Maxwell introduces statistical probability distributions into physics, deriving the Gaussian molecular speed distribution.

Rudolf Clausius introduces molecular mean free path and rotational molecular degrees of freedom.

August Krönig revives atomic kinetic gas theory, deriving pressure from molecular collisions.

Thomson and Maxwell introduce formal physical dimensions [M], [L], [T] and unit scaling laws.

Helmholtz applies the Second Law of Thermodynamics to cosmology, predicting universal thermodynamic equilibrium.

Ångström measures atomic spectral lines, identifying hydrogen in the solar atmosphere.

Edward Frankland discovers combining power of atoms, founding modern chemical bonding.

Bunsen and Roscoe establish the Law of Photochemical Induction and chemical actinometry.

William Thomson unifies Carnot engine efficiency and Joule heating into a single dynamical theory.