The etymology of the term entropy (see: entropy (etymology)), comprised of or embodying the terms: en- (inside) + -trope (transformation) + equivalence-value (1854) + transformation content (1856/1865). |

In 1865, Clausius, using differential notation, redefined entropy dS as follows:

or in modern Greek delta δQ notation (Neumann, 1875), to explicitly defined the differential unit of heat as an inexact differential, we have:

Clausius, accordingly, made the unit of heat the derivative of heat a complete differential or path independent state function, the logic of which became embodied in what Clausius defined as the "second main principle" of the mechanical theory of heat. The mathematical expression of entropy was conceived by Clausius to quantify the effect of irreversibility (or the irreversible change of state of a body), in the working body, e.g. a body of steam in a steam engine, during an engine cycle; an effect that French physicist Sadi Carnot assumed, in 1824, did not occur due to his view that heat was form of caloric particles.

A depiction of the different equation formulations of entropy (using an equation overlay method), shown over a rabbit smelling a flower (indicative of natural governing nature of the second law); the function (δQ/T) on the right hand side of the equation in lower right hand corner being the 1854 "equivalence-value" formulation of heat; the equation in the upper left hand corner being the 1856 "equivalence-value of all uncompensated transformations" formulation of entropy; the second row equation a version of the probability-based Boltzmann entropy (1872) / Planck entropy (1901) / Gibbs entropy (1902); the equation in upper right hand corner being the partial of entropy with respect to some variable X at constant energy. [6] |

Overview

In general, according to Clausius, when a body (working body) changes its state, work is performed

As such, to avoid everything hypothetical, we can exclude the interior work, by confining heat operations to the consideration of cyclical process— that is to say, operations in which the modifications that the body undergoes are so arranged that the body finally returns to its original condition. In such operations the interior work which is performed during the several modifications, partly in a positive sense and partly in a negative sense, neutralizes itself, so that nothing but exterior work remains, for which the theorem of the equivalence of transformations can then be demonstrated with mathematical strictness.

The theorem of the equivalence of transformations argues that when a body goes through a cyclical process, a certain amount of exterior work may be produced, in which case a certain quantity of heat must be simultaneously expended; or, conversely, work my be expended and a corresponding quantity of heat may by gained. This may be expressed by saying:

There may also be another effect of a cyclical process: heat may be transferred form one body to another, by the body which is undergoing modification absorbing heat form the one body and giving it out again to the other. In this case the bodies between which the transfer of heat takes place are to be viewed merely as heat reservoirs, of which we are not concerned to know anything except the temperatures. If the temperatures of the two bodies differ, heat passes, either from a warmer to a colder body, or from a colder to a warmer body, according to the direction in which the transference of heat takes place. Such a transfer of heat may also be designated, for the sake of uniformity, a

The two kinds of transformations that have been mentioned are related in such a way that one presupposes the other, and that they can mutually replace each other. If we call transformations which can replace each other

In addition, if the quantity of heat

A tattoo of the principle of the equivalence of transformations (1856), using the 1875 inexact differential notation δ of German physicist Carl Neumann, on the forearm of Ivanka, a newly graduated philosophy student. [6] |

here

being either positive or negative. It will thus be seen that the passage of heat from a higher to a lower temperature is to be looked upon as a "positive transformation", and its passage form a lower to a higher temperature as a "negative transformation".

If we represent the transformations which occur in a cyclical process by these expressions, the relation existing between them can be stated in a simple and definite manner. If the cyclical process is reversible, the transformations which occur therein must be partly positive and partly negative, and the equivalence-values of the positive transformations must be together equal to those of the negative transformations, so that the algebraic sum of all the equivalence-values become = 0. If the cyclical process is

The theorem respecting the equivalence-values of the transformations may accordingly be stated thus:

must be true for every reversible cyclical process, and the relation:

must hold good for every cyclical process which is in any way possible. The value of

Etymology

Between 1850 and 1865, Clausius published a series of nine memoirs, which in 1865 were collected in the textbookSee main: Entropy (etymology)

Entropy of the universe tends to a maximum

American physicist Michael Guillen argues that the following formulation of the second law:

which states that the entropy of the final state of the universe will be greater than or ‘maximal’ as compared to the initial state entropy of the universe, is one the of the five equations that most changed the world; along with Isaac Newton’s law of universal gravitation, Daniel bernoulli’s law of hydrostatic pressure, Michael Faraday’s law of electromagnetic induction, and Albert Einstein’s mass-energy equivalence relation. [5]

A basic thermodynamic data table, alluding to the methodology according to which one would measure and list the entropy of a given human or rather human molecule, the human molecular formula of which is shown in the bottom row (next to an unknown value of positive entropy). |

Entropy of a human molecule

The conception of the possession of an entropy value of individual person or human molecule or species of human molecules at a specific reference point in time is what is referred to as "human entropy".See main: Human entropy

The first person, historically, to make the suggestion that each person has a different value of entropy was American engineer William Fairburn in mentioned in his 1914 book

In theory, each individual person can be assigned an entropy value, in reference to a base value, similar to smaller molecules. Shown adjacent, for instance, are standard measures of entropy for four different molecules.

A table such as this is similar to the "material entropy" postulate, but with reference on the measure of entropy per species.

Human system entropy

In human systems, the definition of entropy is the same with the translation that the "working body" is defined such that instead of water molecules, confined to the internal regions of a steam engine, put in alternating contact with a hot body (a fire) and a cold body (cool water), driven to do mechanical work (push a piston), we have human molecules, confined to the internal regions of various regions of social systems, put in alternating contact with a hot body (the day sun) and a cold body (the cool night sky), driven to do the daily work of life, e.g. economic work, social work, volunteer work, household work, parenting work, territorial expansion work, interpersonal work, relationship work, etc. [2]See main: Economic entropy, Social entropy, etc.

From a reaction point of view, i.e. human chemistry point of view, boundaries to "working bodies" of human systems, i.e. interactive collections of human molecules confined to economic systems, are defined as being the the 90 percent probability regions in which a specific number of socially interactive or energetically-coupled humans are found. In this point of view, entropy is defined as the internal system energy (internal work) dissipated as humans act on each other, energy that does not find conversion into system external work.

A listing of mostly incorrect misinterpretation definitions of entropy in a letter to The Electrician (London) from Sydney Evershed, January 09, 1903, supposedly in connection to the great “what is entropy debate” (1902-1904) started by British electrical engineer James Swinburne. [4] |

Historically, entropy has been subject to much confusion, misinterpretation, misapplication, a subject about which is prolonged and involved.See main: Entropy misinterpretations

The first dominant person to confuse entropy was Peter Tait who in his 1868

Other famous misinterpretations of entropy were dug out during the great 1902 to 1904 "what is entropy debate", such as are listed adjacent 1903 letter by Syndney Evershed. [4]

See also

● Entropy (quotes)

References

1. Clausius, Rudolf. (1862). "On the Application of the Theorem of the Equivalence of Transformations to Interior Work", (pp. 215-250). Communicated to the *Naturforschende Gesellschaft of Zurich, *Jan. 27th, 1862; published in the *Viertaljahrschrift of this Society, *vol. vii. P. 48; in *Poggendorff’s Annalen,* May 1862, vol. cxvi. p. 73; in the* Philosophical Magazine, *S. 4. vol. xxiv. pp. 81, 201; and in the *Journal des Mathematiques of Paris,* S. 2. vol. vii. P. 209.

2. (a) Thims, Libb. (2007).*Human Chemistry (Volume One)*, (preview). Morrisville, NC: LuLu.

(b) Thims, Libb. (2007). 2. (a) Thims, Libb. (2007).

3. Clausius, R. (1865).

4. Reeve, Sidney. (1907). “The Question of Entropy”

5. Guillen, Michael. (1996).

6. Adeline, Chloe. (2010). “Make Your Life Simple and Focused: With Science!”, SimpleRabbit.com, Apr 24.

Further reading

● Fast, J.D. (1962).

● Arnheiim, Rudolf. (1974).

● McIntyre, Vonda N. (1981).

● Brooks, Daniel R. and Wiley E.O. (1988).

● Dugdale, J.S. (1998).

● Greven, Andreas, Keller, Gerhard, and Warnecke, Gerald. (2003).

● Ben-Naim, Arieh. (2007).

● Grady, Walter T. (2008).

External links

● Entropy – Wikipedia.