To me this is a wonderful example of the power of mathematics and science to go well beyond our normal intuition of how the world around us works works (which was the normal way things were done until only a few hundred years ago).

The fact that we are able to measure things globally indirectly and accurately based on our understanding of physics, hypotheses we make, and then apply those experiments is very cool.

Never mind the marvel of GPS that we've just taken for granted for decades...