1. The zeroth law

The zeroth law can be most simply stated as: ‘If A is in thermal equilibrium with B, and B is in thermal equilibrium with C, then C will be in thermal equilibrium with A.’ ‘The zeroth law’ examines the significance and implications of this most fundamental of laws, and explains the concept of temperature, as well as the thermodynamic definitions of the terms systems, equilibrium and surroundings. The molecular energy distributions investigated by Boltzmann and Maxwell are also of huge importance, proving that, at any temperature, the relative population of a state varies exponentially with the energy of the state.