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 ( ();
Heike Kamerlingh Onnes 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. 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