Heike Kamerlingh Onnes (September 21, 1853 – February 21, 1926) was a Dutch physicist. Onnes' scientific career was spent exploring extremely cold refrigeration techniques and the associated phenomena.

Early years and professorship

Onnes was born in Groningen, Netherlands. His father, Harm Kamerlingh Onnes, was the brickworks owner. His mother was Anna Gerdina Coers of Arnhem.

In 1870, Onnes attended the University of Groningen. Onnes studied under Robert Bunsen and Gustav Kirchhoff at the University of Heidelberg from 1871 to 1873. Onnes, again at Groningen, obtained his masters in 1878 and a doctor's degree in 1879. His thesis was "Nieuwe bewijzen voor de aswenteling der aarde" (tr. New proofs of the rotation of the earth).

From 1882 to 1923 he served as professor of experimental physics at the University of Leiden. In 1904, Onnes founded a very large cryogenics lab and invited other researchers to the location. Onnes being held in high reguard by the scientific community was because of this institution. In 1908 Onnes was the first physicist who made this liquefaction of helium possible (using cryostats). Onnes managed, using the Joule-Thomson effect, to lower the temperature to less than one degree above the absolute minimum (0.9 K). By then this was by far the coldest place on earth.

Superconductivity

Onnes conducted (in 1911) electrical analysis of pure metals (mercury, tin and lead) at very low temperatures. Some, such as William Thomson, believed that electrons flowing through a conductor would come to a complete halt. Others, including Onnes, felt that a conductors electrical resistance would steadily decrease and drop to nil. At 4.2 kelvins the resistance was zero. Onnes stated that the "Mercury has passed into a new state, which on account of its extraordinary electrical properties may be called the superconductive state". Onnes published more articles about the phenomena. Initially, Onnes preferred to call the phenomena "supraconductivity" and, only later, adopted the term "superconductivity".

Among his later achievements was winning the 1913 Nobel Prize in Physics for (in the words of the committee) "his investigations on the properties of matter at low temperatures which led, inter alia, to the production of liquid helium". (Inter alia means "among other things".)

Death and afterwards

He died in Leiden. The instruments Onnes devised for his experiments can still be seen at the Boerhaave museum in Leiden. His student and successor as director of the lab Willem Hendrik Keesom was the first person who was able to solidify helium, in 1926.

Publications

• Onnes, H. Kamerlingh, "Nieuwe bewijzen voor de aswenteling der aarde." Ph.D. dissertation. Groningen, Netherlands, 1879.
  
• Onnes, H. Kamerlingh, "Algemeene theorie der vloeistoffen." Amsterdam Akad. Verhandl. 21, 1881.
  
• Onnes, H. Kamerlingh, "On the Cryogenic Laboratory at Leyden and on the Production of Very Low Temperature." Comm. Phys. Lab. Univ. Leiden 14, 1894.
  
• Onnes, H. Kamerlingh, "Théorie générale de l'état fluide." Haarlem Arch. Neerl. 30, 1896.
  
• Onnes, H. Kamerlingh, "The Superconductivity of Mercury." Comm. Phys. Lab. Univ. Leiden, Nos. 122 and 124, 1911
  
• Onnes, H. Kamerlingh, "On the Lowest Temperature Yet Obtained." Comm. Phys. Lab. Univ. Leiden, No. 159, 1922.
  

See also

• Timeline of low-temperature technology
  
• Timeline of states of matter and phase transitions
  
• Coldest temperature achieved on earth
  
• History of superconductivity
  

Further reading

• Levelt-Sengers, J. M. H., "How fluids unmix : discoveries by the School of Van der Waals and Kamerlingh Onnes". Amsterdam, Koninklijke Nerlandse Akademie van Wetenschappen, 2002. ISBN 9069843579
  
• Onnes, Heike Kamerlingh, (Gavroglou, Kōstas. [ed.], and Goudaroulis, Yorgos [ed.]) "Through measurement to knowledge : the selected papers of Heike Kamerlingh Onnes (1853-1926)". Dordrecht, Boston, Kluwer Academic Publishers, c1991. Goudaroulis, Yorgos. ISBN 0792308255
  
• International Institute of Refrigeration (First International Commission), "Rapports et communications issus du Laboratoire Kamerlingh Onnes". International Congress of Refrigeration (7th; 1936; La Hauge), Amsterdam, 1936.
  

Links and references