Leopold Infeld (20 August 1898 – 15 January 1968) was a Polish

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

who worked mainly in

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...

and

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

(1938–1950). He was a Rockefeller fellow at

Cambridge University The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209, the University of Cambridge is the List of oldest universities in continuous operation, wo ...

(1933–1934) and a member of the

Polish Academy of Sciences The Polish Academy of Sciences (, PAN) is a Polish state-sponsored institution of higher learning. Headquartered in Warsaw, it is responsible for spearheading the development of science across the country by a society of distinguished scholars a ...

Early life

Leopold Infeld was born into a family of

Polish Jews The history of the Jews in Poland dates back at least 1,000 years. For centuries, Poland was home to the largest and most significant Jews, Jewish community in the world. Poland was a principal center of Jewish culture, because of the long pe ...

Kraków , officially the Royal Capital City of Kraków, is the List of cities and towns in Poland, second-largest and one of the oldest cities in Poland. Situated on the Vistula River in Lesser Poland Voivodeship, the city has a population of 804,237 ...

, then part of the

Austro-Hungarian Empire Austria-Hungary, also referred to as the Austro-Hungarian Empire, the Dual Monarchy or the Habsburg Monarchy, was a multi-national constitutional monarchy in Central Europe between 1867 and 1918. A military and diplomatic alliance, it consist ...

(it rejoined an independent Poland in 1918). He studied

physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...

Jagiellonian University The Jagiellonian University (, UJ) is a public research university in Kraków, Poland. Founded in 1364 by Casimir III the Great, King Casimir III the Great, it is the oldest university in Poland and one of the List of oldest universities in con ...

and from 1920 in Berlin, where he had engaged

Albert Einstein Albert Einstein (14 March 187918 April 1955) was a German-born theoretical physicist who is best known for developing the theory of relativity. Einstein also made important contributions to quantum mechanics. His mass–energy equivalence f ...

's help to gain admission to the

University of Berlin The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...

. He obtained a doctorate in 1921. In 1933 he left for

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

, then for the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

and Canada after the death of his second wife, Halina.

Work

Infeld was interested in the

theory of relativity The theory of relativity usually encompasses two interrelated physics theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical ph ...

. He was awarded a doctorate at the

(1921), worked as an assistant and a docent at the University of Lwów (1930–1933) and then as a professor at the

University of Toronto The University of Toronto (UToronto or U of T) is a public university, public research university whose main campus is located on the grounds that surround Queen's Park (Toronto), Queen's Park in Toronto, Ontario, Canada. It was founded by ...

between 1939 and 1950. He collaborated with

Princeton University Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...

(1936–1938). The two scientists jointly formulated the equation describing star movements as well as concurrently writing the book '' The Evolution of Physics''. After the first use of nuclear weapons in 1945, Infeld, like Einstein, became a peace activist. Because of his activities, he was unjustly accused of having communist sympathies. In 1950, he and his family left Canada and returned to communist Poland. He also could not return to the US at that time. In the US, despite having worked previously directly with Einstein, who formally invented nuclear weapons with his famous formula, Infeld risked receiving the death penalty like the Rosenbergs if accused of spying for the Soviet Union. He felt he had an obligation to help science in Poland recover from the ravages of the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. He served as president of the Polish Physical Society between 1955 and 1957. In the staunchly anti-communist climate of the time, many in the Canadian government and media feared that working in a communist country he would betray

nuclear weapons A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either nuclear fission, fission (fission or atomic bomb) or a combination of fission and nuclear fusion, fusion reactions (thermonuclear weap ...

secrets. He was stripped of his

Canadian citizenship Canadian nationality law details the conditions by which a person is a national of Canada. The primary law governing these regulations is the Citizenship Act, which came into force on February 15, 1977 and is applicable to all provinces and ...

and was widely denounced as a traitor. In actuality, Infeld's field was the

—not directly linked to

nuclear weapons research Nuclear weapons design are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types: # Pure fission weapons are the simplest, least technically de ...

. After Infeld's return to Poland, he requested a leave of absence from the

. His request was denied, and Infeld resigned his post. In 1995 the University of Toronto made amends and granted Infeld the posthumous title of

professor emeritus ''Emeritus/Emerita'' () is an honorary title granted to someone who retirement, retires from a position of distinction, most commonly an academic faculty position, but is allowed to continue using the previous title, as in "professor emeritus". ...

. Upon his return to

, Infeld became a professor at the

University of Warsaw The University of Warsaw (, ) is a public university, public research university in Warsaw, Poland. Established on November 19, 1816, it is the largest institution of higher learning in the country, offering 37 different fields of study as well ...

, a post he held until his death. The Born–Infeld model was named after

Max Born Max Born (; 11 December 1882 – 5 January 1970) was a German-British theoretical physicist who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics, and supervised the work of a ...

and Leopold Infeld, who first proposed it. The Infeld-Hull Factorization Method describing general sets of solutions to the

Schrödinger equation The Schrödinger equation is a partial differential equation that governs the wave function of a non-relativistic quantum-mechanical system. Its discovery was a significant landmark in the development of quantum mechanics. It is named after E ...

. Infeld was one of the 11 signatories to the Russell–Einstein Manifesto in 1955 and is the only signatory never to receive a

Nobel Prize The Nobel Prizes ( ; ; ) are awards administered by the Nobel Foundation and granted in accordance with the principle of "for the greatest benefit to humankind". The prizes were first awarded in 1901, marking the fifth anniversary of Alfred N ...

. In 1964 he was one of the signatories of the so-called Letter of 34 to Prime Minister

Józef Cyrankiewicz Józef Adam Zygmunt Cyrankiewicz (; 23 April 1911 – 20 January 1989) was a Polish Socialist (PPS) and after 1948 Communist politician. He served as premier of the Polish People's Republic between 1947 and 1952, and again for 16 years between 1 ...

regarding freedom of culture. Infeld is the author of ''Quest: An Autobiography'' and the biography ''Whom the Gods Love: The Story of

Évariste Galois Évariste Galois (; ; 25 October 1811 – 31 May 1832) was a French mathematician and political activist. While still in his teens, he was able to determine a necessary and sufficient condition for a polynomial to be solvable by Nth root, ...

''.

Personal life

In New Jersey, on April 12, 1939, he married a mathematician who took the name Helen Infeld and they had two children, both born in Toronto, Joan M. and Eric (sometimes spelled Eryk).

Publications

* * *

References

External links