The TARDIS sound comes from Doctor Who, the long-running BBC science fiction series first broadcast in 1963. It was created at the BBC Radiophonic Workshop to give the Doctor's time machine a sound unlike any real engine, and it has accompanied the TARDIS through almost every era of the show since. As Doctor Who fandom grew online, the clip became a shorthand for time travel itself, reused in fan videos, memes, podcasts and edits whenever a character needs to arrive from nowhere. Its staying power comes from that instant recognition.