A group of engineers is hired to design a new lightning rod for a tower being built down town. They figure they'll examine an existing one first to get started, so they go outside an find one built into a flag pole. They take out a tape measure and start taking measurements. As they try to measure the height of the pole the tape just folds over and falls to the ground. They stand there stumped when a physicist walks by. The engineers explain the problem to the physicist, whom, then removes the pole from the ground, lays it flat and measure it. "20 feet" he says and then goes on his way. One of the engineers replies "typical of a physicist... we ask for the height and he gives us the length!"