Today’s Google Doodle (the stylized version of the google logo on the google homepage) honors Emmy Noether, the mathematician behind Noether’s Theorem. Noether’s theorem is incredibly important to modern physics because it explicitly works out the relationship between continuous symmetries of nature and conserved quantities. Thus, invariance with respect to time translation requires conservation of energy, spatial translation invariance leads to conservation of momentum, rotational invariance leads to conservation of angular momentum, U(1) symmetry leads to charge conservation, and so on. Noether’s theorem pops up everywhere in modern physics.
Noether is also noteworthy as a rare female mathematician in an incredibly male-dominated time. In fact, she had a great deal of trouble securing a position as a professor in Germany due to other professors believing that women did not belong on the faculty. Even after finally getting a position, she eventually ended up at Bryn Mawr College after being forced out of her position by the anti-Semitic policies of the Nazis.
Today would have been Noether’s 133rd birthday.