Dutch physicist who specialized in cryogenics.
He was the son of the Catholic Hendrikus Wilhelmus Keesom (5 May 1849, Den Burg – 23 December 1929 0h30 AM, Den Burg), a cattle merchant and Neeltje Dijt (13 June 1851, Zuidhaffel – 17 February 1940, Leiden). Neeltje was the daughter of Pieter Dijt (1815-1893) and Petronella Verberne (1818-1890}. Hendrikus parents, were Hendrik Keesoom (1816-1884) and Antje Verberne (1814-1870).
Willem was the eldest of nine children. After him were born: NN Keesom (1878-1878), Simon Petrus Keesom (1879-1887), Anna Petronella Keesom (1881-1917), Hendrik Keesom (1883-1969), NN Keesom (1884-1884), Simon Cornelis Keesom (1885-1886), Petronella Maria Keesom (1887-1888) and Simon Petrus Keesom (1892-1892).
He dissertated 19 January 1904 under Johannes Diderik van der Waals Sr. at the University of Amsterdam with “Isothermen van mengsels van zuurstof en koolzuur”.
Later Keeson became a student of Heike Kamerlingh Onnes, who had discovered superconductivity (1911), after he succeeded in liquefying Helium (1908).
In 1917 he joined the faculty of the Utrecht veterinary school. Here he developed the first mathematical description of dipole-dipole “Keesom” interactions in 1921.
In 1923 he returned to Leiden as professor of experimental physics. At the Kamerlingh Onnes laboratory in Leiden, he successfully solidified helium in 1926. In 1932 he achieved the temperature of -457.6° F (-272° C), just two degrees Fahrenheit above absolute zero. His book Helium appeared in 1942. He also discovered the lambda-point transition specific-heat maximum between Helium-I and Helium-2 in 1930 (Basic Superfluids p25/Tony Guenault).
In 1924 he became member of the Royal Netherlands Academy of Arts and Sciences.
Personal
On 27 January 1904, he married Anna Maria Aleida Moorman (9 April 1878, Den Helder – 6 February 1923, Utrecht) on the isle of Texel. The notice of marriage was on 10 January 1904 in Den Burg. They got two boys and four girls (See Events), who all survived him. On he 23 February 1927 he married Seraphina Josephina Francisca Maria Gieliam (6 March 1880, Tilburg – ?)
He died on 3 March 1956 21h30 in Leiden.
Link to Wikipedia