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Actually, Marty Didn’t Go Back to the Future: Graphing the Train Scene of BTTF3

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11–20 of 46 posts

Re: Actually, Marty Didn’t Go Back to the Future: Graphing the Train Scene of BTTF3

#12

...but considering that they only need to fall from an height of 258.88 feet to reach 88 miles per hours Marty most likely did made it to the future! Unfortunately he then died instantly by hitting the the bottom of the ravine once he arrived to 1985. :(

Hadn't thought of that! And considering that based on what I calculated in the post he goes off the edge at about 70mph, he probably needs way less that 258 feet right?

Re: Actually, Marty Didn’t Go Back to the Future: Graphing the Train Scene of BTTF3

#13

...but considering that they only need to fall from an height of 258.88 feet to reach 88 miles per hours Marty most likely did made it to the future! Unfortunately he then died instantly by hitting the the bottom of the ravine once he arrived to 1985. :(

Hadn't thought of that! And considering that based on what I calculated in the post he goes off the edge at about 70mph, he probably needs way less that 258 feet right?

The 70mph is horizontal velocity, gravity is vertical acceleration from 0. Total velocity is sqrt(sum of squares). It's unclear how much horizontal velocity the train would lose due to air resistance and due to the unclean launch from the ravine. (Would it fly off the end of the track, or tip off the end and tumble down?)

Re: Actually, Marty Didn’t Go Back to the Future: Graphing the Train Scene of BTTF3

#14
post #4
post #2

There is also no way he could have met himself in the future. Edit: Unless the time machine was capable of visiting parallel universes.

Why not? 1. Marty leaves timeline to go to 2015 2. Marty meets Marty-F in the 2015 3. Marty returns to 1985 and grows up to be Marty-F. Of course this means that he knew, but that's okay.

A good possibility, but Back To The Future's time travel doesn't require 'immediate' consistency. Could be that changes are propagating at 2†, so Marty can meet his future self and watch him fade into a future self that is experiencing his present choices.

† Because the propagation would be occurring in sec/sec, the units cancel, so it's just a number -- I jest, those aren't the same 'seconds' unit, you you see the point.

Re: Actually, Marty Didn’t Go Back to the Future: Graphing the Train Scene of BTTF3

#15
post #6
post #3

> it’s a shame Doc didn’t equip the Delorean with Tesla electric motors when he visited 2015. That would have made things easier considering the Delorean was equipped with a working Mr. Fusion generator in 1885 He put flying car parts into it. Why the hell would he want some lousy electric motors?

Was it working? I always thought Mr Fusion was damaged along with the time circuits when the Delorean was struck by lightning.

The Doc specifically mentions that Mr Fusion only powers the time circuits, not the rest of the car. So to get Back to the Present it would have had to have been functional, given the plutonium system was removed between BTTF1 and BTTF2.

Re: Actually, Marty Didn’t Go Back to the Future: Graphing the Train Scene of BTTF3

#16
post #5

Well I saw the movie, and Marty did make it back to 1985. The problem is that the analysis assumes that every second in the film corresponds to a second in real life. That's not true, the shots overlap in real life but are shown after one another in a sequence to make showing what happened (possibly at the same time) more practical. This overlapping is often used in dramatic representations of real events in movies.…

OP here. You're probably right it's not all real time. I figured it wasn't completely unreasonable to treat it as such because when you watch it, most of it does feel RT and we pretty much see everything that happens in an uninterrupted way. But for the sake of argument, even if the analysis is skewed a bit, it does suggests they were missing a lot of tracks. So if some of the sequence can be considered RT and some o…

;) A classic example that exaggerates the different passing of time of movie vs real time happens in Monty Python and the Holy Grail: https://youtu.be/DPXG4pdPj4w?t=20s

Re: Actually, Marty Didn’t Go Back to the Future: Graphing the Train Scene of BTTF3

#17
post #14
post #4

Earlier quoted context omitted.

Why not? 1. Marty leaves timeline to go to 2015 2. Marty meets Marty-F in the 2015 3. Marty returns to 1985 and grows up to be Marty-F. Of course this means that he knew, but that's okay.

A good possibility, but Back To The Future's time travel doesn't require 'immediate' consistency. Could be that changes are propagating at 2†, so Marty can meet his future self and watch him fade into a future self that is experiencing his present choices. † Because the propagation would be occurring in sec/sec, the units cancel, so it's just a number -- I jest, those aren't the same 'seconds' unit, you you see the p…

Wikipedia would have you believe that "parts per million" is a dimensionless coefficient, by a similar argument. It's not true; for example, grams of gold is not the same unit as grams of seawater.

Re: Actually, Marty Didn’t Go Back to the Future: Graphing the Train Scene of BTTF3

#18
post #14
post #4

Earlier quoted context omitted.

Why not? 1. Marty leaves timeline to go to 2015 2. Marty meets Marty-F in the 2015 3. Marty returns to 1985 and grows up to be Marty-F. Of course this means that he knew, but that's okay.

A good possibility, but Back To The Future's time travel doesn't require 'immediate' consistency. Could be that changes are propagating at 2†, so Marty can meet his future self and watch him fade into a future self that is experiencing his present choices. † Because the propagation would be occurring in sec/sec, the units cancel, so it's just a number -- I jest, those aren't the same 'seconds' unit, you you see the p…

Substantially faster than 2, but somewhat inconsistently. Marty's brother started fading after only 9-10 hours. Marty doesn't start fading until nearly the week is gone. Old Biff starts fading after an hour or so? The tombstone fades immediately, and the matchbook and newspapers change within a few minutes of Marty stealing back the almanac for the last time, or possibly immediately after it's burned.

Re: Actually, Marty Didn’t Go Back to the Future: Graphing the Train Scene of BTTF3

#19
post #4
post #2

There is also no way he could have met himself in the future. Edit: Unless the time machine was capable of visiting parallel universes.

Why not? 1. Marty leaves timeline to go to 2015 2. Marty meets Marty-F in the 2015 3. Marty returns to 1985 and grows up to be Marty-F. Of course this means that he knew, but that's okay.

The problem is that once he leaves 1985 to go to 2015, from everyone else's perspective he would have effectively disappeared. He (and Jennifer) wouldn't be around anymore to grow up and have a family, so there'd be no future Marty or Jennifer to visit. At most, Marty could visit his parents, who would have continued to exist the whole time and would be pretty shocked to see him after he went missing for 30 years.

In order for Marty to go to the future and see himself, he'd need to continue to exist in 1985 somehow. I'm not sure how to reconcile him getting into the DeLorean with Doc and yet simultaneously going back into his house to live the rest of his life normally.

A parallel universe seems like the only way for this to work, despite adding a bunch of extra complexity. It also conveniently allows old Marty to be unaware (to some extent) of young Marty's visit, because old Marty would have lived a life where he didn't take that trip.

Re: Actually, Marty Didn’t Go Back to the Future: Graphing the Train Scene of BTTF3

#20
post #16

Earlier quoted context omitted.

OP here. You're probably right it's not all real time. I figured it wasn't completely unreasonable to treat it as such because when you watch it, most of it does feel RT and we pretty much see everything that happens in an uninterrupted way. But for the sake of argument, even if the analysis is skewed a bit, it does suggests they were missing a lot of tracks. So if some of the sequence can be considered RT and some o…

;) A classic example that exaggerates the different passing of time of movie vs real time happens in Monty Python and the Holy Grail: https://youtu.be/DPXG4pdPj4w?t=20s

I love the little touches. Guard: "hey..."
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