On the day Heike Kamerlingh Onnes first liquefied helium, his laboratory at Leiden University briefly encompassed the coldest place on Earth. It was a wet and windy 10 July 1908. Kamerlingh Onnes, awakened before dawn by his wife Betsy, ordered a carriage at 5am to take him from his fine country house on the river Galgewater to his laboratory in the center of the Dutch university town.
His technicians were already hard at work. The day before, they had increased the stock of liquid air to 75 liters, checked the apparatus for leaks, pumped it out,and then filled it with pure hydrogen. Now the first task was to liquefy the hydrogen. While the pumps thundered away in lab Aa, Kamerlingh Onnes and his assistants rushed around, turning valves,connecting and disconnecting gas cylinders, and carefully watching pressure gauges and thermometers. They didn’t stop for lunch. By 1:30pm, 20 liters of liquid...
