Who's to say there aren't mediums that we simply cannot detect yet with today's technology. We've been doing this cat and mouse thing for a while. Make an observation, it's crazy insane, can't figure it out, learn something new, it makes more sense, and some day it's just taken for granted. Or, we make an observation, try to understand it within the current knowledge-base of Science, and find out 10 years later that we were completely wrong.
...But this conversation is tetering ever so close to the divide of where even theoretical physists start rechecking their assumptions, so let's get back to the newtonian world.
Aww, fine. It was gettin' good though