# How would Abe's Plan to Punch Platts Work?

Here is an excerpt from the Primer explanation:

Abe then puts forward a confusing and potentially dangerous plan to visit Joseph Platts at his home, punch him in the face, then, around 03:00 Friday, to use these boxes to go back in time to 17:00 Thursday and make sure that neither the car alarms nor the punching happen. In theory, as a result, both Aaron and Abe's doubles would stay in bed all night, get into their boxes at 15:15 Friday as normal, and leave this timeline permanently, leaving just one of each of Aaron and Abe behind.

But wouldn't them getting in the box at 15:15 mean that they also exited the box earlier as well?

Shouldn't the timeline look like this:

• Thursday 17:00 - Abe(0) exits machine having just punched Platts.
• Friday 2:00 - Abe(0) scares kids preventing Abe(1) from waking up.
• Friday 8:45 - Abe(2) exits machine having just routinely gone back.
• Friday 15:15 - Abe(1) enters machine ready to go back as is routine.
• Now both Abe(0) and Abe(2) exist in the same timeline.

I am aware that in theory this plan would work in one out of the infinite timelines where Abe(1) enters the machine but Abe(2) hasn't come out yet.

• it makes perfect sense if you just follow the chart: xkcd.com/657 Apr 8, 2014 at 13:58

This is a key puzzle of the movie.

The only thing that they state in the movie is that it will be OK because "at least they'll get in the box" Friday 15:15. Thus we know that they intend not to create permanent doubles. So somehow they think there won't be a 08:45 Abe(2) exit. One possibility is that he's not thinking clearly. Another is that he has a plan that's not fully articulated on-screen.

I believe one approach he might be considering is the following. First, remember that he's been turning the box on at 17:00. That implies that each morning, he gets there at 08:00ish and finds it running. He must turn it off and then back on at 08:30. So, here's the theory: if Abe(0), after doing the punch plan and exiting the box at 17:00, writes a note and leaves it on the machine saying, "Don't turn this off and back on at 08:30; just let it keep running. Whenever you decide to get in, you will go back to 17:00 Thursday." (He could also add "Also, once you're back, at 02:00, stand in front of your house to keep some kid from setting off some car alarms." This would prevent the cycle from repeating.) When Abe(1) arrives at 08:00 to prepare for the day, he'll see the note. If he does what it says, then he won't do the off/on cycle. That means that Abe(2) can never exit at 08:45. Instead, whenever Abe(1) gets in, he'll go all the way back to 17:00, leaving Aaron(0) the only one left. When Abe(1) arrives at 17:00, he should rewrite the same note and in every iteration from then on, it's just an extra long day but not meaningfully different from an ordinary stock day.

## Short version

I don't think Abe believes a Friday morning exit from a "future Abe" is possible.

The Abe hatching this plan already has (thanks to the phone call paradox) what he considers sufficient evidence to invalidate the "single timeline" model, in which causing a paradox will cause a disaster because there can be only one version of history. He wants a controlled experiment to see if what happens will fit a "diverging timelines" model, in which travel backwards in time either generates or allows access to independent "offshoot" versions of history.

He may also believe that the future does not independently exist as a causative agent that can impact the present, because, despite his own experience as a time traveler, he has not yet encountered anyone that he recognizes as "from the future."

Thus the plan makes sense to the Abe on-screen in that scene, though his model of what's going on with time travel likely differs from the one you used in composing this question.

## Long version

Your question is slightly confusing because of the way you're using the parenthetical notation to designate individuals. Most people using this notation use the number in parentheses to indicate the number of trips back that individual has taken. Thus, when you say:

• Thursday 17:00 - Abe(0) exits machine having just punched Platts.
• Friday 2:00 - Abe(0) scares kids preventing Abe(1) from waking up.

this would by the typical convention be written as:

• Thursday 17:00 - Abe(1) exits machine having just punched Platts.
• Friday 2:00 - Abe(1) scares kids preventing Abe(0) from waking up.

since Abe(1) is the one who has come back through time on this particular cycle. I think this may be causing part of your confusion.

Note that the Abe hatching this plan is not Abe(0) in the absolute sense, since he has traveled back several times already by this scene. Perhaps it is better to reference them with relative numbers, like:

• Thursday 17:00 - Abe(N+1) exits machine having just punched Platts.
• Friday 2:00 - Abe(N+1) scares kids preventing Abe(N) from waking up.

Adjusting the notations of Abe(0) and Abe(1), and replacing the absolute numbers with relative numbers as above, I think the schedule you're proposing looks like:

• Thursday 17:00 - Abe(N+1) exits machine having just punched Platts.
• Friday 2:00 - Abe(N+1) scares kids preventing Abe(N) from waking up.
• Friday 8:45 - Abe(N+2) exits machine having just routinely gone back.
• Friday 15:15 - Abe(N) enters machine ready to go back as is routine.

So you can see the fault in that you have N entering a box Friday afternoon but N+2 exiting that box Friday morning. Even if this is not a true fault, your proposed schedule looks like a faultily-reasoned scenario to the Abe doing the planning, as I'll try to make clear below.

First, let's review the dialogue from this scene:

Abe: Well, we can do this, but we have to do it now. Do you have his home address?

Aaron: Why now?

Abe: We were planning to take a trip tomorrow, right? Just like today?

Aaron: Yeah. For stocks.

Abe: Ok, well, half an hour ago, I was asleep, and this car alarm woke me up. These kids were down, skating by, hittin' every car on the block. So... we go right now, do our business with Platts, get back in the box, and come back to right before those kids are settin' off the alarms. All we-- all we really have to do is stand there in plain sight -- it should scare them off. That way my double sleeps through the night, uh, they don't have the conversation we're having now, and they get in the box tomorrow as usual.

Aaron: (pauses to think) Yeah. They'll be changed, but...

Abe: Yeah, but at least they'll get back in the box.

Aaron: Wait -- how do we go back that far, if the machines haven't been running? (pause) Have they been running?

Abe: Yeah. I, uh, started going by at five o'clock and turning them on -- 5 PM. I just got tired of the whole unanswerable quest--

Aaron: (interrupting) Are we doing this as an experiment, or are we doing this for me?

Abe: (pauses) A little of both.

I don't think that the Abe(N) hatching this plan expects to have Abe(N+2) coming out of a box on Friday morning. Remember that this Abe(N) has not yet been surprised by someone coming out of a box without it being part of his plan. If that scenario has already occurred (because Aaron used a failsafe), this Abe(N) does not know about that yet.

Also note that Abe(N) is being pretty daring here: planning to deliberately break symmetry with their "doubles," which is something he never wanted to do before. In all likelihood, this is because the universe continued to exist with no apparent ill effects after the paradox phone call incident (where Aaron's phone rings both the "first" and "second" times through a particular day) somewhat earlier.

It seems clear that, because they survived the phone call paradox, Abe(N) believes (correctly or not) that, after he's gone back and scared off the kids, his double will be not actually be Abe(N) (i.e. the true past version of himself, the himself planning now) but more like Abe(N-1') (i.e. some "other" independently-existing Abe diverging from his own personal historical frame of reference). In all likelihood, he has deduced that the Abe in the hotel when Aaron got his phone call the "second" time was similarly an offshoot "other" version of his past self. However, he noted that, when the afternoon rolled around, that offshoot got into the box and exited the timeline, leaving him as the only Abe in his current timeline.

Abe(N) knows that the "other" Abe (the one still in the hotel after the phone call incident) must have gone "somewhere else." It doesn't really matter whether that offshoot Abe evaporated or went to a splinter timeline inaccessible to the Abe(N) we're talking about here. He's gone. He's not contesting Abe(N) for control of his "life" (i.e. apartment, job, etc.) in this timeline. Abe(N) only knows only that his immediate situation appears to be functional from his current perspective.

Abe(N) expects a similar train of events as a result of his plan. The important thing to recognize (as the viewer) is that Abe(N) is no longer thinking in terms of absolute timelines but relative timelines. He recognizes that the relationship between an Abe(N) and an Abe(N+1) is NOT the same as the relationship between an Abe(N-1) and an Abe(N). He's been Abe(N), and he's seen Abe(N-1) while he was Abe(N). He's never seen Abe(N+1) [or anybody X(N+m)!] when he's been Abe(N). (Though this will shortly change with the Granger Incident.)

So Abe(N)'s thinking is that the schedule will be:

• Abe(N) (his present self) heads off to punch Platts along with "his" Aaron.
• His present self and his buddy Aaron come back to the boxes and use them, going to a new timeline containing an Abe(N-1) and an Aaron(N-1) -- with this "local pair" not really being their own past selves, as he knows now.
• His future post-travel self will prevent the kids from waking up that Abe(N-1) in the new timeline. Symmetry will be broken. Abe(N-1) (the past self he will remember, the one doing the planning now) can not possibly be the same as Abe(N-1') (the one who will be sleeping peacefully through the night in the new timeline).
• His future post-travel self (plus his buddy Aaron) will steer clear of the N-1' pair until the N-1' pair gets into their boxes the next afternoon. The N-1' pair will be going "somewhere else" -- wherever that may be.
• This Abe probably thinks that nobody will have come out of the boxes the next morning, because he no longer believes that there is a single unified timeline such that is required to preserve causality. He is obviously already thinking that causality is not something that must be preserved, as demonstrated by the fact that he is prepared to carry out the Platt-punching experiment in the first place.

As you can see, from this perspective of thinking, your question:

...wouldn't them getting in the box at 15:15 mean that they also exited the box earlier as well?

implies an identity between the individuals exiting/entering the boxes that the Abe in this scene would probably not agree is truly an identity.

I think you overcomplicated the explanation that you ended up confusing yourself.

Also note that Abe(N) is being pretty daring here: planning to deliberately break symmetry with their "doubles," which is something he never wanted to do before. In all likelihood, this is because the universe continued to exist with no apparent ill effects after the paradox phone call incident (where Aaron's phone rings both the "first" and "second" times through a particular day) somewhat earlier.

You'd already called Abe(N) the one sleeping without being disturbed in a previous paragraph and in THIS paragraph you are saying it's the one who was awaken by the kids and wants to punch Pratts. Besides you added that N for no good reason at all, it only overcomplicated the explanation; the other time travels don't matter if you are explaning Abe's plan scene.

Dude... then for some reason you started calling them (N-1') O___o what the hell were you trying to do??? You used 3 different names for the same guy: Abe(N+1), Abe(N) and Abe(N-1'). If you read what you wrote like 5 times you end up understand what you meant but... please you SUPER overcomplicated it all.

We see later in the movie that you have people popping out from other possible futures in the present, so each time they travel to the past and break symmetry in an important way... you have two possible scenarios: 1) the original timeline deletes itself from existance and the new timeline is the only one that keeps existing 2) all possible timelines are real in some kind of multiverse like in the MCU.

We know even later in the movie that the MCU alternative doesn't happen, there's only one reality if you break symmetry... the original timeline disappears. The only way that the original timeline keeps existing is by avoing breaking it. Remember... boxes can be used ONE time. That's the ONLY way there can be 3 Aarons from 3 different realities at the same moment.

Abe's plan would break symmetry in really significative way, therefore there'll be two Aarons and two Abes existing at the same time forever.

Original Abe is awaken by the kids, goes to Original Aaron's house and makes the Punching Pratts Plant.

Friday 3 am: Original Abe and Original Aaron, after punching Pratts, get into the boxes. Thuesday 5 pm: Original Abe and Original Aaron get out of the boxes and prevent the kids from waking New Reality Abe up.

Now you have the Original ones and the New Reality ones. How the hell can they get rid of the new reality ones?

If the New Reality ones go and do business as usual... nothing would change because they wouldn't break symmetry.

Friday 8:30 am: New Reality Aaron and Abe start the boxes and go to the hotel. Friday 3 pm: New Reality Aaron and Abe get into the boxes Friday 9 am: New Reality Aaron and Abe get out of the boxes.

At end of the movie we see one new reality where there are 3 Aarons, 2 from deleted timelines and 1 belonging to the New Reality where 3 different Aarons exist.

You are right about Abe thinking, in that scene, there are mutiple realities each time they break symmetry which end up being wrong.

OOOOOOOOOOOOOOOR (CAUTION overcomplicated crap):

Each time you use a box you create a new universe, but if that were the case then by just using the box once... you'd be creating infinite universes because in each new universe you are using a box again, which in turn creates a new universe in which you're using a box again and so on. Infinite energy... so this can't be the case.

• Hi, welcome to SF&F. You appear to be responding to another answer, but your answer needs to address the question only. You should rewrite this to remove direct references to the other answer and concentrate on creating a better answer to the question. Oct 27, 2020 at 3:10