Scientists Send A Cloud Of Atoms Plunging Below Absolute Zero
Going Negative Atoms distributed in a thermal system. LMU/MPQ MunichAbsolute zero is theoretically the lowest possible temperature, but quantum researchers beg to differ. Absolute zero--that's zero degrees Kelvin, or -459.67 degrees Fahrenheit--is understood by textbook definition to be the absolute coldest anything can be, a temperature threshold at which atoms actually lose all of their kinetic energy and stop moving completely (or at which entropy reaches its lowest value). There can be nothing stiller than completely still, and hence absolute zero is as low-energy as something can go. Right? But researchers have discovered that's not exactly the case. By messing with the distribution of high- and low-energy atoms within a system, a team of physicists at the University of Munich in Germany has created what it defines as a negative temperature system--one that has a temperature south of absolute zero. The researchers describe their system in terms of hills and valleys (picture...