Gravitational waves are the "smoking gun" of the Big Bang. Predicted by Albert Einstein's theory of general relativity in 1916, a massive object like Earth distorts space-time around it like a bowling ball dropped on a trampoline. The larger the object, the more space-time is distorted by it. If a marble were circling around the bowling ball on the dimpled trampoline, it would fall inward, toward the bowling ball, like a rock in space circling a planet.
