Movie plotholes/ The only thing that doesn't add up

[thesporkman]

Originally Posted by duelistjt

Stupid question, but I never really understood why running into your other self would cause a paradox. Enlighten me please.

Well, the simple answer is that it doesn't. Old Biff and '50s Biff were able to interact with one another just fine. Doc's hypothesis was wrong.

[Vivek]

The whole skewed timeline explanations by Doc seems more likely for Marty's better understanding and for the viewer ourselves. There are no multiple timelines in the BTTF Universe. Any changes in the past, replaces the old timeline with a new history. And those changes in history will catch up to people living in the present or future slowly through the ripple effect.

Every plot hole in the BTTF trilogy put forward by fans have been explained by other fans countless times with various theories. But those theories are based on rules which were derived upon through the scenarios in the movies. Of course since there is no actual proof to witness the effects of time travel, there is no way to accept nor deny those theories. But I still believe that there are really no plot holes in the BTTF movies, people just need to be thinking fourth dimensionally.. a lot.

Originally Posted by Strayth

So, how is it even possible that Biff went to the past, gave himself the almanac (which creates the new timeline, "hell") and then COMES BACK to the original future ?

Originally Posted by russell19831983

The future did change around them in 2015 but they were in an alleyway at the time, even the director said that was intentional.

That's right.

http://web.archive.org/web/199905072...m/film_faq.htm

Q: When Doc and Marty are in 1955-A, Doc says they can't return to the future to stop Biff from stealing the DeLorean, because it would be the wrong future. But if that's true, how did Old Biff manage to get back to the same future that he left? Shouldn't he have come back to a different future?

A: As should be clear from the answer to the previous question, we believe Old Biff DID indeed return to a different future -- a "2015-A," which would have transformed around Marty, Doc, Jennifer and Einstein (just as Doc explains how 1985-A would change into 1985 and instantly transform around Jennifer and Einstein). This would happen AFTER Old Biff returned with the DeLorean. For this reason, we made sure that Doc had caught Jennifer and exited the McFly Townhouse before Old Biff returned. Thus, by the time Marty and Doc are carrying Jennifer back to the DeLorean, there COULD be other residents in that townhouse -- or perhaps the McFlys still live there. It is just as believable that the physicality of the neighborhood did NOT change as it is to believe that it did -- so we didn't change it. We decided not to make anything of this idea because this is one of those difficult time travel concepts that general audiences have a real hard time understanding. (Try explaining this stuff to your mother and you'll see what we mean.) A detailed explanation of it would have slowed down the story, and most of the audience doesn't ever think about it. That's why we made certain things ambiguous and left various things open for interpretation in hopes that the possibility of at least one or two explanations would be better than a "definitive" explanation that you could find holes in. Let's face it, time travel is fantasy, so there's no way to "prove" anything. As filmmakers, we try to create a set of rule for our stories and stick by them, and stay consistent within the little "universe" that we've created.

Originally Posted by Strayth

Well, in fact, it's weird they can meet themselves in the future.

Each time they go to the future, they disappear from the present. Indeed they will come back but they're not supposed to be able to witness that future, since the present (past) is what is changing the future.

They're going in a time period where they disappeared in the present, so they should be missing in the future...

Q: When Doc takes Marty and Jennifer out of 1985 and brings them to the future, how can Old Marty and Old Jennifer (and their family) even be in the future? Wouldn't their disappearance from 1985 instantaneously erase their future?

A: To be honest, yes, it very well should erase their existence from the future. This is, in fact, the ultimate paradox of Back to the Future Part II. We really thought about this one for a long time, but we finally decided that after the set-up of Doc saying "Something's got to be done about your kids," the audience would feel cheated if we went to the future and found out they didn't exist. You could, however, argue that existence of Old Marty, Old Jennifer and their kids in the future automatically proves that young Marty and Jennifer will eventually get back to 1985. The flaw in this reasoning is that Doc repeatedly tells us that the future isn't written, so why would this part of the future be "written?" Ah, but Back to the Future Part III may contain the answer to this question after all. When Doc spots the tombstone in 1885 and sees that the name on the photograph of the tombstone has vanished but the date remains, he says "We know this photograph represents what will happen if the events of today continue to run their course into tomorrow." That's a pretty big "if." And it suggests that time travel to the future always takes you to a future based on the events of the time you left -- a logical extrapolation of what the future of that moment holds. Of course, the existence of free will allows for the possibility of infinite futures, which is what Doc says at the end of Back to the Future Part III: "Your future is whatever you make it." But time travel into the future takes you to the most likely future of the moment you left.

Originally Posted by duelistjt

Stupid question, but I never really understood why running into your other self would cause a paradox. Enlighten me please.

Q: Doc says that if Jennifer sees her older self it could create a time paradox that might destroy the universe. Please explain.

A: First of all, let's define TIME PARADOX. A Time Paradox is a situation in which the effect of an incident contradicts or eliminates the cause of that same incident. As an example, imagine that in 1990, 40 year old John Smith goes back in time 30 years and finds his younger self, aged 10, in 1960. Suppose 40 year old Smith pulled a gun and murdered his 10 year old self. Then 10 year old Smith would never grow up to become the 40 year old Smith. How then could 40 year old Smith go back in time to murder "himself'? Thus, the effect of the incident (the murder of 10 year old Smith) eliminated the cause (the existence of the murderer). A paradox, by definition, is impossible. In the case of Jennifer, the shock of seeing herself old causes her to faint. But what if young Jennifer had hit her head on a cement stair, suffered brain damage and died? Then, she would never grow up to marry Marty, they would never have kids, and Doc would never have had reason to bring them to the future in the first place. And if Jennifer never goes to the future, how can she die in the future? (Also, in Back to the Future, if Marty had actually been erased from existence by never having been born, he would have never existed to grow up, go back in time, and interfere with George being hit by the car!) For the record, many scientists use the time paradox concept as an argument as to why time travel has to be impossible. Since time travel allows possibility of a paradox, and since a paradox is impossible, time travel itself must be impossible. However, in the Back to the Future films, time travel DOES exist. Thus, Doc Brown surmises that if a paradox were indeed to occur, the result could be cataclysm of some sort. On the other hand, since a time paradox never truly does take place in the films, it could mean that there's some sort of "self preservation" mechanism in the cosmos which prevents a paradox from ever happening. Perhaps then, this is the reason that both Jennifers faint -- to prevent a potential paradox!

Another commonly asked question with various possibilities.

Q: Doc Brown of 1955 learns a lot about the future from Marty. Shouldn't the Doc of 1985 remember all of those things that happened in 1955?

A: 3 possible answers, all credible. 1) The "Ripple Effect" of time travel (which caused all of the photographs to change) does not affect human memory. 2) The 1955 Doc suffered a memory loss sometime after his adventures with Marty (maybe it was from the drugs he took in the 60's as Reverend Jim!). 3) Doc actually did remember everything, but he still did all the same things he "remembered" because he didn't want to risk disrupting the space-time continuum.

There's a 4th possibility which depends on your view of time travel. There's a theory (we like to call it the "Self-Preservation Instinct of the Space-Time Continuum Theory") that says that the continuum is always trying to keep itself "on course," and when things happen to change it, it always tries to correct itself. It is much like a river, which tries to keep its overall course. Although earthquakes, fallen trees, floods, or other circumstances might disrupt it at points, the river would cut a new channel so that it would end up back at the same place. Thus, the overall physics (or metaphysics) of the space-time continuum would insure that any of Doc's memories of events that might create paradoxes would become hazy -- or be erased.

[Lee Powell]

Originally Posted by Strayth

Well, in fact, it's weird they can meet themselves in the future.

Each time they go to the future, they disappear from the present. Indeed they will come back but they're not supposed to be able to witness that future, since the present (past) is what is changing the future. They're going in a time period where they disappeared in the present, so they should be missing in the future...

Here's an existential explanation that may fill in the blanks:

When Doc, Marty, and Jennifer leave 1985 for 2015, it is not literally "The Future" they experience, it's their own destiny as of that moment in their lives. It is the same experience that Ebenezer Scrooge had in "A Christmas Carol" of witnessing his own fate. The difference in "Back to the Future" is that the characters don't merely observe their interwoven destiny from afar, they interact with it in ways that can potentially alter it.

When Marty initially sees the aged versions of himself and Jennifer which they are destined to become, he has not at that point in his own timeline done anything to alter that eventual fate.

What does change Marty's destiny occurs a bit later in his timeline, when Biff takes the DeLorean into the past and alters his own destiny, which indirectly affects everyone else's as well. Though neither Marty nor Doc notice it before they leave 2015, their destinies have been altered upon Biff's return, as is shown by the drastic alteration in Biff's own fate that erases him from existence at that point in their destiny.

When they return to 1985, Doc and Marty witness how Biff's actions have altered everyone's destiny. If they had then returned to 2015, they would have seen what destiny would now hold for them in their dramatically altered circumstances.

In returning to 1955, however, Doc and Marty gain a fresh opportunity to revise everyone's destiny once again. Their subsequent actions more or less undo the changes that Biff had made, restoring their destiny to approximately what it was before. Thus when Marty returns to 1985, he merges back into a destiny that is evolving in much the same manner as it did before he, Doc, and Jennifer originally departed.

The difference at this point, however, is that Marty has gained insight that he lacked before witnessing his original destiny. He is now wise enough to avoid the foolish traffic accident that was originally destined to sabotage his career and demolish his self-respect. He thus alters his destiny once more, no doubt averting the sad fate he would have otherwise met in 2015.

[Chyron8472]

Originally Posted by Spectral Knight

The future isn't written yet. As far as I understand it, the future they DeLorean would travel to would be that which is more likely destination if all things continue as they are, but any given interjection (such as Marty's learning to deflect insults), can and will change the destination point as it were.

That future existed at the end of BTTF part I and into part II as Marty had yet to learn to deflect the insults, and still would've crashed the car at that point, and as such future still happened for Marty, Doc and Jennifer, just like the past happened for Marty where George was a chicken because they exist 'outside' of the flow. If they change the past so that they no longer exist (i.e. earlier than their departure point), that's when they start to get erased, but they've got free reign to do whatever the hell they like in the future. Even though that future won't happen due to the car crash not happening, Doc, Marty and Jennifer still visited it, and still have memories of it, just like they do of alt 1985.

What you're saying makes no sense.

You're saying that the only real changes that create paradoxes are those that affect the existence (or lack thereof) of the people who caused the changes, and that no other changes matter. I disagree.

The changes time-travellers make to the linear timeline matter if they affect the choices those same people who changed it would have made without it (eg. If the 1985 Marty who went back in time at the end of 1 had known that 1985 Doc was not killed, he wouldn't have told 1955 Doc about it and thus caused a paradox... which is why 1985 Doc at the end of 1 appeared to be dead until the coast was clear.)

The BTTF universe operates on a single-dimension universe, wherein the choices made are the only choices made in one single timeline... as opposed to Star Trek wherein as Data puts it, "anything that can happen does happen in multiple dimensions" of time (which means the new Star Trek movie doesn't cancel out the old movies and shows.) This is why the BTTF characters (ie. Jennifer and Einstein) will still exist in the restored timeline when the ripples in the timeline reach them; because there is only one linear timeline to affect; the rich-Biff timeline no longer exists. [edit]Which itself causes a paradox because if Marty and Doc restored the timeline by destroying the almanac, then Marty and Doc in the rich-Biff 1985 shouldn't have noticed any adverse changes (since they had already been fixed) and therefore not needed to go back and fix them.

About the only way I foresee avoiding these issues is, after you make a choice that affects your time-travelling self's decisions, you have to then meet up with your time-travelling self and tell them to make the same choice you did and for themself to at some point meet themself just as you are doing at the same spot to say the same thing. (eg. in Bill and Ted's Excellent Adventure, Bill and Ted meet Bill and Ted at the Circle-K and say the same things twice on purpose.)[/edit]

With this being said, any actions taken by time-travellers can possibly cause paradoxes if said actions adversely affect the events which lead up to those actions. It's not just limited to the survival or existence of the person. This is why 1955 Doc tells Marty "you must not leave this house. you must not see anybody or talk to anybody. Anything you do could have serious repercussions on future events."

When Marty is not in the car accident, it does more than stop him from getting fired in 2015. According to 2015 Lorraine: "That accident caused a chain reaction of events which sent Marty's life straight down the tubes. If not for that accident, your father's life would have turned out very different. The man in the Rolls Royce wouldn't have pressed charges, Marty wouldn't have broken his hand and he wouldn't have given up on his music. And he wouldn't have spent all those years feeling sorry for himself." This means that at the end of 3, when Marty doesn't get in the accident, it very likely affects Doc's reasons for having taken him to 2015 in the first place, since Marty's future and therefore his family could have turned out differently leading to his kids not ever being arrested... which causes a paradox.

Anyways, saying "the future isn't written yet" only applies when you don't know what the outcome of your choices will be, which Marty and Jennifer do know (at least in part) so that doesn't fit. It's just a nice moral-of-the-story thing to say at the end.

[Chyron8472]

this thread is tl;dr, but I will say this:

Originally Posted by Strayth

So, how is it even possible that Biff went to the past, gave himself the almanac (which creates the new timeline, "hell") and then COMES BACK to the original future ?

Because the BTTF universe, though having one timeline (whereby Einstien and Jennifer can be left in hell-1985 since the one timeline will alter itself around them) it also has a ripple effect, wherein changes made by time-travellers take time to flow through the continuum and affect future events.

When Biff returned to 2015, the ripples hadn't reached them yet. This is also evidenced by the fact that, in BTTF1 when Marty prevents his parents falling in love, he doesn't immediately create a paradox, rather it takes a while for the ripple effect to cause one as shown by the disappearing children in the photo. If Marty had completely disappeared in BTTF1, a paradox would have occurred, since the Marty seen going back in time at the mall at the end of BTTF1 wouldn't have been around to do so and therefore couldn't have disrupted his parents' relationship.

Also, 2015 Biff brought the Delorean back to time-travelling Doc and Marty because he's an idiot.

[Lee Powell]

Originally Posted by Chyron8472

When Marty is not in the car accident, it does more than stop him from getting fired in 2015. According to 2015 Lorraine: "That accident caused a chain reaction of events which sent Marty's life straight down the tubes. If not for that accident, your father's life would have turned out very different. The man in the Rolls Royce wouldn't have pressed charges, Marty wouldn't have broken his hand and he wouldn't have given up on his music. And he wouldn't have spent all those years feeling sorry for himself."

Exactly. What Lorraine is describing is Marty's destiny, which hinges on whether he makes the impulsive choice that leads to the accident. One of the underlying themes of BTTF is that the future is not preordained, it is actively determined by both your own decisions, and the decisions of others as well.

When Marty initially leaves 1985 for 2015, he witnesses the fate that is destined to unfold in the aftermath of his auto accident. When he returns to 1985, Marty witnesses the fate that unfolds from Biff's decision to alter his own past. After traveling back to 1955 to reverse Biff's meddling, Marty returns once more to 1985, and finds its destiny restored to what it was initially.

The difference at this point, however, is that Marty has gained insight that he lacked before witnessing his initial destiny. He is now wise enough to avoid the foolish traffic accident that was destined to sabotage his career and demolish his self-respect. He thus alters his destiny once more, and averts the sad fate he would have otherwise met in 2015.

Originally Posted by Chyron8472

This means that at the end of 3, when Marty doesn't get in the accident, it very likely affects Doc's reasons for having taken him to 2015 in the first place, since Marty's future and therefore his family could have turned out differently leading to his kids not ever being arrested... which causes a paradox.

Yes, the destiny of Marty's children will no doubt change as well. In BTTF, however, the future is not ordained and it is not paradoxical for fate to be altered.

At the point when Doc initially journeyed to 2015, Marty's destiny did lead to the fateful accident, which in turn would lead to his son being arrested. It was destined to happen that way because Marty had not yet gained enough maturity to avoid that fate. But by the end of the movie, the lessons that Marty learned enabled him to make the crucial decision that would change his destiny for the better.

[Chyron8472]

Given the concept of time travel, there can really only be two results that come from travelling in time and changing things: 1) There are multiple dimensions that can and do exist, and any changes made to the current timeline that you inhabit would merely alter the direction that the timeline takes and would never cause a paradox because the timeline you came from would still exist in a different dimension; or 2) There is one dimension of time and any changes you make, however seemingly insignificant, may cause the choices that you made leading up to that change to be altered, which could very well cause the initial motivation for changing the timeline in the first place to have never occurred, causing a paradox.

Think of it this way: Marty goes back to 1955 in BTTF2 and sees his other self (that is, the version of himself that always had a well-to-do family that used the Delorean at the Lone Pine Mall at the end of 1) doing pretty much the same things he did with only minor variations. This part of the timeline is intact because his other self was apparently unaffacted by the changes he made to the timeline in 1. However, at the end of 3 his entire destiny has changed, so if he ever went forward to 2015 again, where would he meet his other time-travelling self? If his kids potentially never got arrested because of the changes why would Doc have taken him him forward to help them in the first place?

The changes Marty made in 1 didn't affect the other version of himself from making the same decisions after going back in time, but altering his destiny at the end of 3 has the capacity to alter many important things, not the least of which is whether his son learns to stick up for himself instead of listening to Griff and ending up in jail.

If Marty avoiding the car accident makes changes to his destiny and keeps his son from going to jail in 2015, then he wouldn't need to go to 2015 in the first place to fix a problem that never happens, meaning he would never have been on the adventure that led him to avoid the car accident, meaning he would have been in the car accident... and so on in a endless loop that causes a paradox.

Basically, the universe of Back to the Future tries to take elements from both a single-dimension universe (where Marty's parents not dating causes himself to start to disappear) and a multiple-dimension universe (where destroying the gravestone doesn't paradoxically stop Marty from finding Doc's grave in the first place but instead leaves him with having taken a picture of an unmarked or non-existent grave) at the same time, which makes no sense because the two concepts contradict each other.

[Chyron8472]

Obviously I'm nitpicking at the movies here. The movies are fun, however contradictory the plot-elements are, and so long as Telltale holds true to the spirit of the movies and makes a fun and compelling game, I'll be happy.

[Lee Powell]

Originally Posted by Chyron8472

Think of it this way: Marty goes back to 1955 in BTTF2 and sees his other self (that is, the version of himself that always had a well-to-do family that used the Delorean at the Lone Pine Mall at the end of 1) doing pretty much the same things he did with only minor variations.

But Marty didn't in fact leave 1985 from the "Lone Pine Mall". At the point when Marty initially traveled to 1955, he departed from the Twin Pines Mall in 1985. On Marty's arrival in 1955, his collision with one of the pine trees altered destiny from that point onward, changing the fate of the mall's name to Lone Pine Mall. But that didn't retroactively change Marty's memory of the mall, since he experienced it before its destiny had been altered by subsequent events in Marty's own timeline.

Originally Posted by Chyron8472

However, at the end of 3 his entire destiny has changed, so if he ever went forward to 2015 again, where would he meet his other time-travelling self? If his kids potentially never got arrested because of the changes why would Doc have taken him him forward to help them in the first place?

In BTTF, the past and the future are not symmetrical. BTTF2 Marty could ensure meeting his previous self in 1955 simply by arriving there at some point after BTTF1 Marty first arrived in 1955.

When returning to a time in the future, however, its destiny may have been altered by events that occurred (from the perspective of Marty's own timeline) after the previous visit. The 2015 destiny that Marty would see the second occasion he traveled there would look dramatically different from the first. The 2015 destiny encountered in Marty's initial visit would have vanished along with his previous time-traveling self, just as 2015 Biff vanished upon returning to an altered 2015 destiny that no longer included his existence.

[Chyron8472]

Originally Posted by Lee Powell

But Marty didn't in fact leave 1985 from the "Lone Pine Mall". At the point when Marty initially traveled to 1955, he departed from the Twin Pines Mall in 1985. On Marty's arrival in 1955, his collision with one of the pine trees altered destiny from that point onward, changing the fate of the mall's name to Lone Pine Mall. But that didn't retroactively change Marty's memory of the mall, since he experienced it before its destiny had been altered by subsequent events in Marty's own timeline.

At the END of BTTF1, Marty runs to the mall and sees his other self get into the Delorean and go to 1955. In BTTF2, it is that version of Marty (not himself) which is on stage singing Johnny B. Goode. My point was that the changes Marty makes in BTTF1 didn't affect his decision-making process which had led him to get stuck in 1955, so a paradox doesn't occur here because either version of Marty's time-travelling choices are the same, regardless of which familial environment he grows up in.


However, there are other changes that Marty makes to the linear timeline that ought to create paradoxes, given that they have a tremendous potential to alter Marty's decisions which led up to making those changes, such as destroying Doc's gravestone (thereby preventing 1955 Copernicus from being drawn to it and alerting Marty to Doc's death) but they don't.

Originally Posted by Lee Powell

When returning to a time in the future, however, its destiny may have been altered by events that occurred (from the perspective of Marty's own timeline) after the previous visit. The 2015 destiny that Marty would see the second occasion he traveled there would look dramatically different from the first. The 2015 destiny encountered in Marty's initial visit would have vanished along with his previous time-traveling self, just as 2015 Biff vanished upon returning to an altered 2015 destiny that no longer included his existence.

This makes no sense. Looking from Marty's personal perspective, the events that took place in 2015 are in his own personal past. He went there and made decisions which shaped his own personal future as well as the linear timeline. However, when he avoided the car accident in 1985, it may have changed the linear timeline and removed the need to save his children from jail (among other things), which means that the linear timeline is in contradiction to Marty's own personal timeline. Marty's personal past conflicts with the timeline's future, if his past self's need to alter the future was eliminated.

Let's put it another way. After Marty avoids the car accident, if Marty goes back in time to a time just before he left with Doc to go to 2015, would he see Doc appear and say to his other self "something's got to be done about your kids!"? Possibly not, because Marty's entire destiny has changed, perhaps to keep his future kids from ever getting in trouble in the first place... and so a paradox occurs.

[Lee Powell]

Originally Posted by Chyron8472

Looking from Marty's personal perspective, the events that took place in 2015 are in his own personal past... when he avoided the car accident in 1985, it may have changed the linear timeline and removed the need to save his children from jail, which means that the linear timeline is in contradiction to Marty's own personal timeline. Marty's personal past conflicts with the timeline's future, if his past self's need to alter the future was eliminated.

Yes, when Marty avoids the accident, his destiny is likely altered dramatically enough to eliminate Doc's original motivation for taking Marty to 2015 in the first place. And Marty can indeed regard his initial 2015 experience as a memory of the destiny that once awaited him in the past, distinguishing it from the altered destiny that now lies in his future. In BTTF, this causes no conflict since Marty's fate is not preordained, and his destiny can be altered even after he has witnessed it himself.

Originally Posted by Chyron8472

After Marty avoids the car accident, if Marty goes back in time to a time just before he left with Doc to go to 2015, would he see Doc appear and say to his other self "something's got to be done about your kids!"? Possibly not, because Marty's entire destiny has changed, perhaps to keep his future kids from ever getting in trouble in the first place... and so a paradox occurs.

When Marty changes his destiny by avoiding the accident, it affects Doc's 2015 destiny as well. (Just as when Biff changes his own destiny, it dramatically alters everyone else's.) Once the original 2015 destiny from which Doc returned to 1985 has vanished, he would no longer reappear in 1985 to retrieve Marty. The BTTF "ripple effect" would propagate the changes throughout the altered timeline, eliminating any potential paradox.

[Clord]

Originally Posted by Javi-Wan Kenobi

Wait, wait... Are you saying that, in the original version of BttF, Marty McFly is mis-called Calvin Klein?
I have to watch the movies without the Spanish dubbing, then. I suppose that, in the 80's, the Calvin Klein brand wasn't as well known in Spain as it is now, and the translators thought that the Spanish people won't get the joke, so they changed the name. In Spain, he's mis-called "Levi Strauss".

Why you use dubs in first place? Dubs are like spitting over great work what is also called BffT trilogy.

Originally Posted by hamza721

i never understood the end of the third movie. Marty and Doc have to get back before Mad Dog kills one of them but after Mad Dog is taken to jail Marty and Doc have all the time in the world to go back to 1985 but instead go immediately

It makes good movie plot for many and they already planned their course of action.

[Spectral Knight]

Originally Posted by Chyron8472

What you're saying makes no sense.

You're saying that the only real changes that create paradoxes are those that affect the existence (or lack thereof) of the people who caused the changes, and that no other changes matter. I disagree.

The changes time-travellers make to the linear timeline matter if they affect the choices those same people who changed it would have made without it (eg. If the 1985 Marty who went back in time at the end of 1 had known that 1985 Doc was not killed, he wouldn't have told 1955 Doc about it and thus caused a paradox... which is why 1985 Doc at the end of 1 appeared to be dead until the coast was clear.)

The BTTF universe operates on a single-dimension universe, wherein the choices made are the only choices made in one single timeline... as opposed to Star Trek wherein as Data puts it, "anything that can happen does happen in multiple dimensions" of time (which means the new Star Trek movie doesn't cancel out the old movies and shows.) This is why the BTTF characters (ie. Jennifer and Einstein) will still exist in the restored timeline when the ripples in the timeline reach them; because there is only one linear timeline to affect; the rich-Biff timeline no longer exists. [edit]Which itself causes a paradox because if Marty and Doc restored the timeline by destroying the almanac, then Marty and Doc in the rich-Biff 1985 shouldn't have noticed any adverse changes (since they had already been fixed) and therefore not needed to go back and fix them.

I agree that there is only one linear timeline, but I disagree to it's effects - we know that once you time-travel and do change the past, your memories of that past remain (Marty knows that the past was changed hence his shock at the family's changed situation) - thus Marty and Doc did notice changes made in alt-1985, as they'd previously experienced the 'right' 1985. That's why it avoids paradoxes.

About the only way I foresee avoiding these issues is, after you make a choice that affects your time-travelling self's decisions, you have to then meet up with your time-travelling self and tell them to make the same choice you did and for themself to at some point meet themself just as you are doing at the same spot to say the same thing. (eg. in Bill and Ted's Excellent Adventure, Bill and Ted meet Bill and Ted at the Circle-K and say the same things twice on purpose.)[/edit]

Except that would cause a severe paradox, as where's the starting point in the cycle? We know Marty didn't meet his own self, so he couldn't go and meet his own self as that's not what happened.. Bill and Ted is fundamentally flawed in terms of temporal travel. In BTTF, we know the starting point - Marty's first travel in the DeLorean back to 55.

With this being said, any actions taken by time-travellers can possibly cause paradoxes if said actions adversely affect the events which lead up to those actions. It's not just limited to the survival or existence of the person. This is why 1955 Doc tells Marty "you must not leave this house. you must not see anybody or talk to anybody. Anything you do could have serious repercussions on future events.

Yup, they certainly can, but I'm not sure how that affects what we're saying.

When Marty is not in the car accident, it does more than stop him from getting fired in 2015. According to 2015 Lorraine: "That accident caused a chain reaction of events which sent Marty's life straight down the tubes. If not for that accident, your father's life would have turned out very different. The man in the Rolls Royce wouldn't have pressed charges, Marty wouldn't have broken his hand and he wouldn't have given up on his music. And he wouldn't have spent all those years feeling sorry for himself." This means that at the end of 3, when Marty doesn't get in the accident, it very likely affects Doc's reasons for having taken him to 2015 in the first place, since Marty's future and therefore his family could have turned out differently leading to his kids not ever being arrested... which causes a paradox.

The thing is when Doc travels forwards, the 2015 he sees is the one we see, even though it's since been changed, it doesn't affect the outcome he saw, because he departed prior to Marty learning to deflect insults. It's a linear timeline, but from the viewpoint of the time travellers we are following. We know when the changes were made, and how. If Marty/Doc went to 2015 post BttF3, it'd be a different future, undoubtably.

Anyways, saying "the future isn't written yet" only applies when you don't know what the outcome of your choices will be, which Marty and Jennifer do know (at least in part) so that doesn't fit. It's just a nice moral-of-the-story thing to say at the end.

Nope, the future isn't written yet. There is though, a 'pencilled in' future based on the 'now' but changes via the medium of time travel will affect the future. BttF avoids paradoxes completely, in my opinion. It's a single timeline in a single universe. Time travellers will have memories of all previous destinations along their journey. IF there's a big enough change in the past, the ripple effect will eventually catch up to them and erase them accordingly, but this isn't instantaneous when they're operating outside of the flow of time (hence why Marty can be in Hill Valley instead of Switzerland in alt-85). It seems like there's a 'margin of error' - will Marty's changed upbringing alter him enough so he don't show up at the Mall with the Doc? Nope. Where as stopping his mum and dad falling in love certainly will - he won't exist.

[doggans]

Originally Posted by Clord

Why you use dubs in first place? Dubs are like spitting over great work what is also called BffT trilogy.

The Back Fo Fhe Tuture trilogy?

The Best Friends Forever Treehouse trilogy?

Oh, wait, I got it. The B[i]ff T[annen] trilogy.

Anyway. Many people prefer watching foreign films dubbed to watching them subtitled. It's just an aesthetic choice, there's nothing wrong with it.

[Lee Powell]

Originally Posted by Spectral Knight

Nope, the future isn't written yet. There is though, a 'pencilled in' future based on the 'now' but changes via the medium of time travel will affect the future.

Yes, and the "pencilled-in future" you describe is what I've been referring to as destiny. When Doc, Marty, and Jennifer leave 1985 for 2015, it is not an inevitable, preordained future they encounter, it's only what destiny holds in store for them as of that moment in their lives. It is the same experience that Ebenezer Scrooge had in "A Christmas Carol" of witnessing his own fate. The difference in BTTF is that the characters don't merely observe their impending destiny as Scrooge did from afar, they interact with it in ways that can potentially change it.

[GhstbstrLMLIII]

Originally Posted by Chyron8472

Also, 2015 Biff brought the Delorean back to time-travelling Doc and Marty because he's an idiot.

WIN. I understand why it's needed for story purposes, but you're actually right. He should have just kept the delorean for himself.

[Lee Powell]

Originally Posted by Chyron8472

At the END of BTTF1, Marty runs to the mall and sees his other self get into the Delorean and go to 1955. In BTTF2, it is that version of Marty (not himself) which is on stage singing Johnny B. Goode.

I think a careful examination of this seemingly simple conundrum may prove illuminating. Marty's return trip from 1955 to 1985 has created a repeating loop in time. Not only does the first Marty arrive just in time to see the second Marty depart, but when that second Marty returns, he will see yet a third Marty depart, and so on ad infinitum. On the surface, it would also appear possible that Marty1 himself could have been preceded by Marty0 who in turn...

There's one clue, however, that shows us that the Marty we have been watching since the start of BTTF1 is in fact Marty0, the original initiator of this temporal loop. Of all the Marty's in question, Marty0 is the only one who departs 1985 from Twin Pines Mall. All subsequent Marty's depart from Lone Pine Mall (and each collide in turn with the second fledgling pine tree in 1955, in order to maintain that lone-pine condition for the next Marty in the loop).

Marty0 is also unique in being the only one who grew up in the down-trodden version of the McFly family instead of the prosperous McFly family we see at the end of BTTF1. All subsequent Marty's benefit from Marty0's pioneering efforts to change his 1985 destiny, and they each follow suit to maintain that fortunate state in a stable repeating loop in the timeline.

In addition to nailing that pine tree, each Marty must accomplish several crucial tasks in 1955 in order to maintain the temporal loop:

1. Reveal the time machine to 1955 Doc, insuring that he will be inspired to re-invent it for the next Marty.
2. Instill confidence in 1955 George McFly to succeed in life, insuring a fortunate destiny for the next Marty.
3. Warn Doc of the 1985 Libyans' threat to his life, so Marty can give the DeLorean back to him on his return.

In BTTF2, Marty0 continues his pioneering efforts to change his destiny. At first he is faced merely with a depressing premonition of his fate in 2015, but the challenge escalates once Biff steals the time machine and wreaks havoc with it in 1955. At the end of BTTF2, we see that the events of this movie were all precipitated by the Marty's that preceded Marty0, who failed to avoid the fateful traffic accident that Marty0 successfully averted.

But for the Marty's who follow in Marty0's footsteps, the 1985-2015 events of BTTF2 never happen at all. Since Marty0's 2015 destiny has changed for the better, the Doc's who follow in Doc0's footsteps have no motivation to return to 1985 at the end of BTTF1 to take Marty to witness his destiny in 2015. Unlike BTTF1, which established a repeating 1955-85 time loop, the events of BTTF2 only happen once, and are experienced only by Marty0 and Doc0.

The Marty's who follow in Marty0's wake do have a final challenge of their own. They must each avoid the fateful traffic accident in order to maintain the fortunate 2015 destiny established by Marty0. However, these Marty's have all had the benefit of growing up in the prosperous version of the McFly family, which Marty0 did not. This should provide them with the self-confidence to ignore the type of juvenile provocation that Marty0 found so difficult to resist.

[techie775]

Sorry if someone's said this but I haven't seen it. I also know this is off base but I've never understood it. The most noticeable thing they goofed to me was in BTTF 3 when in 1955 and Marty and Doc see Doc's Tombstone. This gives Doc in 1955 a complete understanding of what happens to him in 1885, which should get passed on to the 1985 Doc since he's not a different person just aged 30 years. But yet for some reason when Marty gets saved by Doc in 1885 by the 1985 Doc, he has no memory of his own tombstone until he sees the photo and even says he'd wished he'd pay Mad Dog back. I know it helps build a story but it's a little annoying seeing that goof.

[Lee Powell]

Originally Posted by techie775

The most noticeable thing they goofed to me was in BTTF 3 when in 1955 and Marty and Doc see Doc's Tombstone. This gives Doc in 1955 a complete understanding of what happens to him in 1885, which should get passed on to the 1985 Doc since he's not a different person just aged 30 years.

To understand how this is not actually a mistake, it's necessary to pay close attention to the sequence of events. At the time before BTTF1 when the Doc from 1985 was living in 1955, he had not yet traveled back to 1885, and had not yet invented the time machine which Marty used to travel back to 1955. This is the person I call "Doc0", the original instigator who first invented the time machine without the benefit of previewing it during Marty's visit to 1955. Likewise, since the tombstone would not yet have been altered to read "Emmett Brown", Doc0 would not have prior knowledge of his impending fate in 1885. (See my earlier post on BTTF Temporal Metaphysics for a detailed explanation of who "Doc0" and "Marty0" are.)

The person to whom Marty0 showed the tombstone in 1955 was actually Doc1, the first of the Doc's to preview the DeLorean before subsequently re-inventing it in 1985. At that point in BTTF3, Doc0 had been zapped back to 1885, and the BTTF "Ripple Effect" had altered the tombstone to indicate Doc0's fatal destiny. What Doc1 believes at that point is that his own destiny is to someday travel back to 1885 and die there, unless Marty0 can successfully journey back to 1885 and rescue Doc0 before he is killed.

What Doc1 does not yet know, however, is that Marty0 has already altered his own 2015 destiny so that there will no longer be any need for Doc1 to recapitulate Doc0's return to 1985 from 2015 at the end of BTTF1, and the subsequent chain of events in BTTF2 that lead to Doc0 being stranded in 1885. Likewise the 1885 events of BTTF3 are only experienced by Doc0 and Marty0, and are not repeated in a timeloop by subsequent Doc's and Marty's.

[Spectral Knight]

Originally Posted by Lee Powell

I think a careful examination of this seemingly simple conundrum may prove illuminating. Marty's return trip from 1955 to 1985 has created a repeating loop in time. Not only does the first Marty arrive just in time to see the second Marty depart, but when that second Marty returns, he will see yet a third Marty depart, and so on ad infinitum. On the surface, it would also appear possible that Marty1 himself could have been preceded by Marty0 who in turn...

There's one clue, however, that shows us that the Marty we have been watching since the start of BTTF1 is in fact Marty0, the original initiator of this temporal loop. Of all the Marty's in question, Marty0 is the only one who departs 1985 from Twin Pines Mall. All subsequent Marty's depart from Lone Pine Mall (and each collide in turn with the second fledgling pine tree in 1955, in order to maintain that lone-pine condition for the next Marty in the loop).

Marty0 is also unique in being the only one who grew up in the down-trodden version of the McFly family instead of the prosperous McFly family we see at the end of BTTF1. All subsequent Marty's benefit from Marty0's pioneering efforts to change his 1985 destiny, and they each follow suit to maintain that fortunate state in a stable repeating loop in the timeline.

In addition to nailing that pine tree, each Marty must accomplish several crucial tasks in 1955 in order to maintain the temporal loop:

1. Reveal the time machine to 1955 Doc, insuring that he will be inspired to re-invent it for the next Marty.
2. Instill confidence in 1955 George McFly to succeed in life, insuring a fortunate destiny for the next Marty.
3. Warn Doc of the 1985 Libyans' threat to his life, so Marty can give the DeLorean back to him on his return.

In BTTF2, Marty0 continues his pioneering efforts to change his destiny. At first he is faced merely with a depressing premonition of his fate in 2015, but the challenge escalates once Biff steals the time machine and wreaks havoc with it in 1955. At the end of BTTF2, we see that the events of this movie were all precipitated by the Marty's that preceded Marty0, who failed to avoid the fateful traffic accident that Marty0 successfully averted.

But for the Marty's who follow in Marty0's footsteps, the 1985-2015 events of BTTF2 never happen at all. Since Marty0's 2015 destiny has changed for the better, the Doc's who follow in Doc0's footsteps have no motivation to return to 1985 at the end of BTTF1 to take Marty to witness his destiny in 2015. Unlike BTTF1, which established a repeating 1955-85 time loop, the events of BTTF2 only happen once, and are experienced only by Marty0 and Doc0.

The Marty's who follow in Marty0's wake do have a final challenge of their own. They must each avoid the fateful traffic accident in order to maintain the fortunate 2015 destiny established by Marty0. However, these Marty's have all had the benefit of growing up in the prosperous version of the McFly family, which Marty0 did not. This should provide them with the self-confidence to ignore the type of juvenile provocation that Marty0 found so difficult to resist.

I'm lost at this completely. I was following up until the part regarding BTTF2 and that changed my whole interpretation. You say there are multiple Marty's and Doc's - if so, wouldn't the fact that Marty (0+X infinitum) keep travelling to the same point in the space time continuum mean they'd end at the same time. So Marty 0, plus Marty 0+X all occupy the same physical space in the space time continuum (Peabody's place in 1955) - this would be a massive afront to physics, surely?

I'm still thinking there's one Marty, one Doc. And even when there's two (such as the end of BTTF, and 1955 era in BTTF2), there's just one Marty but at different points in his own timeline. The Marty we see at the end of BTTF at the Lone Pine Mall is still Marty 0, but has grown up slightly differently...the 'margin of error' I indicated in my earlier post. It's not a big enough change to stop him from making the choices he did (meet Doc, and show up for the time travel experiment).