After reading the question How Does Superman Fly?How Does Superman Fly? I find I'm still left with a major question on the same topic (and the answer to the question doesn't touch on this).
How does Superman propel himself through the air and change direction and speed? If he just jumped up and start flying, he'd be going in one direction, but he can accelerate and decelerate and change direction. For anything to do this, it would have to have something to push against or to eject some kind of propellent.
This is not the same as how he flies -- if we accept that he can defy gravity, there's still the issue of how he can maneuver while in the air, with nothing to push against, and with no obvious propellent.
How does he propel himself, accelerate, decelerate, and change direction?
Addendum: Also, since he's able to fly in space (and I remember at some point even seeing indications he was able to fly to other planets - which is odd, since it'd require FTL) which would mean he'd be dealing with more than flying on Earth and it'd also mean he might not be able to control his direction if he's far enough from a star (if it were gravimetric control, that is).
