IN TRYING TO DEVELOP a unified theory, Einstein worked closely
with Peter Bergmann (left) and Valentine Bargmann (right), two
young German-born physicists who also had fled the Nazis and who
went on to become renowned scientists in their own right.
Bargmann's wife, Sonja, was the one who translated Einstein's
Scientific American article (and many other manuscripts) into
English. This picture was taken in 1940. Image: LUCIEN AIGNER
Corbis When Albert Einstein started his efforts to develop a
unified theory of physics in the early 1920s, it was such a
hopeful enterprise. Existing theories, including both relativity
and the emerging quantum mechanics, raised as many questions as
they answered, so most physicists agreed on the need for a
grander framework. Ideas poured forth from figures such as
Hermann Weyl, Arthur Stanley Eddington and Theodor Kaluza.
Although these pioneering efforts fell short of achieving
unification, they introduced theorists to such fruitful concepts
as gauge symmetry and extra dimensions.