^
Wow...I never thought about. Well I did...but it neve occurred to me that Doc couldn't be there since he should've been locked up.
I always thought it would be like this with Marty:
He would slowly get new memories of his new life. Ripple effect takes some time sometimes apparently.
But with Doc....it would mean he should've been transported into an asylum.
Wow....I really don't know.
But I was never too fond of the first and second act of BttF2.
What makes BttF2 so great is the last 50 minutes.
I think there are two Martys and Docs in 1985A, just like there are two Martys and Jennifers in 2015.
The thing is, Doc Brown was commited in 1983 (I rewatched the footage where he shows the newspaper). So he didn't have a Time Machine by 1985 and Marty couldn't go back in time. So they have to be there, Time Machine doesn't exist in 1985A, and the main Doc and Marty are not part of the alternative timeline (with a Time Machine, no less).
There is an interesting question though. We know that the Marty from BttFI was in 1955, even if you got there from 1985A (where apparently Doc didn't make the Time Travel machine). The 1985A is a timeline which sprang from 1955 by Biff's changes (meaning if you go from that point in time forward you will still be in the timeline A). But. Marty STILL goes Back to the Future even when Biff gave himself the Almanac, but BEFORE Marty and Doc got back to fix everything (hence the existence of the timeline A). Does he arrive in 1985A, and is there somewhere with Doc and Marty who got back from 2015? (not counting the Marty who went to boarding school and couldn't go back in time)
1) What stopped Marty and Doc to use the gas that was in the burried Delorean in part 3 ? Since gas is available to anyone in 1955, they could fill it without causing any paradox. I mean, don't tell me digging a bit is more dangerous than waiting for either getting shot by Tannen either getting killed in a train wreck.
2) Is there any way to tie BTTF's 2 way of "going into the future", with Einstein's travel in part I ? Since Einstein did disappear from time and went to a future where he was the only Einstein. And Marty didn't and went to a future where he never left.
1) What stopped Marty and Doc to use the gas that was in the burried Delorean in part 3 ? Since gas is available to anyone in 1955, they could fill it without causing any paradox. I mean, don't tell me digging a bit is more dangerous than waiting for either getting shot by Tannen either getting killed in a train wreck.
Because to store a car for such a long amount of time one has to remove all gas from it. Marty went to 1885 after Doc already has put it into storage.
2) Is there any way to tie BTTF's 2 way of "going into the future", with Einstein's travel in part I ? Since Einstein did disappear from time and went to a future where he was the only Einstein. And Marty didn't and went to a future where he never left.
Well, if we take into account the 'photo shows what will happen if events will continue to proceed as they do now' stuff, the BttF2 going into the future could possibly mean that Marty would return to 1985 from his trip into the future and live the life he lived (with car crash and all that). That's why I suppose if Marty would've got cured of his 'chicken' berserk button right in 2015, a ripple effect would've taken place and the future Marty would've been changed by a NEW future Marty, the one who would presumably return to 1985 (unless something unpredictable happens, causing another change of the future) and live ANOTHER life (without the car crash caused by his temper)
EDIT: Also, one of the possible reasons why there's no Doc in the future of 2015 is because Doc never intended to settle down and live in Hill Valley from 1985 to 2015, while Marty did.
1) What stopped Marty and Doc to use the gas that was in the burried Delorean in part 3 ? Since gas is available to anyone in 1955, they could fill it without causing any paradox. I mean, don't tell me digging a bit is more dangerous than waiting for either getting shot by Tannen either getting killed in a train wreck.
2) Is there any way to tie BTTF's 2 way of "going into the future", with Einstein's travel in part I ? Since Einstein did disappear from time and went to a future where he was the only Einstein. And Marty didn't and went to a future where he never left.
First:
When you store a vehicle, you have to empty the gas tank or else you risk the gas tank rusting or the gas becoming contaminated by moisture. I also believe that Doc would not have considered Marty coming to 1885, and thus would have probably used the gasoline in one or more experiments he worked on instead of just keeping it. He could also have sold the gasoline for money for supplies, but I'm not sure he would do that and run the risk of changing history by "inventing" gasoline himself.
It seems to me that the only way to account for both past/present selves and future selves to exist in the future simultaneously is the time ripple effect. If 1985 Marty, Doc and Jennifer were to stay in the future for more than the day they were there, their future selves would eventually disappear, but not immediately disappear.
Einstein only travelled forward one minute, so the ripple effect, if there was one, would have happened near instantaneously since, from Einstein's POV, there was only one minute worth of changes made to the timeline.
Also, Doc Brown spent a lot of time and planning leading up to sending Einstein, so the ripple effect may not have happened at all considering the change was so small and planned so far in advance. When Doc showed up in 1985 at the start of 2, he took Marty and Jen 30 years into the future with very little warning, so the ripple effect would have had to make many more changes with far less preparation.
EDIT: The ripple effect makes changes to the timeline based on actions as they are taken. That is to say that the ripple effect occurred when Marty saved his dad from being hit by the car, but he only had evidence of it with the photo. If there was a ripple effect at all with Einstein, it would have occurred when Doc had first started taking actions to send Einstein, rather than precisely when the car disappeared.
EDIT: Also, one of the possible reasons why there's no Doc in the future of 2015 is because Doc never intended to settle down and live in Hill Valley from 1985 to 2015, while Marty did.
The main reason is because Doc would not have lived to see 2015. He would have been in his nineties of he did live, and that might have been very likely.
"That's right. Twenty-five years into the future. I've always dreamed of seeing the future. Looking beyond my years. Seeing the progress of mankind. I'll also be able to see who wins the next 25 World Series."
He was looking forward to seeing what the future would be like, beyond his years, i.e. after he's passed away.
The main reason is because Doc would not have lived to see 2015. He would have been in his nineties of he did live, and that might have been very likely.
That could've been the case only if: Doc wasn't a time traveller AND rejuvenation clinics would appear only after his death (or if there would be no rejuvenation clinics regardless of his time traveller status). But, since he's a time traveller and he went through a rejuvenation clinic in the future (regardless when they appear, before 2015 or after), he, in case he would've settled down in Hill Valley, would live up to see 2045 at the least (he had 20-30 years to live in his BttFI end-state, and got himself extra 30-40 years).
He was looking forward to seeing what the future would be like, beyond his years, i.e. after he's passed away.
Well, he wasn't expecting to stumble upon the rejuvenation clinics when he said that
I don't get it. Why does "YOU'RE FIRED" get erased from the piece of paper at the end of BTTF3? Is it because Marty made the decision not to race noodles, which then caused Marty never to work for him? But surely Marty was destined to race Noodles?. Or was it something Doc did?
^
Marty changed as a person. He learned to walk away from provocations("nobody calls me chicken!" remember?).
The letter got erased because now his future wasn't written yet.
Another way to put it: The letter comes from a future where Marty crashed into the car.
He didn't crash into the car thus changed the future.
The letter probably changed coz now he wasnt in the accident his hand wouldnt be wrecked and wont have that job and instead he can go on to become a famous musician.
When Marty saved Doc in 1885 and the tombstone disappeared, shouldn't Marty have disappeared too. Marty wouldn't have seen the tombstone in 1955, thus he wouldn't have decided to go back to 1885 to save Doc. Is there a logical explanation here?
Also a question about Paradox's. Well in BTTF 2, Doc said that if Jenniifer bumps into her older self it could cause a paradox, that could destroy the world (in a worst case scenario).
Could anybody explain why? I don't get it. How could bumping into yourself cause a paradox?
When Marty saved Doc in 1885 and the tombstone disappeared, shouldn't Marty have disappeared too. Marty wouldn't have seen the tombstone in 1955, thus he wouldn't have decided to go back to 1885 to save Doc. Is there a logical explanation here?
Also a question about Paradox's. Well in BTTF 2, Doc said that if Jenniifer bumps into her older self it could cause a paradox, that could destroy the world (in a worst case scenario).
Could anybody explain why? I don't get it. How could bumping into yourself cause a paradox?
Worst case is that when future Jeniffer sees her young self she could freak out hit her younger self over the head with something killing her younger self therefore removing her existence.
Hey just wondering, after the 1985A time line was created were Doc and Marty going to fade away since they (the 1985 Doc and Marty) were replaced by the 1985A Doc and Marty where Marty is in Switzerland and Doc is in an assylum and was the time machine going to fade since the time machine could never have been created since Doc was put in an asylum?
Hey just wondering, after the 1985A time line was created were Doc and Marty going to fade away since they (the 1985 Doc and Marty) were replaced by the 1985A Doc and Marty where Marty is in Switzerland and Doc is in an assylum and was the time machine going to fade since the time machine could never have been created since Doc was put in an asylum?
Well, a ripple effect that would erase them in 1985A COULD take place, but I don't like the assumption that much. Because it makes the ripple effect too disorganized, without logic and acting whenever it's convenient for the plot. If Doc and Marty were to be erased because of the alternate timeline, they should've got erased along with Biff in 2015 (when neither Biff, since he was shot, nor Doc, since he would die of old dage, nor the Time Machine could've possibly existed, and possibly no Marty too)
I think there is some effect in Time Travel that protects them from such things, just as it protects their memories.
I don't get it. Why does "YOU'RE FIRED" get erased from the piece of paper at the end of BTTF3? Is it because Marty made the decision not to race noodles, which then caused Marty never to work for him? But surely Marty was destined to race Noodles?. Or was it something Doc did?
^
Marty changed as a person. He learned to walk away from provocations("nobody calls me chicken!" remember?).
The letter got erased because now his future wasn't written yet.
"Your future isn't written yet" is just words of encouragement Doc gave to Marty. It doesn't make sense scientifically especially if Doc has already been to the future again and already knows what happens to Marty.
What the letter being erased means is that since Marty learned to walk away from attempts at being provoked, he is able to stop himself from being provoked by Needles in 2015 and getting himself fired as a result. It is implied that his future is entirely different, but the extent of this still remains to be seen.
"Your future isn't written yet" is just words of encouragement Doc gave to Marty. It doesn't make sense scientifically especially if Doc has already been to the future again and already knows what happens to Marty.
They said they're taking that line seriously.
In the game we might not see the same future as 2015 because yeah well...'the future isn't written' and thus could end up differently.
So if Doc would go to the future it could be another future then if he would try to revisit it at another moment.
In 1955, Doc, Marty and Copernicus discover Doc's tombstone, showing that Emmett Brown died on September 7, 1885, after being shot in the back by Buford Tannen. Marty goes back to 1885 to save his friend, Doc is not killed, and the tombstone (as shown by a changing photograph) is no longer present in 1955. If there is no tombstone in 1955, Marty will not know that he must go back to 1885. But if Marty does not go back to 1885, Doc is killed.
Just a few more things, if 1955 Doc saw his tombstone then shouldnt that give Doc trapped in 1885 knowledge of when and how he will die which should then save Doc from being shot meaning that the tombstone should not be there.
Just a few more things, if 1955 Doc saw his tombstone then shouldnt that give Doc trapped in 1885 knowledge of when and how he will die which should then save Doc from being shot meaning that the tombstone should not be there.
But the Doc whom Marty is going to save is the 1985 Doc who got accidentaly struck by lightning and went back in time from 1955 and DOESN'T know he's going to die, cause he doesn't have the memories of the 1955 Doc who has seen the tombstone and then sent Marty back to 1885. The 1955 Doc probably knows, and his fate most likely differs in the new timeline somewhat (unless, in the future of that timeline, he decides to go to 1885 on purpose to wait for Marty there).
Yea i just meant coz we know that 1985 Doc does remembers what happened in 1955 since he had the letter that Marty gave him in 1955 so wont the 1955 Doc grow up to be the Doc who gets trapped in 1885?
Yea i just meant coz we know that 1985 Doc does remembers what happened in 1955 since he had the letter that Marty gave him in 1955 so wont the 1955 Doc grow up to be the Doc who gets trapped in 1885?
It's a difficult question, considering we're dealing here with the future that has been in the past (in BttFI we're dealing with just the future in the future, Marty goes into the changed future, in another timeline, where Doc remembers meeting him and having the letter). As I said, the Doc who we meet in 1885 doesn't remember meeting Marty for a second time in 1955 and sending him back in 1885, because he didn't - it's another Doc.
My theory is for Marty to meet the 1955 Doc who remembers that, he should go to the future, 1985 I guess, first, so he would go forward to the timeline where Doc remembers it, and then going back to 1885 he would meet the 1955 Doc there who would expect Marty to come.
What about Clara, the reason Clara got saved was because Doc and Marty were checking out the train, but according to the tombstone Doc met Clara without Marty being there. I guess that by coincedence Doc may have been at the train to save her without Marty going to the past anyway.
What about Clara, the reason Clara got saved was because Doc and Marty were checking out the train, but according to the tombstone Doc met Clara without Marty being there. I guess that by coincedence Doc may have been at the train to save her without Marty going to the past anyway.
No, the thing with Clara is much more simpler.
In 1885 with only Doc Clara wasn't in any danger at all - Doc was asked by the Mayor to meet the new teacher at the train station, so he went, met, and they fell in love. When Marty came, Doc learned about Clara from Marty, and decided to NOT meet Clara (by the way, you can notice Clara's back as she's waiting for someone to meet her while Marty and Doc are examining the Hill Valley map at the train station), but by coincidence they saw what probably happened in original 1885 (with no Doc and Marty) - Clara decided to go to Valley alone but the carriage ran, in fear, towards the ravine. Only in the original timeline she fell (hence the afterward renaming into Clayton Ravine), but in the Doc/Marty in 1885 timeline they saved her.
yea ur right stupid me, btw about doc not remembering seeing the tombstone thats because memories arnt affected by the ripple effect right? Meaning extra memories of seeing the tombstone arnt sent to the Doc in 1885.
yea ur right stupid me, btw about doc not remembering seeing the tombstone thats because memories arnt affected by the ripple effect right? Meaning extra memories of seeing the tombstone arnt sent to the Doc in 1885.
Well, there's two theories. One I already told you about: time traveller Doc, doesn't have the other Doc's memories (basically, what you just said). There is a second theory which explains it by Doc forgetting that, or being senile or even just acting like he doesn't remember (makes me wonder why he would pretend to be so surprised when he sees the photograph)... but I don't buy that theory, it seems too ridiculous to me - after all, we're talking about Doc's DEATH here.
I still think it's a case of the writers trying to write in a little more Drama and comic relief, so they didn't think every single scenario through; which is by they most likely chalk it up to Doc being a bit of a "scatter brain" from time travel. I'm sure Doc is aware of multiple timeline possibilities floating around the space-time continuum.
Again, I think it's a simple matter of the time machine protecting, at least temporarily, the time traveler's memories. The reason 1985 Doc had the letter and remembered meeting Marty in the past was because Doc wasn't "protected" by the time machine, whereas Marty was, hence his reaction upon seeing his "new" home in 1985. Since Doc was also a time traveler in BTTF2/3, he was protected, so to speak, from the changes that happened to 1955 Doc in that time period. The letter is a matter of un-disputed fact however. Now, if 1955 Doc hadn't put the letter in his pocket, then he might not have worn the bullet proof vest, and all would be moot. In fact, I'm starting to believe that after Marty left to go to 1885, Doc get the letter because he was curious about what it was that Marty was trying to warn him about.
I believe that it was stated, earlier in this thread, that 1885 Doc apologized for dressing Marty the way he did in 1955 after Marty had to remind him. So, again, I think Doc is absent minded and possibly even moreso due to Temporal Displacement. I don't think there's different Doc's floating around the time continuum. (Talking aside from the multiverse theories)
Also if there was still gas in the DeLorean and they removed the gas from the DeLorean then the DeLorean Marty took to the past from 1955 would have had no gas when they got it in 1955 so it would have changed the past making them have to get gas before sending Marty to 1885, the worst case being that when they are collecting the gas Marty or Doc die somehow causing a paradox (maybe being shot or something)
Also if there was still gas in the DeLorean and they removed the gas from the DeLorean then the DeLorean Marty took to the past from 1955 would have had no gas when they got it in 1955 so it would have changed the past making them have to get gas before sending Marty to 1885, the worst case being that when they are collecting the gas Marty or Doc die somehow causing a paradox (maybe being shot or something)
Even if they had taken the gas from the mine DeLorean, that wouldn't have affected the future. Doc: "I put gas in the tank, and your future clothes are packed." However, if the mine DeLorean in 1885 had gas in it, then the car would've been completely ruined by 1955. And I still think that Doc and Marty were lucky that a 70 year old car still ran in the first place.
Since Johnny B. Goode existed when Marty's parents were the unsuccesful parents, doesn't that mean that Marty must have always been in the past to play Johnny B. Goode so it could be "stolen" by Chuck Berry? Which should mean that his parents should have always been succesful since Marty must have been in the past to help his parents and invent Johnny B. Goode?
Not necessarily. There are a few different options.
1. Chuck Berry only hears the last guitar solo. He never actually hears "Johnny B. Goode". It's possible that he still came up with it on his own separately in each timeline.
2. Assuming Marvin DID tell Chuck how the song went, it's possible that in the original 1985, the song was performed by a different artist!
Since Johnny B. Goode existed when Marty's parents were the unsuccesful parents, doesn't that mean that Marty must have always been in the past to play Johnny B. Goode so it could be "stolen" by Chuck Berry? Which should mean that his parents should have always been succesful since Marty must have been in the past to help his parents and invent Johnny B. Goode?
No, it just means that in the original, pre-time-travel timeline, Chuck Berry wrote the song himself. In the newly created time line, Marty's playing of the song only influences Berry to write the song. Anything that has happened by the "present" (1985) still would have happened if Marty never went back in time. The outcome is the same ("Johnny B. Goode gets written") but the cause is different ("Berry influenced by Marty").
I did think of the outcome being the same but the cause different, I just thought it was a bit weird to think about and was to easy.
Well, you have to remember that there are no "time loops" in the BTTF universe. That's "Bill and Ted" stuff. Anything that was going to happen anyway without the interference of time travel cannot originally be caused by a time traveler. It can, however, be undone or fundamentally changed by a time traveler. For example, in this thread, the question is if Marty can teach the "If you put your mind to it" line to Young Doc. Personally, I think he can. Without Marty traveling back and teaching it to him, Doc comes up with the line anyway. With Marty teaching the line to Young Doc, that would simply be a new cause for Doc learning that advice. Alternately, Marty could do something that prevents Doc from ever learning that advice. But Marty cannot be the original source of the advice, only the new source.
Comments
Wow...I never thought about. Well I did...but it neve occurred to me that Doc couldn't be there since he should've been locked up.
I always thought it would be like this with Marty:
He would slowly get new memories of his new life. Ripple effect takes some time sometimes apparently.
But with Doc....it would mean he should've been transported into an asylum.
Wow....I really don't know.
But I was never too fond of the first and second act of BttF2.
What makes BttF2 so great is the last 50 minutes.
The thing is, Doc Brown was commited in 1983 (I rewatched the footage where he shows the newspaper). So he didn't have a Time Machine by 1985 and Marty couldn't go back in time. So they have to be there, Time Machine doesn't exist in 1985A, and the main Doc and Marty are not part of the alternative timeline (with a Time Machine, no less).
There is an interesting question though. We know that the Marty from BttFI was in 1955, even if you got there from 1985A (where apparently Doc didn't make the Time Travel machine). The 1985A is a timeline which sprang from 1955 by Biff's changes (meaning if you go from that point in time forward you will still be in the timeline A). But. Marty STILL goes Back to the Future even when Biff gave himself the Almanac, but BEFORE Marty and Doc got back to fix everything (hence the existence of the timeline A). Does he arrive in 1985A, and is there somewhere with Doc and Marty who got back from 2015? (not counting the Marty who went to boarding school and couldn't go back in time)
Thus BttF acknlowedges multiverses sadly.
1) What stopped Marty and Doc to use the gas that was in the burried Delorean in part 3 ? Since gas is available to anyone in 1955, they could fill it without causing any paradox. I mean, don't tell me digging a bit is more dangerous than waiting for either getting shot by Tannen either getting killed in a train wreck.
2) Is there any way to tie BTTF's 2 way of "going into the future", with Einstein's travel in part I ? Since Einstein did disappear from time and went to a future where he was the only Einstein. And Marty didn't and went to a future where he never left.
Because to store a car for such a long amount of time one has to remove all gas from it. Marty went to 1885 after Doc already has put it into storage.
Well, if we take into account the 'photo shows what will happen if events will continue to proceed as they do now' stuff, the BttF2 going into the future could possibly mean that Marty would return to 1985 from his trip into the future and live the life he lived (with car crash and all that). That's why I suppose if Marty would've got cured of his 'chicken' berserk button right in 2015, a ripple effect would've taken place and the future Marty would've been changed by a NEW future Marty, the one who would presumably return to 1985 (unless something unpredictable happens, causing another change of the future) and live ANOTHER life (without the car crash caused by his temper)
EDIT: Also, one of the possible reasons why there's no Doc in the future of 2015 is because Doc never intended to settle down and live in Hill Valley from 1985 to 2015, while Marty did.
First:
When you store a vehicle, you have to empty the gas tank or else you risk the gas tank rusting or the gas becoming contaminated by moisture. I also believe that Doc would not have considered Marty coming to 1885, and thus would have probably used the gasoline in one or more experiments he worked on instead of just keeping it. He could also have sold the gasoline for money for supplies, but I'm not sure he would do that and run the risk of changing history by "inventing" gasoline himself.
Second:
Einstein only travelled forward one minute, so the ripple effect, if there was one, would have happened near instantaneously since, from Einstein's POV, there was only one minute worth of changes made to the timeline.
Also, Doc Brown spent a lot of time and planning leading up to sending Einstein, so the ripple effect may not have happened at all considering the change was so small and planned so far in advance. When Doc showed up in 1985 at the start of 2, he took Marty and Jen 30 years into the future with very little warning, so the ripple effect would have had to make many more changes with far less preparation.
EDIT: The ripple effect makes changes to the timeline based on actions as they are taken. That is to say that the ripple effect occurred when Marty saved his dad from being hit by the car, but he only had evidence of it with the photo. If there was a ripple effect at all with Einstein, it would have occurred when Doc had first started taking actions to send Einstein, rather than precisely when the car disappeared.
The main reason is because Doc would not have lived to see 2015. He would have been in his nineties of he did live, and that might have been very likely.
He was looking forward to seeing what the future would be like, beyond his years, i.e. after he's passed away.
That could've been the case only if: Doc wasn't a time traveller AND rejuvenation clinics would appear only after his death (or if there would be no rejuvenation clinics regardless of his time traveller status).
Well, he wasn't expecting to stumble upon the rejuvenation clinics when he said that
Marty changed as a person. He learned to walk away from provocations("nobody calls me chicken!" remember?).
The letter got erased because now his future wasn't written yet.
Another way to put it: The letter comes from a future where Marty crashed into the car.
He didn't crash into the car thus changed the future.
Also a question about Paradox's. Well in BTTF 2, Doc said that if Jenniifer bumps into her older self it could cause a paradox, that could destroy the world (in a worst case scenario).
Could anybody explain why? I don't get it. How could bumping into yourself cause a paradox?
Worst case is that when future Jeniffer sees her young self she could freak out hit her younger self over the head with something killing her younger self therefore removing her existence.
Well, a ripple effect that would erase them in 1985A COULD take place, but I don't like the assumption that much. Because it makes the ripple effect too disorganized, without logic and acting whenever it's convenient for the plot. If Doc and Marty were to be erased because of the alternate timeline, they should've got erased along with Biff in 2015 (when neither Biff, since he was shot, nor Doc, since he would die of old dage, nor the Time Machine could've possibly existed, and possibly no Marty too)
I think there is some effect in Time Travel that protects them from such things, just as it protects their memories.
"Your future isn't written yet" is just words of encouragement Doc gave to Marty. It doesn't make sense scientifically especially if Doc has already been to the future again and already knows what happens to Marty.
What the letter being erased means is that since Marty learned to walk away from attempts at being provoked, he is able to stop himself from being provoked by Needles in 2015 and getting himself fired as a result. It is implied that his future is entirely different, but the extent of this still remains to be seen.
They said they're taking that line seriously.
In the game we might not see the same future as 2015 because yeah well...'the future isn't written' and thus could end up differently.
So if Doc would go to the future it could be another future then if he would try to revisit it at another moment.
Whats your opinion on this?
My opinion on that is that the time machine auto-corrects for that particular brand of paradox. Circular paradoxes give everyone a headache.
But the Doc whom Marty is going to save is the 1985 Doc who got accidentaly struck by lightning and went back in time from 1955 and DOESN'T know he's going to die, cause he doesn't have the memories of the 1955 Doc who has seen the tombstone and then sent Marty back to 1885. The 1955 Doc probably knows, and his fate most likely differs in the new timeline somewhat (unless, in the future of that timeline, he decides to go to 1885 on purpose to wait for Marty there).
It's a difficult question, considering we're dealing here with the future that has been in the past (in BttFI we're dealing with just the future in the future, Marty goes into the changed future, in another timeline, where Doc remembers meeting him and having the letter). As I said, the Doc who we meet in 1885 doesn't remember meeting Marty for a second time in 1955 and sending him back in 1885, because he didn't - it's another Doc.
My theory is for Marty to meet the 1955 Doc who remembers that, he should go to the future, 1985 I guess, first, so he would go forward to the timeline where Doc remembers it, and then going back to 1885 he would meet the 1955 Doc there who would expect Marty to come.
What about Clara, the reason Clara got saved was because Doc and Marty were checking out the train, but according to the tombstone Doc met Clara without Marty being there. I guess that by coincedence Doc may have been at the train to save her without Marty going to the past anyway.
No, the thing with Clara is much more simpler.
In 1885 with only Doc Clara wasn't in any danger at all - Doc was asked by the Mayor to meet the new teacher at the train station, so he went, met, and they fell in love. When Marty came, Doc learned about Clara from Marty, and decided to NOT meet Clara (by the way, you can notice Clara's back as she's waiting for someone to meet her while Marty and Doc are examining the Hill Valley map at the train station), but by coincidence they saw what probably happened in original 1885 (with no Doc and Marty) - Clara decided to go to Valley alone but the carriage ran, in fear, towards the ravine. Only in the original timeline she fell (hence the afterward renaming into Clayton Ravine), but in the Doc/Marty in 1885 timeline they saved her.
Well, there's two theories. One I already told you about: time traveller Doc, doesn't have the other Doc's memories (basically, what you just said). There is a second theory which explains it by Doc forgetting that, or being senile or even just acting like he doesn't remember (makes me wonder why he would pretend to be so surprised when he sees the photograph)... but I don't buy that theory, it seems too ridiculous to me - after all, we're talking about Doc's DEATH here.
Even if they had taken the gas from the mine DeLorean, that wouldn't have affected the future. Doc: "I put gas in the tank, and your future clothes are packed." However, if the mine DeLorean in 1885 had gas in it, then the car would've been completely ruined by 1955. And I still think that Doc and Marty were lucky that a 70 year old car still ran in the first place.
1. Chuck Berry only hears the last guitar solo. He never actually hears "Johnny B. Goode". It's possible that he still came up with it on his own separately in each timeline.
2. Assuming Marvin DID tell Chuck how the song went, it's possible that in the original 1985, the song was performed by a different artist!