And this is the largest gap in the usual skeptic argument, "Well, prove it!" OK, well travel back in time to 1670 and prove: the speed of light in a vacuum, that light is electromagnetic radiation, that bacteria exist, that DNA exists, the mass of an electron, and that sperm and ova make babies. They start from the assumption that science is, right now, able to see and measure all phenomenon. Which is patently false, and any physicist would agree that we don't actually HAVE a full picture of the universe and how it works. It's a very good picture, but it's not complete. Otherwise all the attempts to solve a unified field theory would be done.