Noether's theorem (1918) states that any differentiable symmetry of the action of a physical program provides a corresponding conservation law. Noether's theorem has grown to be a essential tool of recent theoretical physics and also the calculus of versions. Sven’s is on one of the most exciting Ngrams I’ve seen, https://www.evernote.com/shard/s722/sh/840ea114-1fc2-6d4a-6e2e-61ef68576b26/O6g36ciHl8jeUf2jVtOHL2vBUI_Ye_PAj9y6WQtM8qdsIXj670H_1r4Vfg