The programme is listed in Guinness World Records as the longest-running science fiction television show (50 years) in the world and is also a significant part of Britishpopular culture. It has been recognised for its imaginative stories, creative low-budget special effects during its original run, and pioneering use of electronic music (originally produced by the BBC Radiophonic Workshop). In the United Kingdom and elsewhere, the show has become a cult television favourite and has influenced generations of British television professionals, many of whom grew up watching the series. It has received recognition from critics and the public as one of the finest British television programmes, including the BAFTA Award for Best Drama Series in 2006.
The Doctor has been principally played by twelve actors. The transition from one actor to another is written into the plot of the show as regeneration, a life process of Time Lords through which the character of the Doctor takes on a new body and, to some extent, new personality, which occurs when sustaining injury which would be fatal to most other species. Although each portrayal is different, and on occasions the various incarnations have even met one another, they are all meant to be aspects of the same character. The Doctor is currently portrayed by Peter Capaldi, who took up the role after Matt Smith's final appearance in an episode broadcast on 25 December 2013.
While described as "beyond the United Nations", the Torchwood Institute is known to cooperate with UNIT (the United Nations Intelligence Taskforce) to some extent. There appears at present to be some sort of rapport with the Prime Minister although historically this may not always have been the case. To those that have come in contact with Torchwood, they are primarily believed to be a special forces team. They appear to maintain this illusion by using false witnesses, or by sectioning any journalists who threaten to expose the truth, and via the use of memory altering drugs. Following a major incident involving the Institute, the stance of the organisation becomes much less confrontational and secretive.
The Doctor, Vicki, and Steven become involved in the siege of Troy. The story alters the fates of a few characters from the original literature. Vicki remains behind and becomes immortalised as the mythical character Cressida.
Homo sapiens. What an inventive, invincible species. It's only a few million years since they crawled up out of the mud and learned to walk. Puny, defenceless bipeds. They've survived flood, famine and plague. They've survived cosmic wars and holocausts. And now, here they are, out among the stars, waiting to begin a new life. Ready to outsit eternity. They're indomitable.