As Einstein’s general relativity is finally proven experimentally by Sir Eddington’s expedition in 1919, the good news spread like wild fire. A student asked Einstein what if Eddington’s experiment has not found the prediction of his theory (the bending of starlight due to a massive body). Einstein replied:
“Then I would have been sorry for the dear Lord, for the theory IS correct.”
Of course, if the theory was disproven by the experiment, his theory of relativity will not become a pillar for modern physics as we know it.
What Einstein meant was general relativity describes gravity with such a deep inner elegance, with such simple yet powerful ideas, that he finds it hard to imagine that nature can just pass it by. General relativity, in Einstein’s view, was almost too beautiful to be wrong.
In physics, as in art, symmetry is a key part of aesthetics. Physicists describe the two properties of physical laws – that they do not depend on when and where you use them – as symmetries of nature. For example, the physics laws applies on the surface on the earth, applies exactly the same on the moon, on mars, on the edge of the galaxy and so on. By this usage physicist means that nature treats every moment in time and location in all of space identically – symmetrically – by ensuring that the same fundamental laws are in operation. Much in the same way that symmetries affect art and music, such symmetries are deeply satisfying; they highlight an order and coherence in the workings of nature.
The elegance of rich, complex, and diverse phenomena emerging from a simple set of universal laws is at least part of what physicist mean when they invoke the term “beautiful”.
-Adapted and edited from The Elegant Universe by Brian Greene.