Word: columbium
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Dates: during 1940-1949
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Last fortnight Dr. Donald H. Andrews of Johns Hopkins University described a bolometer to top them all. Its sensitive surface is columbium nitride cooled by liquid hydrogen to minus 432° F. At this temperature-close to absolute zero-columbium nitride becomes "superconductive"; its electrical resistance almost vanishes. When a heat ray hits it and warms it only one millionth of a degree, it gives a clear electrical signal...