I am really disappointed at Wikipedia users for not having anything on the Fizeau effect. It is intuitive and logical.
Anyway I wonder if there is a force on a transparent medium as a beam enters it from a region of lower refractive index. Since the beam is slowed down I just assume there would be. This seems like a trivial problem but I don't have time to think now:-) If anyone can affirm this then we have a good clue to some astronomical riddles. David
