  Emmy Noether proved two deep theorems, and their converses, on the connection
between symmetries and conservation laws. Because these theorems are not in the
mainstream of her scholarly work, which was the development of modern abstract
algebra, it is of some historical interest to examine how she came to make
these discoveries. The present paper is an historical account of the
circumstances in which she discovered and proved these theorems which
physicists refer to collectively as Noether's Theorem. The work was done soon
after Hilbert's discovery of the variational principle which gives the field
equations of general relativity. The failure of local energy conservation in
the general theory was a problem that concerned people at that time, among them
David Hilbert, Felix Klein, and Albert Einstein. Noether's theorems solved this
problem. With her characteristically deep insight and thorough analysis, in
solving that problem she discovered very general theorems that have profoundly
influenced modern physics.
