A father and son were testing the springtime winds with a brand-new kite. It was a bit kite, red, with black fringe, colorful, and fancy. And they had a huge spool of string -- crochet thread, as strong as the kite string, but colorful, more economical, and several hundred feet more to the spool. The breezes were blowing stiff, and the kite begged to run wild. And so they let out all the string. And the kite went so high that the little boy couldn't even see it any more. "Is it still there?" he asked. "Yeah, it's still there." "But how do you know for sure?