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Index Entropy

In statistical mechanics, entropy is an extensive property of a thermodynamic system. [1]

198 relations: A priori and a posteriori, Absolute zero, Adiabatic accessibility, Adiabatic process, Air conditioning, Amount of substance, Arieh Ben-Naim, Arrow of time, Attenuation, Autocatalysis, Avogadro constant, Benjamin Thompson, Black hole, Black hole thermodynamics, Boltzmann constant, Boltzmann's entropy formula, Brady Haran, Brayton cycle, Brownian ratchet, Caloric theory, Calorie, Cambridge University Press, Carnot cycle, Channel capacity, Chaos theory, Chemical engineering, Chemical reaction, Chemical species, Chemical substance, Chemical thermodynamics, Chemistry, Classical limit, Claude Shannon, Clausius theorem, Clausius–Duhem inequality, Combination, Component (thermodynamics), Configuration entropy, Conformational entropy, Conservation of energy, Constantin Carathéodory, Correspondence principle, David Callaway, Density matrix, Departure function, Detailed balance, Diesel cycle, Dimensional analysis, Dissipation, Ecological economics, ..., Ecological Economics (journal), Economics, Elliott H. Lieb, Elsevier, Energy, Enthalpy, Entropic explosion, Entropic force, Entropic value at risk, Entropy (arrow of time), Entropy (computing), Entropy (energy dispersal), Entropy (information theory), Entropy (order and disorder), Entropy (statistical thermodynamics), Entropy and life, Entropy of fusion, Entropy of mixing, Entropy of vaporization, Entropy production, Entropy rate, Erwin Schrödinger, Event horizon, Evolution, Exergy, First law of thermodynamics, Free entropy, Friction, Fundamental thermodynamic relation, Gas constant, Geometrical frustration, Gibbs free energy, Globular protein, Gravity, Hawking radiation, Heat, Heat capacity, Heat death of the universe, Herman Daly, Ice, Ideal gas, Inflation (cosmology), Info-metrics, Information theory, Intensive and extensive properties, Internal energy, International System of Units, Isaac Newton, Isolated system, Jacob Bekenstein, Jakob Yngvason, James Clerk Maxwell, James Prescott Joule, John von Neumann, Josiah Willard Gibbs, Joule, Joule–Thomson effect, Journal of Cleaner Production, Kelvin, Kilogram, Laws of thermodynamics, Lazare Carnot, Line integral, List of people considered father or mother of a scientific field, List of thermodynamic properties, Logarithm of a matrix, Logarithmic scale, Loop entropy, Ludwig Boltzmann, Markov chain, Mass, Massachusetts Institute of Technology, Maximum entropy thermodynamics, Maxwell relations, Maxwell's demon, Melting, Microcanonical ensemble, Microstate (statistical mechanics), Mole (unit), Motive power, Multiplicity function for N noninteracting spins, Nat (unit), Natural logarithm, Negentropy, Nicholas Georgescu-Roegen, Nicolas Léonard Sadi Carnot, Non-equilibrium thermodynamics, Open system (systems theory), Orders of magnitude (entropy), Otto cycle, Otto Hittmair, Paul Erlich, Perpetual motion, Peter Atkins, Phase (matter), Phase transition, Phonon, Physics, Polymer, Princeton University Press, Principle of maximum entropy, Probability, Psychodynamics, Quantum mechanics, Quantum statistical mechanics, Randomness, Reflections on the Motive Power of Fire, Relations between heat capacities, Residual entropy, Reversible process (thermodynamics), Roger Penrose, Romanian Americans, Room temperature, Rudolf Clausius, Sackur–Tetrode equation, Scholarpedia, Science, Second law of thermodynamics, Standard conditions for temperature and pressure, Standard molar entropy, State function, Statistical mechanics, Stephen Hawking, Stirling's approximation, T-symmetry, Temperature, Thermal energy, Thermodynamic databases for pure substances, Thermodynamic equilibrium, Thermodynamic potential, Thermodynamic state, Thermodynamic system, Thermodynamic temperature, Thermodynamics, Thermoeconomics, Third law of thermodynamics, Time reversibility, Trace (linear algebra), Tsallis entropy, University of Chicago Press, University of Nottingham, Vaporization, Von Neumann entropy, Water wheel, Wave function collapse, William Thomson, 1st Baron Kelvin, Work (physics), Work (thermodynamics). Expand index (148 more) »

A priori and a posteriori

The Latin phrases a priori ("from the earlier") and a posteriori ("from the latter") are philosophical terms of art popularized by Immanuel Kant's Critique of Pure Reason (first published in 1781, second edition in 1787), one of the most influential works in the history of philosophy.

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Absolute zero

Absolute zero is the lower limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value, taken as 0.

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Adiabatic accessibility

Adiabatic accessibility denotes a certain relation between two equilibrium states of a thermodynamic system (or of different such systems).

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Adiabatic process

In thermodynamics, an adiabatic process is one that occurs without transfer of heat or matter between a thermodynamic system and its surroundings.

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Air conditioning

Air conditioning (often referred to as AC, A/C, or air con) is the process of removing heat and moisture from the interior of an occupied space, to improve the comfort of occupants.

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Amount of substance

Amount of substance (symbol for the quantity is 'n') is a standard-defined quantity that measures the size of an ensemble of elementary entities, such as atoms, molecules, electrons, and other particles.

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Arieh Ben-Naim

Arieh Ben-Naim (Hebrew: אריה בן-נאים; Jerusalem, 11 July 1934) is a professor of physical chemistry who retired in 2003 from the Hebrew University of Jerusalem.

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Arrow of time

The Arrow of Time, or Time's Arrow, is a concept developed in 1927 by the British astronomer Arthur Eddington involving the "one-way direction" or "asymmetry" of time.

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In physics, attenuation or, in some contexts, extinction is the gradual loss of flux intensity through a medium.

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A single chemical reaction is said to be autocatalytic if one of the reaction products is also a catalyst for the same or a coupled reaction.

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Avogadro constant

In chemistry and physics, the Avogadro constant (named after scientist Amedeo Avogadro) is the number of constituent particles, usually atoms or molecules, that are contained in the amount of substance given by one mole.

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Benjamin Thompson

Sir Benjamin Thompson, Count Rumford, FRS (Reichsgraf von Rumford; March 26, 1753August 21, 1814) was an American-born British physicist and inventor whose challenges to established physical theory were part of the 19th century revolution in thermodynamics.

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Black hole

A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it.

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Black hole thermodynamics

In physics, black hole thermodynamics is the area of study that seeks to reconcile the laws of thermodynamics with the existence of black-hole event horizons.

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Boltzmann constant

The Boltzmann constant, which is named after Ludwig Boltzmann, is a physical constant relating the average kinetic energy of particles in a gas with the temperature of the gas.

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Boltzmann's entropy formula

In statistical mechanics, Boltzmann's equation is a probability equation relating the entropy S of an ideal gas to the quantity W, the number of real microstates corresponding to the gas' macrostate: where kB is the Boltzmann constant (also written as simply k) and equal to 1.38065 × 10−23 J/K.

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Brady Haran

Brady John Haran (born 18 June 1976) is an Australian-born British independent filmmaker and video journalist who is known for his educational videos and documentary films produced for BBC News and his YouTube channels, the most notable being Periodic Videos and Numberphile.

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Brayton cycle

The Brayton cycle is a thermodynamic cycle named after George Brayton who describes the workings of a constant-pressure heat engine.

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Brownian ratchet

In the philosophy of thermal and statistical physics, the Brownian ratchet or Feynman-Smoluchowski ratchet is a thought experiment about an apparent perpetual motion machine first analysed in 1912 by Polish physicist Marian SmoluchowskiM.

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Caloric theory

The caloric theory is an obsolete scientific theory that heat consists of a self-repellent fluid called caloric that flows from hotter bodies to colder bodies.

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A calorie is a unit of energy.

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Cambridge University Press

Cambridge University Press (CUP) is the publishing business of the University of Cambridge.

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Carnot cycle

The Carnot cycle is a theoretical thermodynamic cycle proposed by French physicist Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s.

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Channel capacity

Channel capacity, in electrical engineering, computer science and information theory, is the tight upper bound on the rate at which information can be reliably transmitted over a communication channel.

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Chaos theory

Chaos theory is a branch of mathematics focusing on the behavior of dynamical systems that are highly sensitive to initial conditions.

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Chemical engineering

Chemical engineering is a branch of engineering that uses principles of chemistry, physics, mathematics and economics to efficiently use, produce, transform, and transport chemicals, materials and energy.

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Chemical reaction

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.

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Chemical species

A chemical species is a chemical substance or ensemble composed of chemically identical molecular entities that can explore the same set of molecular energy levels on a characteristic or delineated time scale.

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Chemical substance

A chemical substance, also known as a pure substance, is a form of matter that consists of molecules of the same composition and structure.

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Chemical thermodynamics

Chemical thermodynamics is the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the confines of the laws of thermodynamics.

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Chemistry is the scientific discipline involved with compounds composed of atoms, i.e. elements, and molecules, i.e. combinations of atoms: their composition, structure, properties, behavior and the changes they undergo during a reaction with other compounds.

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Classical limit

The classical limit or correspondence limit is the ability of a physical theory to approximate or "recover" classical mechanics when considered over special values of its parameters.

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Claude Shannon

Claude Elwood Shannon (April 30, 1916 – February 24, 2001) was an American mathematician, electrical engineer, and cryptographer known as "the father of information theory".

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Clausius theorem

# The Clausius theorem (1855) states that for a system exchanging heat with external reservoirs and undergoing a cyclic process, one that ultimately returns a system to its original state, where \delta Q is the infinitesimal amount of heat absorbed by the system from the reservoir and T is the temperature of the external reservoir at a particular instant in time.

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Clausius–Duhem inequality

The Clausius–Duhem inequality is a way of expressing the second law of thermodynamics that is used in continuum mechanics.

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In mathematics, a combination is a selection of items from a collection, such that (unlike permutations) the order of selection does not matter.

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Component (thermodynamics)

In thermodynamics, a component is a chemically-independent constituent of a system.

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Configuration entropy

In statistical mechanics, configuration entropy is the portion of a system's entropy that is related to the position of its constituent particles rather than to their velocity or momentum.

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Conformational entropy

Conformational entropy is the entropy associated with the number of conformations of a molecule.

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Conservation of energy

In physics, the law of conservation of energy states that the total energy of an isolated system remains constant, it is said to be ''conserved'' over time.

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Constantin Carathéodory

Constantin Carathéodory (Greek: Κωνσταντίνος Καραθεοδωρή Konstantinos Karatheodori; 13 September 1873 – 2 February 1950) was a Greek mathematician who spent most of his professional career in Germany.

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Correspondence principle

In physics, the correspondence principle states that the behavior of systems described by the theory of quantum mechanics (or by the old quantum theory) reproduces classical physics in the limit of large quantum numbers.

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David Callaway

David J. E. Callaway is a biological nanophysicist in the New York University School of Medicine, where he is Professor and Laboratory Director.

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Density matrix

A density matrix is a matrix that describes a quantum system in a mixed state, a statistical ensemble of several quantum states.

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Departure function

In thermodynamics, a departure function is defined for any thermodynamic property as the difference between the property as computed for an ideal gas and the property of the species as it exists in the real world, for a specified temperature T and pressure P. Common departure functions include those for enthalpy, entropy, and internal energy.

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Detailed balance

The principle of detailed balance is formulated for kinetic systems which are decomposed into elementary processes (collisions, or steps, or elementary reactions): At equilibrium, each elementary process should be equilibrated by its reverse process.

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Diesel cycle

The Diesel cycle is a combustion process of a reciprocating internal combustion engine.

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Dimensional analysis

In engineering and science, dimensional analysis is the analysis of the relationships between different physical quantities by identifying their base quantities (such as length, mass, time, and electric charge) and units of measure (such as miles vs. kilometers, or pounds vs. kilograms) and tracking these dimensions as calculations or comparisons are performed.

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Dissipation is the result of an irreversible process that takes place in homogeneous thermodynamic systems.

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Ecological economics

Ecological economics (also called eco-economics, ecolonomy or bioeconomics of Georgescu-Roegen) is both a transdisciplinary and an interdisciplinary field of academic research addressing the interdependence and coevolution of human economies and natural ecosystems, both intertemporally and spatially.

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Ecological Economics (journal)

Ecological Economics is a peer-reviewed academic journal published by Elsevier on behalf of the International Society for Ecological Economics.

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Economics is the social science that studies the production, distribution, and consumption of goods and services.

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Elliott H. Lieb

Elliott Hershel Lieb (born July 31, 1932) is an American mathematical physicist and professor of mathematics and physics at Princeton University who specializes in statistical mechanics, condensed matter theory, and functional analysis.

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Elsevier is an information and analytics company and one of the world's major providers of scientific, technical, and medical information.

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In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object.

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Enthalpy is a property of a thermodynamic system.

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Entropic explosion

An entropic explosion is an explosion in which the reactants undergo a large change in volume without releasing a large amount of heat.

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Entropic force

In physics, an entropic force acting in a system is a force resulting from the entire system's thermodynamical tendency to increase its entropy, rather than from a particular underlying microscopic force.

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Entropic value at risk

In financial mathematics and stochastic optimization, the concept of risk measure is used to quantify the risk involved in a random outcome or risk position.

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Entropy (arrow of time)

Entropy is the only quantity in the physical sciences (apart from certain rare interactions in particle physics; see below) that requires a particular direction for time, sometimes called an arrow of time.

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Entropy (computing)

In computing, entropy is the randomness collected by an operating system or application for use in cryptography or other uses that require random data.

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Entropy (energy dispersal)

In physics education, the concept of entropy is traditionally introduced as a quantitative measure of disorder.

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Entropy (information theory)

Information entropy is the average rate at which information is produced by a stochastic source of data.

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Entropy (order and disorder)

In thermodynamics, entropy is commonly associated with the amount of order, disorder, or chaos in a thermodynamic system.

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Entropy (statistical thermodynamics)

In classical statistical mechanics, the entropy function earlier introduced by Rudolf Clausius is interpreted as statistical entropy using probability theory.

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Entropy and life

Research concerning the relationship between the thermodynamic quantity entropy and the evolution of life began around the turn of the 20th century.

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Entropy of fusion

The entropy of fusion is the increase in entropy when melting a substance.

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Entropy of mixing

In thermodynamics the entropy of mixing is the increase in the total entropy when several initially separate systems of different composition, each in a thermodynamic state of internal equilibrium, are mixed without chemical reaction by the thermodynamic operation of removal of impermeable partition(s) between them, followed by a time for establishment of a new thermodynamic state of internal equilibrium in the new unpartitioned closed system.

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Entropy of vaporization

The entropy of vaporization is the increase in entropy upon vaporization of a liquid.

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Entropy production

Entropy production determines the performance of thermal machines such as power plants, heat engines, refrigerators, heat pumps, and air conditioners.

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Entropy rate

In the mathematical theory of probability, the entropy rate or source information rate of a stochastic process is, informally, the time density of the average information in a stochastic process.

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Erwin Schrödinger

Erwin Rudolf Josef Alexander Schrödinger (12 August 1887 – 4 January 1961), sometimes written as or, was a Nobel Prize-winning Austrian physicist who developed a number of fundamental results in the field of quantum theory, which formed the basis of wave mechanics: he formulated the wave equation (stationary and time-dependent Schrödinger equation) and revealed the identity of his development of the formalism and matrix mechanics.

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Event horizon

In general relativity, an event horizon is a region in spacetime beyond which events cannot affect an outside observer.

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Evolution is change in the heritable characteristics of biological populations over successive generations.

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In thermodynamics, the exergy (in older usage, available work or availability) of a system is the maximum useful work possible during a process that brings the system into equilibrium with a heat reservoir.

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First law of thermodynamics

The first law of thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic systems.

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Free entropy

A thermodynamic free entropy is an entropic thermodynamic potential analogous to the free energy.

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Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.

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Fundamental thermodynamic relation

In thermodynamics, the fundamental thermodynamic relation is generally expressed as a microscopic change in internal energy in terms of microscopic changes in entropy, and volume for a closed system in thermal equilibrium in the following way.

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Gas constant

The gas constant is also known as the molar, universal, or ideal gas constant, denoted by the symbol or and is equivalent to the Boltzmann constant, but expressed in units of energy per temperature increment per mole, i.e. the pressure-volume product, rather than energy per temperature increment per particle.

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Geometrical frustration

In condensed matter physics, the term geometrical frustration (or in short: frustration) refers to a phenomenon, where atoms tend to stick to non-trivial positions or where, on a regular crystal lattice, conflicting inter-atomic forces (each one favoring rather simple, but different structures) lead to quite complex structures.

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Gibbs free energy

In thermodynamics, the Gibbs free energy (IUPAC recommended name: Gibbs energy or Gibbs function; also known as free enthalpy to distinguish it from Helmholtz free energy) is a thermodynamic potential that can be used to calculate the maximum of reversible work that may be performed by a thermodynamic system at a constant temperature and pressure (isothermal, isobaric).

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Globular protein

Globular proteins or spheroproteins are spherical ("globe-like") proteins and are one of the common protein types (the others being fibrous, disordered and membrane proteins).

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Gravity, or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or gravitate toward) one another.

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Hawking radiation

Hawking radiation is blackbody radiation that is predicted to be released by black holes, due to quantum effects near the event horizon.

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In thermodynamics, heat is energy transferred from one system to another as a result of thermal interactions.

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Heat capacity

Heat capacity or thermal capacity is a measurable physical quantity equal to the ratio of the heat added to (or removed from) an object to the resulting temperature change.

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Heat death of the universe

The heat death of the universe is a plausible ultimate fate of the universe in which the universe has diminished to a state of no thermodynamic free energy and therefore can no longer sustain processes that increase entropy.

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Herman Daly

Herman Edward Daly (born July 21, 1938) is an American ecological and Georgist economist and emeritus professor at the School of Public Policy of University of Maryland, College Park in the United States.

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Ice is water frozen into a solid state.

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Ideal gas

An ideal gas is a theoretical gas composed of many randomly moving point particles whose only interactions are perfectly elastic collisions.

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Inflation (cosmology)

In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe.

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Info-metrics is an interdisciplinary approach to scientific modeling, inference and efficient information processing.

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Information theory

Information theory studies the quantification, storage, and communication of information.

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Intensive and extensive properties

Physical properties of materials and systems can often be categorized as being either intensive or extensive quantities, according to how the property changes when the size (or extent) of the system changes.

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Internal energy

In thermodynamics, the internal energy of a system is the energy contained within the system, excluding the kinetic energy of motion of the system as a whole and the potential energy of the system as a whole due to external force fields.

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International System of Units

The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system, and is the most widely used system of measurement.

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Isaac Newton

Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, astronomer, theologian, author and physicist (described in his own day as a "natural philosopher") who is widely recognised as one of the most influential scientists of all time, and a key figure in the scientific revolution.

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Isolated system

In physical science, an isolated system is either of the following.

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Jacob Bekenstein

Jacob David Bekenstein (יעקב בקנשטיין; May 1, 1947 – August 16, 2015) was a Mexican-born Israeli-American theoretical physicist who made fundamental contributions to the foundation of black hole thermodynamics and to other aspects of the connections between information and gravitation.

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Jakob Yngvason

Jakob Yngvason (born 23 November 1945) is an Icelandic/Austrian physicist and emeritus professor of mathematical physics at the University of Vienna.

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James Clerk Maxwell

James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish scientist in the field of mathematical physics.

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James Prescott Joule

James Prescott Joule (24 December 1818 11 October 1889) was an English physicist, mathematician and brewer, born in Salford, Lancashire.

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John von Neumann

John von Neumann (Neumann János Lajos,; December 28, 1903 – February 8, 1957) was a Hungarian-American mathematician, physicist, computer scientist, and polymath.

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Josiah Willard Gibbs

Josiah Willard Gibbs (February 11, 1839 – April 28, 1903) was an American scientist who made important theoretical contributions to physics, chemistry, and mathematics.

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The joule (symbol: J) is a derived unit of energy in the International System of Units.

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Joule–Thomson effect

In thermodynamics, the Joule–Thomson effect (also known as the Joule–Kelvin effect, Kelvin–Joule effect, or Joule–Thomson expansion) describes the temperature change of a real gas or liquid (as differentiated from an ideal gas) when it is forced through a valve or porous plug while keeping them insulated so that no heat is exchanged with the environment.

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Journal of Cleaner Production

The Journal of Cleaner Production is a peer-reviewed academic journal covering transdisciplinary research on cleaner production.

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The Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.

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The kilogram or kilogramme (symbol: kg) is the base unit of mass in the International System of Units (SI), and is defined as being equal to the mass of the International Prototype of the Kilogram (IPK, also known as "Le Grand K" or "Big K"), a cylinder of platinum-iridium alloy stored by the International Bureau of Weights and Measures at Saint-Cloud, France.

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Laws of thermodynamics

The four laws of thermodynamics define fundamental physical quantities (temperature, energy, and entropy) that characterize thermodynamic systems at thermal equilibrium.

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Lazare Carnot

Lazare Nicolas Marguerite, Count Carnot (13 May 1753 – 2 August 1823) was a French mathematician, physicist and politician.

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Line integral

In mathematics, a line integral is an integral where the function to be integrated is evaluated along a curve.

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List of people considered father or mother of a scientific field

The following is a list of people who are considered a "father" or "mother" (or "founding father" or "founding mother") of a scientific field.

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List of thermodynamic properties

Within thermodynamics, a physical property is any property that is measurable, and whose value describes a state of a physical system.

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Logarithm of a matrix

In mathematics, a logarithm of a matrix is another matrix such that the matrix exponential of the latter matrix equals the original matrix.

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Logarithmic scale

A logarithmic scale is a nonlinear scale used when there is a large range of quantities.

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Loop entropy

Loop entropy is the entropy lost upon bringing together two residues of a polymer within a prescribed distance.

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Ludwig Boltzmann

Ludwig Eduard Boltzmann (February 20, 1844 – September 5, 1906) was an Austrian physicist and philosopher whose greatest achievement was in the development of statistical mechanics, which explains and predicts how the properties of atoms (such as mass, charge, and structure) determine the physical properties of matter (such as viscosity, thermal conductivity, and diffusion).

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Markov chain

A Markov chain is "a stochastic model describing a sequence of possible events in which the probability of each event depends only on the state attained in the previous event".

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Mass is both a property of a physical body and a measure of its resistance to acceleration (a change in its state of motion) when a net force is applied.

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Massachusetts Institute of Technology

The Massachusetts Institute of Technology (MIT) is a private research university located in Cambridge, Massachusetts, United States.

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Maximum entropy thermodynamics

In physics, maximum entropy thermodynamics (colloquially, MaxEnt thermodynamics) views equilibrium thermodynamics and statistical mechanics as inference processes.

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Maxwell relations

Flow chart showing the paths between the Maxwell relations. ''P'': pressure, ''T'': temperature, ''V'': volume, ''S'': entropy, ''α'': coefficient of thermal expansion, ''κ'': compressibility, ''CV'': heat capacity at constant volume, ''CP'': heat capacity at constant pressure. Maxwell's relations are a set of equations in thermodynamics which are derivable from the symmetry of second derivatives and from the definitions of the thermodynamic potentials.

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Maxwell's demon

In the philosophy of thermal and statistical physics, Maxwell's demon is a thought experiment created by the physicist James Clerk Maxwell in which he suggested how the second law of thermodynamics might hypothetically be violated.

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Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid.

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Microcanonical ensemble

In statistical mechanics, a microcanonical ensemble is the statistical ensemble that is used to represent the possible states of a mechanical system which has an exactly specified total energy.

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Microstate (statistical mechanics)

In statistical mechanics, a microstate is a specific microscopic configuration of a thermodynamic system that the system may occupy with a certain probability in the course of its thermal fluctuations.

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Mole (unit)

The mole, symbol mol, is the SI unit of amount of substance.

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Motive power

In thermodynamics, motive power is a natural agent, such as water or steam, wind or electricity, used to impart motion to machinery such as an engine.

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Multiplicity function for N noninteracting spins

The multiplicity function for a two state paramagnet, W(n,N), is the number of spin states such that n of the N spins point in the z-direction.

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Nat (unit)

The natural unit of information (symbol: nat), sometimes also nit or nepit, is a unit of information or entropy, based on natural logarithms and powers of ''e'', rather than the powers of 2 and base 2 logarithms, which define the bit.

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Natural logarithm

The natural logarithm of a number is its logarithm to the base of the mathematical constant ''e'', where e is an irrational and transcendental number approximately equal to.

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The negentropy has different meanings in information theory and theoretical biology.

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Nicholas Georgescu-Roegen

Nicholas Georgescu-Roegen (born Nicolae Georgescu, 4 February 1906 – 30 October 1994) was a Romanian American mathematician, statistician and economist.

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Nicolas Léonard Sadi Carnot

Nicolas Léonard Sadi Carnot (1 June 1796 – 24 August 1832) was a French military engineer and physicist, often described as the "father of thermodynamics".

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Non-equilibrium thermodynamics

Non-equilibrium thermodynamics is a branch of thermodynamics that deals with physical systems that are not in thermodynamic equilibrium but can be described in terms of variables (non-equilibrium state variables) that represent an extrapolation of the variables used to specify the system in thermodynamic equilibrium.

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Open system (systems theory)

An open system is a system that has external interactions.

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Orders of magnitude (entropy)

The following list shows different orders of magnitude of entropy.

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Otto cycle

An Otto cycle is an idealized thermodynamic cycle that describes the functioning of a typical spark ignition piston engine.

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Otto Hittmair

Otto Hittmair (1924–2003) was an Austrian theoretical physicist who made contributions to quantum mechanics, superconductivity and unified field theory.

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Paul Erlich

Paul Erlich (born 1972) is a guitarist and music theorist living near Boston, Massachusetts.

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Perpetual motion

Perpetual motion is motion of bodies that continues indefinitely.

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Peter Atkins

Peter William Atkins (born 10 August 1940) is an English chemist and former Professor of Chemistry at the University of Oxford and a Fellow of Lincoln College.

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Phase (matter)

In the physical sciences, a phase is a region of space (a thermodynamic system), throughout which all physical properties of a material are essentially uniform.

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Phase transition

The term phase transition (or phase change) is most commonly used to describe transitions between solid, liquid and gaseous states of matter, and, in rare cases, plasma.

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In physics, a phonon is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, like solids and some liquids.

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Physics (from knowledge of nature, from φύσις phýsis "nature") is the natural science that studies matterAt the start of The Feynman Lectures on Physics, Richard Feynman offers the atomic hypothesis as the single most prolific scientific concept: "If, in some cataclysm, all scientific knowledge were to be destroyed one sentence what statement would contain the most information in the fewest words? I believe it is that all things are made up of atoms – little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another..." and its motion and behavior through space and time and that studies the related entities of energy and force."Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves."Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physics. (...) You will come to see physics as a towering achievement of the human intellect in its quest to understand our world and ourselves."Physics is an experimental science. Physicists observe the phenomena of nature and try to find patterns that relate these phenomena.""Physics is the study of your world and the world and universe around you." Physics is one of the oldest academic disciplines and, through its inclusion of astronomy, perhaps the oldest. Over the last two millennia, physics, chemistry, biology, and certain branches of mathematics were a part of natural philosophy, but during the scientific revolution in the 17th century, these natural sciences emerged as unique research endeavors in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in academic disciplines such as mathematics and philosophy. Advances in physics often enable advances in new technologies. For example, advances in the understanding of electromagnetism and nuclear physics led directly to the development of new products that have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus.

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A polymer (Greek poly-, "many" + -mer, "part") is a large molecule, or macromolecule, composed of many repeated subunits.

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Princeton University Press

Princeton University Press is an independent publisher with close connections to Princeton University.

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Principle of maximum entropy

The principle of maximum entropy states that the probability distribution which best represents the current state of knowledge is the one with largest entropy, in the context of precisely stated prior data (such as a proposition that expresses testable information).

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Probability is the measure of the likelihood that an event will occur.

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Psychodynamics, also known as psychodynamic psychology, in its broadest sense, is an approach to psychology that emphasizes systematic study of the psychological forces that underlie human behavior, feelings, and emotions and how they might relate to early experience.

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Quantum mechanics

Quantum mechanics (QM; also known as quantum physics, quantum theory, the wave mechanical model, or matrix mechanics), including quantum field theory, is a fundamental theory in physics which describes nature at the smallest scales of energy levels of atoms and subatomic particles.

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Quantum statistical mechanics

Quantum statistical mechanics is statistical mechanics applied to quantum mechanical systems.

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Randomness is the lack of pattern or predictability in events.

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Reflections on the Motive Power of Fire

Reflections on the Motive Power of Fire and on Machines Fitted to Develop that Power is a book published in 1824 by French physicist Sadi Carnot.

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Relations between heat capacities

In thermodynamics, the heat capacity at constant volume, C_, and the heat capacity at constant pressure, C_, are extensive properties that have the magnitude of energy divided by temperature.

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Residual entropy

Residual entropy is the difference in entropy between a non-equilibrium state and crystal state of a substance close to absolute zero.

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Reversible process (thermodynamics)

In thermodynamics, a reversible process is a process whose direction can be "reversed" by inducing infinitesimal changes to some property of the system via its surroundings, with no increase in entropy.

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Roger Penrose

Sir Roger Penrose (born 8 August 1931) is an English mathematical physicist, mathematician and philosopher of science.

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Romanian Americans

Romanian Americans (Romanian: Români americani) are Americans who have Romanian ancestry.

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Room temperature

Colloquially, room temperature is the range of air temperatures that most people prefer for indoor settings, which feel comfortable when wearing typical indoor clothing.

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Rudolf Clausius

Rudolf Julius Emanuel Clausius (2 January 1822 – 24 August 1888) was a German physicist and mathematician and is considered one of the central founders of the science of thermodynamics.

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Sackur–Tetrode equation

The Sackur–Tetrode equation is an expression for the entropy of a monatomic classical ideal gas which incorporates quantum considerations which give a more detailed description of its regime of validity.

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Scholarpedia is an English-language online wiki-based encyclopedia with features commonly associated with open-access online academic journals, which aims to have quality content.

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R. P. Feynman, The Feynman Lectures on Physics, Vol.1, Chaps.1,2,&3.

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Second law of thermodynamics

The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time.

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Standard conditions for temperature and pressure

Standard conditions for temperature and pressure are standard sets of conditions for experimental measurements to be established to allow comparisons to be made between different sets of data.

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Standard molar entropy

In chemistry, the standard molar entropy is the entropy content of one mole of substance under a standard state (not STP).

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State function

In thermodynamics, a state function or function of state is a function defined for a system relating several state variables or state quantities that depends only on the current equilibrium state of the system, for example a gas, a liquid, a solid, crystal, or emulsion.

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Statistical mechanics

Statistical mechanics is one of the pillars of modern physics.

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Stephen Hawking

Stephen William Hawking (8 January 1942 – 14 March 2018) was an English theoretical physicist, cosmologist, and author, who was director of research at the Centre for Theoretical Cosmology at the University of Cambridge at the time of his death.

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Stirling's approximation

In mathematics, Stirling's approximation (or Stirling's formula) is an approximation for factorials.

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T-symmetry or time reversal symmetry is the theoretical symmetry of physical laws under the transformation of time reversal: T-symmetry can be shown to be equivalent to the conservation of entropy, by Noether's Theorem.

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Temperature is a physical quantity expressing hot and cold.

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Thermal energy

Thermal energy is a term used loosely as a synonym for more rigorously-defined thermodynamic quantities such as the internal energy of a system; heat or sensible heat, which are defined as types of transfer of energy (as is work); or for the characteristic energy of a degree of freedom in a thermal system kT, where T is temperature and k is the Boltzmann constant.

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Thermodynamic databases for pure substances

Thermodynamic databases contain information about thermodynamic properties for substances, the most important being enthalpy, entropy, and Gibbs free energy.

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Thermodynamic equilibrium

Thermodynamic equilibrium is an axiomatic concept of thermodynamics.

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Thermodynamic potential

A thermodynamic potential (in fact, rather energyISO/IEC 80000-5, Quantities an units, Part 5 - Thermodynamics, item 5-20.4 Helmholtz energy, Helmholtz function, ISO/IEC 80000-5, Quantities an units, Part 5 - Thermodynamics, item 5-20.5, Gibbs energy, Gibbs function than potential) is a scalar quantity used to represent the thermodynamic state of a system.

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Thermodynamic state

For thermodynamics, a thermodynamic state of a system is its condition at a specific time, that is fully identified by values of a suitable set of parameters known as state variables, state parameters or thermodynamic variables.

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Thermodynamic system

A thermodynamic system is the material and radiative content of a macroscopic volume in space, that can be adequately described by thermodynamic state variables such as temperature, entropy, internal energy, and pressure.

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Thermodynamic temperature

Thermodynamic temperature is the absolute measure of temperature and is one of the principal parameters of thermodynamics.

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Thermodynamics is the branch of physics concerned with heat and temperature and their relation to energy and work.

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Thermoeconomics, also referred to as biophysical economics, is a school of heterodox economics that applies the laws of statistical mechanics to economic theory.

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Third law of thermodynamics

The third law of thermodynamics is sometimes stated as follows, regarding the properties of systems in thermodynamic equilibrium: At absolute zero (zero kelvin) the system must be in a state with the minimum possible energy.

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Time reversibility

A mathematical or physical process is time-reversible if the dynamics of the process remain well-defined when the sequence of time-states is reversed.

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Trace (linear algebra)

In linear algebra, the trace of an n-by-n square matrix A is defined to be the sum of the elements on the main diagonal (the diagonal from the upper left to the lower right) of A, i.e., where aii denotes the entry on the ith row and ith column of A. The trace of a matrix is the sum of the (complex) eigenvalues, and it is invariant with respect to a change of basis.

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Tsallis entropy

In physics, the Tsallis entropy is a generalization of the standard Boltzmann–Gibbs entropy.

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University of Chicago Press

The University of Chicago Press is the largest and one of the oldest university presses in the United States.

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University of Nottingham

The University of Nottingham is a public research university in Nottingham, United Kingdom.

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Vaporization (or vapourisation) of an element or compound is a phase transition from the liquid phase to vapor.

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Von Neumann entropy

In quantum statistical mechanics, the von Neumann entropy, named after John von Neumann, is the extension of classical Gibbs entropy concepts to the field of quantum mechanics.

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Water wheel

A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill.

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Wave function collapse

In quantum mechanics, wave function collapse is said to occur when a wave function—initially in a superposition of several eigenstates—appears to reduce to a single eigenstate (by "observation").

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William Thomson, 1st Baron Kelvin

William Thomson, 1st Baron Kelvin, (26 June 1824 – 17 December 1907) was a Scots-Irish mathematical physicist and engineer who was born in Belfast in 1824.

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Work (physics)

In physics, a force is said to do work if, when acting, there is a displacement of the point of application in the direction of the force.

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Work (thermodynamics)

In thermodynamics, work performed by a system is the energy transferred by the system to its surroundings, that is fully accounted for solely by macroscopic forces exerted on the system by factors external to it, that is to say, factors in its surroundings.

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[1] https://en.wikipedia.org/wiki/Entropy

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