# GR and EM

1. Aug 5, 2005

### εllipse

Alright, so Einstein came up with SR to make Maxwell's EM consistent with dynamics, correct? But SR was only for non-inertial reference frames and ignored gravity, so it was replaced with GR to make SR consistent with gravity. So why have I read (from many sources) that Einstein spent his later years (from 1925 onward) trying to find a way to reconcile GR and EM? Was SR compatible with EM, but somehow GR wasn't? Did some of the changes made between SR and GR conflict with Maxwell's EM?

2. Aug 5, 2005

### LeonhardEuler

The way I understand it (which may not be very well, I'm just going on something I heard once) is that Einstein was trying to come up with a unified theory of gravity and electromagnetism. In GR gravity emerges from the assumption that it is the same as an accelerated frame of reference. However, with EM you just have "charge" and no real reason why it should exist. I think he was somehow trying to come up with a deeper explaination for EM that would link it with gravity. It's not that he was trying to clear up an inconsistancy, he was trying to unify the two in some way.