"She started by examining continuous symmetries. These are symmetries under transformations that can be varied continuously, such as rotations (where the angle can be changed continuously). The result... was stunning. She showed that to every continuous symmetry of the laws of physics there corresponds a conservative law and vice versa. In particular, the familiar symmetry of the laws under translations corresponds to conservation of momentum, the symmetry with respect to the passage of time (the fact that the laws do not change with time) gives us , and the symmetry under rotations produces conservation of angular momentum. ... fused together symmetries and conservation laws—these two giant pillars of physics are actually nothing but different facets of the same fundamental property."