From physics it is known that, in addition to the “usual” us scale degree Aim, is and the Kelvin scale, where zero is equal to -273,15 degrees Celsius. The achievement of this value is no easy task. Previously, scientists have managed to cool to a temperature of absolute zero individual atoms, but to do so is molecule came first.
According to the journal Nature Physics, to achieve a kind of record failed physicists from the Centre for cold matter. They cooled the matter to millionths of a degree above absolute zero. Scientists have been able in his research to approach the minimum possible value of the temperature. It will be recalled that earlier during a series of experiments, scientists managed to reach only a share of one trillion Kelvin, by cooling individual atoms. To solve this problem, the experts had to combine two traditional approach.
The scientists used molecules of calcium fluoride, is placed inside a magneto-optical trap. Inside the trap the substance was cooled with the help of special lasers. During this process, the atoms absorb photons and “re-emit” them, expending more energy than is purchased. In this simple way you can reduce the temperature only up to a certain value (called the Doppler limit).
In order to overcome this limitation, physicists have used another method, which consists in using two moving towards each other of the laser beam. They “take” the excess kinetic energy of the molecules, cooling it to the desired value. Thanks to this manipulation, the temperature of the cooling molecules reached 50-millionth of a degree from absolute zero. According to scientists, the cooling to such very low temperature slows down the molecules and allows the designers to study their properties and structure.
The cool stuff
Vladimir Kuznetsov