Theory:Doctor Who television discontinuity and plot holes/Colony in Space


 * The manner of TARDIS dematerialization and rematerialization is quite different to how it had been depicted during the 1960s. Both TARDISes in this story "pop" in and out of frame, rather than fading in and out. Given that TARDISes would return to "fading" after this serial, the depiction here can be seen as an error.
 * Although the TARDIS typically "fades" in and out, this is not always the case. Sometimes by intent, sometimes due to mechanical/pilot error, the effect can appear different. Two examples of differing materialization/de-materialization effects are The Christmas Invasion and The Runaway Bride.


 * Why the TARDIS doors are now opening with the sound effect of a SIDRAT door / the Dalek city doors is anyone's guess.
 * Why not? Again, the doors make different sounds at different times. Presumably, the SIDRAT door was developed based on TARDIS doors, so the sound may very well be a standard "default" one for TARDISes.


 * Thought that still doesn't explain why the Daleks picked the same sound effect for their doors, unless they were ripping off Time Lord technology even earlier than the Celestial Intervention Agency had feared ...


 * IMC still use tape spools.
 * In Genesis of the Daleks, the Kaleds use magnetic tapes, so its not beyond possibility that governments have returned to that medium for storage, much like records/vinyls becoming popular again in the 21st Century in our world. Also, it is strongly implied that the future has become a grim, over-populated place in which resources have to be very carefully managed, in which case it is by no means unlikely that obsolete equipment would be returned to service in lieu of more sophisticated but more expensive alternatives (hence also the use of obsolete firearms).


 * The Brigadier is fortunate that when he walks to where the TARDIS vanished and tells it to 'come back at once', that it does so in a different corner of the room.
 * With the exceptions of 'Logopolis' and 'Parting of the Ways', when the TARDIS is being specifically directed to materialize around someone/thing, the TARDIS never materializes around an object or person, or even inside solid matter. It is reasonable to assume that the TARDIS performs some kind of scan of the area it is about to arrive in and thus deflects its exact point of materialization accordingly to avoid causing damage or harm to anyone/thing.


 * Jo's skepticism about the TARDIS being mobile is odd as she saw it dematerialize in the last story.
 * In the short time that she has known him, the Doctor has shown little ability to make it mobile when he wants it to be.
 * In the previous story, from Jo's perspective, the TARDIS dematerialized...and then rematerialized in the same place. From her viewpoint, it's questionable whether it could move or not.


 * If the Master was so ready to kill the Doctor at the end of episode four, why does he use a non-lethal gas when the Doctor goes into his TARDIS? He only learns that the Doctor can guide him into the primitive city after he releases the gas.
 * The Master has shown that he would rather kill the Doctor with a more personal touch. Remote control from a distance away, without being able to gloat about it, would be unexpected.


 * Dent radios Earth referring to his ship as "Survey Ship 43" but the tail is clearly labeled 157.
 * The label refers to some other designation then, such as the model of ship that it is.


 * It could also refer to the order the survey ships were sent out. It's not unlikely; after all if you look at our current airplanes, there is a plane number and a flight number, and most of the time they're different.


 * When Jo and the Doctor are sneaking into the Master's TARDIS, the Doctor jostles one of the doors that had the alarm beam. This would certainly break the beam. And why does the Master's alarm use a light beam instead of going off when the door is opened? Besides, given the placement of the beam, it would have been broken until the doors were open. The alarm should have gone off the second the Master closed the doors.
 * He set the system up himself, and somewhat recently (it was not there in Terror of the Autons). He clearly would not set it up so that it went off when he simply closed the door, but only when something breaks the beam from in between the sensors.


 * Don't forget that he might have keyed to not respond to his genetics. It probably works on the same principle as the main TARDIS systems, that is, able to identify its owner by a genetic scan and therefore allow access.


 * When Morgan finds the key to the Master's TARDIS, the "ground" it is on is a flat concrete floor with a little sand thrown on it.
 * Having never been on an alien planet personally, it's hard to say that none of them would have ground like that. A flat, rock surface with a shallow layer of sand does not seem unreasonable.


 * In Episode Three, as Winton, pursued by IMC guards, falls at Caldwell's feet, seagulls can be heard.
 * It's quite plausible that the planet has some form of life which sounds similar enough to seagulls; Mary Ashe does say in Episode 1 there are birds on Uxarieus.


 * One might question the 'compassion' of the leader of the Uxarieans, as the Doctor calls it. He would have his own people slaughtered without even a warning rather than give the Doomsday weapon to the Master.
 * As indicated, he feels that letting the Master have the weapon would be an unacceptable risk to all life.


 * Like the Daleks before them, the Uxarieans have evolved into symbiotic dependence around a technology that has become their living hell. By the stage of this story, they are clearly unable even to to feed themselves and would be dying off but for the colonists, yet they cannot even survive without the city / weapon that seems to function as some sort of network hub to their telepathic communion: they just seem to wander aimlessly as soon as it is deactivated and set to destruct. Since the city / weapon is also rendering the planet's soil toxic, Ashe's food donations are merely delaying the inevitable. Faced with a choice between saving his people by following the Dalek example and becoming living weapons, or a mass mercy killing / suicide (depending on how telepathically linked the Uxarieans may be), the leader makes an understandable choice.


 * In Episode Two, why does the Doctor drive the IMC patrol buggy when he's a prisoner? (Apart from the fact that Jon Pertwee fancied doing so on the day of filming!)
 * There is no formal declaration that he's a prisoner, but it's likely that the reason the Doctor is driving is so he can be watched. It's easier to have the Doctor drive and have easy access to a weapon than try and drive and hold a weapon at the same time.


 * The 23rd of March 2472 will be a Thursday, not a Tuesday.
 * Its possible that in the future of the Whoniverse, a Calender changeover similar to the changeover from the Julian calendar to the Gregorian calendar which caused eleven days (2 September through 14 September 1752) to get "lost" will occur.


 * The 23rd of March 2472 will be a Wednesday, but the date is actually the 3rd of March 2472 at least from what I saw, and that's still a correct problem (3/3/2472 is Thursday). However, remember that time is relative. We don't know what "time" reference they are using. There are different ages on Gallifrey, so it's certainly possible that 2472 in one age is a few millenia away from 2472 in another age.
 * And really, the above calendar change explanation still holds.