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Topic: Entropy


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  A Student’s Approach to the Second Law and Entropy
Entropy measures the spontaneous dispersal of energy: how much energy is spread out in a process, or how widely spread out it becomes — at a specific temperature.
The equation for the entropy increase in the mixture uses the relative molar quantities of liquids that were mixed.
That increased entropy of the solvent in a solution is the cause of the "colligative effects" that we study: (1) osmotic pressure, (2) boiling point elevation, and (3) freezing point depression.
www.entropysite.com /students_approach.html   (2516 words)

  
  Entropy - Wikipedia, the free encyclopedia
In thermodynamics, entropy, symbolized by S, is a state function of a thermodynamic system defined by the differential quantity dS = dQ / T, where dQ is the amount of heat absorbed in a reversible process in which the system goes from the one state to another, and T is the absolute temperature.
Entropy is one of the factors that determines the free energy in the system and appears in the second law of thermodynamics.
Entropy is said to be thermodynamically conjugate to temperature.
en.wikipedia.org /wiki/Entropy   (3219 words)

  
 Encyclopedia :: encyclopedia : Entropy   (Site not responding. Last check: 2007-08-19)
In thermodynamics and statistical mechanics, the thermodynamic entropy (or simply the entropy) S is a measure of the internal microscopic disorder present in a system at thermodynamic equilibrium; or, equivalently, the number of possible internal configurations available to the system.
In Boltzmann's definition, entropy is a measure of the number of possible microscopic states (or microstates) of a system in thermodynamic equilibrium, consistent with its macroscopic thermodynamic properties (or macrostate).
The entropy in such a state would be that of a classical ideal gas plus contributions from molecular rotations and vibrations, which may be determined spectroscopically.
www.hallencyclopedia.com /Entropy   (4811 words)

  
 [No title]   (Site not responding. Last check: 2007-08-19)
Entropy as defined by Shannon is closely related to thermodynamic entropy as defined by physicists and many chemists.
The entropy of English text is about 1.5 bits per character (Try compressing it with the PPM compression algorithm!) The entropy rate of a data source means the average number of bits per symbol needed to encode it.
Entropy is effectively the strongest non-lossy compression possible, which can be realised in theory by the use of the typical set or in practise using Huffman, Lempel-Ziv or Arithmetic coding.
www.wikiwhat.com /encyclopedia/i/in/information_entropy.html   (397 words)

  
 Information entropy - Wikipedia, the free encyclopedia
Entropy effectively bounds the performance of the strongest lossless (or nearly lossless) compression possible, which can be realized in theory by using the typical set or in practice using Huffman, Lempel-Ziv or arithmetic coding.
Thus, the entropy of the source alphabet, with its given empiric probability distribution, is a number equal to the number (possibly fractional) of symbols of the "ideal alphabet", with an optimal probability distribution, necessary to encode for each symbol of the source alphabet.
The ratio of the entropy of the source alphabet with the entropy of its optimized version is the efficiency of the source alphabet, which can be expressed as a percentage.
en.wikipedia.org /wiki/Information_entropy   (2291 words)

  
 Entropy, Disorder and Life
Entropy and the second law are powerful tools that allow one to calculate the properties of systems at equilibrium.
Boltzmann's entropy equation talks about a specific kind of system--an isolated system with a specified constant total energy E (although the constant E does not explicitly appear in the equation, it is implied and crucial) in a state of equilibrium.
This line of argument considers the overall macroscopic state of the system to be not a particular protein or a particular gene, but just "a protein" or "a gene", and considers the statistical ensemble to be the whole group of possible configurations of the same set of smaller constituent molecules.
www.talkorigins.org /faqs/thermo/entropy.html   (1968 words)

  
 [No title]
The thermodynamic entropy S, often simply called the entropy in the context of chemistry and thermodynamics, is a measure of the amount of energy in a physical system which cannot be used to do work.
In 1877, Boltzmann realised that the entropy of a system may be related to the number of possible "microstates" (microscopic states) consistent with its thermodynamic properties.
For instance, a calculation of the entropy of ice by the latter method, assuming no entropy at zero temperature, falls short of the value obtained with a high-temperature reference state by 3.41 J/K/mol.
wikiwhat.com /encyclopedia/t/th/thermodynamic_entropy.html   (2481 words)

  
 Entropy and the second law of thermodynamics
Thus, the definition of entropy as a measure or indicator of the greater dispersal of energy is visibly demonstrated by the plots.
From a molecular viewpoint, the calculation and explanation of entropy change in forming a solution from A and B liquids (or A as an ideal solute and B as the solvent) is not as simple as those we have considered.
Entropy measures the energy dispersal for a system by the number of accessible microstates, the number of arrangements (each containing the total system energy) for which the molecules' quantized energy can be distributed, and in one of which – at a given instant – the system exists prior to changing to another.
www.2ndlaw.com /entropy.html   (7244 words)

  
 § 24. entropy. 4. Science Terms. The American Heritage Book of English Usage. 1996
Originally, Clausius intended for the entropy of a system to be associated with the amount of thermal energy put into a system that could not be extracted as mechanical work.
As the scientific understanding of entropy evolved, a subjective sense of entropy developed that associated entropy with energy that is irreversibly lost and with disorder.
Despite the narrative force that the concept of entropy appears to evoke in everyday writing, in scientific writing entropy remains a thermodynamic quantity and a mathematical formula that numerically quantifies disorder.
www.bartleby.com /64/C004/024.html   (570 words)

  
 Entropy and the Laws of Thermodynamics
Today the word entropy is as much a part of the language of the physical sciences as it is of the human sciences.
The concept of entropy is particularly abstract and by the same token difficult to present.
In breaking the vicious circle of repetitiveness in which the ancients were trapped, and in being confronted with biological evolution generating order and organization, the concept of entropy indirectly opens the way to a philosophy of progress and development (see: the direction of evolution).
pespmc1.vub.ac.be /ENTRTHER.html   (921 words)

  
 JCE 1999 (76) 1385 [Oct] Shuffled Cards, Messy Desks, and Disorderly Dorm Rooms - Examples of Entropy Increase? ...
The thermodynamic entropy change from human-defined order to disorder in the giant Egyptian stones themselves, in the clothing and books in a room or papers on a desk, and in the millions of cards in the world's casinos is precisely the same: Zero.
Entropy is increased in the shuffler's and in the billiard cue holder's muscles, in the tornado's wind and the earthquake's stressnot in the objects shifted.
The point is that information "entropy" in all of its myriad nonphysicochemical forms as a measure of information or abstract communication has no relevance to the evaluation of thermodynamic entropy change in the movement of macro objects because such information "entropy" does not deal with microparticles whose perturbations are related to temperature.
jchemed.chem.wisc.edu /Journal/Issues/1999/Oct/abs1385.html   (2476 words)

  
 Entropy Encyclopedia Article @ LaunchBase.org (Launch Base)   (Site not responding. Last check: 2007-08-19)
As shown in the preceding discussion of the illustration involving a warm room (surroundings) and cold glass of ice and water (system), the difference in temperature begins to be equalized as portions of the heat energy from the warm surroundings become spread out to the cooler system of ice and water.
This is the first-ever mathematical formulation of entropy; at this point, however, Clausius had not yet affixed the concept with the label entropy as we currently know it; this would come in the following two years.
In 1876, chemical engineer Willard Gibbs, building on the work of those as Clausius and Hermann von Helmholtz, situated the view that the measurement of "available energy" ΔG in a thermodynamic system could be mathematically accounted for by subtracting the "energy loss" TΔS from total energy change of the system ΔH.
www.launchbase.org /encyclopedia/Entropy   (2803 words)

  
 Entropy Explained
In traditional thermodynamics, entropy is a measure of the amount of energy in a closed system that is no longer available to effect changes in that system.
Since ordering requires an increase in entropy, it is a bit ironic to find creationists claiming entropy as an anti-ordering process (which it is not) in order to "prove" special creation, when it would make more sense to use it as an ordering process to "prove" divine arrangement of the laws of physics.
For further discussion see Dr. Frank Lambert's Entropy Is Simple (which covers almost all the important issues surrounding entropy) and Brig Klyce's The Second Law of Thermodynamics (which analyzes how physicists have misled laymen with their sloppy writing).
www.infidels.org /library/modern/richard_carrier/entropy.html   (1007 words)

  
 Entropy
Entropy is defined as the degree of freedom that particles of matter have.
The change in entropy, delta S, is the difference between the final entropy and the initial entropy of a system.
The standard molar entropy of a substance is entropy value of the substance at stanard state.
members.aol.com /profchm/entropy.html   (1491 words)

  
 AllRefer.com - entropy (Physics) - Encyclopedia
Originally defined in thermodynamics in terms of heat and temperature, entropy indicates the degree to which a given quantity of thermal energy is available for doing useful work : the greater the entropy, the less available the energy.
This means that although energy cannot vanish because of the law of conservation of energy (see conservation laws), it tends to be degraded from useful forms to useless ones.
In information theory the term entropy is used to represent the sum of the predicted values of the data in a message.
reference.allrefer.com /encyclopedia/E/entropy.html   (426 words)

  
 Entropy   (Site not responding. Last check: 2007-08-19)
Entropy, or average self-information, measures the uncertainty of a source and hence provides a measure of the information it could reveal.
Entropy is a measure of uncertainty in a random variable and a measure of information it can reveal.
The entropy rate is a measure of the uncertainty of information content per output symbol of the source.
cnx.org /content/m10164/latest   (773 words)

  
 Entropy and the Second Law of Thermodynamics
So whereas the first law expresses that which remains the same, or is time-symmetric, in all real-world processes the second law expresses that which changes and motivates the change, the fundamental time-asymmetry, in all real-world process.
Clausius coined the term "entropy" to refer to the dissipated potential and the second law, in its most general form, states that the world acts spontaneously to minimize potentials (or equivalently maximize entropy), and with this, active end-directedness or time-asymmetry was, for the first time, given a universal physical basis.
The disequilibrium produces a field potential that results in a flow of energy in the form of heat from the glass to the room so as to drain the potential until it is minimized (the entropy is maximized) at which time thermodynamic equilibrium is reached and all flows stop.
www.entropylaw.com /entropy2ndlaw.html   (473 words)

  
 Entropy
Entropy of system, is a measure of the avaialability of its energy.
Specific entropy of a system is the entropy of the unit mass of the system and has the dimension of energy/ mass/temperature.
The SI unit of specific entropy is J/(Kg.
www.taftan.com /thermodynamics/ENTROPY.HTM   (64 words)

  
 ENTROPY
Entropy is a quantity that, in its two contexts, characterizes not only all form and life in the universe, but all signal, language, information and written material ever produced anywhere.
Entropy within this theory is the "measure of the rate of transfer of information in [that] message" (OED).
Another consequence of the second law of thermodynamics, is that the entropy, or disorder, of the universe must increase for a reaction or event to occur (thus over time the universe proceeds toward the most probable state--hypothetically a "heat-death" of complete uniformity as mentioned by Pynchon in "Entropy").
www.pynchon.pomona.edu /entropy   (2066 words)

  
 Entropy and Art
It follows that the entropy principle defines order simply as an improbable arrangement of elements, regardless of whether the macro-shape of this arrangement is beautifully structured or most arbitrarily deformed; and it calls disorder the dissolution of such an improbable arrangement.
Entropy theory, on the other hand, is not concerned with the probability of succession in a series of items but with the overall distribution of kinds of items in a given arrangement.
The catabolic effect, then, increases entropy in two quite different ways: directly by the fortuitous destruction of patterns that are unlikely to be rebuilt by mere chance; indirectly by removing constraints and thus enlarging the range of tension reduction, which increases entropy by simplifying the order of a system.
acnet.pratt.edu /~arch543p/readings/Arnheim.html   (16441 words)

  
 Creative Entropy Web Design and Hosting
Creative Entropy, Inc. was formed as a partnership in April 2000 following 15 years of collaboration and technical mayhem.
You won't find flash and glitz on a Creative Entropy site, but you also won't wait 5 minutes for a page to load or wade through meaningless drivel to find what you're looking for.
Creative Entropy sites are now receiving 4 million sessions
www.creative-entropy.com   (263 words)

  
 Entropy
The entropy is a measure of the probability of a particular result.
The entropy is a measure of the disorder of a system.
The entropy measures the heat divided by the absolute temperature of a body.
www.upscale.utoronto.ca /GeneralInterest/Harrison/Entropy/Entropy.html   (3423 words)

  
 Entropy (1999/I)   (Site not responding. Last check: 2007-08-19)
Entropy had it all for me because it was funny, tragic (funny tragic) and dramatic.
After all, I don't think there is a single soul out there that hasn't felt some sort of incident or disaster in our romantic lives, and can't look back at it and laugh at in jest.
I give Entropy an "8" just because it was so entertaining and visual, and while there will be many that will call this plainly over-rating, I don't care, I just really enjoyed the movie and could watch it again and again.
www.imdb.com /title/tt0156515   (461 words)

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