| It's a very different thing. I'm not just talking about the age of the theory. I'm talking about the length of the period during which it was tested so many times, to the level of precision that no other theory got tested and stood. General relativity was, and still has never been tested to anywhere near that level of precision, and that many times.
And in fact, we still have strong reasons to doubt general relativity because there may or may not be deviations from it observed in galaxies and large scale universe. General relativity may be correct in that scale (with the ad-hoc addition of a cosmological constant) but to be consistent with those observations, one requires the existence of black holes, dark energy and and dark matter, things we never truly observed and don't know for sure exists (although it is our best explanation at this moment). We don't really understand how gravity behaves in very small scales, extremely large scales, or in the presence of very strong energy densities. One thing we know for sure is, general relativity is not the ultimate theory of gravity, it spectacularly fails in very small scales. We would like to stress-test all aspects of general relativity to 1 in a billion precision as well, but we can't. This is basically because gravity is very weak and you can't design all sorts of controlled experiments to test it. The best you can do is to make observations in the vicinity of readily massive things like Earth, Sun or a black hole, which you have no control over. You can't make two black holes, pit them together and see what happens in the lab. A situation very different from the quantum theory. Physicists did expect to observe gravitational waves, and it wasn't a shocker to anyone. The thing that makes is very big deal for physicists is that we now have a whole new way probing things that we couldn't before, in particular things which we don't understand yet, including the violations of general relativity which we do expect to see. We don't expect to see deviations in quantum theory (unless you bring a black hole nearby your quantum computer). |