All Einstein did was apply the Pythagoras theorem properly to the problem, changing it a bit to properly fit the problem. He found that the correct formula was

All Einstein did was apply the Pythagoras theorem properly to the problem, changing it a bit to properly fit the problem. He found that the correct formula was actually quite simple, differing only by a sign from Pythagoras' theorem. And so Plato was right. "God geometrizes continually"