ABSTRACT
The expanse of Einstein's influence and legacy is simply too vast for an accurate overview. In lieu of any more comprehensive summation, consideration is given to just three areas, both physical and philosophical, where his impact is, or should be, readily recognized: the further developments in what he termed his "lifework", general relativity; the pursuit of theoretical unification in fundamental physics; and the innovative understanding of the scope and limits of physical theories that can, with certain provisos, be recognized as a "realism". The general theory of relativity stood well outside the mainstream of theoretical physics. Einstein returned to the Schwarzschild solution in April 1939 with a paper in Annals of Mathematics arguing that the so-called Schwarzschild singularities do not exist. In particular, he argued that the total gravitational mass within a given radius of a contracting spherical star cluster would always remain below a certain bound for any realistic system of solar masses.
