Temperature is typically thought of as the average energy of individual atoms or molecules within a given collection. For atoms of similar mass, this "kinetic temperature" would basically be their ...

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 ...