Math & science · 1877

Statistical mechanics

Boltzmann explains entropy as counting the ways atoms can be arranged.

S = k log W linked the microscopic and macroscopic worlds. Statistical mechanics set the stage for Planck's quantum and for information theory.

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 3