At least Einstein’s General Relativity was testable....
Yes well sort of, in that we could see the stars that were behind the sun during an eclipse, and we could fly an atomic clock around the globe and check it against one that was still on the surface, they were different by exactly the amount the math predicted. But all those tests only established that Newton was out as far as a cosmology was concerned and Relativity took its place. Once Quantum mechanics was understood, no one allowed it to falsify the theory. A unified theory is important and string theory seemed to do it.
Relativity is true, but it contradicts Quantum Mechs.
Quantum theory is true but if followed to its logical conclusions, it falsifies Relativity, if it can be said that Einstein falsifies Newton.
String theory can unite them! Too bad it contradicts the observations.
A theory that can be used to prove anything and its opposite can only have value to the "math is beautiful" people. Newton is so beautiful and works so well right up to the point it doesn't, just like Quantum Physics, just like Relativity, just like String Theory.
Delighted for someone to correct me, but not please with the "electric universe"...(sigh.)