Hans Mueller (1900–1965) was a Swiss

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 caus ...

and professor at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

(MIT). He created

Mueller calculus Mueller calculus is a matrix method for manipulating Stokes vectors, which represent the polarization of light. It was developed in 1943 by Hans Mueller. In this technique, the effect of a particular optical element is represented by a Mueller ...

. Mueller was born October 27, 1900, in Amriswil, canton

Thurgau Thurgau (; french: Thurgovie; it, Turgovia), anglicized as Thurgovia, more formally the Canton of Thurgau, is one of the 26 cantons forming the Swiss Confederation. It is composed of five districts and its capital is Frauenfeld. Thurgau is part ...

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

. His father was Ernst Müller and mother Mathilde Meier. Hans attended school in

Frauenfeld Frauenfeld (Alemannic: ''Frauefäld'') is the capital of the canton of Thurgau in Switzerland. The official language of Frauenfeld is (the Swiss variety of Standard) German, but the main spoken language is the local variant of the Alemannic Sw ...

and proceeded in 1919 to

Eidgenössische Technische Hochschule (colloquially) , former_name = eidgenössische polytechnische Schule , image = ETHZ.JPG , image_size = , established = , type = Public , budget = CHF 1.896 billion (2021) , rector = Günther Dissertori , president = Joël Mesot , ac ...

. He graduated with a teacher's diploma for science and mathematics in 1923. In graduate work his advisors were

Peter Debye Peter Joseph William Debye (; ; March 24, 1884 – November 2, 1966) was a Dutch-American physicist and physical chemist, and Nobel laureate in Chemistry. Biography Early life Born Petrus Josephus Wilhelmus Debije in Maastricht, Netherlands, D ...

and

Paul Scherrer Paul Hermann Scherrer (3 February 1890 – 25 September 1969) was a Swiss physicist. Born in St. Gallen, Switzerland, he studied at Göttingen, Germany, before becoming a lecturer there. Later, Scherrer became head of the Department of Physics ...

. In 1925, Mueller and Debye set out for a visit to MIT. Mueller was offered a position as instructor and in time became a popular professor. In 1928 he submitted his dissertation, ''On the Theory of Electric Charge and Coagulation of Colloids'' to ETH for the doctorate in physics. In 1935, he was promoted to

associate professor Associate professor is an academic title with two principal meanings: in the North American system and that of the ''Commonwealth system''. Overview In the ''North American system'', used in the United States and many other countries, it is a ...

. He was elected in 1936 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 k ...

. (search on year=1936 and institution=Massachusetts Institute of Technology) As a Guggenhiem Fellow, he was at the

Cavendish Laboratory The Cavendish Laboratory is the Department of Physics at the University of Cambridge, and is part of the School of Physical Sciences. The laboratory was opened in 1874 on the New Museums Site as a laboratory for experimental physics and is named ...

of Cambridge University in 1937–38. In 1942, he became a full professor. In research, Mueller measured

luminous intensity In photometry, luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. ...

and studied

polarization of light Polarization ( also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of t ...

. He wrote several papers on

Rochelle salt Potassium sodium tartrate tetrahydrate, also known as Rochelle salt, is a double salt of tartaric acid first prepared (in about 1675) by an apothecary, Pierre Seignette, of La Rochelle, France. Potassium sodium tartrate and monopotassium phosphat ...

s. The development of his matrix calculus was initially classified, but he made an exposition to the

Optical Society of America Optica (formerly known as The Optical Society (OSA) and before that as the Optical Society of America) is a professional society of individuals and companies with an interest in optics and photonics. It publishes journals and organizes conference ...

in 1948. His student Nathan Grier Park III wrote a thesis, ''Matrix Optics'' expounding the method. Hans Mueller died June 10, 1965, in

Belmont, Massachusetts Belmont is a town in Middlesex County, Massachusetts. It is a western suburb of Boston, Massachusetts, United States; and is part of the Greater Boston metropolitan area. At the time of the 2020 U.S. Census, the town's population stood at 27,295 ...

References

{{DEFAULTSORT:Mueller, Hans 1900 births 1965 deaths ETH Zurich alumni Massachusetts Institute of Technology School of Science alumni Massachusetts Institute of Technology School of Science faculty Optical physicists Swiss emigrants to the United States Fellows of the American Physical Society People from Thurgau