A Brill Calendar: February 21

Leiden: The Coldest Place on Earth

Few Leyden Professors can claim they brought the city to the front-page of newspapers world-wide.

One is Heike Kamerlingh Onnes, who liquefied Helium gas on Sunday, June 10, 1908; the first physicist to do so. It made the city for the ‘coldest place on earth’ and contributed to Leyden’s fame as the Olympus of Physics. Onnes (born in Groningen, on September 1853 - alumnus of Groningen & doctoral thesis in 1879, and winner of the Nobel Prize 1913, and Leyden Professor of Experimental Physics since 1882), founded, invented, organized and managed an unprecedented Cryogenic Laboratory like an army commander in both strategy and tactics; with team-members for troops.

One of the students he impressed, the hardly less distinguished physicist H. B. G. Casimir – a wise & generous scientist if there ever was one - wrote extensively on this class-conscious Titan; in an erudite and witty recollection of his personal career, (‘Haphazard Reality – Half a Century of Science’, (1983) published in the original English by Harper & Row, Publishers, New York, translated into Dutch the same year). One recollection concerns Onnes’ funeral in the church-yard of Voorschoten village near Leyden; (the great professor having died February 21 1926).

After the obituary service in the city, his technical staff was supposed to follow the hearse drawn by four black horses on foot, the subaltern craftsmen dressed formally in black with top-hats to match. However, as soon as Leyden’s outskirts came insight the animals opted for a brisk trot. When the cortege reached its destination, Kamerlingh Onnes’s work-force arrived panting & sweating. One of them is reported to have wiped his forehead before smiling and then saying: “Now that’s the Old Boss all-right; even after his death he keeps you running!”

It is seldom that Onnes impressed peers and pupils by his empathy in daily tasks & chores. But it is very like the Leyden alumnus Casimir to add after this anecdote that this idea of ‘keeping running’ also applies figuratively; and that many generations of physicists have worked - and still work - in the domain Onnes opened up.