Hans Kramers

Hans Kramers
Hans Kramers in c. 1928
Born	Hendrik Anthony Kramers 2 February 1894 Rotterdam, Netherlands
Died	24 April 1952 (aged 58) Oegstgeest, Netherlands
Nationality	Dutch
Fields	Physics
Alma mater	Leiden University
Doctoral advisor	Niels Bohr Paul Ehrenfest
Doctoral students	Henri Brinkman Dirk ter Haar Lamek Hulthén Nico van Kampen Jacob Kistemaker Tjalling Koopmans Luitzen Johannes Oosterhoff
Known for	Kramers–Heisenberg formula Wentzel–Kramers–Brillouin approximation Kramers–Kronig relation Kramers–Wannier duality Kramers model for polymer chains Kramers–Anderson superexchange Kramers' degeneracy theorem Kramers' law Kramers' opacity law
Notable awards	Lorentz Medal (1947) Hughes Medal (1951)

Hendrik Anthony "Hans" Kramers (2 February 1894 – 24 April 1952) was a Dutch physicist who worked with Niels Bohr to understand how electromagnetic waves interact with matter.

Background and education

Hans Kramers was the son of Hendrik Kramers, a physician, and Jeanne Susanne Breukelman. On 25 October 1920 he was married to Anna Petersen. They had three daughters and one son.

In 1912 Hans finished secondary education (HBS) in Rotterdam, and studied mathematics and physics at the University of Leiden, where he obtained a master's degree in 1916. Kramers wanted to obtain foreign experience during his doctoral research, but his first choice of supervisor, Max Born in Göttingen, was not reachable because of the first world war. Because Denmark was neutral in this war, as was the Netherlands, he travelled (by ship, overland was impossible) to Copenhagen, where he visited unannounced the then still relatively unknown Niels Bohr. Bohr took him on as a Ph.D. candidate and Kramers prepared his dissertation under Bohr's direction. Although Kramers did most of his doctoral research (on intensities of atomic transitions) in Copenhagen, he obtained his formal Ph.D. under Ehrenfest in Leiden, on 8 May 1919.

Academic career

After working for almost ten years in Bohr's group and becoming an associate professor at the University of Copenhagen, Kramers left Denmark in 1926 and returned to the Netherlands. He became a full professor in theoretical physics at Utrecht University, where he supervised Tjalling Koopmans. In 1934 he left Utrecht and succeeded Paul Ehrenfest in Leiden. From 1931 until his death he held also a cross appointment at Delft University of Technology.

Kramers was one of the founders of the Mathematisch Centrum in Amsterdam.

In 1925, with Werner Heisenberg he developed the Kramers–Heisenberg dispersion formula. He is also credited with introducing in 1948 the concept of renormalization into quantum field theory.

Recognition

Kramers became member of the Royal Netherlands Academy of Arts and Sciences in 1929, he was forced to resign in 1942. He joined the Academy again in 1945.^[1] Kramers won the Lorentz Medal in 1947 and Hughes Medal in 1951.

References

1. "Hans A. Kramers (1894 - 1952)". Royal Netherlands Academy of Arts and Sciences. Retrieved 28 July 2015.

• Dresden, Max (1987). H.A. Kramers – Between Tradition and Revolution. Springer. ISBN 0-387-96282-4.
• Belinfante, F. J.; ter Haar, D. (1952). "Hendrik Anthony Kramers: 1894–1952". Science 116 (3021): 555–556. Bibcode:1952Sci...116..555B. doi:10.1126/science.116.3021.555.

External links

• H.B.G. Casimir, Kramers, Hendrik Anthony (1894–1952), in Biografisch Woordenboek van Nederland. (in Dutch)
• J.M. Romein, Hendrik Anthony Kramers, in: Jaarboek van de Maatschappij der Nederlandse Letterkunde te Leiden, 1951–1953, pp. 83–91. (in Dutch)
• Ph.D. candidates of H.A. Kramers: 1929-1952
• Publications of H.A. Kramers