This is something that getting into analysis courses and finding your way into higher level physics and chemistry classes drives home. It's perfectly valid to u

This is something that getting into analysis courses and finding your way into higher level physics and chemistry classes drives home. It's perfectly valid to use a scientific theory that has been shown to be incorrect on some scale - so long as you are not in that scale. Yes, relativity is a better understanding of gravity than Newton's inverse square law, but it's still pretty valid for me to take the acceleration due to gravity as 9.8 meters/second^2 (which is an even lower level approximation) because I live on the surface of the Earth. If I am designing cars, or roads, or buildings, or (most) airplanes, or sewer systems, this is a pretty good assumption. Having been trained as a physicist, there is nothing the community would love more than results which show we need to develop new theories - mostly because that means more work for physicists. At any rate, I love Asimov's writing.