The amount of disorder in a data source.

A measure of the degree of disorder or randomness in a system; the higher the entropy, the greater the disorder.

In cryptography, a measure of uncertainty, or in other words, the distance between order and chaos. The higher the entropy, the more disorderly a thing (e.g. a cryptographic key) is. The higher the entropy in the key, the harder it is to crack using a brute force attack. _____________________________________________________________________________

A measure of how much randomness or disorder is within a physical system.

A thermodynamic quantity (S), it is a measure of disorder of a system, i.e. the higher the disorder, the higher the entropy value.

Tendency of systems to become more disordered (and thus more uniform) over time; also a measure of disorder; in thermodynamics, a measure of the amount of heat energy in a closed system that is not available to do work.

a fundamental thermodynamic quantity which measures how much heat energy is unavailable for conversion to work.

(en´ tro pee) [Gr. en: in + tropein: to change] • A measure of the degree of disorder in any system. A perfectly ordered system has zero entropy; increasing disorder is measured by positive entropy. Spontaneous reactions in a closed system are always accompanied by an increase in disorder and entropy.

The principle that all things tend to become more disordered and break down over time, unless certain conditions are met.

The level of disorder in a system.

a measure of the extent to which the energy in a system is available for doing work. Entropy increases as energy is dispersed when it is used.

Refers to the degree of disorder: increasing entropy means increasing disorder.

In this context, a measure of randomness, also used as a name for pure, raw, randomness collected in a computer or in a physical process. In cryptography, entropy is measured in bits. If you flip a perfectly balanced coin, you can collect one bit of entropy from that toss. If you roll a perfect dice, the result 1 to 6 represents approximately 2.6 bits of entropy. An extremely important basic law is that you cannot generate entropy by any deterministic algorithm. What this means is that if you as input to an encryption algorithm give a key, consisting of lets say 30 bits of entropy, no matter what you do with that key in the algorithm, it's still just 30 bits of entropy - and that's what ultimately limits the security. Thus, if an algorithm claims 2048-bit key length, you must figure out how to get that many bits of entropy into the key to achieve full strength. This is usually hard, for example if you use the 26 letters of the alphabet, 2048 bits represent a sequence just under 435 letters long. That's a mighty long passphrase to remember.

Thermodynamic quantity that measures the degree of disorder in a system; the higher the entropy, the more the disorder.

a measure of the disorder of the molecules in substances. Large organisms are seen to be more ordered than small organisms.

A measure of the disorder in a system. If your desk is neat and organized - you can say the entropy is low whearas if it is unorganized and there is stuff scattered all over the place you can say the entropy is high. The Second Law of Thermodynamics says that the entropy of the Universe always increases

In common usage: the tendency of systems to deteriorate toward a disordered state.

the tendency of the universe to move towards a state of disorder; measure of thermal energy that is not available to do work How can we gauge correctly the point at which the system reached this stage of entropy

(communication theory) a numerical measure of the uncertainty of an outcome; "the signal contained thousands of bits of information"

(thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work; "entropy increases as matter and energy in the universe degrade to an ultimate state of inert uniformity"

The observation that everything in the material Universe will eventually, inevitably wind-down, burn-out, fall apart ... well, I'm sure you get the (dismal) picture.

A term describing the natural and inevitable decay of all systems. System entropy can be managed. Estimation Activity of approximating the time, effort, costs, and benefits of developing systems.

the theory that closed systems tend towards disorganization. All organized systems--be they sand castles or solar systems--tend to become less ordered and have less available energy over time.

The tendency of systems to lose energy and order and to settle to more homogenous (similar) states. Often referred to as 'Heat Death' or the 2nd Law of Thermodynamics.

The production of heat in every energy change. The gradual "winding down" of the universe. The amount of disorder and randomness in a system.

A measure of the disordered, degraded energy that is unavailable for work.

A quantity that determines the direction of processes in thermodynamical systems. See Gian's introductory article.

EN-tro-pee Randomness or disorder. 8, 113

A thermodynamic quantity representing the unavailability of a system's thermal energy for conversion into mechanical work, often interpreted as the degree of disorder or randomness in the system.

Measure of randomness or disorder in a system

A tendency towards disorder within a closed system, as potential energy gets "spent". "The physical Universe's macrocosmic proclivities of becoming locally ever more dissynchronous, asymmetric, diffuse, and multiplyingly expansive". (Buckminster Fuller)

disorder. Entropy is a measure of the disorder of a system.

the disorder of a system, said always to increase with time by the second law of thermodynamics

the process defined by the second law of thermodynamics which defines the inevitable, ultimate decay of the energy of the universe.

A measure used to determine the disorder in the population, according to Shannon Information Theory. In this measure, the probability of occurrence of a single genotype i, pi, is approximated by ni/N: H = -Sumi( ni/N · log(ni/N) ) where ni is the current abundance of this genotype and N is the total number of strings in the population.

a measure of the amount of energy unavailable for work within a system or process; a measure of the probability of distribution or randomness (disorder) within a system.

The degree of disorder in a system. As energy is transferred from one form to another, some is lost as heat; as the energy decreases, the disorder in the system&emdash;and thus the entropy&emdash;increases.

A measure of the unavailable or unusable energy in a system; energy that cannot be converted to another form.

Is a measure of the unavailability of energy in a substance.( 030)

A thermodynamic quantity that measures the fraction of the total energy of a system that is not available for doing work.

a measure of disorganization

quantity to describe the degree molecular disorder resp. the degree of molecular mobility of a physical system; the amount of entropy is increasing when the molecular disorder is rising, e.g. by elevating the temperature

A measure of the disorder or chaos of a closed system.

(the measure of the absence of information about a system. the measure of the unavailability of a system's energy to do work. )

a thermodynamic quantity that expresses the degree of disorder or randomness in a system. The entropy of an open system tends to increase unless energy is expended.

This term comes from the field of thermodynamics and is a measure for the disorder of a system.

the amount of Energy that is not available for work during a certain process

a measure of the amount of energy in a system that cannot be used to perform work; high entropy means that the energy in the system has very little capacity to do work.

Entropy is more easily defined in terms of a change in entropy rather than its absolute value. A change in entropy, dS, is given by the amount of heat, dQ, rejected or absorbed by a liquid/gas system divided by the thermodynamic (or absolute) temperature, T, at which the heat exchange occurs, i.e. dS = dQ/T. In a truly adiabatic process (in which there is no heat rejection or absorption) the change in entropy is zero.

The degree of randomness of or disorder of a system.

Direct measurement of the disorder of a system.

A thermodynamic state or property that measures the degree of disorder or randomness of a system. For more information see Thermochemistry

a thermodynamic quantity which is a measure of the degree of disorder within any system. [The greater the degree of order the higher the entropy; for an increase in entropy S is positive. Entropy has the units of joules per degree K per mole.

The natural tendency of a system to progress toward disorganization, depletion and, in essence, death

A measure from Information Theory which refers to the degree of disorder of data. The higher the entropy of a dataset, the more diverse and mixed its values. Many of the mining algorithms in MineSet operate by dividing data so as to minimize entropy.

A measure of the disorder of a physical system.

A measure of the randomness or disorder of a system. See also: Thermodynamics, First Law Thermodynamics, Second Law

One of the main notions of thermodynamics, where it is normally viewed as a measure of disorder. In isolated systems, it is used to determine the way in which the system will change if heated or cooled, compressed or expanded. Thermodynamics holds that the entropy of a system can never decrease but only increase and that a state of maximum entropy is marked by a state of balance in which no further conversion of energy is possible. This has been used to justify the erroneous idea of the "heat death of the universe." In recent years, I. Prigogine has reinterpreted the Second Law of Thermodynamics in a way which defines entropy differently. According to Prigogine, entropy does not mean higher disorder in the generally accepted sense, but an irreversible process of change which generally leads to more highly ordered states.

1. A measure of the dispersal or degradation of energy. 2. A measure of the disorder or randomness in a closed system. For example, the entropy of an unburned piece of wood and its surroundings is lower than the entropy of the ashes, burnt remains, and warmed surroundings due to burning the that piece of wood.

(physics) Measure of disorganization or degradation in the universe that reduces available energy, or tendency of available energy to dwindle. Chaos, opposite of order.

The measure of the randomness in a system. Also, the amount of thermal energy that is unavailable to do work.

A measure of a system's degree of randomness or disorder. H is the relative entropy of the target and background residue frequencies. (Karlin and Altschul, 1990). H can be thought of as a measure of the average information (in bits) available per position that distinguishes an alignment from chance. At high values of H, short alignments can be distinguished by chance, whereas at lower H values, a longer alignment may be necessary. (Altschul, 1991)

In thermodynamics, a measure of chaos and unavailable energy in a physical system. In other contexts (even in the social sciences), a term used by analogy to describe the extent of randomness and disorder of a system and consequent lack of knowledge or information about it.

the measure of randomness or disorder of a system; in chemical reactions and molecular processes, spontaneous progress is always made in a direction which will increase the total state of disorder; as an analogy, throwing a bundle of confetti in the air will result in many isolated pieces scattered all over the ground, not the single bundle from which the pieces originated.

A measure of the amount of energy in a disordered form (i.e., unavailable for work) within a system.

Entropy is the measure of the disorder or randomness of energy and matter in a system.

The capacity of a system or a body to hold energy that is not available for changing the temperature of the system (or body) or for doing work.

A measure of disorder or randomness in a system. The 2nd law of thermodynamics states any spontaneous change is accompanied by an overall increase in entropy overall. For example, when water evaporates molecules are dispersed over greater distances resulting in an increase in entropy.

The universal tendency for energy in a closed system to equalize. On a universe-wide scale, it is the inevitable degradation of matter and energy to an inert uniform state incapable of sustaining life.

A thermodynamic state variable denoted by ( denotes specific entropy, entropy per unit mass). The rate of change of entropy of a thermodynamic system is defined as where is the heating rate in a reversible process and is absolute temperature. Integration of this equation yields the entropy difference between two states. The entropy of an isolated system cannot decrease in any real physical process, which is one statement of the second law of thermodynamics. The specific entropy of an ideal gas, , may be expressed as where pg is the specific heat at constant pressure of that gas, is its gas constant, and and are its temperature and pressure. The entropy of a liquid, ;t7, is where is the specific heat of the liquid.

Measure of disorder and randomness. When creating random challenges for doing Authentication, they should be selected with high entropy.

In cryptography, a mathematical measurement of the amount of uncertainty or randomness.

A way to measure variability other than the variance statistic. Some decision trees split the data into groups based on minimum entropy.

Ecological entropy is a measure of biodiversity in the study of biological ecology.

In thermodynamics, entropy is a measure of how close a thermodynamic system is to equilibrium. A thermodynamic system is any physical object or region of space that can be described by its thermodynamic quantities such as temperature, pressure, volume and density. In simple terms, the second law of thermodynamics states that for a system, the differences in intensive thermodynamic quantities such as temperature, pressure, and chemical potential tend to even out as time goes by, unless there is an outside influence which works to maintain the differences.

In thermodynamics, statistical entropy is the modeling of the energetic function entropy using probability theory. The statistical entropy perspective was introduced in 1870 with the work of the Austrian physicist Ludwig Boltzmann.

Entropy is the only quantity in the physical sciences that "picks" a particular direction for time, sometimes called an arrow of time. As we go "forward" in time, the Second Law of Thermodynamics tells us that the entropy of an isolated system can only increase or remain the same; it cannot decrease. Hence, from one perspective, entropy measurement is thought of as a kind of clock.

The thermodynamic concept of entropy can be described qualitatively as a measure of energy dispersal at a specific temperature. Changes in entropy can be quantitatively related to the distribution or the spreading out of the energy of a thermodynamic system divided by its temperature. Similar terms have been in use from early in the history of classical thermodynamics, and with the development of statistical thermodynamics and quantum theory, entropy changes have been described in terms of the mixing or "spreading" of the total energy of each constituent of a system over its particular quantized energy levels.

In thermodynamics, entropy, historically, has often been associated with the amount of order, disorder, and or chaos in a thermodynamic system.