An important thing to consider here is that the first engineering project which had to make use of Einstein's Theory of Relativity was GPS --- the time/position

An important thing to consider here is that the first engineering project which had to make use of Einstein's Theory of Relativity was GPS --- the time/position calculations to triangulate location based on satellites is so exacting that it has to take into account gravimetric distortions based on the receivers being further down in the gravity well than the GPS satellites: https://xkcd.com/808/ https://xkcd.com/808/