entropy
Sign in to saveEntropy is a scientific concept, most commonly associated with states of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the microscopic description of nature in statistical physics, and to the principles of information theory. It has found far-ranging applications in chemistry and physics, in biological systems and their relation to life, in cosmology, economics, and information systems including the transmission of information in telecommunication.
AI overview
Entropy is a measure of disorder, randomness, or uncertainty that appears throughout nature and science, from the behavior of heat and molecules to the organization of information. It matters because understanding entropy helps explain fundamental processes in physics, chemistry, biology, economics, and technology—essentially how systems change and evolve across virtually all scientific disciplines.
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Key facts
- Physical quantity.name
- Entropy
- Physical quantity.unit
- joules per kelvin (J⋅K−1)
- Physical quantity.symbols
- S
- Physical quantity.baseunits
- kg⋅m2⋅s−2⋅K−1
via Wikipedia infobox
Article
39 sectionsContents
- History
- Etymology
- Definitions and descriptions
- State variables and functions of state
- Reversible process
- Carnot cycle
- Classical thermodynamics
- Statistical mechanics
- Entropy of a system
- Equivalence of definitions
- Second law of thermodynamics
- Applications
- The fundamental thermodynamic relation
- Entropy in chemical thermodynamics
- World's technological capacity to store and communicate entropic information
- Entropy balance equation for open systems
- Entropy change formulas for simple processes
- Isothermal expansion or compression of an ideal gas
- Cooling and heating
- Phase transitions
- Approaches to understanding entropy
- Standard textbook definitions
- Order and disorder
- Energy dispersal
- Relating entropy to energy ''usefulness''
- Entropy and adiabatic accessibility
- Entropy in quantum mechanics
- Information theory
- Measurement
- Interdisciplinary applications
- Philosophy and theoretical physics
- Biology
- Cosmology
- Economics
- See also
- Notes
- References
- Further reading
- External links
Entropy is a scientific concept, most commonly associated with states of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the microscopic description of nature in statistical physics, and to the principles of information theory. It has found far-ranging applications in chemistry and physics, in biological systems and their relation to life, in cosmology, economics, and information systems including the transmission of information in telecommunication.
Entropy is central to the second law of thermodynamics, which states that the entropy of an isolated system left to spontaneous evolution cannot decrease with time. As a result, isolated systems evolve toward thermodynamic equilibrium, where the entropy is highest. "High" entropy means that energy is more disordered or dispersed, while "low" entropy means that energy is more ordered or concentrated. A consequence of the second law of thermodynamics is that certain processes are irreversible.