It's the question of our time. Most people feel pretty strongly about the answer, yay or nay, but MythBusters will finally attempt to answer it with a real plane and a real treadmill in an episode tonight.
Editorial note: Whoa! You've found a super-old post here on BuzzFeed, from an earlier era of the site. It doesn't really represent where we are anymore, and may in fact be totally broken, but we're leaving it up as a part of our early history.