Thermodynamics is the branch of physics that studies the effects of changes in temperature, pressure and volume of a physical system (a material, a liquid, a set of bodies, etc.), at a macroscopic level. The term "thermo" means heat and dynamics refers to motion, so thermodynamics studies the movement of heat in a body. Matter is composed of different particles that move disorderly. Thermodynamics studies this disorderly movement.
The practical importance of thermodynamics lies primarily in the diversity of physical phenomena it describes. Knowledge of this diversity has resulted in enormous technological productivity.
Historical evolution of thermodynamics
Technological developments, such as steam engines or thermometers, were initially carried out empirically. But nu was until the 19th century when scientists like Carnot and Joule formalized their results and determined the theoretical causes of their functioning.
Study of thermodynamics
The main elements we have to study thermodynamics are:
- The laws of thermodynamics. These laws define how energy can be exchanged between physical systems in the form of heat or work.
- Entropy. Entropy is a magnitude that can be defined for any system. Entropy defines the disorder in which the internal particles that form matter move.
In thermodynamics the interactions between different systems are studied and classified, which leads to define concepts as thermodynamic system and its contour. A thermodynamic system is characterized by its properties, related to each other by the state equations. These can be combined to express internal energy and thermodynamic potentials, useful for determining equilibrium conditions between systems and spontaneous processes.
With these tools, thermodynamics describes how systems respond to changes in their environment.
Applications of thermodynamics
Thermodynamics can be applied to a wide variety of science and engineering subjects, such as motors, phase transitions, chemical reactions, transport phenomena, and even black holes.
The results of thermodynamics are essential for other fields of physics and chemistry, chemical engineering, aerospace engineering, mechanical engineering, cell biology, biomedical engineering, and materials science to name a few.
Last review: December 1, 2016