Robert Richardson (1937-2013) Discoverer of Superfluidity in Helium-3

COMMENT OBITUARY Robert Richardson (1937-2013) Discoverer of superfluidity in helium-3.

obert Richardson, along with physicist his PhD, he and his young family moved we compressed liquid helium-3 until it David Lee and myself, discovered that to Ithaca, New York, where he became a began to solidify, causing the mixture helium-3, a rare but stable isotope of postdoctoral researcher for David Lee in of liquid and solid to cool. We initially Rhelium, becomes a superfluid when cooled to the low-temperature group at Cornell Univer- (mistakenly) believed that we had pro- a minuscule fraction of a degree above abso- sity. Richardson joined the Cornell faculty in duced magnetic order in the solid helium-3, lute zero. Until that discovery, in the early at about 0.002 Kelvins. In fact, 1970s, the superfluidity effect — in which we had observed a new physical state: a liquid flows without friction — had been superfluidity in liquid helium-3. The seen only in helium-4, whose atoms are three of us shared the 1996 Nobel Prize bosons. No one had been able to produce in Physics for this discovery. the phenomenon with fermions, whose Richardson won or shared many nuclei have spin properties different from awards and honours apart from the Nobel those seen in bosons. prize, including the Sir Francis Simon The discovery astounded the physics Memorial Prize in 1976 and the Oliver E.

CORNELL UNIVERSITY PHOTOGRAPHY community, which had all but given up Buckley Condensed Matter Prize in 1981. trying to produce the phenomenon in That year, he was also made a fellow of the helium-3. In the decades since, the under- American Association for the Advance- standing of superfluidity in this isotope ment of Science. He became a member has influenced the development of all of the US National Academy of Sciences sorts of superconducting materials, with in 1986. applications ranging from power grids Richardson was an exceptional citizen, to nuclear magnetic resonance (NMR) at Cornell University and in the broader instruments. It has also helped astrophys- physics community. From 1990 to 1996, icists to better understand neutron stars, he served as director of the laboratory which have superfluid cores. of atomic-state physics at Cornell. From Richardson, who died on 19 February, 1998 to 2007 he was the university’s first was born in Washington DC in 1937. He vice-provost for research. Richardson grew up in Arlington, Virginia, where was also a member of the US National his father worked for a local telephone Science Board, which oversees policy company. As a boy, Richardson was a issues related to research and education keen hiker, camper and birdwatcher. in science and engineering. He was a member of the Boy Scouts of Richardson, or Bob to those who knew America and became an Eagle Scout, the him, was competitive, passionate and highest rank attainable in the programme, creative, but also humble and consid- in the shortest time allowed. 1968 as an assistant professor in the physics erate. The great sadness of his life was the Richardson received his undergraduate department, and ultimately became a full tragic death, in 1994, of his younger daugh- and master’s degrees in physics at Virginia professor there. I was one of Lee’s graduate ter, Pamela, from heart failure. As a way Polytechnic Institute in Blacksburg, before students when Richardson became a pro- of dealing with their grief, Bob and Betty, spending six months as an officer in the fessor. Often working late into the night, together with Alan Giambattista, a physicist US Army. Before his military service, he Richardson was always around and willing at Cornell, threw themselves into writing a had intended to earn a master’s in business to give advice, irrespective of whose students physics textbook entitled College Physics. administration, but he was unimpressed we were. Bob went out of his way to help and guide by the management courses he took in By the early 1970s, chemists and materials young scientists. He was an avid participant the Army and decided to pursue a PhD in scientists had for decades been probing the in ‘penny pitching’ — a game, played ritually physics instead. behaviour of materials using NMR — in in the low-temperature lab for many years, In 1960, Richardson began his PhD which nuclei in a magnetic field absorb that involves tossing pennies at a wall to work in Horst Meyer’s laboratory at Duke and re-emit electromagnetic radiation at see whose coin lands closest to it — and he University in Durham, North Carolina. a specific frequency, depending on the often hosted croquet matches at his home. It was at Duke that Richardson met Betty properties of the atoms and the strength of He once challenged a graduate student who McCarthy, who was also a graduate student the field. But Richardson played a key part had been training for a marathon to a race up in physics. The two married in 1962; their in using the technique for extremely low- several flights of stairs; the student declined, daughters, Jennifer and Pamela, were born temperature studies. The question he, Lee wanting to keep Bob’s health intact. ■ in 1965 and 1966. In Meyer’s lab, Richardson and I set out to answer was whether the direc- learned how to make the equipment needed tion of the nuclear spins in solid helium-3 Douglas D. Osheroff is professor emeritus to investigate how collections of atoms could spontaneously order at sufficiently low at Stanford University, Stanford, California behave at very low temperatures. temperatures. 94305, USA. In 1966, soon after Richardson received To produce very low temperatures, e-mail: [email protected]