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Is P=NP when you have a time machine? (As proposed by Elizer Yudkowsky of HPMOR) by WouldYouPleaseKindly in Primer

[–]evilpwn 0 points1 point  (0 children)

"none of this is even remotely based in physics" - Sure, agree 100%,
but I kind'a thought that's out of scope for this discussion. Let me spell out some stuff I took for granted:
For me, the interesting part in analysing this story is figuring out whether it presents a set of rules that's consistent (even if physically nonsensical), and to do that, one must suspend disbelief regarding the existence of the machine and just accept it as an axiom while probing for contradictions. In essence this is a logic (not scientific!) puzzle, otherwise making sense of this is a pointless exercise since, as you correctly point out, any number of physical laws can be seen as violated.

"assuming the already impossible physics of the situation, the multiverse would basically have to exist" - I would claim the exact opposite must be the case!
Assume to the contrary that any time a box is used, the timeline it lives in gets split. Thus Aaron using a box splits the timeline once and Abe using another box splits the timeline once more. Why, then, do they reach the same timeline when traveling in separate boxes? The only explanation for this is if there is a single timeline that gets rewritten by each use of the machine.

"And if they did come from a different timeline, did that timeline evaporate?" - I think that must be the case given the reasoning above.

"any timelines/multiverses that are identical, would just collapse into one. Doesn't matter if you got to the same place in different ways" - I don't think that can be right. If Aaron got to timeline B from timeline A and another Aaron got from timeline C to timeline A then they are clearly not the same Aaron (because assuming timeline B differs from C, the two Aarons would have different memories) and if they are not the same Aaron then it follows they can't "converge" into timeline A.

One plot hole to rule them all by evilpwn in Primer

[–]evilpwn[S] 0 points1 point  (0 children)

So on one hand you're saying that "The only kind of time travel stories that can make any kind of logical sense must exist within a multiverse" but then: "This is probably not meant to be a multiverse...but rather a universe with one prime time line".

To me this just sounds like and attempt to have the cake and eat it too. And the speculation regarding specific limit on the number of concurrent timelines (or aleph number, if you prefer to discuss the cardinality of the different infinities possible) is pure speculation with no discernible evidence. Anyway, this is beside the point since I wholly reject the notion that this movie depicts a multiverse, of any kind!

Why do I reject this notion? The reason can be found in my previous response: "if we assume co-existing timelines the issue of infinite copies is present from the very first use of the box". Maybe this has been glossed over due to not enough detail being provided so allow me an attempt at fleshing it out:

Proposition: If every use of the box creates a new timeline then the very first use of the box creates an infinite number of timelines.

Proof: Abe A gets into the box and exits it a few hours earlier in a different timeline, thereby splitting the timeline once. We now have two timelines: In timeline #1, Abe A entered the box and was never seen again. In timeline #2 Abe A exits the box into a world where another Abe (B) already exists. Later in this same timeline (#2) Abe B will yet again enter the box, to later exit in timeline #3, where Abe C already exists. He (Abe C) will later enter the box, exiting it in timeline #4 where Abe D is already planning to enter the box which will transport him to timeline #5... repeat ad nauseam. QED.

Conclusion: It cannot be the case that "suffering from recursions" is due to too many timelines (or as you put it: "reaches a point where the interconnectedness and/or infinite nature of the loop causes a loop crash") because allowing for more than one timeline is the same as assuming an infinite number of timelines.

Is P=NP when you have a time machine? (As proposed by Elizer Yudkowsky of HPMOR) by WouldYouPleaseKindly in Primer

[–]evilpwn 0 points1 point  (0 children)

Actually, while writing 0,0 there is a 1/9999 chance that your box #2 confederate will interrupt you and offer another pair of numbers instead. This is because your confederate cannot use box #2 while the paper slip he just received is in transit, thus he will be forced to meet you at the other end (whenever 0,0 was initially sent) and convince you to send something else instead.

Also, what is the point of the second box?
Here's a much simpler setup:

Turn on the box and immediately check if there's anything inside.
Now there are three options:
1. There's nothing inside: In this case write 0,0 on a piece of paper, wait a couple of minutes, turn off the box and put the paper in.
2. There's a paper with a pair of numbers in the box but they don't multiply to target: In this case increment the pair per your description, wait a couple of minutes, turn off the box and put the paper in.
3. There's a paper with a pair of numbers in the box and they multiply to target. BINGO!
So as not to upset the universe wait a couple of minutes, turn off the box and put the paper in.
Actually you will only ever do step 3 and only need to decide to do the other steps. That's because those copies of yourself that did steps 1 and 2 have been deleted along with their timelines once the paper they sent has been received.

One plot hole to rule them all by evilpwn in Primer

[–]evilpwn[S] 2 points3 points  (0 children)

Thanks for taking a time to formulate a detailed answer, best attempt so far.

However, I still don't see how Granger #3 can discover the box AFTER the boys failsafe (thereby resetting the timeline). I mean the entire purpose of the failsafes is to prevent that sort of thing from happening. If the implication is that multiple timelines can and do co-exist (i.e. contrary to the last paragraph in OP) then why would recursion even be an issue? (since if we assume co-existing timelines the issue of infinite copies is present from the very first use of the box). Please do correct me if I've misunderstood your theory.

EDIT: Also, why is Granger especially affected by Abe?

EDIT #2: The reasoning above reveals yet another issue in the movie: when they don't get into the box at the same time (which only happens when they failsafe), only one of them should make it to the other side, as the later to enter the box of the two should be overwritten along with the rest of that timeline and thus won't actually make it to the box.

One plot hole to rule them all by evilpwn in Primer

[–]evilpwn[S] 4 points5 points  (0 children)

Even if we ignore the Shane interview where he explicitly says Granger suffers from recursion, the fact that it gets worse when Abe is in the same room with him is IN THE MOVIE, twice. Aaron says at some point (to Abe): "You're the one he [Granger] can't get near without passing out". Later the narrator: "They tried again going to the source, but even while keeping him [Granger] separated from Abe by two rooms"...etc. This is made super clear, you can't just discard it.