Laws of Thermodynamics

1st Law of Thermodynamics

“Energy can be transformed from one form to another but can be neither created nor destroyed.”

Rudolf Clausius and William Thomson (1860)

2nd Law of Thermodynamics

“Heat always moves from hotter objects to colder objects (or "downhill"), unless energy in some form is supplied to reverse the direction of heat flow.”

Rudolf Clausius (1860)

3rd Law of Thermodynamics

“The entropy of a system approaches a constant value when its temperature approaches absolute zero.”

Walther Nernst (1912)

Zeroth Law of Thermodynamics

“If two systems are both in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.”

 Ralph H. Fowler (1930)