Entropy (order and disorder)

In thermodynamics, entropy is often associated with the amount of order or disorder in a thermodynamic system. This stems from Rudolf Clausius' 1862 assertion that any thermodynamic process always "admits to being reduced [reduction] to the alteration in some way or another of the arrangement of the constituent parts of the working body" and that internal work associated with these alterations is quantified energetically by a measure of "entropy" change, according to the following differential expression: ∫ δ Q T ≥ 0 {\displaystyle \int \! {\frac {\delta Q}{T}}\geq 0} where Q = motional energy ("heat") that is transferred reversibly to the system from the surroundings and T = the absolute temperature at which the transfer occurs.

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