Willem Hendrik Keesom () (21 June 1876,

Texel Texel (; Texels dialect: ) is a municipality and an island with a population of 13,643 in North Holland, Netherlands. It is the largest and most populated island of the West Frisian Islands in the Wadden Sea. The island is situated north of De ...

– 3 March 1956,

Leiden Leiden (; in English and archaic Dutch also Leyden) is a city and municipality in the province of South Holland, Netherlands. The municipality of Leiden has a population of 119,713, but the city forms one densely connected agglomeration wit ...

) was a Dutch

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 ...

who, in 1926, invented a method to freeze liquid

helium Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...

. He also developed the first mathematical description of dipole–dipole interactions in 1921. Thus, dipole–dipole interactions are also known as Keesom interactions. He was previously a student of

Heike Kamerlingh Onnes Heike Kamerlingh Onnes (21 September 1853 – 21 February 1926) was a Dutch physicist and Nobel laureate. He exploited the Hampson–Linde cycle to investigate how materials behave when cooled to nearly absolute zero and later to liquefy helium f ...

, who had discovered

superconductivity Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike ...

(a feat for which Kamerlingh Onnes received the 1913

Nobel Prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...

in Physics). He also discovered the

lambda point The lambda point is the temperature at which normal fluid helium (helium I) makes the transition to superfluid helium II (approximately 2.17 K at 1 atmosphere). The lowest pressure at which He-I and He-II can coexist is the vapor−He-I−He-II t ...

transition specific-heat maximum between Helium-I and Helium-II in 1930. In 1924 he became member of the

Royal Netherlands Academy of Arts and Sciences The Royal Netherlands Academy of Arts and Sciences ( nl, Koninklijke Nederlandse Akademie van Wetenschappen, abbreviated: KNAW) is an organization dedicated to the advancement of science and literature in the Netherlands. The academy is housed ...

. In 1966, the minor planet '' 9686 Keesom'' was named after him.

References

External links

* Albert van Helden
''Willem Hendrik Keesom 1876 – 1956''
In: K. van Berkel, A. van Helden and L. Palm ed., A History of Science in the Netherlands. Survey, Themes and Reference (Leiden: Brill, 1999) 498–500. * Scientists of the Dutch School

@ Royal Netherlands Academy of Arts and Sciences. * P.H. van Laer
''Keesom, Wilhelmus Hendrikus (1876-1956)''
in Biografisch Woordenboek van Nederland. 1876 births 1956 deaths People from Texel 20th-century Dutch physicists Members of the Royal Netherlands Academy of Arts and Sciences University of Amsterdam alumni Leiden University faculty {{netherlands-scientist-stub

See also

References

External links