Einstein, in fact, failed to derive the general validity of E = mc^2. HE ONLY CONJECTURED IT.



The expanding of the universe is derived from the Einstein equation with a number of unverified assumptions. Some assumptions have been proven wrong.



In fact, the Einstein equation is not valid for dynamic problems because it has no bounded dynamic solutions.

1.     C.
Y. Lo, Einstein's Radiation Formula and Modifications to the Einstein Equation,
Astrophysical J. 455, 421-428 (1995).