Einstein’s Other Theory of Everything

Einstein finished his masterwork, the theory of general relativity, in 1915. He was 37 years old and would live for another 40 years. He spent these decades in the attempt to explain that everything—matter, energy, and even ourselves—were simply deformations of spacetime. 

Einstein, feeling that his theory of general relativity was incomplete, wanted to develop a unified field theory—a framework that would combine space and time with energy and matter. (Indeed, it was Einstein who coined the term “unified theory.”) He ultimately failed. But I have begun to wonder if his idea, as ambitious as it was startling, isn’t worth revisiting.

Einstein built his unified theory off of general relativity, which says that gravity is a property of spacetime. This is often depicted with a marble that matter in it to describe what we see happening in the universe.