@JD, in my theory of events a rewind causes a split, one side of which necessarily contains Allen-prime. Any rewind not containing the frame of reference we care about doesn't have a rewind we care about. the theory is as complete as I can get it, and is still very easy to handwave by simply ignoring the logical consequences.

The reason I have the "no persistent branches" requirement is twofold: 1) to make the story easy to tell, since we can traverse the multiverse in bounded time; 2) I want to avoid the ontological problem of having one 'true' timeline with a 'good' outcome, and uncountably many with possibly 'bad' outcomes. Also, your synchronous write-lock method only solves the two time-travellers problem by only allowing one to travel at a time. I want asynchronous access to the timestream.

Also, I'm a little confused about your first worked example. How can Allen ever "start first" if Barry has already made his jump?

@2012rcampion, in this, after the cancellation, the rewind isn't there any more. Happy rewinding Barry isn't in this timeline anymore - after the split, Allen-primes Barry will get shut down by Allen-prime, after which they both try again. I developed the idea after deciding that having no one notice was really important. Expanding rewind waves creates a differential that would be noticed, I think. Last mover advantage doesn't work - it didn't happen from first mover perspective in his timeline. Anyway you go you need to pick a reference, or else have causality issues in your writing.

@2012rcampion - also, i just wanted to offer something different, with maybe some dealing with bigger problems with paradoxical time.

Ok, I'm still confused. If the rewind "isn't there" after it happens then why does a Lurch happen in the first place? What I think you're getting at is that a Lurch creates two timelines: one where the chronologically first jump succeeds, and we don't care about the second because it hasn't happened yet; and another where neither succeeds? But this creates two different pasts for the same event!? Maybe a diagram would help me out here.

I'm out and about right now - can you put up a chatroom for this, to get it off here? I dont think you'll use it but I'd love to talk it out.

I would also like to talk this out... it seems like another model I haven't seen before

Okay, I've worked up a primitive hand drawn doodle thing. and pasted it here.

I did what I did because I couldn't dream up a better way to collapse the events caused by other jumpers, and I wanted it to be extensible to a number of travellers, inside of most of your other requirements.

Obviously if we can get you an easier to write mechanism for what is left inside of a paradox or a conflict, you should take that and run with it. The Whovians simply let weird things happen as a suspension of disbelief, which, is perfectly valid.

Notably, they have the guy who can break sideways through alternate timelines and dimensions.

But we don't, and nobody exists that can see what happens after, say, Allen diverges the first time, or Barry is successful on his first attempt. Barry-1's Allen hasn't rewound yet - and might not.

Ok, I think I get what you're trying to say. Let me talk it out and see if you agree.

So at some point Barry goes one year into the past. This creates an alternate timeline (Happy Barry) that branches off from the "current" one at a point one year ago.

The Barry in that timeline may not jump any more, meaning that that timeline's Allan can jump with no trouble.

However, in the current timeline, he Lurches.

This is because Allan has tried to jump back, and has stopped at the moment Barry tried to jump.

Now Allan-prime and Barry-prime are both existing at the same time.

So now, if one jumps back before the other, he can succeed (in another timeline branch)

And notions of before/after make sense because they're effectively synchronized by the Lurch.

Is that it?

You've got it. I'd think of Barry prime as Barry 2. But yeah. Sorry at work.

I think this is actually compatible with my original model

Basically my model is one where the timeline ends at each jump

And we follow the new branch

But in this case you don't follow that branch

and continue the current one

So my model is the "always successful" branch from your model.

So what follows is just a matter of personal preference...

I like pruning all the 'lurch' timelines, 'cause that gives one path that a linear narrative can follow

Basically at every branch point you take the shorter branch, traverse it completely, then traverse the longer branch

where the longer branch is infinitely deep

But your model gives a lot of choice

At each branch point, both branches continue indefinitely

So as the author you can choose to follow the 'happy' branch or the 'lurch' branch each time

The only thing I don't know is how a reader would interpret this

They might think that you're making an arbitrary choice at each branch

which you sort of are, I guess?

Actually it would make a great model for a choose-your-own-adventure type story

Nonlinear storytelling, exploring a branching timeline? Very cool

The reader need only be as aware of any of this as he cares to be, honestly. If you hold the frame of reference the right way, you get the ease of use of Bill and Teds paradox games.

I always thought that Bill and Ted (at least the modern-day time loops) took place in a 'fixed-history' model

qntm.org/excellent

Hm. Perhaps i misspoke on that point. But there is a lot of flexibility. Especially later if you decide someone can go all Paul Atreides on the whole thing.

??

It's been a while since I've read Dune...

As he developed he could see the potential timelines developing, except around special events - which later he saw anyway.

I imagine this is a lot like the Matrix Oracle.

"except around special events"

I remember the Oracle saying that you can't see past a choice you don't understand

Does sound a bit familiar.

I can see why you don't really want to go back to the well of multiple timelines, though. I just think a blanket denial of it cuts off too much potential for the fiction. Granted a lot of it is trope-tastic. But still.