When summer hits, it's amusement park season. Crowds rush the open doors of theme parks across the world. In Istanbul, it's Luna Park. Paris, Tokyo, and Los Angeles have Disneyland. Some people wait in line for hours for their favorite rides. Roller coasters provide much of the draw for young and old alike. There's the thrill of the height, the rush of sound, the feeling of being weightless, and then the falling down, down, down! In fact, the names of the rides alone hint at the thrill that is to come: Australia has the Tower of Terror and Japan the Steel Dragon.