Definition
Thermodynamics
Thermodynamics is the branch of physics concerned with heat, work, temperature, and their relation to energy, radiation, and physical properties of matter. It describes how macroscopic variables, such as entropy and pressure, are related to the microscopic statistical behaviour of atoms and molecules.
Laws
Zeroeth Law
Definition
Link to originalZeroeth Law of Thermodynamics
The Zeroeth Law of Thermodynamics states that if two thermodynamic systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
First Law
Definition
Link to originalFirst Law of Thermodynamics
The First Law of Thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic systems. It states that energy can neither be created nor destroyed in an isolated system; it can only be transformed from one form to another.
Second Law
Definition
Link to originalSecond Law of Thermodynamics
The Second Law of Thermodynamics states that the total entropy of an isolated system can never decrease over time; it can only remain constant or increase. In other words, such a system will naturally progress toward a state of maximum disorder or equilibrium.
Third Law
Definition
Link to originalThird Law of Thermodynamics
The Third Law of Thermodynamics states that the entropy of a system approaches a constant value as its temperature approaches absolute zero. For a perfect crystal, this entropy is exactly zero.
Relation to Life
The study of thermodynamics was historically driven by the need to understand steam power and the Industrial Revolution. However, it is equally fundamental to biology. As Erwin Schrödinger noted in What Is Life?, organisms must feed on “negative entropy” to maintain their dynamic stability and avoid the “heat death” predicted by the Second Law.