Drinking at the top of a skyscraper

So Jim is drinking at a bar on the top of a skyscraper. He notices a man walk up to the other end of the bar, order a large beer, drink it all in one gulp, run to the edge of the roof and jump.

Jim becomes alarmed, he runs to look over the edge - expecting the worst - but, to the man's surprise, the guy isn't splattered all over the street. In fact he seems to have disappeared completely.

Puzzled, Jim walks back to his bar stool, and right before he asks the bartender if he saw what just happened- the guy steps out of the elevator, walks back up to the bar and does it all over again.

Jim is dying to know how this man does it!

Next time the man steps out of the elevator Jim runs up to him and asks "how do you do it? How are you jumping from the roof and living?", the man replied "it is simply science. You drink the large beer as quick as you can, the carbonation stays in your stomach for a few minutes, and our high elevation strengthens the effects of the carbonation in the beer. So after you jump, you begin falling slower and slower as you get closer to the ground. It is truly a rush, but you have to hurry as this temperature gives the best results!"

Jim then feels compelled to try this, runs over to the bartender, orders and drinks as fast as he can a large beer - runs over to the edge, jumps, and plummets to his death on the street.

The bartender looks over at the man and says "Superman, you're such an asshole when you're drunk."