Astronomy professors rave about how nutty it is that the only way we can measure it is through our understanding Newtonian mechanics alongside the implications.
Special Relativity, not Newton, but otherwise spot on. History is full of these "I have no idea on the why or how, but here is a bunch of math to describe and make predictions" when it comes to natural phenomena. Hell, speaking of Gravity, what is it? I mean Why is there Gravity? We understand DNA and evolution magnitudes more in depth than we do one of the four universal forces of the universe!