Theory:Doctor Who television discontinuity and plot holes/A Christmas Carol


 * Once the Doctor lands in a place he becomes part of those time events, meaning he can't go back in time to alter the events he previously landed, so how exactly did he go back in time and changed Kazran if the Doctor landed when Kazran was old and he became part of the events?


 * How can Abigail's family not age, yet Kazran does?


 * By the the year 4000, it can be assumed that longevity has been extended somewhat. So Abigail's family- who live fairly normal and presumably not-too-stressful lives- wouldn't have appeared to age all the much. Whereas Kazran lives a rather bitter and negative existence, has appeared to age far more greatly.


 * Yet, her young nephew is still a child when they meet old Kazran. Even with prolonged longevity, a child would most likely mature into adulthood at roughly the same rate.


 * Obviously a number of years has passed because her sister is shown to be a middle-aged woman when she meets Kazran for the first time.


 * Abigail's family does age. The confusion is due to the child actor playing two roles. Look at the credits, Bailey Pepper is credited as playing both "Boy" and "Benjamin." Meanwhile, Steve North is credited as "Old Benjamin." When Abigail's family goes to plead for Abigail's release, it is her sister Isabella, Isabella's son Benjamin, and Ben's two children, one of whom is the boy who throws coal at Kazran. Just as Michael Gambon plays father and son, Bailey Pepper is cast as two generations of the Pettigrew family.


 * Add to this, there's an actress credited as playing Isabella, and another playing "Old Isabella". For the older family in the 'present' we see: Abigail's sister, grown up nephew, unnamed grand-nephew (but same actor as young Benjamin) and (presumably) a grand-niece. For the younger family in the 'past' we saw only: Isabella, Eric (presumably her husband) and Abigail's nephew (young Benjamin); notice there was no niece. The families are quite different.


 * How can the Doctor so casually alter time?


 * The long and short is "suspension of disbelief". If we're going to theorize though on how the Doctor gets away with it: The people he is acting to save and manipulating are the "little people" - the ones that really don't count so changing their fate doesn't affect much. Also there is a swing to the changes in Kazran - the Christmas at Sinatra's being the obvious push-back.


 * In the Doctor Who Confidential that accompanies the episode, Moffat says the Doctor changes time and people's lives every time he lands on a planet. He's just being more direct about it. And not that long ago, in The Waters of Mars, the Doctor showed he could, in theory, even change a fixed point in time, at least briefly, if he set his mind to it.


 * How come Kazran seems exactly the same when time has been altered? These were huge changes.


 * The POV the story follows is for the most part that of Kazran. He is aware his history is being manipulated, and for the story to work, is comparing the changes. Also, the only physical change shown was to the paining. We don't see the stash of photos or the damaged sonic screwdriver "appear" in the present nor do we see them prior to Kazran unearthing them.


 * Time is not linear. Kazran only started to acquire his new memories from the point in time where the Doctor decided to go back in time help young Kazran. (Otherwise old Kazran wouldn't be able to have 2 sets of memories.) Note also that the integrity of the timeline is easily maintained because Kazran became bitter again (albeit for different reasons) when he learnt Abigail had only 1 day left to live. It was only 'present-day' Kazran that overcame his bitterness when he almost hit his younger self.


 * Another possibility is that the Doctor's interference created an alternate universe. We have our main POV: Kazran a bitter old man learning to overcome his bitterness. And, presumably (as in the Charles Dickens version), the changed Kazran would spend the rest of his days doing good in the community, to the bewilderment of others. And we have an alternate universe where Kazran who did not grow up bitter. He would have been a respected and well-like man. This Kazran would have managed the clouds differently, and probably not even endangered the cruiser in the first place. NOTE: The alternate version didn't start with the Kazran we saw growing up, because that version of him became bitter again. This one would have started with the young Kazran who saw his older self near the end of the story. This explanation also conforms to some of the theories surrounding the lack of "Blinovitch Limitation Effect" below.


 * Abigail never spent a whole day outside the chamber at a time. So technically she still had time left.


 * Yes, she had a day left. But very little is established as to how long she was out in the Christmases we saw, or that those were the only ones that occurred. Without that, the timer could be counting down the interval between each thaw and refreeze, or it could be ticking off a "day" per opening and closing of the unit.


 * Why can't the Doctor cure Abigail of her disease?


 * We don't know what the disease is, or how difficult it is to cure. That being said, even if he could do some research or take her away to a time/place where there might be a cure, he's not really in the business of making every person he meets immortal.


 * Who said anything about immortality? Curing her of her disease (as simple as bringing her to a super advanced medical facility in the future) wouldn't grant her immortality.


 * The Doctor says that he has changed Kazran so much that the machine won't work for him. Surely the machine would have been altered to fit within the new timeline?


 * The controls "catching up" with Kazran depends on how watching a timeline change actually works. The temporal dynamics could be such that the controls or Kazran hit an end state first. They are out of synch and the Doctor gives the most obvious answer at the time.


 * It's also possible that, due to Kazran's "nicer" temperament after the Doctor's interference in his childhood, his father decided to design the controls such that they only responded to himself; that is, he didn't even trust "new Kazran" enough to let him run the machine.


 * The Doctor explains it himself "No, your father would never have programmed it for the man you are now."


 * Why did Amy and Rory have the policewoman uniform and Roman armour anyway?


 * Use your imagination - they are on their honeymoon so a few possibilities immediately present themselves.


 * Also, it's an indication that contrary to some fan speculation, they do remember the events of Series 5 (and maybe the Doctor had a centurion outfit in his wardrobe).


 * In the time that the Doctor disregarded rules set down for the universe's safety, he could have probably got all the ship's inhabitants into his TARDIS and taken them to a friendlier planet.


 * It is said at the beginning that the TARDIS cannot lock on to the crashing ship.


 * Then he could have made the TARDIS materialize on the ship before he was unable to lock onto it. If the ship was about to crash on the planet he could have told Kazran about that. It would threaten his business, therefore he would let the ship land. Even if it wouldn't have, the Doctor could lie to convince him.


 * Well its commonly established that one can't go back on there own time track, as that would create a paradox about not needing to go back in the first place. If that were possible then he wouldn't have had any problems ever: like why he couldn't rescue Adric or stop the Dalek invasion. As for your second point the Doctor did tell him, and Kazran didn't care. Evidently one ship crashing isn't going to make that much of a difference to his empire, or else he would have acted. As for your third, not knowing what sort of man he was up against, the Doctor had already told him the truth. So lying's out of the question, unless you're suggesting he tried to memory wipe him.


 * Amy and Rory already went on their honeymoon - it was mentioned in Death of the Doctor.


 * And we end the episode with them about to go on another.


 * When the two Kazrans touch, this should result in a paradox due to the Blinovitch Limitation Effect. (TV: Mawdryn Undead, Father's Day).


 * Probably doing this wrong editing wise. In the case of Rose, she was a future version displaced to the past, where as Kazran was a past version displaced to the future. There shouldn't be a paradox generated from this kind of situation, since the past version, being displaced from it's own time into the future, or present it your prefer, is merely generating a memory for the future instead of altering the past with a displaced future. The situations aren't similar besides to instances of one existence interacting, which the Doctor himself has done.


 * Yes, and that's a valid point. However, several possible explanations have been given above. The Doctor may have taken precautions to prevent this. We know Time Lords can do so, and note that the TARDIS door is distinctly open while the two Kazrans interact.


 * Another possibility is that the young Kazran is from just after he and the Doctor first met. And as such, before the Doctor changed Kazran: meaning that although they were the same person, they different versions of the same person. Like how Amy was able to touch her younger self without any problems in The Big Bang because, due to the changes in time, they had become two different people.


 * It seems like it is possible in the Whoniverse for there to be two "endpoints" in time which are joined together. One endpoint moves through time at the normal rate, whereas the other end moves at a faster rate (e.g The Girl in the Fireplace, Prisoner Zero). So perhaps Time Lords have some ability to control this. The Doctor creates two endpoints, one in Kazran's "present", the other in his past, and links them, perhaps by means of the "movie projector". The endpoint in Kazran's present moves forward at a normal rate, so he can be aware of changes being made in his past. The other endpoint moves forward at a faster rate. The Doctor is changing Kazran's past, but in such a way that it only affects Kazran and Abigail. Another way to think of this might be: - when the Doctor travels into Kazran's past and starts changing things, this creates an alternate universe version of Kazran. Over the course of the episode, the original version of Kazran is gradually replaced by the alternate universe version of him, whilst everything else - e.g. the controls, remain in their original universe state.


 * The episode dialogue explains why they can touch. The Doctor changed Kazran so much that he is "not the same man". He has changed to the point where the isomorphic controls no longer recognise him. Therefore he can easily touch his younger self because he has basically regenerated. The same argument can be used to explain how Amy Pond is able to touch her younger self, and Rose Tyler her infant self, (NOTE: Rose never actually touches her infant self in Father's Day). Because they are no longer the same people once they travel with the Doctor. (Also, an episode of Torchwood, TV: Reset, establishes that the Doctors' companions are physically altered by travelling in the TARDIS).


 * This isn't actually correct, as Rose touching her infant self does create a paradox. (NOTE: Rose never actually touches her infant self in Father's Day.) I propose a different explanation: the TARDIS can alter or stabilise paradoxes that are expected (presumably, the Doctor has taken active precautions for this). The main support for this theory is that the Doctor is actively messing around with Kazran's timeline, but there are no side effects of this (the changing of Kazran is intentional, thus not a side effect). The interior of the TARDIS is not present for most of the episode in TV: Father's Day after an unexpected timeline change when Rose prevents her father's death. In TV: The Big Bang the two versions of Amy have a different personal history with the lack of stars. (It's implied that Young Amy can still see them and is questioned by psychiatrists about them, which doesn't occur in the original timeline; also, it's not known whether her original meeting with the Doctor occurs in this timeline.) This is why she can touch her younger self (because they are people with the same genetic makeup, but different personal histories). This also explains why the Blinovitch Limitation Effect does occur with the Sonic Screwdriver, as it's an inanimate object, it does not have an alternate timeline.


 * NOTE: Rose most certainly does touch her infant self in Father's Day: Pete takes baby Rose from Jackie and puts her in adult Rose's arms. The Doctor attempts to stop it, but is fractionally too slow. In spite of how short the duration of contact was, this allows a Reaper to appear inside the church and swallow the Doctor. Considering its significance on the plot, it was a really hard scene to miss.


 * When the two Brigadier's touch the effect is an explosion. When the two sonic screwdrivers touched in the previous episode it created a small spark. Therefore the effect seems to vary so it is possible the discharge is so small it is hard to see.


 * That only happens because the Brigadier is larger, and time was shrinking so there was less temporal energy. I still don't see the problem, it's already been agreed that the Doctors changing the time line is the reason they can touch. Because like Amy, although they are genetically the same, they are now two different people.


 * Tell you what, let's apply a little physics here. The Blinovitch Limitation Effect takes place when matter comes into physical contact with a time-shifted version of itself. But think about it: if something like that were to really happen, then surely it must occur at a molecular level. For instance, the Brigadier's right hand touched the Brigadier's right hand, finger to finger and palm to palm. So the EXACT SAME molecules and cells were coming into contact with themselves. The same for the sonic screwdriver in The Big Bang - it touches its own head. But here, as far as I could see, no part of Kazran's body actually touched its counterpart on his other self. In fact, direct contact was blocked for the most part by their dressing-gowns. So there you go.


 * If you want to apply physics, you have to do it right. It can't possibly be the exact same cells and molecules. Most of the molecules in your body's surface won't even be there tomorrow, much less in a couple decades. Your body is constantly breaking down molecules and building new ones, and constantly using external materials like the food you eat and the air you breathe to do so. That's basically what being alive is. Sure, the new molecules are pretty similar to the old ones, but then they're also pretty similar to the ones on my surface, or even my cat's, and obviously any two mammals touching doesn't cause a Blinovitch explosion. And, even if that weren't true, and you really did somehow keep all the same molecules, how could Kazran having such different emotions that he's "a different person" possibly mean that he suddenly has all different molecules than he used to?


 * So, whatever the sense is in which Rose is "the same person" 18 years later but Kazran or Amy is not, it's not molecular or cellular; it's clearly either something at an emergent higher level (this being Doctor Who, it could be "psychic" or "morphic field" or something else that's pseudoscience in our world, or it could be something that's plausibly scientific but beyond a human layman's understanding so the Doctor doesn't give us a scientific paper to explain it), or it could be something lower-level that's specifically related to the energy of time travel (that we again presumably don't have the temporal physics to understand, even if it isn't just pseudoscience nonsense).


 * The doctor shows a picture of Santa Claus. But in The Doctor Dances, the Doctor says he is Santa Claus. Was he just joking?


 * I'm sure there's plenty of explanation for Santa's in shopping centres not being the same as the real one. And who's to say he's not joking here?


 * Yes, the Doctor was joking when he said he was Santa Claus. And, in case you're wondering, Rose was joking when she said he was Mr. Spock in the previous episode. He is, in fact, neither Santa nor Spock.


 * The doctor says there are no such thing as isomorphic controls, yet he countered The Master who at the time owned a laser screwdriver which had isomorphic controls.


 * The Doctor says Kazran is a fibber. And then, when he can't operate the the controls, he immediately concedes that he was wrong. Clearly, didn't think isomorphic controls are impossible, just that Kazran didn't have the technology for them.


 * And there are good reasons for him to think that. A few times, we've seen a human claim to have isomorphic controls, and every single time they've been lying. (Most recently, in Miracle Day.) And we've seen humans pretty far into future technology, and there's no indication that they ever develop tech that works on "morphic fields" even though they're a real thing in the Doctor Who universe.


 * Not to mention that the Doctor himself has fibbed about a few things having morphic controls, and once (the Bride of Peladon audio) he even admitted that he didn't expect it to be a very good bluff but it works surprisingly often, so of course if he suspects someone's trying it on him he's going to call their bluff.