text: That's a pretty self-centered view of the universe-- if I can't see it, it doesn't exist...\n\nThe way I understand it, a point is just an abstraction, but it is a useful idea, so I don't see it as pointless.  While you'll never be able to exactly measure the location of a point, you can get to the right area, within experimental precision, so even though you can't see the point, you can know about where it is, so it's useful.\n\nAs for the mass question-- the universe is not limited by the resolution of your measuring devices.  Just because we can't measure a mass, doesn't mean it doesn't exist-- only that we can't measure it.  But. we may be able to someday, whether directly, or by some other, trickier method.