Heike Kamerlingh Onnes a "Kamerlingh Onnes Laboratorium" named after him, as well as a plaque and several machines used by Kamerling Onnes in the main hall of the physics department. The Kamerlingh Onnes Award was established in his honour, recognising further advances in low-temperature science. 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. Heike Kamerlingh Onnes Professor Heike Kamerlingh Onnes FRSFor HFRSE FCS ( ();
Jacob Clay Jacob Clay Jacob Clay () (1882–1955) was a prominent Dutch physicist who first suggested and provided evidence that cosmic rays are charged particles. Clay was born "Jacob Claij" in Berkhout on 18 January 1882 as the son of Pieter Claij and Neeltje Molenaar. After attending the Erasmiaans Gymnasium, he studied physics at the University of Leiden under Heike Kamerlingh Onnes and Hendrik Antoon Lorentz. After obtaining his Ph.D. degree in 1908 he married Tettje Clay-Jolles with whom he had a son. After teaching in Leiden and at the Technische Hogeschool in Delft from 1906 to 1920, he was appointed Professor