships with the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

of London and with the Academies of Sciences of Belgium, Sweden, Turin, Prague, Romania and China. He became a Commander of the

Legion of Honour The National Order of the Legion of Honour (french: Ordre national de la Légion d'honneur), formerly the Royal Order of the Legion of Honour ('), is the highest French order of merit, both military and civil. Established in 1802 by Napoleon ...

in 1926 and was made Commander of the

Order of Léopold The Order of Leopold ( nl, Leopoldsorde, french: Ordre de Léopold, ) is one of the three current Belgian national honorary orders of knighthood. It is the oldest and highest order of Belgium and is named in honour of its founder, King Leo ...

(Belgium). In 1919, Perrin proposed that

nuclear reaction In nuclear physics and nuclear chemistry, a nuclear reaction is a process in which two nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides. Thus, a nuclear reaction must cause a transformatio ...

s can provide the source of energy in stars. He realized that the mass of a helium atom is less than that of four atoms of hydrogen, and that the mass-energy equivalence of Einstein implies that the nuclear fusion (4 H → He) could liberate sufficient energy to make stars shine for billions of years. A similar theory was first proposed by American chemist

William Draper Harkins William Draper Harkins (December 28, 1873 – March 7, 1951) was an American physical chemist, noted for his contributions to surface chemistry and nuclear chemistry. Harkins researched the structure of the atomic nucleus and was the first to p ...

in 1915. It remained for

Hans Bethe Hans Albrecht Bethe (; July 2, 1906 – March 6, 2005) was a German-American theoretical physicist who made major contributions to nuclear physics, astrophysics, quantum electrodynamics, and solid-state physics, and who won the 1967 Nobel ...

and

Carl Friedrich von Weizsäcker Carl Friedrich Freiherr von Weizsäcker (; 28 June 1912 – 28 April 2007) was a German physicist and philosopher. He was the longest-living member of the team which performed nuclear research in Germany during the Second World War, under ...

to determine the detailed mechanism of stellar nucleosynthesis during the 1930s. In 1927, he founded the Institut de Biologie Physico-Chimique together with chemist André Job and physiologist André Mayer. Funding was provided by

Edmond James de Rothschild Baron Abraham Edmond Benjamin James de Rothschild (Hebrew: הברון אברהם אדמונד בנימין ג'יימס רוטשילד - ''HaBaron Avraham Edmond Binyamin Ya'akov Rotshield''; 19 August 1845 – 2 November 1934) was a French memb ...

. In 1937, Perrin established the Palais de la Découverte, a

science museum A science museum is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, industry and industrial machinery, etc. Modern trends in ...

. Perrin is considered the founding father of the National Centre for Scientific Research (

Centre National de la Recherche Scientifique The French National Centre for Scientific Research (french: link=no, Centre national de la recherche scientifique, CNRS) is the French state research organisation and is the largest fundamental science agency in Europe. In 2016, it employed 31,63 ...

(CNRS)). Following a petition by Perrin signed by over 80 scientists, among them eight Nobel Prize laureates, the French education minister set up the Conseil Supérieur de la Recherche Scientifique (French National Research Council) in April 1933. In 1936, Perrin, now an undersecretary for research, founded the Service Central de la Recherche Scientifique (French Central Agency for Scientific Research). Both institutions were merged under the CNRS umbrella on October 19, 1939. His notable students include

Pierre Victor Auger Pierre Victor Auger (; 14 May 1899 – 24 December 1993) was a French physicist, born in Paris. He worked in the fields of atomic physics, nuclear physics, and cosmic ray physics. He is famous for being one of the discoverers of the Auger effect, ...

. Jean Perrin was the father of Francis Perrin, also a physicist.

Personal life and death

Perrin was an atheist and a socialist. He was an officer in the engineer corps during

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. After the death of Perrin's wife Henriette in 1938, Nine Choucroun (1896–1978), founder of the '' Nine Choucroun Prize'', became Perrin's partner. In June 1940, when the Germans invaded France, Choucroun and Perrin escaped to Casablanca on the ocean liner ''Massilia'', with part of the French government. In December 1941, they boarded the ''SS Excambion'' to New York City, arriving on December 23.Diane Dosso, " Le plan de sauvetage des scientifiques français, New York, 1940–1942 ", ''Revue de synthèse'', Vol. 127, Nr. 2, octobre 2006, p. 429-451 Perrin died at Mount Sinai Hospital in New York on 17 April, 1942 at the age of 71. After the War, in 1948, his remains were transported back to France by the cruiser ''Jeanne d'Arc'' and buried in the

Panthéon The Panthéon (, from the Classical Greek word , , ' empleto all the gods') is a monument in the 5th arrondissement of Paris, France. It stands in the Latin Quarter, atop the , in the centre of the , which was named after it. The edifice was b ...

Works

Perrin, Jean – Atomes, 1913 – BEIC 6564725

* ''Les Principes. Exposé de thermodynamique'' (1901)/''Principles of thermodynamics'' * ''Traité de chimie physique. Les principes'' (1903)/''Physical chemistry principles'' * ''Les Preuves de la réalité moléculaire'' (1911)/''Evidences of molecular reality'' * * ''Les Atomes'' (1913)/''The Atoms'' * ''Matière et lumière'' (1919)/''Matter and light'' * ''En l'honneur de Madame Pierre Curie et de la découverte du Radium'' (1922)/ ''In honor of Mrs Pierre Curie and the discovery of Radium'' * ''Les Éléments de la physique'' (1929)/''Elements of physics'' * ''L'Orientation actuelle des sciences'' (1930)/''Current orientation of sciences'' * ''Les Formes chimiques de transition'' (1931)/''Transition chemical forms'' * ''La Recherche scientifique'' (1933)/''Scientific research'' * ''Cours de chimie. 1ère partie. Chimie générale et métalloïdes'' (1935)/ ''Chemistry courses: general chemistry and metalloids'' * ''Grains de matière et grains de lumière'' (1935)/''Grains of matter and grains of light'' ** ''Existence des grains''/''Existence of grains'' ** ''Structure des atomes''/''Structure of atoms'' ** ''Noyaux des atomes''/''Kernels of atoms'' ** ''Transmutations provoquées''/''Induced transmutations'' * ''Paul Painlevé: l'homme'' (1936)/''Paul Painlevé: the man'' * ''L'Organisation de la recherche scientifique en France'' (1938)/''The organisation of scientific research in France'' * ''À la surface des choses'' (1940-1941)/''At the surface of things'' ** ''Masse et gravitation'' (1940)/''Mass and gravitation'' ** ''Lumière'' (1940)/''Light'' ** ''Espace et temps'' (1940)/''Space and time'' ** ''Forces et travail'' (1940)/''Forces and work'' ** ''Relativité'' (1941)/''Relativity'' ** ''Électricité'' (1941)/''Electricity'' ** ''L'énergie'' (1941)/''Energy'' ** ''Évolution'' (1941)/''Evolution'' * ''L'Âme de la France éternelle'' (1942)/''The soul of eternal France'' * ''Pour la Libération'' (1942)/''For Liberation'' * ''La Science et l'Espérance'' (1948)/''Science and hope'' * ''Oeuvres scientifiques de Jean Perrin'' (1950)/''Scientific works of Jean Perrin''

References

External links

* *
Mouvement brownien et molécules, by Jean Perrin, 1923
on Vidéothèque du CNRS (French)
Jean Perrin et la réalité moléculaire
on Vidéothèque du CNRS (French) {{DEFAULTSORT:Perrin, Jean Baptiste 1870 births 1942 deaths 20th-century French chemists 20th-century French physicists École Normale Supérieure alumni Burials at the Panthéon, Paris Foreign Members of the Royal Society French atheists French socialists Commandeurs of the Légion d'honneur Nobel laureates in Physics French Nobel laureates University of Paris alumni Members of the French Academy of Sciences Corresponding Members of the Russian Academy of Sciences (1917–1925) Corresponding Members of the USSR Academy of Sciences Honorary Members of the USSR Academy of Sciences Theoretical physicists French physical chemists French National Centre for Scientific Research scientists Recipients of the Matteucci Medal 19th-century French physicists Presidents of the Société Française de Physique