"einstein became isolated in his research over a Generalized Theory of Gravitation and was ultimately unsuccessful in his attempts at constructing a theory that would unify General Relativity and quantum mechanics." alicia - that's the holy grail of modern physics - to come up with a grand theory of everything that unifies the four fundamental forces. 50 yrs since einstein's dealth, lotsa great physicists have died trying to solve this problem. and the criticism of string theory is that none of that shit can be verified experimentally, cos we are dealing with extremely small "stuff," so many reputed physicists of today, including sheldon glashow are strong critics of string theory. looking forward to hearing more about einstein's work on brownian motion and photoelectricity.....