termodinamikos

Teromodinamikos (thermodynamics) is the branch of physics that studies the relationships between heat, work, temperature, and energy in physical systems. It uses macroscopic observables such as pressure, volume, temperature, and entropy to describe how energy is transferred and transformed during processes, and it seeks universal principles that apply regardless of material details.

Central to termodinamikos are four laws. The Zeroth Law defines thermal equilibrium and allows the definition of temperature. The First Law, or the law of energy conservation, asserts that energy in an isolated system remains constant, changing form between heat and work. The Second Law introduces entropy and states that natural processes tend toward increased disorder and that no engine can be 100% efficient in converting heat to work. The Third Law posits that the entropy of a perfect crystal approaches zero at absolute zero, providing a reference for absolute entropy.

Thermodynamics uses state functions such as internal energy (U), enthalpy (H), entropy (S), Gibbs free energy (G), and Helmholtz free energy (A). Equations of state relate measurable properties; the ideal gas law PV = nRT is a common example. Processes are characterized as isothermal, isobaric, isochoric, or adiabatic, and cycles, such as the Carnot cycle, define limits on efficiency. Phase transitions and chemical reactions are described using chemical thermodynamics.

Subfields include classical thermodynamics, statistical thermodynamics, chemical thermodynamics, and engineering thermodynamics. Applications span power generation, refrigeration, heating, engines, material processing, and climate science. The field combines experimental calorimetry with theoretical models and increasingly relies on statistical methods to connect microscopic behavior with macroscopic properties.