Read about Emmy Noether, a Great Mathematician and Forgotten Hero of Relativity - largely because she was a Woman

A wonderful summary of how Emmy Noether helped other great mathematicians get a handle on Einstein's General Relativity back in the first quarter of the 20th century can be found here.  Many of her contemporaries, including Einstein, suggested she is the most important woman in the history of mathematics. What is now known as Noether's theorem is at the heart of all physical theories, which states if there is a conservation law, then there must be a quantity that is invariant, and vice versa. For GR, she basically showed energy is still conserved, but it is much more challenging to see it, compared to classical systems and theories, because of the warping of spacetime by mass-energy densities.