Instruct: Given a question, retrieve relevant documents that can help answer the question.
Query: How many doctors are in Doctor Who?
The Doctor is the title character in the long-running BBC science fiction television programme Doctor Who. Since the show's inception in 1963, the character has been portrayed by thirteen lead actors. In the programme, "the Doctor" is the alias assumed by a centuries-old alien—a Time Lord from the planet Gallifrey—who travels through space and time in the TARDIS, frequently with companions. The transition to each succeeding actor is explained within the show's narrative through the plot device of "regeneration", a biological function of the Time Lord race that allows a change of cellular structure and appearance with recovery following a potentially fatal injury.
For many years there was much confusion amongst "Doctor Who" fans as to whether the Cybermen had originated on Mondas or Telos. "The Tomb of the Cybermen" merely states "Telos was their home planet," seemingly at odds with the statements in "The Tenth Planet" that Mondas is where the Cybermen have originated. The first edition of "The Making of Doctor Who" (1972) gives Telos as their home planet, as do several 1970s novelisations of the Cybermen stories by co-creator Gerry Davis. With the episodes becoming easily accessible and the issue being covered in magazines like "Doctor Who Magazine" the uncertainty declined in the 1980s and "Attack of the Cybermen" (1985) sought to resolve the conflicting claims by detailing how the Cybermen had conquered Telos. In 2017, the episode "The Doctor Falls" addressed this controversy in passing, by indicating that the Cybermen were created independently in multiple locations, including both Mondas and Telos.
The book opens with a discussion of a woman in her thirties who suffered daily stomach cramps and serious weight loss, and who visited some 30 doctors over a period of 15 years. Several misdiagnoses were made before she was finally found to have celiac disease. Groopman explains that no one can expect a physician to be infallible, as medicine is an uncertain science, and every doctor sometimes makes mistakes in diagnosis and treatment. But the frequency and seriousness of those mistakes can be reduced by "understanding how a doctor thinks and how he or she can think better".
As with his predecessor, all the Second Doctor's original episodes were in black-and-white. Later guest appearances in The Three Doctors (1972–73), The Five Doctors (1983) and The Two Doctors (1985) were in colour. However, Troughton's reign as the Doctor was more notable for what does not exist than for what does, as many of the episodes featuring the Second Doctor were junked by the BBC; a full list of incomplete Doctor Who serials shows how many of these episodes are missing from the BBC Archives.
In "The Lodger", after the Eleventh Doctor shows Craig who he is, he points to his face and says, "Eleventh". However, in "The Name of the Doctor", when the Doctor rescues Clara from inside his own time stream, they both see another figure that Clara doesn't recognise. The Doctor then reveals that this is a past incarnation that he deemed unworthy of the name "Doctor" due to the atrocities he committed during the Time War, and only accepted him after learning the truth of how the war ended ("The Day of the Doctor"). Ultimately, in "The Time of the Doctor" the Eleventh Doctor reveals that, counting the War Doctor and the Tenth's aborted regeneration, he is actually in his final incarnation, reaching a point where he is dying of old age after centuries of conflict with the Daleks and others on the planet Trenzalore. However, at the behest of Clara, the Time Lords grant the Doctor a new regeneration cycle, allowing a thirteenth regeneration into an incarnation known as the Twelfth Doctor. The Twelfth Doctor is later able to regenerate into a female incarnation known as the Thirteenth Doctor after suffering fatal injuries during a battle.
In the New Series Adventures novel Only Human by Gareth Roberts, Rose asks the Doctor how he would know that marrying for love is overrated, to which he cryptically answers, "Who says I don't? You ask the Lady Mary Wortley Montagu." In a December 2005 interview on BBC Four, actor David Tennant, who had just taken the role of the Tenth Doctor, described the relationship between the Doctor and Rose as "basically a love story without the shagging". He later stated that Rose was the Doctor's girlfriend, though it was never explicitly stated on screen.[72]
Because each new Doctor is different from his previous incarnations, how their personalities interact varies when two or more different incarnations encounter each other. Time Crash featured Peter Davison returning as the Fifth Doctor. This event is explained as occurring due to the current Doctor having left his shields down when rebuilding the TARDIS following "Last of the Time Lords" and then accidentally crossing the Fifth Doctor's timeline, allowing the two TARDISes to merge. When the Tenth Doctor effortlessly averts the impending Belgium-sized hole in the Universe caused by this temporal anomaly, he reveals having known what to do because he saw himself do it as the Fifth Doctor and remembered. He goes on to tell the Fifth Doctor how fond he was of his incarnation and how he influences the current Doctor's personality.[59] However, in their two meetings, the Second Doctor and Third Doctor had a degree of antagonism towards each other, with the patriarchal First Doctor critical of them both. During the Virgin New Adventures, the Seventh Doctor was occasionally at odds with his subconscious memory of his previous incarnation as his memory of his past self became increasingly associated with the Valeyard, his dark, future self, but he eventually accepted his dark side and 'reformed' his memory of his former self, although it was never established how the two Doctors would interact if they had met in person.
The number of previous incarnations of the Doctor was at first unclear within the series. In the Fourth Doctor story "The Brain of Morbius" (1976), the Doctor participates in a mental ‘duel’ with another Time Lord and the machine to which their minds are connected begins to project the faces of the "losing" contestant’s regenerations in chronologically descending order. As the Doctor is overpowered by Morbius, the images change successively to those of the third, second and first Doctors, then eight further faces appear. It was the intention of producer Philip Hinchcliffe and script editor Robert Holmes that images were even earlier incarnations of the Doctor. However, the narrative does not explicitly confirm that the faces do represent incarnations of the Doctor, even though, as the faces are shown, Morbius cries "How far Doctor? How long have you lived?", indicating that they are not incarnations of Morbius, but rather that it is the Doctor's past being shown.
As well as appearing in the BBC children's programmes "Dark Season" (alongside Kate Winslet) and "Moondial", Pearce appeared in the "Doctor Who" serial "The Two Doctors" as Chessene, a bloodthirsty alien. She was associated with "Doctor Who" through her appearance in "The Fearmonger" as Sherilyn Harper, an audio drama by Big Finish Productions, and as Admiral Mettna in the webcast story "Death Comes to Time". Pearce returned once again to "Doctor Who" from 2015, this time opposite John Hurt, as a regular in the Big Finish audio series based on the adventures of the War Doctor, portraying Cardinal Ollistra, a leader of the Time Lords in the Time War who often clashes with the Eighth Doctor and the War Doctor over how far the Time Lords should be willing to go to achieve victory. 
Comedian and singer Mitch Benn's 2002 album "Radio Face" features a song entitled "Doctor Who Girl". The song talks about how the singer would like to find a girlfriend who is like the female companions of "Doctor Who".
In Canada, TVOntario aired the program starting in 1976 with "The Three Doctors" and continued with the rest of the original series on a weekly basis until 1990 with series airing two to three years behind the BBC. TVO was also available to many viewers in the United States living in states bordering the Great Lakes. In order to fulfill the network's originally strict mandate as an educational broadcaster, TVO's transmissions of the Third Doctor's stories were hosted by Dr. Jim Dator, a futurist teaching to the University of Toronto, while the first three seasons of Fourth Doctor stories were hosted by science fiction writer Judith Merril, who called herself the "UnDoctor". Both hosts would fill out the show's half-hour time slot through introductions and longer extros which would analyze and discuss the episode critically for several minutes often explaining how a story was at variance with scientific concepts, how it related to science fiction genres, or putting the episodes in a socio-political context. Afterward, this broadcast requirement was relaxed and the extra time was used for the network's standard short subject programming such as "Eureka!". TVO continued to broadcast "Doctor Who" until it lost the rights to the programme in 1990.
Critics heavily praised Peter Capaldi's performance in his last outing in "Twice Upon a Time" along with the Twelfth Doctor's evolution over the course of three series. Sam Wollaston of "The Guardian", who considered himself a friend of the Twelfth Doctor, said it was hard to say goodbye to this brilliant Doctor, which has been "warm, wise, kind, funny and human". Patrick Mulkern named Capaldi his ideal kind of Doctor: "senior, crusty, steely, funny but with anguish burning through those wizened eyes". "The Mirror" noted that 12th Doctor's journey from "The Time of the Doctor" through to "Twice Upon a Time" has been epic: "From his early days as cranky and prickly foil to Clara, to a more caring, teacher figure alongside Bill it's been sublime to watch. And this evolution within a single regeneration is something only an actor like Capaldi could have pulled off". The A.V. Club agreed, stating the episode gave Capaldi a "beautiful final showcase that demonstrates just how much he’s grown into the role since his rather ominous beginnings back in season eight". Ross Ruediger regarded the Twelfth Doctor as "the pinnacle" of "Doctor Who". He admitted that the actor came into the show at not exciting time for the series, but he managed to make it exciting over again. He felt Capaldi's Doctor arguably the only Doctor in the shows history who grew as a character: "The Doctor we saw in "The Doctor Falls" is a drastically different sort of man than the person we met way back in "Deep Breath" — and yet they are absolutely, believably the same character". In the end, Ruediger acknowledged that it was marvelous to watch how this character learned and grew: "It’s not something that this series has ever really dared tackle before, but now that it’s been done and accomplished so successfully, it will be difficult for the show to turn back. Peter Capaldi raised the bar for who and what the Doctor can be, and the series is all the better for it". Alasdair Wilkins from "Inverse" stated that defining word for the 12th Doctor is "kind": "It’s what moves him at the Christmas Armistice in Ypres, and it’s part of his final advice to his next self. That the incarnation who began his existence so prickly and aloof would end it as the champion of kindness speaks to just how much this Doctor grew and developed over this three seasons". He said that it shows how brilliant Capaldi's performance has been. Wilkins noted how 12th Doctor gradually warmed up, realising showing his true self – reason for his older appearance – meant being "unashamedly, unreservedly kind". He went on to say that Capaldi played the Doctor's kindness as "the most urgently honest expression of himself, and in doing so made his Doctor vulnerable and open in a way none of his predecessors ever really attempted".
In "The Time of the Doctor", the Eleventh Doctor describes his new regeneration ability as the start of a new 'cycle', implying that he's been restored to the customary twelve regenerations. However, in "Kill the Moon", the Twelfth Doctor says he's "not entirely sure [he] won't keep regenerating forever," once again raising the question regarding any limits to this ability. In "Hell Bent", Rassilon asks the Doctor "How many regenerations did we grant you?", and during "The Doctor Falls", two incarnations of the Master express uncertainty about how long it would take them to kill the Doctor, further implying that the Doctor has a finite number of regenerations even as the exact amount remains undetermined.
Many professional "Doctor Who" writers, for both the current TV series and the books, began their careers writing for fanzines, including Paul Cornell, Rob Shearman, Matt Jones, Marc Platt, Gareth Roberts, Clayton Hickman, David Howe and Stephen James Walker.
In "Journey's End", the Tenth Doctor manages to avert his own regeneration by using some of the energy to heal himself, then channeling the remaining energy into his severed hand, thus retaining his appearance and personality. That regenerative energy was a key point in a "human–Time Lord biological metacrisis" inadvertently caused by Donna Noble that creates the Meta-Crisis Doctor while she obtains a Time Lord intellect. Later in the series, during the events of "The Time of the Doctor" the Eleventh Doctor revealed that it was considered a full regeneration; he just kept the same face due to "vanity issues", and that he was now in his final (13th) life (given that the Tenth Doctor counted as two regenerations and the revelation of the existence of the War Doctor, this made a total of 12 regenerations). However, during the same episode, the Doctor is given a new cycle of regenerations by the Time Lords, allowing him to regenerate for the thirteenth time into the Twelfth Doctor, with the Twelfth Doctor ("Kill the Moon") and Rassilon ("Hell Bent") each expressing uncertainty about how many regenerations the Doctor now has.
Short Trips: How The Doctor Changed My Life is a Big Finish original anthology edited by Simon Guerrier and based on the long-running British science fiction television series "Doctor Who". The theme of the collection is how the Doctor affects those he meets.
The Doctor decides that he can not avoid coming to face to face with who he is anymore, and leads Ian through his memories. He watches over the early adventures which they shares, and recalls the moment where Ian stopped the Doctor from killing an injured tribesman so that they could escape. The Doctor reveals that as he continued to travel with Ian, he grew more and more fond of the pair, and decided to try and be more like them after they had left, taking more youthful companions and began to see the universe in a way much closer to the way that they had. Ian is amazed by the spectacles of heroism that is flashed before them as the Doctor recalls this, but the Doctor notes that there was also a dark side to this—recalling the many death which fell behind him, deaths which would lead to wars and more deaths. He recalls how we started the Time War inadvertently between his people and the Daleks, and how he had to end the war to save the universe. As Ian shows the Doctor all the good that he has done for the universe and all the lives that he has saved, the Doctor is finally able to accept himself for how the universe sees him and the pair escape the psychic realm.
There, a year after the Other had vanished into the Looms, the Doctor found Susan wandering the streets of the city — she had never made it to the spaceport. Like the Hand, although the Doctor did not look anything like the Other, Susan recognised that there was a connection, and when she addressed him as "Grandfather", both of them knew that it was somehow right. The implication was that the Other had been genetically reincarnated as the Doctor, although how much of the Other is in the Doctor and how much he remembers of his past life, if at all, is unclear. Susan and the Doctor then left in the TARDIS to travel through time and space. These events are seemingly contradicted by "The Name of the Doctor", which portrays the First Doctor and Susan entering the TARDIS together.
Alasdair Wilkins from "The A.V. Club" called the episode a "perfect finale", explaining that the Twelfth Doctor is a Doctor who knows who he is, portrayed by an actor who knows exactly how he wants to play the part of the character, both of which are played into the narrative of the story and blending into the storyline of the Doctor refusing to regenerate. He complimented how the multiple storylines of the series were wrapped up and brought to a satisfying conclusion, as well as respecting the reality of the character's emotions, which were performed with only a couple of small missteps.
Howe and Stephen James Walker set up the publishing house Telos Publishing in 2000. The first publication under the Telos name was the first edition of "Howe's Transcendental Toybox", written by Howe and Arnold T. Blumberg. (A later edition was described by the BBC's "Doctor Who" website as a "definitive collector's guide to Doctor Who merchandise".) Telos' second publication was a collection of tie-in fiction to the Channel 5 horror series "Urban Gothic". Telos published "Doctor Who" novellas from 2001 to 2004, when BBC Worldwide declined to renew its license. Telos continues to publish non-"Doctor Who" works and unofficial Doctor Who reference works, including "The Handbook", collecting the previously written Virgin Publishing guide books "Doctor Who The Handbook" in one volume in 2005, and the 2003 book "The Television Companion" (by Howe and Walker, and previously released as "Doctor Who: The Television Companion" in 1998 by BBC Publishing; the BBC "Doctor Who" website described it as the "definitive guide to "Doctor Who""). In 2007–2008, Howe also served as the editor for "Time's Champion", an independent "Doctor Who" novel based on Craig Hinton's final unpublished novel and completed by his friend Chris McKeon, which features the Sixth Doctor and the Valeyard.
The character featured in comic strips in "Doctor Who Magazine" between 2005 and 2006 as well as in several short stories in the "Doctor Who Annual 2006". In Steven Moffat's Ninth Doctor short story "'What I Did on My Christmas Holidays' by Sally Sparrow" the Doctor and the TARDIS are inadvertently separated twenty years in time by a fault in the time machine and the Doctor is able to instruct Sally how to bring it back to him in the past. This short story later became the basis of the third series episode "Blink". The Ninth Doctor has appeared in IDW Comics "Doctor Who: The Forgotten" and "Doctor Who: Prisoners of Time".
Zerinza was the first, and for many years the only regular Australian Doctor Who fanzine. It ran continuously from 1976 to 1986 when edited and published by Antony Howe, for the Australasian Doctor Who Fan Club (ADWFC), reaching issue number 35. Since then, there have been several isolated issues on special topics, sporadically up to mid-2000, edited by others but most with some degree of input from Howe (e.g. three almost completed issues, and using other materials in his files). Reviews, articles and interviews in this "high-quality" fanzine were authoritative and are cited in serious studies of Doctor Who and some have been republished in books of interviews. The fanzine was for a decade the journal for the ADWFC (membership and subscription being combined) and it played a key role in creating and expanding Doctor Who fandom in Australia, reaching about 1,000 subscribers by the mid-1980s. It was partly founded to rally fans against the Australian Broadcasting Commission's decision to cease purchasing the Doctor Who series (made in mid-1976), launching a "Save Doctor Who Campaign" with the first issue, it contained relating news items thereafter. Zerinza, and Howe (as founder and President of the ADWFC), were often credited by fans with the subsequent decision by the ABC to resume and increase screening the series (from 1978).
In The End of Time the Tenth Doctor mentions marrying Queen Elizabeth I and implies that they had sex, stating: "her nickname [the Virgin Queen] is no longer...". The joke continues in "The Beast Below", featuring future British monarch Queen Elizabeth X or Liz Ten, and the marriage is finally shown in "The Day of the Doctor" during an adventure with Zygons. In the 2010 Christmas special, "A Christmas Carol", the Eleventh Doctor accidentally marries Marilyn Monroe but later questions the authenticity of the chapel in which they were married. Steven Moffat did not consider the marriages to Elizabeth I and Marilyn Monroe to count when questioned on how many wives the Doctor had had, remarking that he was married to Susan's grandmother and River Song.
Horrified that the man who raised her had been lying to her, Ruth shot the Doctor and watched his face change. Ruth shot the new incarnation of the Doctor, and as he changed again, wondered how many times she would have to shoot him before he stayed dead.
In an interview with "Doctor Who Magazine", Steven Moffat revealed that the Eleventh Doctor had an entirely different costume until close to the start of filming. The original look had a swashbuckling feel which "Doctor Who Magazine" editor Tom Spilsbury described as "a little like something Captain Jack Sparrow wears in the "Pirates of the Caribbean" movies". However, Matt Smith was unhappy with the costume as he felt it reflected how someone else would dress the Doctor, rather than how the Doctor would dress himself. Smith also mentioned in a 2012 interview that his Doctor was going to have a "very long black leather jacket, but it was too "Matrix"-style". The eventual costume, in particular the bow-tie, was influenced by Patrick Troughton's Second Doctor, after Matt Smith fell in love with the Troughton story "The Tomb of the Cybermen".