Obi-Wan: Ahsoka, you were asking why the air over the wing has to keep up with the air underneath.
Ahsoka: Ooh, yes. Do you know?
Obi-Wan: Indeed I do. Attend: the air is not passing over the wing, the wing is passing through the air, so the curved upper side stretches the air forced over it apart, reducing pressure, producing lift. The lift pushes up, the weight pushes down. So as long as the lift is more than the weight, up we go. And that, my friend, is how an aeroplane flies.
Ahsoka: Got it! Right, yes! Cracking! I completely get it now.
Obi-Wan: Good. You see, it's actually quite easy to grasp when it's explained properly by someone who understands -
Ahsoka: So that's why planes can’t fly upside down!
Obi-Wan: Er, yes they can.
Obi-Wan: Well of course they can, haven't you seen the Red Arrows?
Ahsoka: But...doesn't that mean the curved side of the wing is on the bottom, so the lift is pushing down as well as the weight? How does that work?
Anakin: Yes, Obi-Wan. How does that work?
Obi-Wan: Well, Ahsoka, there's a very simple explanation, but just to finish what we were saying, Anakin, I think it's entirely up to you whether you let the lothcat in the hold freeze to death.
Obi-Wan: No one wants to hear the explanation, what a shame.