Theory:Doctor Who television discontinuity and plot holes/Earthshock


 * The Cybermen use emotional words like "Excellent". Positive emotion is supposedly absent in Cybermen. The Doctor elaborates on this when the Leader uses "fondness", but the Leader claims it is a word like any other, just like "destruction".
 * As stated, they view these as being just words, without the underlying emotional connection that humans might associate with them.
 * The Cyber Leader does seem unduly proud of his emotionlessness, however, considering he clearly has a sadistic little chuckle at the thought of human beings dying in terror, and he is decidedly less than stoical in his own death scene. This is probably intentional scripted irony, though (possibly inspired by the equally hypocritical though rather less menacing Cyber Leader of "Revenge of the Cybermen"). Either the Cybermen have taken the Dalek lead that a little of the nastier emotions makes more effective killers, or their diminished power has made them sloppier at brainwashing their converts.
 * The Cyber Leader does seem unduly proud of his emotionlessness, however, considering he clearly has a sadistic little chuckle at the thought of human beings dying in terror, and he is decidedly less than stoical in his own death scene. This is probably intentional scripted irony, though (possibly inspired by the equally hypocritical though rather less menacing Cyber Leader of "Revenge of the Cybermen"). Either the Cybermen have taken the Dalek lead that a little of the nastier emotions makes more effective killers, or their diminished power has made them sloppier at brainwashing their converts.


 * Why did they draw attention to the Cyber-bomb on Earth by having androids kill anyone who approaches it?
 * However, they don't start killing people until they've actually reached the cavern where the bomb is being held, so this may have been a last resort.


 * Why didn't the Doctor take some troopers with him to talk to the Captain rather than trying to convince her with a pretty suspicious-sounding story?
 * He couldn't see that far ahead.


 * When the Cybermen are deactivated or 'asleep', they are placed in large metal cannisters. When the Cybermen are woken up in Episode 3, they rip the canisters apart to get out, so why are none of the cannisters seen ripped open and instead seen in a normal state throughout Episode 4?
 * Not all Cybermen may have been activated as the activated Cybermen evacuate the ship afterwards.


 * When Kyle falls onto the rocks from exhaustion, they shift and move around, as though made of lightweight material.
 * This is more likely a production oversight.


 * As Scott prepares to gun down the two Cybermen, the emotionless creatures seem to be gossiping, complete with hand gestures.
 * They are simply communicating. Nowhere is the implication given that they are "gossiping".


 * During the cliffhanger, it's obvious that the three columns of Cybermen are mirror images: watch the middle one's right hand disappear
 * It's a directorial trick, not intended to be believed in the first place. The director just did it to look cool, he wasn't implying that it actually looked like that.


 * The steel bulkhead the Cybermen destroy flaps around as thought made of cardboard — the pieces of door also look like cardboard.
 * While the doors doubtlessly were made of cardboard, there is a narrative reason for their flimsiness. The bombs are specially designed to change the molecular structure of the materials they are attached to.


 * The Cybermen set four explosive charges around the outside of the bulkhead, but only the middle is damaged.
 * It is somewhat unclear whether this is a production error or not. While it may not have been the most desirable special effect, it does have a logical narrative explanation. Constructions such as walls and bulkheads are often at their weakest points in the middle, where they are not being buttressed by other bulkheads.


 * Not only does the Cyberdevice miraculously allow the freighter to travel through time, it also transports it to the side of the Galaxy that Earth was on 65 million years ago.
 * Time travel is usually shown to occur with fixed spatial coordinates relative to their start point in spacetime.


 * If the Cybermen are fully anticipating the bomb to destroy the Earth, why are they concealed on the freighter in the first place?
 * The limited range at which they can remotely detonate the bomb/control the androids, means they would have to be within the boundaries of human space and the best place to hide is on an Earth ship.


 * The Androids seem to be good shots early on - killing 3 people in a matter of seconds - but when they reach the Doctor they completely miss!
 * During their initial assaualt the androids are not under fire themselves, but when they fire on the Doctor and the battle continues the androids are recieving fire from the remaining troopers Even though they are androids their accuracy will be diminished by having to evad incoming fire. Also, two words: character shield.


 * No-one in the Earth crew expresses any surprise at the size of the TARDIS- nor do they question the Doctor as to where he came from and how he got such technology.
 * Lt Scott expresses surprise through his facial expression, but presumably he feels there are more pressing matters than asking questions about the TARDIS.


 * What happened to the person viewing the scanner screen? And why do the radios stop working? - surely he'd alert them to another dot (when Adric came out of the TARDIS) coming on the screen


 * The Cyber Leader says the sentence "Your technology is primitive next to ours, mistakes will not be made." in a distinctly sing-song type of voice.
 * Why does the guy reading the scanner pick up only the Doctor as an alien? Nyssa is a Trakenite, is she not?


 * where did the Cybermen get copies of Doctor Who clips from? And why do they show one from Wheel in Space, when describing the events of Tomb of the Cybermen?

As he says, though, the console is damaged a the key moment.