Thermodynamics is a branch of science that deals with the energy and work of a system. The first law of thermodynamics deals with conservation of energy. The conservation of energy states that energy can't neither be created nor destroyed. This concept is applied to a thermodynamic system. The second law of thermodynamics is commonly referred to as the law of increasing entropy. Entropy is defined as a measure of unusable energy within a closed or isolated system. The third law of thermodynamics refers to a state known as absolute zero. Absolute zero is the lowest point of the Kelvin temperature scale. The third law of thermodynamics basically states that the entropy of a pure perfect crystal is at zero or zero Kelvin.

In addition to these three law there is also an additional fourth law. This law is called the zeroth law of thermodynamics. The zeroth law states that two thermodynamic systems in thermal equilibrium with the same environment are in thermal equilibrium with each other. There are two reason why the zeroth law of thermodynamic does not appear as a basic postulate in this new theory. The first reason is that there are experimental situations that exist where the zeroth law fails. The other reason is that the zeroth law is a consequence of the first and second laws of thermodynamics.

First law of thermodynamics:
external image thermo1.gif

Second law of thermodynamics:
external image thermo1.gif

Third law of thermodynamics:
external image D1%20T08.jpg