Absolute Zero

Absolute zero temperature is the lowest temperature that a system can theoretically attain. According to the third law of thermodynamics, this temperature can only be theoretically achieved, although modern technologies, such as laser cooling, have been used to cool gases to just a few billionths of a Kelvin. Absolute zero is set at -273.15 C and serves as the starting point of the Kelvin temperature scale. Consequently, there are no negative temperatures on this scale.