Echoes of Time Travelers

[Rogers]

There are many instances, particularly in Parts 2 and 3, where Doc or Marty travel to the past to accomplish some goal, but when they succeed in that goal, they eliminate the original purpose of going back. (Going to 1955 to retrieve the almanac, saving Doc from the west and destroying the tombstone, the list goes on.) This would seemingly be a variation of the Grandfather Paradox, as we are led to believe that BTTF exists on one constantly evolving timeline. But even though there is only one timeline, we have several different "realities" or "versions" of that timeline. (1985a, Twin Pines 1985, future where Marty gets in an accident)

The problem is that once one of these alternate realities get erased, people in
that reality aren't supposed to affect the timeline anymore. Take 2015 where Biff steals the almanac. If Old Biff from 2015 goes to 1955, only to create an alternate reality where Doc and Marty don't show up in 2015, how can he go back in time with the almanac? The answer, I think, is that no matter how many times you alter the timeline, an "echo" of older versions of time travelers must still exist to complete whatever action they are meant to complete.

To illustrate this more clearly, let's look at Part 2 when Doc and Marty go back to 1955. They see Old Biff hand over the almanac, an almanac from a version of 2015 that no longer exists. The Old Biff they see can't possibly be who Biff grows into anymore either, because once he gives Young Biff the almanac he creates 1985a. Doc and Marty would have had to take the time machine to 2015a in order for that Old Biff to even have a chance of using it. Therefore, this Old Biff should not exist. BUT HE DOES...He exists as an echo, a remnant from a destroyed reality. As soon as Old Biff drives off from 1955 at 88 mph, he'll just cease to exist because there's no timeline for him to go back to.

There are several "echos" present in the series. Once Marty goes back home in Part 3, the version of him in 1955 who travels to the Wild West must also be an echo. In BTTF the Game, there is a Citizen Brown timeline where the time machine was never invented, yet we still see Doc and Marty in a photo taken in the 30s. They were echoes.

Any thoughts on this theory?

[sn939]

Originally Posted by Rogers

There are many instances, particularly in Parts 2 and 3, where Doc or Marty travel to the past to accomplish some goal, but when they succeed in that goal, they eliminate the original purpose of going back. (Going to 1955 to retrieve the almanac, saving Doc from the west and destroying the tombstone, the list goes on.) This would seemingly be a variation of the Grandfather Paradox, as we are led to believe that BTTF exists on one constantly evolving timeline. But even though there is only one timeline, we have several different "realities" or "versions" of that timeline. (1985a, Twin Pines 1985, future where Marty gets in an accident)

The problem is that once one of these alternate realities get erased, people in
that reality aren't supposed to affect the timeline anymore. Take 2015 where Biff steals the almanac. If Old Biff from 2015 goes to 1955, only to create an alternate reality where Doc and Marty don't show up in 2015, how can he go back in time with the almanac? The answer, I think, is that no matter how many times you alter the timeline, an "echo" of older versions of time travelers must still exist to complete whatever action they are meant to complete.

To illustrate this more clearly, let's look at Part 2 when Doc and Marty go back to 1955. They see Old Biff hand over the almanac, an almanac from a version of 2015 that no longer exists. The Old Biff they see can't possibly be who Biff grows into anymore either, because once he gives Young Biff the almanac he creates 1985a. Doc and Marty would have had to take the time machine to 2015a in order for that Old Biff to even have a chance of using it. Therefore, this Old Biff should not exist. BUT HE DOES...He exists as an echo, a remnant from a destroyed reality. As soon as Old Biff drives off from 1955 at 88 mph, he'll just cease to exist because there's no timeline for him to go back to.

There are several "echos" present in the series. Once Marty goes back home in Part 3, the version of him in 1955 who travels to the Wild West must also be an echo. In BTTF the Game, there is a Citizen Brown timeline where the time machine was never invented, yet we still see Doc and Marty in a photo taken in the 30s. They were echoes.

Any thoughts on this theory?

Well, this isn't exactly a new theory...in fact its pretty much the most commonly accepted theory among the BTTF fandom. And really, its the ONLY plausible theory when explaining paradoxes like the entire plot of BTTF2!

I do agree with this theory for the most part, except that I'm really not comfortable with the terminology of 'echo theory'...simply because I feel that time travelers from erased timelines DO have an existence as flesh and blood entities who CAN affect reality. They exist as long as the most likely future doesn't preclude their existence...the moment the probability of their future existence drops to 0, they get erased.

So when Doc and Marty travel back to 1955 in BTTF2 and see the Marty from BTTF1, it would be easy to term that Marty as an 'echo' of the original Twin Pines Marty (since the 'most likely future' at the time is 1985-A, where the time machine wasn't invented and Marty was in Switzerland)...but THAT Marty is still every bit as real as he was in the context of the first film. He's not just some hologram or some illusion, or a puppet walking down a set path...he's every bit as real as 'our' Marty, and has free will. That is why Doc and Marty take particular pains not to interfere with him and let the chain of events unfold as they did originally.

This becomes especially important when we consider situations where 'our' Marty and Doc end up in alternate timelines where the time machine wasn't invented. Say, consider the Citizen Brown timeline. Owing to Marty and Doc's actions in 1931, an alternate timeline is created which results in Doc having a radically different life, never meeting Marty and never developing the time machine. Doc is erased from existence the moment they touch down in the new alternate 1986, but Marty continues to exist and explore this new alternate world. Now, you can argue, in this timeline, the Marty and Doc who were in 1931 (as seen in the photograph) were 'echoes' who briefly existed simply to avoid a paradox. And yet, that Marty is very much alive and in existence after returning to 1986...and indeed, capable of making further time travel trips. So 'our' Marty is far more than just a mere echo.

But honestly, the game totally confused the issue with regards to alternate timelines and alternate selves, by erasing Doc, and not Marty, when they arrive in FCB 1986. Why would the rules work differently for Doc, and not for Marty? Original Doc gets erased as soon as FCB comes into existence, FCB Doc gets erased as soon as the final timeline comes into existence...but Marty remains constant throughout...

[Michael J Fox is Canadian]

Originally Posted by sn939

But honestly, the game totally confused the issue with regards to alternate timelines and alternate selves, by erasing Doc, and not Marty, when they arrive in FCB 1986. Why would the rules work differently for Doc, and not for Marty? Original Doc gets erased as soon as FCB comes into existence, FCB Doc gets erased as soon as the final timeline comes into existence...but Marty remains constant throughout...

The rationale is the age gap; Marty is relatively the same age in 1986 with and without time travel but doc is decades apart if you remove time travel, lets say old doc lived for 100 years, you cant have a 100 year doc in a 1986 without time travel if he was born in 1913. Likewise old doc did not go to 1931 at age 73 without time travel hence old docs return.

[sn939]

Originally Posted by Michael J Fox is Canadian

The rationale is the age gap; Marty is relatively the same age in 1986 with and without time travel but doc is decades apart if you remove time travel, lets say old doc lived for 100 years, you cant have a 100 year doc in a 1986 without time travel if he was born in 1913. Likewise old doc did not go to 1931 at age 73 without time travel hence old docs return.

I've heard that explanation before and I really don't buy it. Why would the timeline erase Original Doc based on a prediction of the life span of his alternate self. If the future isn't written, then on what basis would the timeline decide that FCB Doc won't live beyond a certain age, and moreover, transfer this assumption to the Original Doc who HAS already lived beyond that age?!!

Okay, let us assume Original Doc is chronologically around 100 (I seriously doubt that, but just for the sake of argument). Now, FCB Doc may very well not live to be 100...but how can the timeline KNOW that?!! The future isn't written...so FCB Doc could die the very next day at age 72 by being run over by a car. Or he could die at age 80. Or with VERY GOOD advancements in health care (likely under the sterile regime of Hill Valley in this timeline), he could potentially even live to 120 for all anyone knows!!! It all depends on the choices he, and others around him, make. Human life span isn't predetermined...it has fluctuated, sometimes to extremes, and the space-time continuum really can't predict it.

[Michael J Fox is Canadian]

Originally Posted by sn939

I've heard that explanation before and I really don't buy it. Why would the timeline erase Original Doc based on a prediction of the life span of his alternate self. If the future isn't written, then on what basis would the timeline decide that FCB Doc won't live beyond a certain age, and moreover, transfer this assumption to the Original Doc who HAS already lived beyond that age?!!

Okay, let us assume Original Doc is chronologically around 100 (I seriously doubt that, but just for the sake of argument). Now, FCB Doc may very well not live to be 100...but how can the timeline KNOW that?!! The future isn't written...so FCB Doc could die the very next day at age 72 by being run over by a car. Or he could die at age 80. Or with VERY GOOD advancements in health care (likely under the sterile regime of Hill Valley in this timeline), he could potentially even live to 120 for all anyone knows!!! It all depends on the choices he, and others around him, make. Human life span isn't predetermined...it has fluctuated, sometimes to extremes, and the space-time continuum really can't predict it.

But the point is that Doc should not be that age in 1986. He's lived at least 10 years away from his timeline and probably closer to 20. 18 year old Marty should exist in 1986 either way whereas docs age should rely solely on whether or not he has time traveled.

[sn939]

Originally Posted by Michael J Fox is Canadian

But the point is that Doc should not be that age in 1986. He's lived at least 10 years away from his timeline and probably closer to 20. 18 year old Marty should exist in 1986 either way whereas docs age should rely solely on whether or not he has time traveled.

Okay, let me put it this way...

FCB Doc is 72, has never time traveled...

Original Doc is closer to 90 (a more reasonable estimate), but looks younger because of an early trip to the future...

Now the way I see it, Original Doc would get erased because his very existence is an anomaly in this timeline...why would he get erased based on whether or not a specific incident in his alternate self's timeline occurred?

Again, for your theory to work, one needs to assume that-

a) The exact age at which FCB Doc will die has been pre-determined by the space-time continuum i.e. an element of predestination DOES exist in the BTTF-verse (which squarely contradicts the 'future isn't written' argument.

b) That the space-time continuum would erase the Original Doc, NOT because he's an anomaly who logically shouldn't exist anymore, but based on its predictions about the maximum possible age his alternate self would attain.

[Tornreaper]

The way I see it if Doc's age changed he would fade INTO a new looking a Doc instead of fading OUT.

The reason why Doc faded was because he never time traveled. But why Marty didn't fade is beyond me. Even if someone else made the time machine using Doc's FC ideas he should still fade because Marty's reason for time travel is mostly with the help of Doc. If Doc didn't get stuck in 1931 then Marty would have no reason to go there.

But I still think the theory about his age is absurd.

[Rogers]

Originally Posted by Tornreaper

The way I see it if Doc's age changed he would fade INTO a new looking a Doc instead of fading OUT.

The reason why Doc faded was because he never time traveled. But why Marty didn't fade is beyond me. Even if someone else made the time machine using Doc's FC ideas he should still fade because Marty's reason for time travel is mostly with the help of Doc. If Doc didn't get stuck in 1931 then Marty would have no reason to go there.

But I still think the theory about his age is absurd.

I'm inclined to think that Doc fading out faster than Marty in the Citizen Brown timeline is just a plothole, which doesn't bother me very much because its not part of the main trilogy. I still like to take things from the game into account, such as Emmett's backstory and Kid Tannen because they seemed like they were intended to expand the BTTF-verse. I am just more forgiving with mistakes in the writing and the general silliness when it comes to the game.

As far as this age theory goes, I don't really buy it either. It seems awfully contrived to me. I suppose it's better than any explanation I've heard though, if you really want to resolve the discrepancy.

With this kind of stuff, it makes it easier for me to think if I use simple examples. Let's say Joe from the year 2000 spends 15 years building a time machine, and finishes it in 2015. He goes to 1985, and gets stranded when the time machine breaks. He then waits until the year 2000, when the parts he needs become available, but winds up taking the only parts that his 2000 self can use to build it in the first place. When he goes back to 2015, no time machine should exist. Does that mean he would instantly lose his memories and be some failed scientist? (Even weirder, does this mean that the time machine itself would still exist because its fadeout process was slower?)

This is the logistic equivalent of Citizen Brown timeline if the age theory was true. And it just begs the question...why would the age be such an important factor when the time machine itself doesn't even fade away? I thought the whole point was that time machine should be gone, as long as its still there there's no reason why Doc should have faded away faster.

[Tornreaper]

Originally Posted by Rogers

I'm inclined to think that Doc fading out faster than Marty in the Citizen Brown timeline is just a plothole, which doesn't bother me very much because its not part of the main trilogy. I still like to take things from the game into account, such as Emmett's backstory and Kid Tannen because they seemed like they were intended to expand the BTTF-verse. I am just more forgiving with mistakes in the writing and the general silliness when it comes to the game.

As far as this age theory goes, I don't really buy it either. It seems awfully contrived to me. I suppose it's better than any explanation I've heard though, if you really want to resolve the discrepancy.

With this kind of stuff, it makes it easier for me to think if I use simple examples. Let's say Joe from the year 2000 spends 15 years building a time machine, and finishes it in 2015. He goes to 1985, and gets stranded when the time machine breaks. He then waits until the year 2000, when the parts he needs become available, but winds up taking the only parts that his 2000 self can use to build it in the first place. When he goes back to 2015, no time machine should exist. Does that mean he would instantly lose his memories and be some failed scientist? (Even weirder, does this mean that the time machine itself would still exist because its fadeout process was slower?)

This is the logistic equivalent of Citizen Brown timeline if the age theory was true. And it just begs the question...why would the age be such an important factor when the time machine itself doesn't even fade away? I thought the whole point was that time machine should be gone, as long as its still there there's no reason why Doc should have faded away faster.

Faster? Marty and the time machine didn't fade at all!

[sn939]

Originally Posted by Tornreaper

The way I see it if Doc's age changed he would fade INTO a new looking a Doc instead of fading OUT.

The reason why Doc faded was because he never time traveled. But why Marty didn't fade is beyond me. Even if someone else made the time machine using Doc's FC ideas he should still fade because Marty's reason for time travel is mostly with the help of Doc. If Doc didn't get stuck in 1931 then Marty would have no reason to go there.

But I still think the theory about his age is absurd.

Logically, it makes sense that Doc faded because FCB Doc never time traveled, and therefore the time traveling 'rejuvenated' version of Doc simply cannot exist. But then, in the Hell Valley and Tannen Mob timelines too, the alternate Docs never time traveled, and yet, 'our' Doc didn't fade! And that still didn't account for Marty...the alternate Marty's certainly didn't time travel in ANY of these alternate timelines, and yet Marty never faded...

Originally Posted by Rogers

I'm inclined to think that Doc fading out faster than Marty in the Citizen Brown timeline is just a plothole, which doesn't bother me very much because its not part of the main trilogy. I still like to take things from the game into account, such as Emmett's backstory and Kid Tannen because they seemed like they were intended to expand the BTTF-verse. I am just more forgiving with mistakes in the writing and the general silliness when it comes to the game.

As far as this age theory goes, I don't really buy it either. It seems awfully contrived to me. I suppose it's better than any explanation I've heard though, if you really want to resolve the discrepancy.

With this kind of stuff, it makes it easier for me to think if I use simple examples. Let's say Joe from the year 2000 spends 15 years building a time machine, and finishes it in 2015. He goes to 1985, and gets stranded when the time machine breaks. He then waits until the year 2000, when the parts he needs become available, but winds up taking the only parts that his 2000 self can use to build it in the first place. When he goes back to 2015, no time machine should exist. Does that mean he would instantly lose his memories and be some failed scientist? (Even weirder, does this mean that the time machine itself would still exist because its fadeout process was slower?)

This is the logistic equivalent of Citizen Brown timeline if the age theory was true. And it just begs the question...why would the age be such an important factor when the time machine itself doesn't even fade away? I thought the whole point was that time machine should be gone, as long as its still there there's no reason why Doc should have faded away faster.

Honestly, I think the only possible explanation is that Original Doc faded because it was a drastic change to HIS past which altered the timeline. Emmett Brown, as the inventor of the flux capacitor, is the lynchpin of the space-time continuum...rewriting his ENTIRE life (from age 17 onwards at any rate), such that he never even developed the IDEA of time travel screwed up the timeline SO badly, that not only was the Original Doc instantly erased, but the Delorean itself began to malfunction. Notice how the Delorean seemed to be affected by some kind of storm when Marty and Doc left 1931 at the end of Episode 2...it never really happened before. Its probably a clue that the timeline was REALLY f#cked up!!!

[Michael J Fox is Canadian]

Originally Posted by sn939

Okay, let me put it this way...

FCB Doc is 72, has never time traveled...

Original Doc is closer to 90 (a more reasonable estimate), but looks younger because of an early trip to the future...

Now the way I see it, Original Doc would get erased because his very existence is an anomaly in this timeline...why would he get erased based on whether or not a specific incident in his alternate self's timeline occurred?

Again, for your theory to work, one needs to assume that-

a) The exact age at which FCB Doc will die has been pre-determined by the space-time continuum i.e. an element of predestination DOES exist in the BTTF-verse (which squarely contradicts the 'future isn't written' argument.

b) That the space-time continuum would erase the Original Doc, NOT because he's an anomaly who logically shouldn't exist anymore, but based on its predictions about the maximum possible age his alternate self would attain.

Then how do you explain Marty fading in part I? The timeline should logically be correcting itself now that time travel has been erased. There was also much more that changed with Doc than Marty. For instance doc's biology itself changes quite a bit between timelines.

[Tornreaper]

Originally Posted by sn939

Honestly, I think the only possible explanation is that Original Doc faded because it was a drastic change to HIS past which altered the timeline. Emmett Brown, as the inventor of the flux capacitor, is the lynchpin of the space-time continuum...rewriting his ENTIRE life (from age 17 onwards at any rate), such that he never even developed the IDEA of time travel screwed up the timeline SO badly, that not only was the Original Doc instantly erased, but the Delorean itself began to malfunction. Notice how the Delorean seemed to be affected by some kind of storm when Marty and Doc left 1931 at the end of Episode 2...it never really happened before. Its probably a clue that the timeline was REALLY f#cked up!!!

I don't buy that either. Remember that in this timeline Marty is a nerd, doesn't like music, and even his name changed to Martin! That's a significant change to his life. Plus I honestly don't think how significant a change is should matter.

Also Doc did invent the idea for the time machine. In episode 3 it is shown that the flux capacitor is the only thing that wasn't erased in his note book.

Originally Posted by Michael J Fox is Canadian

Then how do you explain Marty fading in part I? The timeline should logically be correcting itself now that time travel has been erased. There was also much more that changed with Doc than Marty. For instance doc's biology itself changes quite a bit between timelines.

Is that a real question? Marty faded (Or started to fade) in episode 1 because he would cease to exist! It has nothing to do with age!

[sn939]

Originally Posted by Michael J Fox is Canadian

Then how do you explain Marty fading in part I? The timeline should logically be correcting itself now that time travel has been erased. There was also much more that changed with Doc than Marty. For instance doc's biology itself changes quite a bit between timelines.

Marty starts to fade out because the probability of his very EXISTENCE is coming precariously close to 0 when George and Lorraine almost don't kiss. Its really that simple...

The argument you're making for Doc is far more convoluted...

Okay, let us assume the age-related argument for Doc is true. Now imagine this scenario-

Original Marty is at least a little over two weeks older than FCB Marty, because of all the time travel he's done in the movies and the game so far.

Now let us assume that at some point while he's in FCB 1986, Marty decides to kill off his alternate counterpart. So he hires an assassin and gives that assassin PRECISE instructions to kill his alternate self exactly ONE WEEK later! The assassin has a 100 percent success rate and essentially, there is absolutely NO CHANCE in hell that FCB Marty can avoid getting killed. His fate is sealed. The most likely future is one where FCB Marty is DEAD a week from now.

Now, by your logic, the moment Original Marty gives the assassin the instructions which seal his alternate counterparts fate beyond a shadow of a doubt...he should fade from existence! Why? Because if FCB Marty is X years old, and Original Marty is X+2 years old...then Original Marty cannot possibly exist any longer because the timeline KNOWS that FCB Marty is not going to live beyond X+1 years...never mind the fact that the killing is scheduled for a WEEK later!

You can see now how illogical and convoluted this argument is...

[Michael J Fox is Canadian]

Originally Posted by sn939

Marty starts to fade out because the probability of his very EXISTENCE is coming precariously close to 0 when George and Lorraine almost don't kiss. Its really that simple...

The argument you're making for Doc is far more convoluted...

Okay, let us assume the age-related argument for Doc is true. Now imagine this scenario-

Original Marty is at least a little over two weeks older than FCB Marty, because of all the time travel he's done in the movies and the game so far.

Now let us assume that at some point while he's in FCB 1986, Marty decides to kill off his alternate counterpart. So he hires an assassin and gives that assassin PRECISE instructions to kill his alternate self exactly ONE WEEK later! The assassin has a 100 percent success rate and essentially, there is absolutely NO CHANCE in hell that FCB Marty can avoid getting killed. His fate is sealed. The most likely future is one where FCB Marty is DEAD a week from now.

Now, by your logic, the moment Original Marty gives the assassin the instructions which seal his alternate counterparts fate beyond a shadow of a doubt...he should fade from existence! Why? Because if FCB Marty is X years old, and Original Marty is X+2 years old...then Original Marty cannot possibly exist any longer because the timeline KNOWS that FCB Marty is not going to live beyond X+1 years...never mind the fact that the killing is scheduled for a WEEK later!

You can see now how illogical and convoluted this argument is...

Well there is no proof an alternate marty still exists. In fact there's proof it doesn't work this way; the eastwood timeline is an alternate timeline for marty (who is from twin pine). He's been there for 6 months and there's clearly no eastwood Marty lurking around.

There is proof the timeline can predict the future without time travel; in part II when Marty burns the almanac, the newspapers from 1973 and 1983 immediately change. Not unreasonable at all to predict FCB does not live to age 90.

[sn939]

Originally Posted by Michael J Fox is Canadian

Well there is no proof an alternate marty still exists. In fact there's proof it doesn't work this way; the eastwood timeline is an alternate timeline for marty (who is from twin pine). He's been there for 6 months and there's clearly no eastwood Marty lurking around.

There is proof the timeline can predict the future without time travel; in part II when Marty burns the almanac, the newspapers from 1973 and 1983 immediately change. Not unreasonable at all to predict FCB does not live to age 90.

The Eastwood timeline MAY be an 'alternate timeline' in the technical sense, but it differs very much from the kind of alternate timeline we're discussing here (Citizen Brown, Hell Valley etc.) in one very pertinent way...the fact that Eastwood Marty, UNLIKE FCB Marty or Hell Valley Marty, time traveled. From Doc and Marty's POV, it doesn't matter what changes...as long as a few basic facts stay the same (Doc coming up with the flux capacitor, inventing the time machine, becoming friends with Marty, the experiment at the mall, Marty getting sent back to 1955 etc.) happen, they still consider it the 'normal' timeline, albeit with a few changes.

There is no way Hell Valley Marty OR FCB Marty ever time traveled. So, if you claim there is no alternate Marty, then the question arises...WHAT happened to the alternate Marty? He clearly existed...people in the FCB timeline have memories of him...did he simply cease to exist the moment 'our' Marty showed up in 1986? What sense does that make really? If at all a Marty was to be erased, shouldn't it be 'our' Marty? (since that's clearly what happened to 'our' Doc)

As far as your second point goes...true, the timeline has always been able to predict the 'most likely future' based on the current status quo, but consider the kind of predictions it has made. The timeline has 'predicted', as of November 12th 1955, that without Biff having the Almanac, George McFly will be alive and well in 1973 and win an award. A plausible enough prediction to make, given the current status quo (George having just gained confidence by punching out Biff is likely to become a writer, and Biff can't do a thing about it!) But remember, the only reason this prediction has manifested itself in a material form is because a material piece of the future is in the past...namely, the newspaper. The newspaper is intrinsically 'linked' to its time period of origin and as such is a window to what will happen at that point of time along the current timeline. Its not the timeline itself making the prediction. Also, other predictions, like the probability of Bufford killing Marty in a duel, or Griff being arrested for vandalising the Courthouse are pretty straight-forward predictions to make. But predicting the total life span of a person, given the MILLIONS of factors that affect that, is another matter entirely...

What I'm trying to point out also, that its not the continuum ITSELF predicting the future, as much as objects linked to the future by virtue of their origin giving a window to a certain time period...

[Jennifer]

I think Doc faded because the old Doc couldn't exist in this timeline without the rejuvenation treatments he received in 2015. Since the trip to extend his life took place in 1985, and the event didn't occur in the new timeline, he faded out.

It makes sense in terms of the movies if you take into account that Old Biff faded out in 2015 because he would have been killed by that point in the Hell Valley timeline.

[Tornreaper]

Originally Posted by Jennifer

I think Doc faded because the old Doc couldn't exist in this timeline without the rejuvenation treatments he received in 2015. Since the trip to extend his life took place in 1985, and the event didn't occur in the new timeline, he faded out.

It makes sense in terms of the movies if you take into account that Old Biff faded out in 2015 because he would have been killed by that point in the Hell Valley timeline.

That still doesn't make sense. He doesn't need those treatments to survive. He'll just fade into a new Doc.

I give up. There is no reason for Doc to fade out and not Marty. It's just a plot hole because of shitty writers. TTG ruined Back to the Future.

[Jennifer]

Originally Posted by Tornreaper

That still doesn't make sense. He doesn't need those treatments to survive. He'll just fade into a new Doc.

But Old Doc isn't actually from 1986. He can't just fade into his 1986 self. That's not how it works in the Back to the Future universe, or else Marty would have faded into Switzerland Marty in Back to the Future II because Marty was a week older than he should be. Citizen Brown is the 1986 Doc. He already exists. 21st century Citizen Brown doesn't exist, so Doc can't either.

It doesn't mess with the message of the future isn't written, because it still falls within the rules of the Back to the Future universe. Doc's message to Jennifer and Marty in Back to the Future III is more like the future in any particular timeline already exists (or else there wouldn't be a Marty and Jennifer in 2015 in Back to the Future II), but it still can be written to how they want it because they haven't lived it yet.

The reason Doc faded is a matter of the time ripple effect. The ripple effect catches up to people faster if they go past the time period where the error that caused them to not exist had occurred. Because Doc went past 1931 (where the changes to his life occurred that caused him to not live into the 21st century), he couldn't beat the ripple effect to save his life, just as Biff couldn't beat the ripple effect when he went past the 1990's (since Bob Gale said it was intended that Lorraine killed Biff in the 1990's in the Hell Valley timeline).

[sn939]

Originally Posted by Jennifer

But Old Doc isn't actually from 1986. He can't just fade into his 1986 self. That's not how it works in the Back to the Future universe, or else Marty would have faded into Switzerland Marty in Back to the Future II because Marty was two weeks older than he should be. Citizen Brown is the 1986 Doc. He already exists. 21st century Citizen Brown doesn't exist, so Doc can't either.

It doesn't mess with the message of the future isn't written, because it still falls within the rules of the Back to the Future universe. Doc's message to Jennifer and Marty in Back to the Future III is more like the future in any particular timeline already exists (or else there wouldn't be a Marty and Jennifer in 2015 in Back to the Future II), but it can be changed since they haven't lived it yet.

The reason Doc faded is a matter of the time ripple effect. The ripple effect catches up to people faster if they go past the time period where the error that caused them to not exist had occurred. Because Doc went past 1931 (where the changes to his life occurred that caused him to not live into the 21st century), he couldn't beat the ripple effect to save his life, just as Biff couldn't beat the ripple effect when he went past the 1990's (since Bob Gale said it was intended that Lorraine killed Biff in the 1990's in the Hell Valley timeline).

I agree...it makes perfect sense for Doc to fade because his timeline was drastically changed after 1931. What we're trying to make sense of here, is why did Doc fade and Marty and the Delorean NOT fade?!!

In the Hell Valley timeline, and the Tannen Mob ruled timeline in Ep 2, both Marty and Doc didn't fade. Even if you assume the Citizen Brown timeline messed up things SO badly as compared to the other two timeline, then why didn't BOTH Marty and Doc fade?!!

Honestly, the only workable theory IMO is that Doc is fundamentally different from any other time traveler in that he's the inventor of time travel, and so changing his past critically tends to scr#w things up more and have unpredictable effects!

[Jennifer]

Originally Posted by sn939

I agree...it makes perfect sense for Doc to fade because his timeline was drastically changed after 1931. What we're trying to make sense of here, is why did Doc fade and Marty and the Delorean NOT fade?!!

Doc's changes led to the end of his life, so the ripple effect hit him quickly. Marty and the DeLorean weren't unaffected by the ripple effect. They were just affected at a slower rate because Marty is still alive in 1986 in the Citizen Brown timeline, and the DeLorean that the time machine was made from still would have been manufactured in the Citizen Brown timeline (as would the base components that made up the gadgets inside of it).