On the absolute temperature scale, which is used by physicists and is also called the Kelvin scale, it is not possible to go below zero – at least not in the sense of getting colder than zero kelvin.

This press release is available in German. What is normal to most people in winter has so far been impossible in physics: a minus temperature. On the Celsius scale minus temperatures are only ...

Coaxing a gas to a negative temperature on the kelvin scale has produced, paradoxically, the hottest temperature ever measured. The study, published in the Jan. 4 Science, will help physicists learn ...