In thermodynamics, the law of increasing entropy is loose metaphor for the second law of thermodynamics. In the 1964 Translator’s Introduction to Boltzmann’s Gas Theory, for instance, physics historian Stephen Brush, comments that: “Boltzmann was able to deduce immediately a very important result from his equation, which was not at all obvious from Maxwell’s original formulation: a quantity called H, which can be identified with the negative of the entropy, must always decrease or remain constant, if one assumes that the velocity distributions of two colliding molecules are uncorrelated. The molecular interpretation of the law of increasing entropy is thus intimately related to the assumption of molecular chaos and the relation between entropy and probability.” He continues, “H remains constant only when the gas attains a special velocity distribution which had previously been deduced by Maxwell (1859) in a less convincing manner.” [1]
References
1. Boltzmann, Ludwig. (1964). Lectures on Gas Theory (pgs. 9). New York: Dover.