Thermodynamics is the branch of science that studies the relationships between heat, work, energy, and matter. It explains how energy is transferred and transformed in physical and chemical processes. Instead of focusing on the microscopic behavior of individual atoms or molecules, thermodynamics deals with the overall, macroscopic properties of systems such as temperature, pressure, volume, and energy.
At its core, thermodynamics is based on a set of fundamental principles called the laws of thermodynamics:
- Zeroth Law – Defines temperature and establishes the concept of thermal equilibrium.
- First Law – States that energy cannot be created or destroyed, only transformed from one form to another (law of conservation of energy).
- Second Law – Explains that energy transformations are not 100% efficient and introduces the concept of entropy (a measure of disorder).
- Third Law – States that as a system approaches absolute zero temperature, its entropy approaches a minimum value.
Thermodynamics is widely applied in engineering, chemistry, physics, and everyday life—for example, in engines, refrigerators, power plants, and even biological processes like metabolism.