Termodünaamikas

Termodünaamikas is the branch of physics that studies energy transformations and the interactions between matter and energy. It analyzes how heat and work are exchanged between a system and its surroundings and how macroscopic properties such as temperature, pressure, and volume evolve as a result. The field covers both equilibrium thermodynamics, which treats systems in or near steady states, and non-equilibrium thermodynamics, which deals with irreversible processes and transport phenomena.

Core concepts include a defined system, surroundings, and state variables that describe the system's condition. Thermodynamic state functions—internal energy, enthalpy, entropy, and Gibbs free energy—characterize equilibrium states. The Zeroth Law establishes the concept of temperature and thermal equilibrium; the First Law embodies conservation of energy, ΔU = Q − W for a closed system; the Second Law introduces entropy and constrains the direction of natural processes; the Third Law concerns entropy at absolute zero.

Mathematical tools include equations of state, thermodynamic potentials, and Legendre transforms; Maxwell relations connect measurable quantities. Typical process classifications are isothermal, isobaric, isochoric, and adiabatic. The field encompasses both classical thermodynamics and statistical thermodynamics, the latter linking microscopic microstates to macroscopic observables.

Applications are broad, spanning engines and refrigerators, power plants, chemical reactions, phase transitions, and materials science. The subject has a long history, with foundational contributions from Carnot, Clausius, Kelvin, and Gibbs, among others.