# Fanwank the biggest BttF plothole **URL:** \ **Category:** Cafe Society\ **Created:** [September 7, 2014, 1:33pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764 "2014-09-07T13:33:56Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Mr.Kobayashi](https://avatars.discourse-cdn.com/v4/letter/m/4af34b/32.png) [@Mr.Kobayashi](https://boards.straightdope.com/u/Mr.Kobayashi)\ **Post date:** [September 7, 2014, 1:33pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/1 "2014-09-07T13:33:56Z")
I know the Dope has many experts on temporal displacement and I need your help handwaving away the biggest plothole in the _Back to the Future_ trilogy - why _Part II_ should never even have happened. It’s been bugging me for ages In the first film, Doc Brown’s dog Einstein becomes the world’s first non-Brazilian time traveller by travelling forward in the future one minute. During that minute he has vanished, Marty mistakes this for disintegration. Then he appears as he was, right on schedule. In the second, Doc, Marty and Jennifer travel thirty years in the future where they encounter their future selves. Eh? Shouldn’t they be missing for thirty years? Einstein didn’t meet a version of him that was one minute older. What’s the explanation, time travel aficionados? ---
**Author:** ![USCDiver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/uscdiver/32/354_2.png) [@USCDiver](https://boards.straightdope.com/u/USCDiver)\ **Post date:** [September 7, 2014, 1:39pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/2 "2014-09-07T13:39:34Z")
Um, because at the end of the movie they went back to the present to live out their lives. ---
**Author:** ![Mr.Kobayashi](https://avatars.discourse-cdn.com/v4/letter/m/4af34b/32.png) [@Mr.Kobayashi](https://boards.straightdope.com/u/Mr.Kobayashi)\ **Post date:** [September 7, 2014, 1:43pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/3 "2014-09-07T13:43:18Z")
> [@USCDiver](#): > > Um, because at the end of the movie they went back to the present to live out their lives. But then their future selves would have been aware of this; future Jennifer is shocked to the point of collapse by her past self - she has no idea that she came to future when she was younger, which is something that’s pretty hard to forget. ---
**Author:** ![PSXer](https://avatars.discourse-cdn.com/v4/letter/p/48db29/32.png) [@PSXer](https://boards.straightdope.com/u/PSXer)\ **Post date:** [September 7, 2014, 6:50pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/4 "2014-09-07T18:50:49Z")
In that timeline old Jennifer never knew the time machine was real she thought it was a dream ---
**Author:** ![Aquadementia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aquadementia/32/555_2.png) [@Aquadementia](https://boards.straightdope.com/u/Aquadementia)\ **Post date:** [September 7, 2014, 6:56pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/5 "2014-09-07T18:56:47Z")
The dog never went to the trouble of traveling back one minute. That was just a minute he jumped over and was never present to see himself arrive one minute in the future. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [September 7, 2014, 7:04pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/6 "2014-09-07T19:04:26Z")
I’d have to refresh myself on the movies but I believe this is covered by there being multiple timelines involved. The Jennifer that freaked out over seeing her younger self came from the timeline in which the time-travel did not happen. As a result of learning why his family became pathetic losers, Marty avoided the accident that set that whole future in motion, and the Jennifer of 2015 would never encounter the younger one. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [September 7, 2014, 7:47pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/7 "2014-09-07T19:47:12Z")
> [@Mr.Kobayashi](#): > > I know the Dope has many experts on temporal displacement and I need your help handwaving away the biggest plothole in the _Back to the Future_ trilogy - why _Part II_ should never even have happened. It’s been bugging me for ages > > In the first film, Doc Brown’s dog Einstein becomes the world’s first non-Brazilian time traveller by travelling forward in the future one minute. During that minute he has vanished, Marty mistakes this for disintegration. Then he appears as he was, right on schedule. > > In the second, Doc, Marty and Jennifer travel thirty years in the future where they encounter their future selves. Eh? Shouldn’t they be missing for thirty years? Einstein didn’t meet a version of him that was one minute older. > > What’s the explanation, time travel aficionados? Doc never encountered his future self, did he? In fact, he would have gone to great pains to avoid doing so. When he and Marty went back to 1955 in BttF 2, he did run into his past self, but he was careful not to give him a good look at his face. ---
**Author:** ![Quimby](https://avatars.discourse-cdn.com/v4/letter/q/22d042/32.png) [@Quimby](https://boards.straightdope.com/u/Quimby)\ **Post date:** [September 7, 2014, 8:20pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/8 "2014-09-07T20:20:45Z")
A worse one is how did Biff bring the time machine back to Marty and the Doc when he had already changed history? Even if he went back to 2015, it should have been the 2015 of the dark Casino timeline. The fanwank answer to both of these issues is in the BTTF universe changes in the timeline take time to propagate throughout the timeline giving the heroes time to have the adventure. ---
**Author:** ![Jragon](https://avatars.discourse-cdn.com/v4/letter/j/e19b73/32.png) [@Jragon](https://boards.straightdope.com/u/Jragon)\ **Post date:** [September 7, 2014, 8:27pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/9 "2014-09-07T20:27:14Z")
The answer for all of these questions is that it’s established that the BttF universe works on slow ripples forward, rather than creating an instantaneous changes. This is made clear by the original movie – the picture of Marty’s family fades out slowly. So the reason they can meet themselves in the future is because them leaving hasn’t “caught up” in meta-time to the time machine. The ripple-effect hasn’t taken hold yet. Same with Biff. He changed the future with the almanac, but he came to non-Casino 2015 because that time ripple hadn’t caught up yet. Of course, this raises the question of why Doc Brown wanted them to interfere with a future that may not have happened, but it’s possible he was just playing Ghost of Christmas Future there. (Not that BttF doesn’t have plenty of time travel related plot holes) ---
**Author:** ![Mr.Kobayashi](https://avatars.discourse-cdn.com/v4/letter/m/4af34b/32.png) [@Mr.Kobayashi](https://boards.straightdope.com/u/Mr.Kobayashi)\ **Post date:** [September 7, 2014, 10:40pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/10 "2014-09-07T22:40:18Z")
Thanks for the answers, I love _Back to the Future_ as the greatest trilogy in film so ironing out any latent niggles is good for the soul > [@Aquadementia](#): > > The dog never went to the trouble of traveling back one minute. That was just a minute he jumped over and was never present to see himself arrive one minute in the future. That’s true, but if he did go back and then wait one minute he’d have the knowledge - if he were human - of travelling into the future then back again, which Marty and Jennifer in the future don’t. That’s why I don’t get years of loserdom rather than them vanishing and reappearing in 2015, although I think the above posited ripple-effect taking time to ‘catch-up’ is the best explanation. > [@PSXer](#): > > In that timeline old Jennifer never knew the time machine was real she thought it was a dream Ah yes, forgot about that. But it wouldn’t explain futureMarty’s cluelessness. ---
**Author:** ![SykoSkotty](https://avatars.discourse-cdn.com/v4/letter/s/c0e974/32.png) [@SykoSkotty](https://boards.straightdope.com/u/SykoSkotty)\ **Post date:** [September 8, 2014, 2:18pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/11 "2014-09-08T14:18:18Z")
Unrelated tidbit : I recently re-watched Part II, and the scene of Marty walking around the town square in 2015 showed flying cars, holographic movie ads, robotic wait staff, hoverboards, auto drying, auto fitting jackets, auto-lacing shoes, robotic gas station attendants, instantaneous weather reports…and (wait for it)… A public phone booth. ---
**Author:** ![joebuck20](https://avatars.discourse-cdn.com/v4/letter/j/74df32/32.png) [@joebuck20](https://boards.straightdope.com/u/joebuck20)\ **Post date:** [September 8, 2014, 7:55pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/12 "2014-09-08T19:55:12Z")
It’s always baffled me that people see this as a plot hole. I think it just means that Marty and Jennifer returned to the present day safely. As for why their older selves don’t seem to remember going to the future, someone pointed out above that Jennifer would have assumed it was all a dream. And Marty, well, his life had turned to shit by that point, and he had probably become hazy on the details of his trip to the future in light of all his problems. Also keep in mind 1985 Marty never encountered 2015 Marty. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [September 8, 2014, 8:20pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/13 "2014-09-08T20:20:39Z")
> [@joebuck20](#): > > It’s always baffled me that people see this as a plot hole. I think it just means that Marty and Jennifer returned to the present day safely. > > As for why their older selves don’t seem to remember going to the future, someone pointed out above that Jennifer would have assumed it was all a dream. And Marty, well, his life had turned to shit by that point, and he had probably become hazy on the details of his trip to the future in light of all his problems. Also keep in mind 1985 Marty never encountered 2015 Marty. At that point in the trilogy he also had not yet gone back to 1885 and gotten the advice from his ancestor Seamus about not reacting to people calling him a coward. ---
**Author:** ![GESancMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gesancman/32/2923_2.png) [@GESancMan](https://boards.straightdope.com/u/GESancMan)\ **Post date:** [September 8, 2014, 8:45pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/14 "2014-09-08T20:45:22Z")
> [@joebuck20](#): > > And Marty, well, his life had turned to shit by that point, and he had probably become hazy on the details of his trip to the future in light of all his problems. Also keep in mind 1985 Marty never encountered 2015 Marty. He very well could have remembered it. “Tonight is the night my past self visits!” But Doc would have drilled into his head how important it was not to interfere - his very existence could depend on it. ---
**Author:** ![AncientHumanoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ancienthumanoid/32/278_2.png) [@AncientHumanoid](https://boards.straightdope.com/u/AncientHumanoid)\ **Post date:** [September 8, 2014, 8:46pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/15 "2014-09-08T20:46:45Z")
Wibbly wobbly… ---
**Author:** ![interface2x](https://avatars.discourse-cdn.com/v4/letter/i/c0e974/32.png) [@interface2x](https://boards.straightdope.com/u/interface2x)\ **Post date:** [September 8, 2014, 11:26pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/16 "2014-09-08T23:26:05Z")
> [@Quimby](#): > > A worse one is how did Biff bring the time machine back to Marty and the Doc when he had already changed history? Even if he went back to 2015, it should have been the 2015 of the dark Casino timeline. > > The fanwank answer to both of these issues is in the BTTF universe changes in the timeline take time to propagate throughout the timeline giving the heroes time to have the adventure. He didn’t bring the time machine back because, according to a deleted scene, [he faded away right there in 1955.](https://www.youtube.com/watch?v=124-bZmfbPQ) ---
**Author:** ![AncientHumanoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ancienthumanoid/32/278_2.png) [@AncientHumanoid](https://boards.straightdope.com/u/AncientHumanoid)\ **Post date:** [September 8, 2014, 11:27pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/17 "2014-09-08T23:27:17Z")
Ah… like MArty in the family picture until George finally kissed the girl ---
**Author:** ![Balance](https://avatars.discourse-cdn.com/v4/letter/b/ccd318/32.png) [@Balance](https://boards.straightdope.com/u/Balance)\ **Post date:** [September 8, 2014, 11:29pm UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/18 "2014-09-08T23:29:27Z")
> [@Jragon](#): > > The answer for all of these questions is that it’s established that the BttF universe works on slow ripples forward, rather than creating an instantaneous changes. This is made clear by the original movie – the picture of Marty’s family fades out slowly. Thanks for fielding it, but I’ve been making this point on the SDMB since at least 2001. There will always be another thread asking about it. That’s why I have a numbered explanation handy, which covers a bunch of the secondary questions that always seem to follow. > [@Balance](#): > > I refer to my explanation for the way time travel works in the BttFverse as Temporal Hysteresis. (Hysteresis, by the way, refers to the state of a system being dependent not just on current conditions, but past conditions.) Here’s the quick version: > > 1. The timeline is resistant to change. The effects of a new change to history propagate slowly forward along the timeline, but the effects of changes that revert key events back to their original state propagate very quickly. > > 2. The propagation speed of a changewave is affected by a number of factors. The “breadth” of the wave–i.e. how extensively the change affects things–is a major one. For example, the changewave caused by Doc arranging for a piece of paper to sit in a box for 70 years was much narrower than one that erased three children from existence, and consequently propagated much faster. > > 3. The propagation speed of a changewave is not constant. It slows as it triggers secondary changewaves. This is why it took less time for the changewave from Marty’s interference to catch up to Dave than it did to progress from Dave’s birth to Marty’s–unmaking Marty’s siblings triggered major secondary changewaves, slowing the primary one. Even very narrow changewaves will gradually slow, as they inevitably initiate some secondary changewaves, however minor. (I speculate that the rate asymptotically approaches realtime, but establishing that would require far more data than we have.) > > 4. Changewaves propagate independently. The reversion wave triggered by the kiss propagated much faster than the novel changewave caused by George’s change in attitude. This is why Marty’s memory of his original life was restored along with his existence. > > 5. A time traveler is insulated from the effects of a changewave while undergoing temporal displacement. > > 6. Temporal displacement appears effectively instantaneous from the perspective of the time traveler, but this is an artifact of their disassociation from the timestream. Changewaves continue to propagate through the timestream while the traveler is in transit. Indeed, it is possible that the time vehicle cannot reenter a point in the timestream that is in flux due to a changewave, effectively leaving the traveler in a holding pattern until the changes at the target coordinates are complete. The changewave was already through 1985 when Marty reentered the timestream–it changed while he was outside of time, so he wasn’t affected. Note that we saw a very noticeable effect of the change already in place when he approached the mall. > [@Jragon](#): > > (Not that BttF doesn’t have plenty of time travel related plot holes) I’m pretty sure that at this point I’ve covered all the alleged time travel holes. The list above handles most of them, but if there are others you’d like addressed, I will dig up my answers for them. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [September 9, 2014, 12:04am UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/19 "2014-09-09T00:04:47Z")
> [@interface2x](#): > > He didn’t bring the time machine back because, according to a deleted scene, [he faded away right there in 1955.](https://www.youtube.com/watch?v=124-bZmfbPQ) Umm, no, he didn’t. It’s clearly 2015. Note Marty and Doc taking off in the flying Delorean after Biff returned it. And the “I brake for birds” bumper sticker. The filmmakers explained it as Lorraine shooting Biff in the 1985-A timeline, erasing Biff from all future timelines. When Marty restored the original timeline in 1955, presumably Biff returned to existence and continued to live until at least 2015. ---
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [September 9, 2014, 12:54am UTC](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764/20 "2014-09-09T00:54:42Z")
> [@cochrane](#): > > Umm, no, he didn’t. It’s clearly 2015. Note Marty and Doc taking off in the flying Delorean after Biff returned it. And the “I brake for birds” bumper sticker. And the neon curbs. [Next page](https://boards.straightdope.com/t/fanwank-the-biggest-bttf-plothole/697764.md?page=2)