It's not the case--protons were observed first, and then theory was developed to explain them, among other things.
General relativity might be wrong, but it's probably not over-fitted because it's quite simple as far as theoretical constructs go.
And it has a pretty good track record. Both black holes and gravity waves were "invented" because the theory seemed to indicate that they should exist, even though there was no evidence yet. Both were spectacularly confirmed last year.
That said, we know there is some shortcoming in either GR or quantum mechanics (or both), because they don't agree under certain conditions. Dark matter, being a gravitational phenomena that seems like it might be a new kind of particle, is potentially in that same area.
General relativity might be wrong, but it's probably not over-fitted because it's quite simple as far as theoretical constructs go.
And it has a pretty good track record. Both black holes and gravity waves were "invented" because the theory seemed to indicate that they should exist, even though there was no evidence yet. Both were spectacularly confirmed last year.
That said, we know there is some shortcoming in either GR or quantum mechanics (or both), because they don't agree under certain conditions. Dark matter, being a gravitational phenomena that seems like it might be a new kind of particle, is potentially in that same area.