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Researchers at the Pennsylvania State University are announcing the possible discovery of an entirely new phase of matter: an ultra-cold, "supersolid" form of helium-4. Writing in the 15 January 2004 issue of the journal Nature, Penn State physicist Moses H. W. Chan and his graduate student, Eun-Seong Kim, explain that their material is a solid in the sense that all its helium-4 atoms are frozen into a rigid crystal lattice, much like the atoms and molecules in a normal solid such as ice. The difference is that "frozen," in this case, doesn't mean "stationary." Because helium-4 lattice is so very cold, less than one tenth of a degree above absolute zero, the laws of quantum uncertainty take over. In effect, the helium atoms start to behave as if they were both solid and fluid-at the same time. Under the right circumstances, in fact, some fraction of the helium atoms can begin to move through the lattice like a substance known as a "superfluid": a liquid that moves with no friction whatsoever. Thus the name "supersolid." Chan and Kim's work, which was funded by the National Science Foundation (NSF), is described in a Penn State press release posted on the EurekAlert site. That site has an embargo of 1 pm Eastern time, 14 January 2004. After that time, the release will also be available at http://www.science.psu.edu/alert/Chan1-2004.htm. In addition, NSF has prepared an animation that illustrates the basics of Chan and Kim's experimental setup, and the supersolid behavior they believe they have detected. Principal Investigator: Moses H.W. Chan, (814) 863-2622, Mhc2@psu.edu The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering, with an annual budget of nearly $5.3 billion. NSF funds reach all 50 states through grants to nearly 2,000 universities and institutions. Each year, NSF receives about 30,000 competitive requests for funding, and makes about 10,000 new funding awards. The NSF also awards over $200 million in professional and service contracts yearly. Receive official NSF news electronically through the e-mail delivery system, NSFnews. To subscribe, send an e-mail message to join-nsfnews@lists.nsf.gov. In the body of the message, type "subscribe nsfnews" and then type your name. (Ex.: "subscribe nsfnews John Smith") Useful NSF Web Sites:
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