Question: For Doc to be so worried about corrupting the timeline in this movie (especially when it comes to falling in love with Clara) he surely doesn't seem to think twice about destroying the locomotive that will no doubt have a huge effect on the timeline. I doubt there were many trains on that railroad, with that mode of transportation now gone, Hill Valley itself could be wiped out.
Answer: Doc must have reasoned that the loss of the locomotive would have a minor impact on Hill Valley, if at all. The railroad company would likely have replaced the destroyed locomotive. Obviously Doc was correct as there seems to have been no impact on Hill Valley's economy whatsoever and the train lines continue to run into the 1980's.
Answer: Corrupting time was a worry for Doc, however, he also recognized that it was at least partially unavoidable. Otherwise, Doc would never even be able to go buy food, because how would he know that the meal he ordered wasn't one that someone else was meant to choke on? Occupational hazard of time travel.
Chosen answer: In the timeline that the original Marty and Doc came from, Hill Valley exists so that town obviously survived that incident. An accident already occurred on that day in their history. They just didn't know it was them that caused it.
That is not how time travel works in these movies. In fact, the entire series revolves around the timeline being changed whenever they travel into the past. There are no stable time loops. The train was not destroyed in the original time line.
It's tough to say whether or not the train wasn't destroyed in the original timeline. Maybe by some lucky chance the train would suffer an accident similar to that anyways maybe just a bit earlier. There's really no indication either way. It's also possible they build another train or had others in service. I doubt they didn't have some backup plan in case the train was out of commission for a long period of time or destroyed.
Question: Doc seemed hell-bent on destroying the DeLorean. So why did he go to the future and get a hover conversion done on the train? Why didn't he just build the train, return to his own time and then destroy the train?
Answer: He didn't return to the Old West, both of them had a desire to go to the final frontier. Their favorite author is Jules Verne, who wrote "From Earth to the Moon."
Answer: Doc was happy living in the Old West but returned to the future to collect his dog, Einstein, and he didn't want Marty to worry about him. He probably also wanted to make sure that Marty had made it safely back to his own time, to properly say goodbye, and make sure the DeLorean was never used again. He never indicated he would destroy the train, only the DeLorean. The hover conversion on the train would have been done in the Old West, not in the future.
I doubt he was able to make the train hover in the old west, whilst he could easily go to the future with it and do it there, like he did with the DeLorean. He did say he has been to the future with it, so it's logical to assume that's where he upgraded it.
Doc never says he went further into the future with the train or did the hover conversion there. If he could build a time-traveling locomotive in the 1880s, then he could create a hovering one, as he had the knowledge. Marty asks if he's going back to the future, and Doc says no because he's already been there. That could be interpreted a number of ways. It's a sci-fi movie, and there is a lot of suspension of disbelief employed here.
While the movie isn't explicit about when or where the Time Train was built, other sources do indicate its hoverconversion was done in the future. While Doc could invent a machine that was capable of time travel (the mechanics of which aren't really discussed), he had to travel to the future to convert the DeLorean and couldn't even fix the DeLorean in the past.
What 'other sources' indicate Doc travelled to the future for the hover conversion? Any fan speculation is invalid. I also don't get the argument. While Doc was unable to fix the DeLorean when Marty was in the Old West, he could, and did, in later years, build the time-travel train in the past. He could not otherwise have gone anywhere into the future to do anything. Time-travelling without the hover ability would be extremely difficult as a locomotive would be noticeable and require taking off and landing on empty train tracks. Doc would have to hide the locomotive while converting it. He would also have to know before time-travelling that the railroad tracks he took off on still existed in the future, as he could possibly arrive smashing into what became an urban development. This should be considered as both a deliberate plot hole and a plot device using "suspension of disbelief" solely intended to give the series a spectacular finale.
The comics reveal that Doc Brown traveled to 2017 in a prototype time machine and purchased materials which he brought back with him to the 1890s to use on the Time Train.
Question: Just before Doc shows his plan with the DeLorean and the train Marty checks the walkie-talkies and Doc confirms it that they work. How are they able to get the walkie-talkies to work in 1885? I'm thinking Doc invented something so Doc and Marty can communicate with each other with them.
Answer: Given Doc's scientific ability (and some suspension of disbelief) it would be easy enough to rig up a makeshift battery that would last long enough. Or indeed they've just got lucky and the walkie-talkies' batteries still have enough life in them. They're not mobile phones, they don't need masts or any infrastructure, they just connect directly to each other.
Like you said, walkie-talkies work independently of any infrastructure, which is what I think the question was more about. However, the battery was invented way before 1885 with the first lead acid rechargeable battery being invented in 1859 with pasted electrode batteries being invented in the 1880's. So it's less about Doc rigging up a battery and just using what's already available or charging the batteries it came with (if we are assuming the batteries ran out of power).
The best batteries they had in those days were crude, wet batteries made out of earthenware and filled with sulphuric acid. They were cumbersome, dangerous and didn't have a lot of voltage or low current. Hardly suitable for a walkie-talkie that needs at least 9 volts. But I suppose it's possible Doc had some charged self-made batteries sitting at home to keep them going.
Definitely not "crude", certainly not as advanced as today, but the lead acid battery is the same technology a lot of batteries use today. They even had electric vehicles prior to 1885. My point was Doc didn't have to invent technology that didn't exist (as opposed to what some say he would have to do to get an 80's camcorder to play on a 50's TV). They had rechargeable batteries back then so it wouldn't be a stretch that Doc could recharge the batteries he had.
Answer: 1955 Doc got him some new batteries ("Just in case, fresh batteries for your walkie talkie. Oh what about that floating device?") They only used them on the train so the batteries would still be charged. In regards to how they work, they don't rely on phone masts, satellites, WiFi etc as they send radio waves to each other and not to any sort of base station.
Corrected entry: When the DeLorean suddenly appeared in 1885, the Indians have absolutely no reaction at all. There is no possible way that they wouldn't have been the least bit spooked or confused, and we should have seen some semblance of this in their actions, but they just keep charging on like nothing happened. It'd be like a an alien spaceship appearing out of nowhere in Times Square and people not even batting an eyelash.
Correction: Even putting aside that not reacting the way you expect is not a mistake, they were more focused on being chased by the cavalry, and they may well have assumed the Delorean was another "white man" invention like the locomotive.
Would it not be a bit mysterious if the Americans had invented the car but still ride horses?
The Indians did not know that it was a car or what its purpose was. All they saw was a strange device obviously invented by the "white man."
Question: Marty shows Doc in 1885 the image of the tombstone, and he says that he wished he'd paid Buford off. Why can't he just round up 80 dollars to give to Buford and apologise for not doing that in the first place?
Answer: Adjusting for inflation, $80 back in 1885 is equivalent to about $2,143.65 today. Not something you can just conjure up easily, least of all back then. And Marty couldn't just take 1985 money back to 1885 and expect people to accept it.
Except that Doc was in 1885 and could have just gone to the bank and withdrew the $80's.
How? He arrives in 1885 and magically has the equivalent of $2,100 already in a bank account? He presumably borrowed it from Buford in the first place precisely because he didn't have that much cash available.
Doc didn't borrow money from Buford. He time-traveled with a briefcase filled with currencies from different time periods, including the 1800s. Doc had shoed Buford's horse for $5, for which Buford never paid him. When one shoe later came off later, causing Buford to be thrown, Buford shot the horse and demanded Doc pay him $75 for it and $5 for a broken bottle of whiskey.
Where would have get the $80 from? You're assuming he had the $80 available to him. The bank wouldn't just give out the money for free.
You can't take out $80 in 1985 money, and give it to someone in 1885. It would look like play money to them. U.S. currency looked a lot different back then.
Well he could technically get that amount worth in gold or silver.
And, as stated, since Doc was in 1885, more specifically, eight months in 1885, he could have just taken the money out of the bank considering he had a job as a blacksmith.
In Back to the Future 2, Doc shows Marty a briefcase full of money from different time periods, including various mid-1800 currencies, that he carried with him in the DeLorean. (There are online screen shots of the contents.) Doc refused to pay Tannen the $80 because he never owed it to him. Tannen was extorting him.
Answer: Buford was a crazed gunfighter, even if they paid off the $80 that wouldn't have satisfied him. He loved to shoot and kill. He wanted a showdown to show people he is to be feared and not messed with.
Corrected entry: There really should have been no reason for Marty to risk going back to 1885 to rescue Doc. Obviously, 1985 Doc being killed by Tannen, did not negate his eventual existence (as evidenced by 1955 Doc still existing). It's understandable Marty would want to prevent his friend being murdered, but when they learned of this fact in 1955, this event had already happened 70 years ago. 1955 Doc surely would have realized the pointlessness of Marty going to rescue his future self in the past when 1955 Doc would eventually become 1985 Doc again through the natural course of time. In light of this, surely 1955 Doc would have explained to Marty there was no reason to go back and possible cause more damage to the Space-Time Continuum.
Correction: You're missing the point; if Doc is killed in 1885, there will be a paradox. 1955 Doc wouldn't know that he went back to 1885 yet, so wouldn't know he could be killed, so wouldn't think to warn Marty in 1985. Besides, Seamus would have been killed because of Doc's influence in 1855, so Marty never would have existed either. There were plenty of valid reasons to go back to 1885.
Actually there wouldn't be a paradox. First, even though Doc is killed in 1885, the 1955 version is his younger self and not warning Marty of anything. He doesn't warn him of anything actually. Second, Seamus wouldn't have been killed because of Doc's influence. Where does that even come in? There really isn't a reason for Marty to risk going back there other than wanting to help his friend.
Corrected entry: When Doc and Marty are in the blacksmith shop, Doc reads the picture tombstone: Shot in the BACK for a matter of $80. Even Buford emphasises this in the previous scene; "one day you gonna get a bullet in your back". However, in the festival scene when Buford is about to shoot Doc, Doc is facing FORWARD. If Marty had not been there to stop the bullet with the frisbee, Doc would have been shot in the chest, not the back. (00:36:00 - 00:58:45)
Correction: You're not thinking fourth dimensionally. If Marty had not gone back in time, he and Doc wouldn't have saved Clara. If Clara hadn't been at the dance, Doc may well have not been at the dance. Biff would then have shot him somewhere else and in the back. Marty being there messes up the whole time continuum. Doc even mentions something along the lines of Buford being early during that scene.
In the original timeline both Doc and Clara were at the dance. Without Marty being there Doc would have been shot in the back. When Tannen says "told you to watch your back smithy," that's what prompted Doc to reply that he felt early since he knew he wouldn't be dead until the 7th. Basically in the original timeline, Tannen shot Doc in the back at the dance and he bled out until finally dying on Monday the 7th.
Question: When towing the car across the desert, why did Marty keep checking the speedometer? Did he really expect a horse to gallop at 88MPH?
Answer: At that point in the film, Doc and Marty were looking for any possible means to move the DeLorean regardless of how fast it could actually go; while using horses may have been an unlikely option, Doc and Marty were just grasping at straws at that point and were willing to try anything.
But then Doc says that even the fastest horse in the world could only run at 35 mph so why even try it.
Answer: They were using the horses to get the DeLorean from the cave to the town. Why not test the speedo at the same time?
Question: When Marty is in the bar on the morning of the showdown, Seamus shows up saying something told him that he should be there, as if his future depended on it. Was he right? Did what happened that morning affect Seamus' future?
Chosen answer: Seeing as how Seamus is one of Marty's ancestors and something significant to Seamus' future DID happen that day (Marty didn't get killed), Seamus was definitely right.
Question: When the 1985 Doc is suddenly transported back to 1885 at the end of BTTF 2 and Marty discovers that he has been murdered, because there is a Doc in 1955 that has already been born after the 1985 Doc has died in the West, why did he go to the trouble of going all the way back to 1885 when Doc was still alive? Is there any actual legitimate time travel reason for this, or did he just do it out of instinct to help his close friend?
Answer: Technically when Doc got transported to 1885, he should not have existed in 1955 because he died. This is the problem I'm having with part 3. The movie should not have happened this way. It should have been where doc did not exist nor the time machine. Part 3 should've never happened.
That's not how most time travel (if any) stories work. Just because someone dies in the past doesn't prevent them from being born since they were already born and alive before going to the past. Think of it this way, if instead of 1885 he travelled to 2085 and died, would that prevent him from being born? The only reason Marty was in danger of disappearing and not existing (i.e. being born) was because his parents were in danger of never getting together.
It was the 1985 Doc that went back to 1885 so he would still be alive in 1955.
The Doc that got sent to 1885 was the Doc from 1985 so therefore it wouldn't have affected 1955 Doc at all.
The one in 1955 hasn't done anything 1985 Doc did.
Question: Doc is quite a resourceful and clever guy. Why didn't he set to work on repairing the flying circuits which would have enabled them to use Mr Fusion to reach 88mph, instead of the engine?
Answer: Mr fusion only powers the flux capacitor. The engine is needed to get the car up to 88mph whether flying or not and the only way to get the car any power is by the use of petrol, which didn't exist in 1885.
At the beginning of the movie, when 1955 Doc reads the letter that 1985 Doc sent to Marty, he reads that the lightning bolt activated the time circuits and at the same time destroyed the flying circuits. Because of this, the Delorean will never fly again.
These answers are correct. Plus, to the original question: as clever as Doc is, keep in mind he got the flying conversion done in 2015. Definitely no way he would have been able to repair something so futuristic with 1885 tools at his disposal. He couldn't even get gas.
Yet just a few years later he had built from scratch a flying time-traveling locomotive, all with 1885 tools and parts.
There's no indication he built the flying train in 1885. It's suggested he had been time traveling with his wife and kids and says he's already been to the future. Whether this is in the DeLorean or the train it's not clear, but the dialogue suggests he's been to the future in his train with the family and could have modified his train to fly with future technology.
Question: Back in 1885 why doesn't Doc change the letter he sent to Marty, asking him to bring a can of gas?
Answer: When Marty received the letter from Doc in 1955, as seen in the second movie, Doc wrote down that he didn't want Marty to go to 1885 to rescue him because he was happy living in the past. Instead, he wanted Marty to take the Delorean straight back to 1985 and then destroy it so it could never be used for personal gain again.
But once Marty appears in the past Doc could easily change the letter, changing things such that Marty would bring gas with him.
Answer: This would create a different timeline, not the timeline they are in.
Answer: That would not be possible as in 1885, Doc sent the letter on September 1st, and 1955 Doc sent Marty to 1885 on September 2nd so it was a day later and on the 1st, Doc was not expecting Marty to turn up. However, one CAN ask why Marty and Doc didn't go to the local Western Union office and change it (or write a new one) there since it was in their possession per the gentleman in part 2.
Changing the letter while Marty is in 1885 with Doc would accomplish nothing, because it doesn't it instantly travel to the future. Marty at the end of Part II, for his part, may receive the letter almost immediately, but the letter itself had to wait 70 years to be delivered to him.
I mean, there's no solid rules to time traveling, but just for argument's sake it seems like the letter idea could work... in the franchise, when something is set in motion, the effects usually take place immediately. Take for instance when George and Lorraine kissed at the dance in Part 1. The picture of Marty and his siblings went right back to normal, even though the kids had not been born yet. Doc and Marty changing the Western Union letter "could" have had an immediate effect and a gas can could have materialized in the Delorean, much like we've seen newspaper headlines change before our very eyes, disappearing gravestones, etc.
In your examples, the changes occur to future events. The items that changes, like the picture and newspaper, are from the future themselves. They can't change the past by changing events in the future (like they do in Bill and Ted's). This is why Doc and Marty couldn't go back to 2015 to stop old Biff from taking the DeLorean.
Answer: The letter that Marty received in 1955 was dated September 1st, 1885; sending Marty back any earlier than that date could potentially cause a time paradox, which was something Doc took great care to avoid throughout the majority of the film trilogy.
zendaddy621
Marty can go back anytime in the 8 months and tell Doc that he will be murdered and to send a letter that was dated September 1st.