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CORNELL ALUMNI NEWS a Preeminent Group of Physicists Discovers How Oddly Matter Behaves When Cooled to Very Low Temperatures

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CORNELL ALUMNI NEWS a Preeminent Group of Physicists Discovers How Oddly Matter Behaves When Cooled to Very Low Temperatures CORNELL ALUMNI NEWS A preeminent group of physicists discovers how oddly matter behaves when cooled to very low temperatures Strange Doings Near Absolute Zero By William Steele '54 It started in the early '60s, about the An inauspicious omen, perhaps, but The group has also received a subtler time the low temperature laboratory in a way it symbolized a beginning. Out but perhaps equally satisfying accolade: started to fall into a hole. Cornell had of the hole behind Rockefeller would their graduate students are much in de- just hired David Lee out of the low tem- rise Clark Hall, home for the newly mand. "They have a remarkable reputa- perature physics group at Yale. Al- created Laboratory of Atomic and Solid tion in the scientific community for the though only a lowly $4,500-a-year State Physics (LASSP). In Room H-8 in students they turn out," says Prof. Her- instructor, he became the reigning mon- the basement the new low temperature bert Johnson, director of the Materials arch of low temperature research; he facility Lee was to design would reach Science Center. "When students come inherited a garage-sized brick and con- temperatures 1,000 times colder than out of here they are prepared to set up a crete building behind Rockefeller Hall anything possible in the "Rockefeller laboratory from virtually a bare room. that housed a helium liquifier and other Annex." He would be joined by col- They have seeded a number of univer- apparatus for cooling things to within a leagues John Reppy and Robert Rich- sities throughout the country and the few degrees of absolute zero. ardson, and the trio would build the low world." Excavations for the basement of temperature experimental group into To which Lee adds wryly: "Where Clark Hall were going on just a few feet one that Prof. Neiί Ashcroft calls some of them are now in dire competi- away. One day Lee came to work and "probably the most prestigious in the tion with us!" found a crack in the floor; each day it world." In many places it would be unusual to grew longer and wider, until it extended Ashcroft is director of LASSP and have three professors working in one up the wall and made a gap wide enough their boss, so is admittedly prejudiced; field, but at Cornell it's becoming stan- for him to watch the construction work- but the world has indeed beaten a path dard practice. "One of the things that's ers walking by. The lab was evacuated to the doors of H-8. In March, 1981, been rather nice about the way Cornell "precipitously," Lee recalls, as the floor Richardson, Lee, and Douglas Osher- has developed in physics," Richardson began to cant toward the hole. off, PhD '73, now at Bell Laboratories, says, "is that instead of trying to cover received the Oliver E. Buckley Solid every possible field they tried to In a public lecture in Rockefeller Hall, State Physics Prize from the American strengthen certain areas." Prof Robert Richardson transfers Physical Society for the discovery and The concentration, he says, allows the liquid helium into a transparent subsequent study of the superfluid state group to share ideas and equipment and vacuum flask for an experiment in low of liquid helium-3. In 1976 they had re- makes it easier to attract outside talent; temperature physics. The fog above the ceived the Simon Memorial Prize from there's a visiting professor in low tem- apparatus is from the cold helium gas. the British Institute of Physics for the On the wall behind, small magnets are perature physics almost every year. In projected to illustrate how matter same discovery. In August 1981, Reppy return, the trio spend their share of time aligns magnetically at very low was a co-recipient of the Fritz London on the road. Reppy has taken sabbati- temperatures. See page 20 for the final Memorial Award for important contri- cals at the universities of Manchester phase of this demonstration. butions to the study of liquid helium. and Sussex in England, Richardson has MAY 1982 spent a year in Finland, while Lee is the arranged to have Strauss' Also Sprach "far eastern expert," with visits to Ja- Zarathustra played in the background as pan and China on his record. he poured liquid helium, raising spectac- Although Ashcroft likes to call them ular clouds of mist. (The lecture, titled "The Three Horsemen of the Apoca- "A World without Disorder: Absolute lypse," all three say, in almost the same Zero," was videotaped and can be words, "We are not a team." viewed at Rockefeller Hall or borrowed "We are individuals who strongly in- for public showings.) teract," says Lee. In teaching, the three professors are "Individual entrepreneurs," says consciously a team. The low tempera- Richardson. ture group generally includes ten or "A loose coalition," says Reppy. twelve graduate students and two or There are certainly no leaders and no three post-docs (again, more than you'd followers. Lee sums up the relationship find in one field in most places). Stu- this way: "For us, the axiom in plane ge- dents are not only allowed, but encour- ometry is wrong; the whole is not equal aged to seek help from any professor, to the sum of its parts. The axiom and to interact among themselves. doesn't take into account the interaction Lee claims that "students tend to between the parts." learn more from each other than from They certainly don't look like a team, their professors, anyway." To foster though Richardson and Lee might be such interaction, Richardson has orga- taken for brothers. Both are lanky, with nized a Thursday night low temperature conventional short hair and unconven- seminar that may be the only such meet- tional twinkles in their eyes. Richard- ing on campus with a negative honorar- son's voice has a kind of Jimmy Stewart ium: the speaker is expected to provide throatiness; Lee's has the stutter. In this beer and crunchies for the assemblage. company Reppy is the misfit: shorter, One of the reasons these students have with longish hair and beard and a lined been so successful, Reppy says, is that outdoorsman's face that faintly suggests they have tended to stay in school longer Profs John Reppy, above, and David he should be carrying a bagpipe. than most. "During a large part of the Lee, and a jokingly mislabeled vat for Described by most as quiet, Reppy in- time we were around," he says, "it's a low temperature experiment. deed prefers the loneliness of long-dis- been a bad job market, so students tance running; he's competed five times wanted to be well-trained to be sure of new understanding of the forces that in the Boston Marathon, and claims to getting a job." With a kind of inverted hold matter together. The Cornell group have run a 4:40 mile about three years modesty, he adds that it's easy to turn has specialized in the study of liquid he- ago (at the age of 48). But he's also a out good students if you have good ma- lium. So far there seems to be no practi- mountain climber, and that's certainly terial coming in, and that Cornell is now cal application for any of this research, an activity that calls for cooperation. He getting the cream because of its good but liquid helium is definitely fascinating seems to have inveigled Lee into some of reputation. stuff. It was the last of the gases in the these activities, at least to the extent of The job market is getting a lot better atmosphere—once thought to be "per- running around campus. Richardson these days. Low temperature physics is, manent gases"—to be liquified, at a sticks to more sedentary hobbies like if you'll pardon the expression, "hot." temperature of about four degrees above gardening and playing piano to his Its most visible spinoff is superconduc- absolute zero. daughter's violin. tivity, the effect that allows certain While most of America is struggling Richardson is often the most visible of metals to carry an electric current with with (and generally rejecting) a change- the three, being both joiner and orga- zero resistance at temperatures near ab- over from the Fahrenheit temperature nizer. He sits on several local boards and solute zero. Engineers are hard at work scale to the metric-style Celsius scale, committees and is often an organizer in on superconducting generators and scientists long ago switched to a scale of national scientific meetings. A confer- transmission lines. Superconducting "absolute temperature" called the Kel- ence on liquid helium held at Cornell last magnets may provide the means to vin scale, which starts at absolute zero summer was largely his creation. Says create a magnetic "bottle" strong (-273° C or -459° F) and goes up. One Johnson: "He interfaces well with peo- enough to contain a hydrogen fusion re- degree Kelvin is equal to one degree Cel- ple ... He can analyze problems that action. sius; on the Kelvin scale water melts at have both scientific and people compo- By about 1995 the Japan National 273K and boils at 373K. nents. If I have a question about some- Railroad hopes to cut the 350 mile ride With Kelvin temperatures the degree thing I usually go to Bob—but he on its famed "bullet train" from three symbol is usually left out, both in writ- doesn't speak for them; they talk it over hours to one by levitating the train a few ing and speaking.
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