The word thermodynamics means the part of physics responsible for the study of phenomena related to heat. It is especially about the macroscopic properties of matter, the forms of energy , emphasizing temperature . It also studies the changes in thermal energy between different systems as well as the chemical and mechanical consequences of these changes. This is important for understanding how caloric energy is transformed into mechanical energy and vice versa. Precisely, this discipline owes its development to the need to improve the efficiency of steam engines and explains why not every machine can be efficient.
Thermodynamics studies systems in equilibrium. This means that the different properties to consider in a system , such as pressure, volume and mass, remain constant. The starting point for entering this discipline is the knowledge of its laws: the zero law of thermodynamics or thermal equilibrium, the first law of thermodynamics or the principle of energy conservation, the second law of thermodynamics related to work and heat, and the third law of thermodynamics about the impossibility of reaching absolute zero.
The zero law states that if system A and system B have the same temperature and B has the same temperature as system C, then A and C also have the same temperature. The first law of thermodynamics states that energy cannot be created or destroyed, it can only be transformed; thus heat is a form of energy that can be converted into mechanical work. On the other hand, the second law of thermodynamics highlights that it is only possible to carry out a work from the passage of heat from a body with a lower temperature to one with a higher temperature; moreover, this law gives an explanation of why there is a part of energy that cannot be converted into work. Finally, the third law of thermodynamics states that absolute zero is impossible to achieve with a finite number of steps,
Thermodynamics is one of the most important disciplines in the development of science; its fame is due in part to the concerns that sparked the industrial revolution . However, it is worth emphasizing that its laws are valid only for macroscopic systems, but unfounded at the quantum level .