OK, I had difficult explaining this one in the title.

Which is your preferred time travel mechanic; how time travel works and affects the travellers, time zones and history?

Are you a change history without paradoxes kind of person? A man goes back to shoot his Granddad and succeeds: Either creating a two timelines or the traveller is stuck in this old time.

Are you a change history with paradoxes kind of person? A man goes back to shoot his Granddad and succeeds: He is immediately unwritten from time, so his grandfather lives, so he is born, so he kills his grandfather, so he is unwritten ad infinitum.

Are you a change history but paradoxes are prevented kind of person? A man tries to shoot his Granddad but the gun jams, or he gets hit by a brick before he can. Like fixed points in time. No matter what you do you can't cause a paradox.

Are you a history happened as it happened and time travellers are just part of it kind of person? A man tries to shoot his granddad and fails, no matter what he tries, he can't succeed. His granddad learns of this, distrusts his grandkids probably causing the feud that caused the traveller to try to kill him in the first place. Or as the Doctor may say, "Part of events"!.


I'll leave it at these for now. The only options are also based around you being able to visit history at all!

I might make one later for if you prefer Seeing the past but not being able to interfere, being in your younger selves body, or being there in person. But that's a whole other kettle of fish.

Let's see...


Absolutely not. That makes no sense.


That sounds like it could cause a mess like The Wedding of River Song, so I'll pass.


That sounds like no fun.


That sounds almost like real life. I'll go with that one.

my head hurts

I just take it as it comes, man....

I like the Cyberman at Kwik Fit.

Sadly the mechanisms in Doctor Who are broken. The fixed points in time are nonsense that exist only for the convenience of the writers. Still a hugely entertaining and imaginative show though.

The last one sounds like reality (if time travel is actually possible!) at the risk of a universe without free will.

So I vote for the last one.

I'm a "By His Bootstraps" and "All You Zombies" kind of time traveller. (courtesy of RAH).

Ah yes! I am like this the best myself. And excellent call outs to some great stories there!

History cannot be changed at all; you were always part of events!


Because none of the others make the slightest bit of sense, other than as a plot convenience.

What actually can irritate me only slightly however is that they actually use all of them and just pick whichever suits the story at the time. The fixed points in time contrivance mentioned above is their way to have their cake and eat it. But it's not exactly hard science fiction so it doesn't really matter.

If you like your time travel stories served without the mindless "race against time to save history" aspect I recommend "Continuum". It's been renewed for a 2nd series and has the added attraction of Rachel Nichols in the lead role.

The problem with history being unchangeable is that it erases free will, since from the programme's point of view everything is history whether it has happened yet or not. And once there's no free will there's also no culpability.

You don't need to invoke the idea of God to see that you're heading towards a Calvinist double predestination sort of solution where what you're going to do is already what you're going to do but you can decide your own motivation for doing it.

I personally prefer the idea that paradoxes can occur because I like stories which involve them and their effects.
With regards to what I believe about reality though, I don't think time travel to the past is at all possible. History is fixed and cannot be changed. What happens is decided in the present and the present is all that exists. The past only exists in the memories of living things.
Paradoxes are paradoxes and are as such completely impossible. The fact that time travel can result in paradoxes doesn't say to me that if you travel to the past you need to be careful, it says to me that time travel to the past is inherently impossible.

No single point of view or frame of reference is any more or less special than any other. It's what Einstein made explicit with his theories of relativity, general and special.

All appearances to the contrary, free will is just an illusion caused by the passage of time. However, the point is moot because our consciousness is part of space-time and can never stand outside of it with that God-like view of the universe.

That kinda makes sense, The past has been written and though that can be changed in it's written form if chosen to be, is that truth or is there still more to find, to change that truth as it is or was?


(oh my, I got my thinking head on.)

I think the change history without paradoxes makes the most sense. Physics is relative, so going back and killing your grandad would create a new timeline because events were changed. You would not have been born but would still stay stuck in the old time because that is what happened from your point of view. From your granddads point of view he is still alive because those aren't the events he experienced.
I probably got my science wrong, but that's just my idea.

A few thoughts:

Your last two options are the same thing, and the most in line with current physics thinking. (The Novikov self-consistency principle)

'Fixed points', in Doctor Who parlance appears to be less of a hard rule about where paradoxical changes are impossible, but where there would be terrible, reality-shattering consequences if they were to happen, or where they're really hard to do.

And the only problem with free will is where you already know what's going to happen (like the Doctor knowing what happens to Amy). Otherwise there's no difference from the point of view of the person making the choice.

I agree with this, it would be nicer if there were some fixed rules about time travel in the Doctor Who universe, rather than making something else up when it's convenient for the story. Still, I suppose that would limit the stories a bit.

I rationalise the concept of time travel and how it affects history by subscribing to the hypothetical theory that there are an infinite number of parallel time streams, which of course have an infinite number of relative points between them at any given moment.
If you travel in time, you don't actually jump backwards and forwards in the time stream you're currently in, you actually jump sideways from one stream to another, the other stream being at a different point in history relative to where you were.
If you change something in that time stream, it has a knock-on effect on everything else in that stream, but doesn't affect any other stream at all, so when you return to where you were everything is exactly as it was before.
So, no paradoxes!

Which is okay for a show (or film series) that doesn't have to deal with as many contradictions as Who has to. It's hard enough keeping track of the characters and historical events in one universe, never mind an infinity of them!

Damn. I picked the wrong one. I'm an *A* not a *D*.

Brilliant link! I've never heard the logic of it given a name before.

Free will is only an issue if you have that god-like "outside of space-time" view of the universe. When you're "in the middle of it" it's a very convincing illusion. It makes it a problem for religious types because it ultimately makes god responsible for everything.

The ultimate "it's not my fault, it's my genes/upbringing/I was made that way/predestination paradox" type of excuse.

I opted for the last one. History cannot be changed - if you go back to it......you are obviously part of that history.