Two men are getting very drunk

Two men are getting very drunk at a bar on top of a skyscraper .
One man looks at the other and says I bet the the force of air between this skyscraper and the one next to it would allow a man to jump off the top of one and the air would lift him back to the top of the other one.
The second guy tells him bullshit.
The first guy says I'll prove it.
The two men go out on the roof and the first guy jumps off.
Sure enough he falls almost to the ground and swoops back up to the roof of the other building.
The second guy is so excited he has to try it.
He jumps off the roof and splats on the pavement.
When the first guy returns to the bar the bartender says Superman you are a mean drunk.