Courtesy of the Intellectual Property Office www.ipo.gov.uk here's an interesting story.
On a December night, fifty years ago, a strange and previously unknown creature was introduced to the people of planet Earth. It was a distillation of everything bad: it was super-intelligent; it was armed to the teeth - or the plunger, to use the vernacular humanoid descriptor of the day; it was capable of interstellar travel, telekinesis and time travel; it consisted of an unholy fusion of bad metal and black bile. It was, of course, a Dalek.