George wakes Dick in the middle of the night after seeing (or imagining or dreaming) a UFO shaped like a cup. In one of the discussions that followed, Dick lists the possibilities: 1) George can't prove that what he saw was real 2) Those who are making fun of George can't prove he didn't. Bertrand Russell, English philosopher, devised a story to illustrate the principle of the Burden of Proof. He suggested that there could be a teapot orbiting the sun between the orbits of Earth and Mars. Like George's UFO, nobody could prove whether it existed or not. At the end of the episode, nobody was sure what happened.