Heike Kamerlingh Onnes

It’s the birthday of Heike Kamerlingh Onnes, who was born in 1853 in Groningen, the Netherlands. Onnes studied physics at the Universities of Groningen and Heidelberg. When he was appointed physics professor at Leiden University, he set about establishing a laboratory for low-temperature physics. In 1908 Onnes succeeded in liquifying helium at 1.5 K. On 8 April 1911 he discovered that the resistance in a solid mercury wire immersed in liquid helium vanished abruptly when the temperature fell below 4.2 K. He wrote in his notebook that day: “Mercury has passed into a new state, which on account of its extraordinary electrical properties may be called the superconductive state.” Two years later Onnes was awarded the Nobel physics prize, but it would take almost half a century before John Bardeen, Leon Cooper and J. Robert Schrieffer devised a theory that could account for the phenomenon that Onnes had discovered.

Date in History: 21 September 1853