For those of you unfamiliar with Doctor Who, he is the hero of the world's longest running sci-fi show. Although the show is only 50 years old, The Doctor is 2,000 years old. He is a Time Lord from the planet Gallifrey, has two hearts, and travels in a spaceship that looks exactly like a 1950's British police box that is called the TARDIS. TARDIS stands for time and relative dimension in space, so the Doctor can travel backwards and forwards in time and to other worlds.