science · 15 August 1994 · 30 years ago
In 1994, the National Institute of Standards and Technology (NIST) issued a press release that physicists there recently cooled atoms to 700 nanokelvins, the coldest temperature ever recorded for matter. NIST scientists chilled a cloud of cesium atoms very close to absolute zero using lasers to catch the atoms in an optical lattice. The atoms reached 700 nanokelvins, or 700 billionths of a degree above absolute zero. Zero kelvin (-273ºC), or absolute zero, is the temperature at which atomic thermal motion would cease. Since the late 1970s, physicists have sought to use lasers to cool atoms closer to absolute zero, primarily for improving atomic timekeeping, certain experimental measurements and lithography processes for the semiconductor industry.
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