the countryside to take in the scenery. As you are driving down a country road, you come upon a roadside sign that reads, Caution! This sign has sharp edges on it. Do not touch the edges of this sign. Speeding past the sign, you think to yourself, “How odd! why would someone put a sign like that up on the road? That is really weird. It must be some kind of joke.” Moments later, still querying in your mind about the odd sign, you find the front end of your car barreling over a bridge that has been