TARDIS

The TARDIS (; acronym for "Time And Relative Dimension(s) In Space") is a fictional hybrid of a time machine and spacecraft that has, since 1963, appeared in the British science fiction television series Doctor Who and its various spin-offs. While a TARDIS is capable of disguising itself, the exterior appearance of the Doctor's TARDIS typically mimics a police box, an obsolete type of telephone kiosk that was once commonly seen on streets in Britain in the 1940s and 50s. Its interior is shown as being much larger than its exterior, commonly described as being "bigger on the inside".

Due to the significance of Doctor Who in popular British culture, the shape of the police box is now more strongly associated with the TARDIS than its real-world inspiration. The name and design of the TARDIS is a registered trademark of the British Broadcasting Corporation (BBC), although the design was originally created by the Metropolitan Police Service.

Name

TARDIS is an acronym of "Time And Relative Dimension in Space". The word "Dimension" is alternatively rendered in the plural. The first story, An Unearthly Child (1963), used the singular "Dimension". The 1964 novelisation Doctor Who in an Exciting Adventure with the Daleks used "Dimensions" for the first time and the 1965 serial The Time Meddler introduced the plural in the television series – although the script had it as singular, actor Maureen O'Brien changed it to "Dimensions". Both continued to be used during the classic series; in "Rose" (2005), the Ninth Doctor uses the singular (although this was a decision of actor Christopher Eccleston—the line was plural in the script for the episode) and the series has continued with the singular from that point forward.