Beauty, Melody, and Entropy are an Equivalence Class Suppose that we were asked to arrange the following in two categories– distance, mass, electric force, entropy, beauty, melody. I think there are the strongest grounds for placing entropy alongside beauty and melody and not with the first three.Sir Arthur Stanley Eddington, OM, FRS (1882-1944), a British astronomer, physicist, and mathematician in The Nature of the Physical World, 1927 Sir Arthur Stanley Eddington