You all may want to visit this website. It’s informal, but covers this territory and may be marginally insightful.
“Marty, You’re not thinking Fourth Dimensionally!”
Even if the rest of the movie was fanciful with some very outlandish things like Flying cars and “Mr Fusion”, they tried to maintian some sort of reality based consequence set involving time travel. I found that to be quite odd, but for the same reasons very entertaining.
There is a very simple answer to this: neither Doc or Marty thought of doing that. It would have been possible; it simply didn’t occur to them.
- Rick
Huh? There’s only one DeLorean around. 
No, Saint Zero, there were two DeLoreans in 1885. And at least one unseen-but-implied timeline. Let me see if I got this straight:
Doc Brown went back in time to 1885, leaving Marty in 1955, and decided to stay. But he knew Marty had to get back to 1985 from 1955, so he hid the DeLorean in a cave, wrote a letter to Marty with directions to the car and made arrangements for the letter to be delivered to Marty in 1955 moments after Doc left him.
Then Doc Brown died sometime before the twentieth century (forget just when).
Marty found the DeLorean, but knew Doc Brown wouldn’t survive long in the past. So Marty took the DeLorean back to 1885 to a time before Doc Brown was murdered, but (and here’s the important part) after Doc Brown stashed the DeLorean in the cave.
So co-existent in 1885 we have:
cave DeLorean
and
seventy-years-aged DeLorean.
See?
Now, possibly Doc didn’t want to use cave DeLorean to power aged DeLorean because of the paradoxes it would create, but we were never told that explicitly onscreen.
To be honest, It never occurred to me before today. Thanks for the tweak, GuanoLad!
To tweak the multiple timeline scenario bit, I remember hearing of a story once where it was posited that time was more of a sphere than a straight line going in one direction. The different points within the sphere (which could probably be considered dimensions) would interact and intersect, but not in a strictly linear fashion.
Kind of similar to Sliders I guess.
It had been sitting there for 9 months. The gas would’ve gone bad by then. Remember, Doc got there in January, but Marty didn’t get there till September.
The biggest problem with BTF time travel is that Marty, knowing Doc Brown would be killed in 1985 in the first film, sets the DeLorean 10 minutes before Doc’s slaying at the hands of the angry Libyian terrorists. How about an hour, Marty? Even a day for chrissakes.
Modian, in light of the fact that they were willing to try high-proof alcohol to fuel the car, surely you’ll concede that nine-month-old gasoline would have been better.
I routinely fried up my boat every spring with six- or seven-month old gasoline, with never a problem. I don’t think gas goes bad after only nine months, anyway.
- Rick
Wow, that never occurred to me either. I guess they didn’t pursue it because it WOULD create a major paradox (unless they just used some of the fuel… hmmmm). If the fuel from the cave DeLorean is used, then Marty would have found a DeLorean with an empty gas tank. But he didn’t, so thats a paradox. Also, I’m guessing they didn’t say this explicitly because it was too complex for most of the audience to grasp.
I’ve always thought the biggest problem with BTF2 is the contradiction of what happens when they leave Jennifer behind. Doc says the world would just transform around her, but when Biff successfully delivers the almanac, they stay in the future that is no longer the “true” future until they time travel again.
I don’t buy this theory at all. The reason Marty and his siblings didn’t pop out of existence instantly was because the future was not yet determined. It was still possible for them to be born, but it was LESS possible and becoming less and less possible, thus they were fading.
The meeting of the Jennifers did create a paradox because since the young Jennifer has not yet traveled back to the present, the old Jennifer has no memory of doing the things young Jennifer is doing. (the movie seems to assume that the “normal” course of time does not include changes caused by time travelers - once the time traveler task is complete, the changes become part of the future) Luckily, rather than trying to puzzle out the paradox and destroy the universe, old Jennifer simply faints.
Old Biff wasn’t fading. He is staggering because he is an old man. Actually, old Biff should have never returned to that future. He should have returned to the future where he is king of the world. But maybe some kind of shadow Biff returns to all other possible futures at the same time. Of course this creates all sorts of new issues.
I don’t know about the Doc Brown - tombstone thing but I’m sure it had nothing to do with the rate of changes occurring.
The only movie I’ve ever seen where time travel makes sense is 12 Monkeys. In that one, you can never make any changes because if you make a change in the past it would have affected the present already. Everything you are going to do has already been done, basically.
And then there is the mystery of how Doc Brown got into and out of the DeLorean’s gull-wing doors when he was transporting it via the truck (in the first movie).
Or then again, maybe I’m not thinking fourth-dimentionally.
Actually, the Old Sick Biff thing was a plot thread that wasn’t pursued. Probably on the cutting room floor (it may be explained on the DVDs which are supposed to come out this year) but something was meant to happen that suggested Biff had foolishly sentenced himself to death by his greedy actions. Or something like that.
I’m sorry, but 12 Monkeys makes no sense to me.
Bruce Willis’ character is instructed to leave recorded messages when neccessary with the idea that the recordings will survive into the future and alert his bosses to the situation.
So why can’t they just listen to all the messages at once? If the messages are all recorded in the past, they must logically all exist somewhere before Willis is ever sent back. Are they trying to avoid some kind of paradox? If so, how do they know when to listen to a message? Once they’ve listened to it, they know what it contains, but until then, they have no idea.
I remember being very irritated by this aspect of the movie.
It is to the eternal embarrassment of fighters of ignorance everywhere that the threads in this forum that get the most views and posts have to do with stupid movies.
You’re right, I don’t know how I missed that, must have been way too into the movie. Its been a while since I’ve seen it actually, I’ll have to watch that one again sometime.
Hey how about the Bill and Ted time travel scenario?
“Dude, we need a key for this door”
“No problem, we’ll just have to remember to go back in time and put it here after this is all over. Then it should be here waiting for us right now!”
“Good idea dude… SWEET, here’s the key!!!”
I thought of this while watching the movie. My retcon was that, as Doc Brown had been using the flight mod (powered by the fusion generator), he simply didn’t have any gas in the car. With the flight circuits fried, that became a problem. Alternatively, he could have drained the tank while preparing the car for storage, so that Marty and his 1955 self wouldn’t gave to clean gunk out of the tank before using it.
dil:
So Doc didn’t really understand the mechanism of time travel.
Just what’s so stupid about it?
Oh, and as for the “they couldn’t have used up any fuel because that would have left a non-full tank” explanation: they could have used just some of it, or used all of it, then come back and replaced it.
You know, petroleum was available in 1885, and a guy as resourceful and inventive as Doc Brown certainly would’ve been able to refine it into a proper grade of gasoline for the DeLorean.
I forget why we thought he’d need to, though. This thread spins me right 'round, baby, right 'round…
Don’t forget, Five, that courtesy of Marty’s shortsightedness they were short on time. No doubt Doc could have refined the fuel, but he didn’t have time to locate raw materials, acquire them, build the apparatus, and refine the gas before being shot. It’s not a trivial operation.
As for the Jennifer/Biff problem…throughout the movies, events are generally consistent with a single reality through which changes to the past propagate at varying rates. Doc Brown’s “make-see” explanation was not unlike some I’ve thrown at my coworkers: not really accurate, but as close as I can come without mortally confusing them. I thought of it as a metaphor. When Marty changed 1955, it took hours for the changes to begin affecting his older brother, whose birth was presumably around 10 years down the line. Marty, whose birth was 15 years away, isn’t affected for days. When Old Biff returned to his own time, the change-wave had 60 years to propagate to reach his time. The changes had reached 1985 by the time the time-travelers got back (or took effect while they were in no position to notice it). So, destroying the Almanac would produce a change-wave that would change 1985 around Jennifer, possibly before the previous wave even reached 2015. Interestingly, changes made to restore the previous timestream, or major parts of it, seem to propagate more quickly than initial alterations.
(And, yes, I’m aware that this is ridiculous. I just wanted to have fun with time travel babble for a while.)