Two guys, quite sloshed, were arguing in a rooftop bar.
“Bah! Evolution is just a theory,” said one, slurring his words and waving his hand dismissively.
“Right—and so is gravity!” replied the other, equally sloshed. “Look—I’ll show you! <hic>…”
To prove his point, he then ran to the parapet, jumped off the roof, spun around in the air, and floated back to his barstool.
“See?” he said to the first guy, triumphantly, and reached for his beer glass again. “Now you try it.”
So the first guy runs to the parapet, jumps off the roof—and plummets forty storeys to the ground.
The bartender, seeing this, turns to the second guy, and says: