How time did Einstein waste on a unified field theory

[g.lemaitre]

The weak force was not discovered until 1953 or thereabouts so that pretty much made Einstein's attempt to unify all forces an impossible task. Does anyone know how much time he wasted on trying to find a unified field theory? Other than write a paper on gravitational lensing and the EPR paradox did he make a lot of contributions after the discovery of GR?

 

[HallsofIvy]

I wouldn't say that he "wasted" any time on it! While he was not ultimately successful, what he did was worthwhile in itself and lead to new insights into both relativity and quantum physics.