Heike Kamerlingh Onnes bigraphy, stories - Physicist

Heike Kamerlingh Onnes : biography

September 21, 1853 - February 21, 1926

Heike Kamerlingh Onnes (21 September 1853 – 21 February 1926) was a Dutch physicist and Nobel laureate. He pioneered refrigeration techniques and used these to explore how materials behave when cooled to nearly absolute zero. He was the first to liquefy helium. His production of extreme cryogenic temperatures led to his discovery of superconductivity in 1911: for certain materials, electrical resistance abruptly vanishes at very low temperatures.Dirk van Delft, Freezing physics, Heike Kamerlingh Onnes and the quest for cold, edited by Edita KNAW, Amsterdam, 2007.

Legacy

Some of the instruments he devised for his experiments can be seen at the Boerhaave Museum in Leiden. The apparatus he used to first liquefy helium is on display in the lobby of the physics department at Leiden University, where the low temperature lab is also named in his honor. His student and successor as director of the lab Willem Hendrik Keesom was the first person who was able to solidify helium, in 1926.

The Onnes effect referring to the creeping of superfluid helium is named in his honor.

The crater Kamerlingh Onnes on the Moon is named after him.

Onnes is also credited with coining the word "enthalpy".

Onnes' discovery of superconductivity was named an IEEE Milestone in 2011.

University of Leiden

From 1882 to 1923 Kamerlingh Onnes served as professor of experimental physics at the University of Leiden. In 1904 he founded a very large cryogenics laboratory and invited other researchers to the location, which made him highly regarded in the scientific community. The laboratory is known now as Kamerlingh Onnes Laboratory.

Liquefaction of helium

On July 10, 1908, he was the first to liquefy helium, using several precooling stages and the Hampson-Linde cycle based on the Joule-Thomson effect. This way he lowered the temperature to the boiling point of helium (-269 °C, 4.2 K). By reducing the pressure of the liquid helium he achieved a temperature near 1.5 K. These were the coldest temperatures achieved on earth at the time. The equipment employed is at the Boerhaave Museum in Leiden.

Superconductivity

In 1911 Kamerlingh Onnes measured the electrical conductivity of pure metals (mercury, and later tin and lead) at very low temperatures. Some scientists, such as William Thomson (Lord Kelvin), believed that electrons flowing through a conductor would come to a complete halt or, in other words, metal resistivity would become infinitely large at absolute zero. Others, including Kamerlingh Onnes, felt that a conductor's electrical resistance would steadily decrease and drop to nil. Augustus Matthiessen pointed out when the temperature decreases, the metal conductivity usually improves or in other words, the electrical resistivity usually decreases with a decrease of temperature.Matthiessen, A. Philosophical Transactions; 1862 and also Philosophical Transactions; 1864

On April 8, 1911, Kamerlingh Onnes found that at 4.2 K the resistance in a solid mercury wire immersed in liquid helium suddenly vanished. He immediately realized the significance of the discovery (as became clear when his notebook was deciphered a century later). He reported that "Mercury has passed into a new state, which on account of its extraordinary electrical properties may be called the superconductive state". He published more articles about the phenomenon, initially referring to it as "supraconductivity" and, only later adopting the term "superconductivity.".

Kamerlingh Onnes received widespread recognition for his work, including 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".

Honors and awards

  • Matteucci Medal (1910)
  • Rumford Medal (1912)
  • Nobel Prize in Physics (1913)
  • Franklin Medal (1915)
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