SPOILER ALERT…SORT OF. DEPENDS IF YOU’VE SEEN DAY OF THE DALEKS, REALLY.
Daleks, UNIT, time travel and a dystopian Earth: Day of the Daleks encapsulates Doctor Who perfectly.
For a show about a time traveller – nay, a Lord of Time, Doctor Who didn’t do time travel stories that often, pre-Moffat, and Day stands out as a fine example of new territory that somehow is also very familiar. As previously noted, there are so many elements that are Doctor Who at its best, so while the playful paradox is employed to give the tale an overall science-fiction feel, there’s an excess of classic qualities that ensure it blends in with the rest of 1970s Who. This may ensure it is omitted from lists of ‘must-watch’ tales, but it’s definitively Who, and an essential tale of time travel.
Day plays with time superbly; guerrillas from a ruined future come back to stop their own timeline. Magnificent. And completely impossible, according to scientists. This paradox is one of the reasons, it’s argued, that time travel – specifically into the past – is not possible. Any slight change could erase your own future. Meaning you never travelled back to change your past. But that means that the future you stopped is created again, which equals in you travelling back one more and so on, so forth. The paradox can only be broken by an external force, which, in the case of Day of the Daleks, is the Doctor. It’s summed up quite nicely as the Grandfather Paradox.
The show has played fast and loose with paradoxes ever since. In the following season’s The Three Doctors, it’s established that the Time Lords’ Laws of Time prevent people meeting themselves or (in The Hand of Fear) being transported back into time. But this hasn’t stopped writers from exploring the concept.
In Day of the Daleks, the Doctor briefly mentions the Blinovitch Limitation Effect as an explanation to Jo that the same person cannot meet their past or future selves. The effect is, arguably, a time loop or a release of energy, shortening out the time differential.
This meeting of past and future selves is showcased in tales celebrating the titular Time Lord: The Three Doctors, The Five Doctors, and The Two Doctors, as well as the special, Time Crash. But Day of the Daleks established the paradox as a central plot device before any of the Doctors teamed up. This idea proved so successful, The Three Doctors debuted at the start of the following season, despite Terrance Dicks, script editor, protesting in the Day of the Daleks DVD commentary that this sort of concept doesn’t bear thinking about.
The Blinovitch Limitation Effect is further explored in Mawdryn Undead, in which two Brigadiers meet, resulting in a massive displacement of energy.
Brief examples of the Blinovitch Limitation Effect can be found throughout the show’s 48 years – and counting – of narrative. Steven Moffat is probably best known for his time-twisting tales – just look at Blink, The Girl in the Fireplace, The Wedding of River Song… or the entire life of Amy Pond! But let’s take The Big Bang as a fleeting example of the Limitation Effect. The same sonic screwdriver at different points in its time stream touch and a small burst of energy is released. But then, in the following story, A Christmas Carol, Kazran Sardick meets himself – and hugs. So this is a confusing one. Is it an oversight by the ‘Grand Moff’? (I doubt it, personally.) Is this just an example of the time loop effect? (Possibly.)Or has the Doctor played around with Sardick’s life so much, the effect is suppressed as they’re somehow different people… and yet the same? (Makes sense in the context of that tale.) Hmm…
But back to matters in hand…
Day of the Daleks might also show the Time Lord’s interfering nature. The future Earth, ruled by the Daleks, is created, unknowingly, by the guerrillas coming back in time. The loop is broken by the Doctor, exiled to Earth by the Time Lords. The Time Lords can see all of time unfolding, so could this be an example of their interference? If the Doctor was not exiled, the loop would surely have continued forever… right? Let’s face it; the Time Lords certainly have previous, despite their rule of non-intervention. They’ve been portrayed as a very corrupt society, so it would be in their nature to iron out any paradoxes. And that’s where the Doctor comes in.