Superfluidity finding earns physics Nobel.A report in the April 3, 1972 Physical Review Letters Physical Review Letters is one of the most prestigious journals in physics.[1] Since 1958, it has been published by the American Physical Society as an outgrowth of The Physical Review. described the discovery of a new phase of solid helium (SN: 4/15/72, p. 249). It took several more months for the report's authors, Douglas D. Osheroff Douglas Dean Osheroff (born August 1, 1945) is an American physicist. He shared the Nobel Prize in Physics in 1996 with David Lee and Robert C. Richardson for discovering the superfluidic nature of 3He. , Robert C. Richardson There are at least two famous people with the name Robert C. Richardson. These are:
n. A fluid, such as a liquid form of helium, exhibiting a frictionless flow at temperatures close to absolute zero. su , a state of matter in which atoms move in a coordinated manner, allowing the liquid to flow without resistance. Last week, Osheroff, Richardson, and Lee won the 1996 Nobel Prize in Physics The Nobel Prize in Physics (Swedish: Nobelpriset i fysik) is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the six Nobel Prizes. The first prize was awarded in 1901. for this finding. "It was a tremendous discovery made by extremely careful experimentalists," says physicist Russell J. Donnelly of the University of Oregon The University of Oregon is a public university located in Eugene, Oregon. The university was founded in 1876, graduating its first class two years later. The University of Oregon is one of 60 members of the Association of American Universities. in Eugene. As liquids and solids are cooled toward absolute zero, they sometimes undergo phase transitions, in which their structure changes. In the late 1930s, researchers found that liquefied helium-4, the most common helium isotope, becomes a superfluid at a temperature of 2.17 kelvins. Theorists predicted that helium-3 would also become a superfluid but at a lower temperature. However, experimental work couldn't proceed until resear- chers obtained a supply of helium-3 as a by-product of tritium tritium (trĭt`ēəm), radioactive isotope of hydrogen with mass number 3. The tritium nucleus, called a triton, contains one proton and two neutrons. It has a half-life of 12.5 years and decays by beta-particle emission. production in hydrogen bomb experiments of the 1950s. Many research groups started looking for Looking for In the context of general equities, this describing a buy interest in which a dealer is asked to offer stock, often involving a capital commitment. Antithesis of in touch with. superfluid helium-3, but no one succeeded until Osheroff, then a graduate student at Cornell, noticed a change in the cooling rate of a sample consist- ing of both solid and liquid helium-3 at a temperature of 2.7 millikelvins. The Cornell team had expected to find a transition to a particular magnetic state near that temperature. Instead, their measurements suggested that helium-3 had settled into an ordered phase that differed fundamentally from the expected magnetic state. Initially, the researchers interpreted the result as a phase transition in the solid form of helium-3. Additional measurements indicated that a pair of phase changes had produced two distinct superfluid states of liquid helium-3. "Though an accidental discovery, it was a very important one," Donnelly notes. It marked the start of intensive research on the peculiarities of quantum effects in liquids. Osheroff, now at Stanford University, has continued the work, studying transi- tions between two forms of superfluid helium-3 (SN: 7/18/92, p. 38). Richardson and Lee are investigating the behavior of thin metal films and other materials at low temperatures. |
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