Echo, a repeated sound. The term is usually used to refer to sound that is reflected from a surface and returned to its source after a noticeable delay. A person can typically hear his or her own echo where a hard surface, such as the side of cliff, reflects sound waves directly back to the person. The use of echoes to locate objects is called echolocation.
Space collisions are the universe's car wrecks. Only in outer space, it's stars, asteroids and even galaxies doing the smashing.
Whether you invented a revolutionary pair of skivvies or a way to turn cow manure into vanilla flavoring, we have an award for you. The Ig Nobels are proving that science isn't all seriousness and superstring theory.