Two men were sitting at a bar at the top of a skyscraper. Both were bending their elbows at a steady rate. The first man said, "You know, there's such an updraft on the outside of this building, that if you jump off, you'll fall for a bit, but the updraft will catch you, and bring you right back up to this balcony.
The second guy said, "I don't believe it, you'll have to prove this to me."
So the first guy goes over the balcony and jumps off. He falls and falls and falls, and then he slows in mid drop, and begins rising back up. Finally, he lightly steps back onto the balcony. "See, I told you," he says.
The second guy says, "I've got to try that." So he jumps off the balcony, and falls and falls and falls and falls. Finally, splat on the ground.
The first guy returns to the bar and orders another drink.
As he serves the drink, the bartender says, "You're a mean drunk, Superman."