How cold is absolute zero?
According to the NOVA series, absolute zero “is a temperature so cold that the physical world as we know it transforms completely, electricity and fluids flow without resistance, and the speed of light can be reduced to 38 miles per hour.” While the idea of harnessing cold began hundreds of years ago with early alchemists, the quest for cryogenics at the Laboratory is nearly as old as the institution itself. “The earliest members of our group initially teamed up to determine the properties of plutonium with high precision, recognizing that measurements of some of its properties at cryogenic temperatures were essential for developing an understanding of this very unusual metal,” said Laboratory Fellow Greg Swift, of Condensed Matter and Thermal Physics (MPA-10), who is included as an expert on the “Absolute Zero” series Web site. Swift and Lab Fellow Joe Thompson of Condensed Matter and Thermal Physics recently chronicled a brief history of their group. After early experiments with plut
Gabriel Fahrenheit invented the thermometer to grade the degrees of temperature. Before them, people relied on guesswork to tell how much hotter or cooler an object was. The Fahrenheit scale is clumsy because it was based on the temperature of the human body. The centigrade scale is not so limited. It is based on the freezing and melting point of water, scientific facts which apply to many things. When scientists found that cold is merely the absence of heat; they became curious about the total lack of heat. When an object reaches this point, it can get no colder. This point is absolute zero, the basis of the absolute temperature scale. Translated onto the Fahrenheit scale, absolute zero is minus 459.8 degrees. On the centigrade scale, absolute zero is minus 272.3 degrees.
