Back to the Future II plot hole?

OK, one more Back to the Future thread. This one’s about the second movie.

In the alternate 1985 Doc Brown explains that since old Biff went back and gave the sports almanac to young Biff, it created a separate time line and that they couldn’t go back to the future to fix things, because they’d still be in the new time-line.

So, how did old Biff get back to the original future? Shouldn’t he have gone to the alternate future?

It happens like this:

Old Biff in the original future timeline sees Doc Brown and Marty McFly, and he sees they have a time machine. He also sees Marty throw away that sports almanac. While Doc Brown and Marty are busy in the original future Old Biff steals the time machine, taking the sports almanac with him. He goes back to the original 1955 and gives young Biff the almanac.

Meanwhile, Doc Brown and Marty are under the impression they set things right in the future and go back to 1985, only to discover that they’re in a new 1985 timeline in which Biff has become all powerful.

Also, I think it’s may be the case that Biff witnessed a departure of the time machine in 1985 in the original timeline. So old Biff in 2015 had probably spent the last 30 years wondering if he really saw a time machine back in 1985. When he sees Doc Brown and Marty show up in 2015, he knows instantly that the time machine wasn’t just some hallucination and that he could use it to his advantage.

Right, but they can do so because old Biff returns the Delorean back to where stole it from. My question is, how did he get back to the original future?

Ah, that’s a good point.

My only guess would be that things don’t happen instantaneously like they should. For example in the original Back to the Future, under a logical understanding of time travel, the moment the past was changed so much that Marty shouldn’t exist, Marty should have just disappeared. Boom.

Instead, Marty starts to slowly fade out. In the world of Back to the Future it looks like there is some weird stuff going on where major changes that happen at one point in time take “time” to propagate out.

Imagine if you would, that you could watch the “timeline” of Back to the Future from some sort of outer-dimension. A change in 1955 will create a new timeline arc, but it takes time before it “replaces” the original arc. I believe what happens is by giving the almanac to young Biff in 1955, Old Biff is actually totally destroying the original timeline that comes after that, and it will be replaced by a new one. (So the Doc’s drawing of a divergent timeline is sort of correct, except he fails to mention the original just ceases to exist entirely.)

Apparently those things aren’t instantaneous, and during the “propagation” time, you could still move back and forth on the original timeline, before it is destroyed.

Obviously that doesn’t make sense, but it does seem to comply with other instances of such things in the movies (like Marty being in a “race” to save himself in the first movie. Obviously if things were instantaneous like they “should” be, Marty would have just stopped existing the moment he got hit by his grandfather’s car instead of his dad.)

I see what the OP is saying. I suppose it could be considered a plot whole.

Here’s my explanation. From other things in the movies it appears that changes in the time line take “time” (very meta, I know) to percolate forward through the time line. Elderly Biff returned to the future he left and got there “before” the changes had percolated up the time line. If you’ll recall, he appeared to be suffering, apparently as if he were about to disappear, similar to the way the subjects in the photo in the first movie disappeared slowly over time.

I know that doesn’t make a lot of sense. Why wouldn’t that whole version of the future be deteriorating rather than just Biff? But I think it’s what the writers were trying to portray.

ETA: I see that Martin Hyde and I said pretty much the same thing.

Fanwank: The DeLorean, being a super-advanced bit of technology has at least a rudimentary intelligence. Sensing that the timeline had in some way become corrupted or maligned, instinctively sought out the help from the two people that it knew could fix things - Doc & Marty from the original timeline.

Biff likely wasn’t even trying to get back to his original timeline - he would’ve wanted to go back to his proper point in history - albiet in the new timeline he created.

What Doc didn’t have time to explain was that the DeLorean probably had enough power in it to make a one-time only “cross-timeline” jump back to the point at which it started out. Any other such “cross-timeline” jumps would’ve stressed the hull integrity of the DeLorean to the breaking point, rendering it useless.

How the timelines work.

This helps, I think.

I don’t think there were parallel time lines that existed simultaneously. There was only one that changed due to their shenanigans.

Didn’t Doc say something like “that time line no longer exists?” or am I misremembering?

Yeah, I guess slow changing time-line does explain it.

And I do wonder if Doc was right, and there are now two time-lines. But that wouldn’t make sense, because if that’s the case, then: A) Altering the past wouldn’t endanger your existence, and B) It would be pointless to try and fix anything like Marty’s son going to jail, since all you would do is create two realities. One where he goes to jail, and one where he doesn’t. Also, Biff would probably be pissed wondering why he wasn’t a millionaire or billionaire when he returned to the future.

There’s a bit of ambiguity when Biff leaves the car after returning to 2015. He stumbles out and it appears he has a heart attack (or may even have been shot). If you accept the propagation theory, which does explain much of what happens, it’s very plausible the “heart attack” is his reaction to him being phased out of the timeline; we just don’t see him disappearing like Marty’s hand in the first movie. IIRC, Marty experiences convulsions as well in BTTF1; when George and Lorraine kiss and Marty’s existence is re-established, he snaps back up straight (the instant reaction is also explainable by the propagation theory, since he was in such close proximity to them).

The funny thing is I’m quite sure the reactions or lack-thereof to the timeline changes were purely arbitrary, being made up so they would make for better shots and a more understandable movie, and it winds up adhering to this AFAICT unique theory of time travel.

I actually seem to recall seeing old Biff disappear once he got back to the original future. Wasn’t there a version that showed this or am I imagining it?
I think it was in one of those parts that get cut out of the movie and video release but that they throw back in when it’s on local TV (The Goonies and Police Academy are two movies that also do this with deleted scenes).

Course, I could also be thinking of the book…but yeah, in SOME version I could have sworn he disappears not long after coming back.

Wow, a wikipedia page on the timelines fo Back To The Future. The Internet is an amazing thing.

I knew I wasn’t crazy.

Start at 59 seconds and watch to 1:40.

That scene, I remember, was actually in the movie one of the times it was on a local station.

So it seems he wasn’t really “able” to return to the original timeline after all. Oh, sure, he was able to get there…but not stay there.

No, you didn’t imagine it. I saw the clip on a BTTF TV special.

Here’s the clip of Biff fading from time.

I think I remember from a commentary that the reason Biff fades out instead of just being in a better (for him) future (like Marty coming back to a rich family) was that Biff was killed in 198something by Loraine.

You’re not thinking fourth dimensionally!

In the commentary, Bob Gale remarks that as we are watching Doc, Marty, and Jennifer exit the house, the timeline Biff adjusted it to is now propagating behind them; the evidence of which is Biff’s “heart attack”, which is the result of Lorraine having shot him in the 1985A he created; karma at work.

The key is that each timeline change takes some amount of time to work its way through the years.

See also that when Doc and Marty visit 1985A, it’s technically a timeline where Doc never built a Time Machine in the first place and so the whole of the time space continuum should collapse and reset back to default; but it doesn’t, because they skip in and out of 1985A, and back to 1955, so quickly they’re ahead of the adjustment ripple, and manage to avoid the consequences.

Of course all this must mean that as the new time-line comes into being, the old one goes away so that eventually there’s only one time-line.

The real plot hole is that this flimsy little booklet can hold the scores from tons of games across many sports over a 50 year period. If you look at something like the Baseball Encyclopedia or such those suckers are thick. That’s not even considering the possible “ripple” effects that the presence of said time travelers would have in that time (an eccentric time-traveling inventor waves his arms vigorously in Southern California, which eventually leads to a seagull drifting into the path of a pass at a UCLA game 50 miles away).

Yeah, I was wondering about that too. Maybe they use tiny print. :smiley: