What does thermodynamics mean?
Thermodynamics is the branch of physics that examines how heat, work, temperature, and energy relate to one another. It provides principles for predicting how physical and chemical systems change when energy is transferred or transformed. The subject is central to the design of engines, refrigerators, power stations, chemical plants, and many other technologies, as well as to the study of phase changes, equilibrium, and the behavior of matter at different temperatures and pressures. Its laws connect microscopic properties, such as the motion of particles, with measurable properties such as pressure, volume, and temperature. In everyday language, the word can also mean the heat and energy behavior of a particular system, as in "the thermodynamics of a black hole." Although often associated with formulas and technical vocabulary, thermodynamics rests on ideas that concern everyone, including why a hot drink cools, why ice melts, and why no heat engine can operate with perfect efficiency.
nounThe branch of physics concerned with the relationships between heat, work, temperature, and energy, particularly the transformations of energy within physical and chemical systems.
- The branch of physics that studies heat, work, temperature, energy, and the behavior of physical and chemical systems.
"The thermodynamics of the reaction explains why the temperature rises as the mixture reacts."
"Engineers used thermodynamics to determine the efficiency of the new cooling system."
"Her lecture in statistical thermodynamics connected molecular behavior with observable changes in pressure and volume."
Thermodynamics is normally used as a singular mass noun; a separate plural form is not standard in ordinary scientific usage.
"The thermodynamics of the atmosphere determines how air temperature changes with altitude."
In an isolated system, entropy never decreases: thermodynamics turns everyday intuitions about heat and efficiency into laws of nature.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of thermodynamics
Thermodynamics is a 19th-century compound formed from Greek thermē, meaning "heat," and dynamics, a term derived from Greek dynamikos, meaning "powerful" or "energetic." The element thermodynamics therefore refers broadly to the dynamics or behavior of heat. Several scientific words based on thermē, including thermal, thermometer, and thermoscope, reflect the same Greek root.
Related word forms
How thermodynamics is actually used
The word is formal and scientific. It normally names a field of study and is generally treated as a singular mass noun; expressions such as "the thermodynamics of the system" refer to the relevant heat and energy relationships rather than to multiple bodies of theory.
Easily confused with thermodynamics
Thermodynamics is the broader study of heat, work, and energy relationships, whereas thermochemistry focuses specifically on heat changes associated with chemical reactions and processes.