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.

A cloud of atoms with a temperature beyond absolute zero – which is also bizarrely hotter than any positive temperature imaginable – could be a mysterious new quantum state of matter. Luca Donini at ...

Nernst's theorem—a general experimental observation presented in 1905 that entropy exchanges tend to zero when the temperature tends to zero—has been directly linked to the second principle of ...