The Tardis is the Doctor's time and space machine in Doctor Who, a British science fiction series that began in 1963, and its familiar blue police box exterior has become one of television's most recognisable images. Fans use the name as instant shorthand for something bigger on the inside, hidden in plain sight or able to travel through time. Clips naming the Tardis circulate among Doctor Who communities and meme editors because the line explains the joke in one breath, making it useful long after viewers first met the box.