George Placzek (; September 26, 1905 – October 9, 1955) was a

Moravia Moravia ( , also , ; cs, Morava ; german: link=yes, Mähren ; pl, Morawy ; szl, Morawa; la, Moravia) is a historical region in the east of the Czech Republic and one of three historical Czech lands, with Bohemia and Czech Silesia. The m ...

n physicist.

Biography

Placzek was born into a wealthy Jewish family in

Brünn Brno ( , ; german: Brünn ) is a city in the South Moravian Region of the Czech Republic. Located at the confluence of the Svitava and Svratka rivers, Brno has about 380,000 inhabitants, making it the second-largest city in the Czech Republic ...

(now Brno,

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

), the grandson of Chief Rabbi Baruch Placzek.
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He studied physics in

Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and List of cities in the Czech Republic, largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 milli ...

and

Vienna en, Viennese , iso_code = AT-9 , registration_plate = W , postal_code_type = Postal code , postal_code = , timezone = CET , utc_offset = +1 , timezone_DST ...

. In the 1930s, Placzek was known as an adventurous person with sharp sense of humor, a tireless generator of novel physics ideas which he generously shared with his colleagues. The scope of Placzek's pilgrimage around the world's physics centres in the 1930s was unique among his colleagues. He worked with

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 ...

Edward Teller Edward Teller ( hu, Teller Ede; January 15, 1908 – September 9, 2003) was a Hungarian-American theoretical physicist who is known colloquially as "the father of the hydrogen bomb" (see the Teller–Ulam design), although he did not care for ...

Rudolf Peierls Sir Rudolf Ernst Peierls, (; ; 5 June 1907 – 19 September 1995) was a German-born British physicist who played a major role in Tube Alloys, Britain's nuclear weapon programme, as well as the subsequent Manhattan Project, the combined Allie ...

Werner Heisenberg Werner Karl Heisenberg () (5 December 1901 – 1 February 1976) was a German theoretical physicist and one of the main pioneers of the theory of quantum mechanics. He published his work in 1925 in a breakthrough paper. In the subsequent serie ...

Victor Weisskopf Victor Frederick "Viki" Weisskopf (also spelled Viktor; September 19, 1908 – April 22, 2002) was an Austrian-born American theoretical physicist. He did postdoctoral work with Werner Heisenberg, Erwin Schrödinger, Wolfgang Pauli, and Niels Boh ...

, Enrico Fermi,

Niels Bohr Niels Henrik David Bohr (; 7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922 ...

Lev Landau Lev Davidovich Landau (russian: Лев Дави́дович Ланда́у; 22 January 1908 – 1 April 1968) was a Soviet-Azerbaijani physicist of Jewish descent who made fundamental contributions to many areas of theoretical physics. His ac ...

Edoardo Amaldi Edoardo Amaldi (5 September 1908 – 5 December 1989) was an Italian physicist. He coined the term "neutrino" in conversations with Enrico Fermi distinguishing it from the heavier "neutron". He has been described as "one of the leading nuclear ...

Emilio Segrè Emilio Gino Segrè (1 February 1905 – 22 April 1989) was an Italian-American physicist and Nobel laureate, who discovered the elements technetium and astatine, and the antiproton, a subatomic antiparticle, for which he was awarded the Nobe ...

, Otto Frisch, Leon van Hove, and many other prominent physicists of his time. His wife, Els Placzek () was an ex-wife of physicist

Hans von Halban Hans Heinrich von Halban (24 January 1908 – 28 November 1964) was a French physicist, of Austrian- Jewish descent. Family He was descended on his father's side from Polish Jews, who left Kraków for Vienna in the 1850s. His grandfather, Hei ...

. He lost all his relatives to

Holocaust The Holocaust, also known as the Shoah, was the genocide of European Jews during World War II. Between 1941 and 1945, Nazi Germany and its collaborators systematically murdered some six million Jews across German-occupied Europe; ...

, casting a tragic shadow on his life. Placzek's major areas of scientific work involved a fundamental theory of

Raman scattering Raman scattering or the Raman effect () is the inelastic scattering of photons by matter, meaning that there is both an exchange of energy and a change in the light's direction. Typically this effect involves vibrational energy being gained by a ...

, molecular spectroscopy in gases and liquids,

neutron The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons beh ...

physics and

mathematical physics Mathematical physics refers to the development of mathematical methods for application to problems in physics. The '' Journal of Mathematical Physics'' defines the field as "the application of mathematics to problems in physics and the developme ...

. Together with Otto Frisch, he suggested a direct experimental proof of nuclear fission. Together with

and others, he was instrumental in clarifying the role of Uranium 235 for the possibility of nuclear chain reaction. During his stay in Landau's circle in

Kharkiv Kharkiv ( uk, wikt:Харків, Ха́рків, ), also known as Kharkov (russian: Харькoв, ), is the second-largest List of cities in Ukraine, city and List of hromadas of Ukraine, municipality in Ukraine.Joseph Stalin Joseph Vissarionovich Stalin (born Ioseb Besarionis dze Jughashvili; – 5 March 1953) was a Georgian revolutionary and Soviet political leader who led the Soviet Union from 1924 until his death in 1953. He held power as General Secretar ...

's regime. His first-hand experience of this influenced the political opinions of his close friends, in particular, fathers of nuclear and thermonuclear bombs,

Robert Oppenheimer J. Robert Oppenheimer (; April 22, 1904 – February 18, 1967) was an American theoretical physicist. A professor of physics at the University of California, Berkeley, Oppenheimer was the wartime head of the Los Alamos Laboratory and is often ...

and

. Later, Placzek was the only Czech with a leading position in the

Manhattan project The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project w ...

, where he worked from 1943 till 1946 as a member of the British Mission; first in Canada as the leader of a theoretical division at the Montreal Laboratory and then (since May 1945) in Los Alamos, later replacing his friend Hans Bethe as the leader of the theoretical group. Since 1948, Placzek was a member of the

Institute for Advanced Study The Institute for Advanced Study (IAS), located in Princeton, New Jersey, in the United States, is an independent center for theoretical research and intellectual inquiry. It has served as the academic home of internationally preeminent schola ...

Princeton Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the ni ...

, USA. Unlike many trailblazers of nuclear physics, George Placzek did not leave his recollections or life story notes. Many new facts about Placzek's life and his family roots emerged in connection with a Symposium held in Placzek's memory. Placzek's premature death in a hotel in Zurich was very likely a suicide influenced by his long-time serious illness.

References

{{DEFAULTSORT:Placzek, George 1905 births 1955 deaths 1955 suicides Charles University alumni Moravian Jews Czech nuclear physicists Jewish physicists Manhattan Project people People associated with nuclear power People from the Margraviate of Moravia Scientists from Brno Czechoslovak Jews

Biography

See also

References