Theodore H. Berlin (8 May 1917, New York City – 16 November 1962, Baltimore) was an American

theoretical physicist Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict natural phenomena. This is in contrast to experimental physics, which uses experi ...

Education and career

Berlin graduated in 1939 with a B.S. in

chemical engineering Chemical engineering is an engineering field which deals with the study of the operation and design of chemical plants as well as methods of improving production. Chemical engineers develop economical commercial processes to convert raw materials ...

from

Cooper Union The Cooper Union for the Advancement of Science and Art, commonly known as Cooper Union, is a private college on Cooper Square in Lower Manhattan, New York City. Peter Cooper founded the institution in 1859 after learning about the government-s ...

. He graduated in 1940 with M.S. and in 1944 with Ph.D. from the

University of Michigan The University of Michigan (U-M, U of M, or Michigan) is a public university, public research university in Ann Arbor, Michigan, United States. Founded in 1817, it is the oldest institution of higher education in the state. The University of Mi ...

. His thesis advisor was

Kazimierz Fajans Kazimierz Fajans (Kasimir Fajans in many American publications; 27 May 1887 – 18 May 1975) was a Polish-Jewish physical chemist, a pioneer in the science of radioactivity and the co-discoverer of chemical element protactinium. Education and ca ...

. (article related to Berlin's thesis) He was a research physicist from 1944 to 1946 at the

, a lecturer from 1946 to 1947 at

Johns Hopkins University The Johns Hopkins University (often abbreviated as Johns Hopkins, Hopkins, or JHU) is a private university, private research university in Baltimore, Maryland, United States. Founded in 1876 based on the European research institution model, J ...

, and an associate professor from 1948 to 1949 at

Northwestern University Northwestern University (NU) is a Private university, private research university in Evanston, Illinois, United States. Established in 1851 to serve the historic Northwest Territory, it is the oldest University charter, chartered university in ...

. At

he was from 1949 to 1954 an associate professor and from 1955 to 1961 a full professor. As a

Guggenheim Fellow Guggenheim Fellowships are grants that have been awarded annually since by the John Simon Guggenheim Memorial Foundation, endowed by the late Simon and Olga Hirsh Guggenheim. These awards are bestowed upon individuals who have demonstrated d ...

for the academic year 1952–1953, he was at the

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

on leave of absence from Johns Hopkins. From 1961 until his death from a heart attack in 1962, he was a full professor at the

Rockefeller University The Rockefeller University is a Private university, private Medical research, biomedical Research university, research and graduate-only university in New York City, New York. It focuses primarily on the biological and medical sciences and pro ...

. Berlin was a Fellow of the

American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of ...

. He was an associate editor for the ''

Journal of Chemical Physics ''The Journal of Chemical Physics'' is a scientific journal published by the American Institute of Physics that carries research papers on chemical physics.Physical Review ''Physical Review'' is a peer-reviewed scientific journal. The journal was established in 1893 by Edward Nichols. It publishes original research as well as scientific and literature reviews on all aspects of physics. It is published by the Ame ...

'', and ''

Physical Review Letters ''Physical Review Letters'' (''PRL''), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society. The journal is considered one of the most prestigious in the field of physics ...

''. He was appointed to the

editorial board The editorial board is a group of editors, writers, and other people who are charged with implementing a publication's approach to editorials and other opinion pieces. The editorials published normally represent the views or goals of the publicat ...

of ''

The Physics of Fluids ''Physics of Fluids'' is a monthly peer-reviewed scientific journal covering fluid dynamics, established by the American Institute of Physics in 1958, and is published by AIP Publishing. The journal focus is the dynamics of gases, liquids, and c ...

'', starting on 1 January 1962. His doctoral students include

Louis Witten Louis W. Witten (born April 13, 1921)ORAL HISTORIES: Louis Witten< ...

Scientific output

At the beginning of his career, Berlin did research on

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, statistical mech ...

(quantum theory of molecules). He is known for his work with Kac on the ''

spherical model The spherical model is a model of ferromagnetism similar to the Ising model, which was solved in 1952 by T. H. Berlin and M. Kac. It has the remarkable property that for linear dimension ''d'' greater than four, the critical exponents that govern ...

'', a generalization of the

Ising model The Ising model (or Lenz–Ising model), named after the physicists Ernst Ising and Wilhelm Lenz, is a mathematical models in physics, mathematical model of ferromagnetism in statistical mechanics. The model consists of discrete variables that r ...

statistical mechanics In physics, statistical mechanics is a mathematical framework that applies statistical methods and probability theory to large assemblies of microscopic entities. Sometimes called statistical physics or statistical thermodynamics, its applicati ...

, which was developed as a mathematical model for

ferromagnetism Ferromagnetism is a property of certain materials (such as iron) that results in a significant, observable magnetic permeability, and in many cases, a significant magnetic coercivity, allowing the material to form a permanent magnet. Ferromagne ...

. In contrast to the

, the spherical model's spin variable on the lattice can assume continuous values (with the restriction that the sum of the squares of the spins is equal to the number of lattice positions). The spherical model can be solved exactly in the presence of an external field and shares that property of exact solvability with very few models of

Personal life

In 1944 Berlin married Patricia May Cleary. They had sons Geoffrey N., Dennis A., Michael K., and Alexander L. A daughter died in infancy.

References

{{DEFAULTSORT:Berlin, Theodore H. 1917 births 1962 deaths Cooper Union alumni University of Michigan alumni Johns Hopkins University faculty 20th-century American physicists Fellows of the American Physical Society