Spiders can Fly--Why Can't Spiderman?

Imagine you're a spider marooned on a post in the middle of a large lake. A human might fret over escaping such a trap, but as a spider, you know just what to do. You raise your rear end to the breeze, shoot out a spray of gossamer threads, and wait until a rising air current carries you up, up and away. A crab spider spins silk lines into the breeze in preparation for a ballooning flight. (view full size)Image Credit: Moonsung Cho. Remarkably, the threads don't have to cup the air like a balloo...