Thermodynamics: The 2016 advent calendar
Day 1

The zeroth law

Chemical engineer Valeska Ting reveals the significance of the zeroth law of thermodynamics.

The first, second and third laws of thermodynamics get all the glory. They’re the most well known and frequently mentioned. But underpinning them all is a final law so fundamental that, although it was established last, had to be moved to the front of the list: the zeroth law. In the first film of our 2016 advent calendar, chemical engineer Valeska Ting explores the zeroth law of thermodynamics.

The zeroth law is essentially an observation: if two systems are both in thermal equilibrium with a third, they are also in equilibrium with each other. This seemingly simple mantra is essential to our concept of temperature, as Valeska, armed with some very hot glasses, explains.