# Explain Laws of Thermodynamics

The fundamental principles of thermodynamics were originally expressed in three laws.

## What is thermodynamics?

When a given object or body A is in thermal equilibrium with a body or object B and separately with a body or object C, it’s necessary that B and C would also be in thermal equilibrium with each other. This statement tells us that thermal equilibrium is simply a Euclidean relation between thermodynamic systems. Thermal equilibrium is also a proven reflexive relation. Equivalence relations are those which are both reflexive as we will as Euclidean. Hence, thermal equilibrium is simply a transitive relationship. Another result is that the equilibrium relationship is always symmetric: If a body A is in thermal equilibrium with another body or object B, B is in thermal equilibrium with A. Hence it can be said that two systems are in thermal equilibrium with each other.

### Laws of thermodynamics

• The Zeroth Law states that if two bodies are in thermal equilibrium with some third body, they are also in equilibrium.
• The first law of thermodynamics, also known as the Law of Conservation of Energy, states that energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another.
• The second law of thermodynamics says that the entropy of any isolated system always increases. Isolated systems spontaneously evolve towards thermal equilibrium in the state of maximum entropy of the system.
• The third law of thermodynamics states that a system’s entropy approaches a constant value as the temperature approaches absolute zero.

Thermodynamics is simply a macroscopic science that studies various energy inter-actions, notably heat as we will at work transfer, with the matter that brings about significant changes in the macroscopic properties of a measurable substance. It’s basically a phenomenological science based on certain laws of nature, which are always obeyed as we will as never seem to be violated.