Back to The Future/Headscratchers

Back to the Future

 * How does Marty take a 1985 camcorder and hook it up to a 1955 TV system? Even if Marty brought cables, I don't think that TVs of that era had any inputs (besides the antenna). The Doc doesn't look like a A/V expert. The only way he could do that if he took apart the TV and used a soldering iron. What gives?
 * According to the DVD, the filmmakers couldn't even make that work. They tried, but ultimately put a new television set inside a 1950s model and tinted the footage black and white.
 * Don't forget, Doc's a Mad Scientist. If he can make a time machine, he can get a camera to work on a TV set.
 * Actually, Marty is the one hooking up the camcorder in a deleted part of that scene. He even asks Doc for an adapter that hasn't been invented yet, and somehow still manages to get the TV working correctly with just the parts from the lab. And an earlier version of the screenplay had Marty as an A/V whiz of sorts, so maybe it's a hidden talent of Marty's that the filmmakers didn't really expand on in the films proper.
 * On the other hand, the scene might've been deleted because the filmmakers realized how hard it'd actually be and decided to let the audience assume he had Doc's off-screen help.
 * In the 70's my family would ask me for miracles like this. Since my grandma had an early 1970's VCR with RCA inputs we could pull it off easily but without that you would need some sort of RF converter (common now...) or a camcorder with RF output and/or a 75->300ohm adapter (pretty common adapter back then actually) and I only saw one camera like that, and that one in the mid 80's no less, the rest were RCA output. Of course none of this even applies if there is something about 1955 TV's different from 60's and 70's TV's I was asked to do this on.
 * Marty is an aspiring professional guitarist. I speak from experience when I say that there are guitarists who wouldn't know an ohm from a dog turd, but are freaking whizzes at jury-rigging electronics. They kind of have to be.
 * Possibly Doc had previously modified that TV as part of one of his non-time-travel-related experiments?
 * I have a lot of experience with hacking TV sets, starting in 1967 or so (and working on sets going back to late 50s), and I don't really think Doc would have had much trouble adding a video input to a 1950s TV set. An old set like that would be a lot easier to do that to than a modern one as the needed connection point would have been a wire between two components, not a circuit board trace. And while the video timing was changed slightly from B&W sets to color, it didn't change that much; the camcorder's output would be well within the range of the TV's horizontal and vertical hold controls. Marty, though, could not have done it without Doc's help, at least not given what we see in the film. Maybe the "adapter" he asked for was to connect the camcorder to Doc's mod, Doc having already done the inside-the-set work.
 * What the heck was Marty doing going over to Doc's garage at the beginning of the film, anyway? He can't possibly blame the fact that he was late for school on Doc's clocks-- he was only there for a few minutes, and he was wearing a wristwatch.
 * He probably went by to use the speaker since Doc had said he'd be out, and spent more time there than we actually saw, maybe straightening things up and getting ready a bit, and didn't think to look at his wristwatch because he was surrounded by clocks that all said the same thing.
 * The first couple times Marty tries to tell Doc about the future (and the fact that he'll get shot), one thinks he ought to have been far more assertive.
 * Doc's just as stubborn and assertive about not wanting to listen. Plus, it's kind of a hard thing to broach with someone, especially a close friend -- "Hey, you're gonna die in thirty years!"


 * Who the hell keeps their car keys in the trunk?!
 * Most likely, one of Biff's helpers must of swiped the keys from the top of the car and threw them in the trunk so no one could get him out.
 * Or maybe the band member who owns the car just set them down by accident in there and forgot to pick them back up. This troper's done that more times than he'd like to admit (fortunately, he always keeps a spare key in his wallet).


 * Marty could have traveled to any point in 1985. Why choose a point that was only eleven minutes before Doc got shot?! That wouldn't exactly be enough time to do anything about it even if he got there. Why not a day? When he got to 1985, he could have called Doc and told him.
 * It could be any number of reasons. Maybe some of that paradox talk actually seeped through and Marty was trying to interfere in events he clearly remembers (at least some of them) as little as possible? Maybe he was just in panic mode and went with the first idea that came to him. After all there was a lot going on at the moment.


 * When Doc taped up the letter and found out what Marty had been trying to tell him all this time, why was a bulletproof vest his only precaution? A bulletproof vest won't exactly save you from getting shot in the head, so he's damn lucky that didn't happen. Why not get a gun or something?


 * Nevermind that even the best modern bulletproof vests are not going to stop even one 7.62 round at 5 times the range he got shot at. Even if he had some sort of phlebotinum vest he is not going to be able to sit up for a while.
 * He had a gun, but he threw it away when he was confronted by multiple men with assault rifles who weren't intimidated. And he probably wore a vest because he calculated it gave him the best chances of survival without tipping Marty off to its presence and thus causing a paradox. He probably reinforced the vest with metal plates or something and just took a chance they wouldn't hit him in the head.
 * More precisely his Colt Single Action Army jammed when he tried to use it. Then he threw it away. In the third film we see that he owned a very similar gun back in 1955 (probably owing to his fascination with the old West) if its the same gun and if it wasn't new to begin with that would explain why it breaks. As for the bulletproof vest its time to initiate protocol Willing Suspension of Disbelief. Most Hollywood films get the durability of these things wrong for the sake of telling a good story.
 * As Cracked.com pointed out, after crashing into the photo booth, the Libyan terrorists are still there, but we don't hear from them for the rest of the movie-- or the rest of the trilogy, for that matter. What's up with that?
 * I always figured the crash killed them. Just because a car doesn't blow up doesn't mean its occupants are OK (and the photo booth was already on fire from the DeLorean's time jump, so even if they were just knocked out, they probably burned to death soon after).


 * How in the world did Marty manage to cross the wire at exactly the right second? Especially considering the problems with the car's ignition? Talk about catching a lucky break.
 * When lightning goes so slow you can see it crawl across the wire, hitting it at just the right moment is presumably not too hard. As for why lightning was slow, that's a good question.
 * Could be a Genius Bonus, actually. Lightning doesn't actually strike downwards from clouds to ground, it goes up from ground to clouds. Presumably the differential charge between ground and sky had been building up for a while, and was still waiting to happen when the time machine's hook hit the cable. Because the sudden contact between wire and hook created a better conduit for the electrical discharge than the clock tower alone, lightning that would've otherwise gone off an unknown number of seconds later instead took this path of least resistance immediately.


 * Okay, seriously, what was the thing with Marty tearing a whole page out of a phone book just to get one number? And why was the café owner so blasé about it?
 * Well, it has its own trope. Maybe Marty had just seen too many movies.
 * Marty was in a hurry and either couldn't have, or didn't bother to, write the information down or memorize it carefully. As for the cafe owner: who knows, who cares? He may have hardly noticed it, or have been unconcerned since it was only one page in the book so what were the odds that anyone would need it in the future? Besides, Marty just ran out of there, perhaps before he could formulate a response.
 * Notice that the cafe owner is pretty aggravated with Marty at that point, snapping at him to order something. It may be less that he's not annoyed by the ripping out the page, but more that the ripping out would not be accompanied by a compensating purchase.
 * Marty runs right out after ripping out the page (if memory serves) before anyone can say anything, but probably the guy is just happy that the strange young man with the life preserver who tries to "get a Tab" without ordering things first is finally leaving. It would seem to him like the least bizarre behavior he's seen from Marty.
 * Do we know he's the cafe's owner, or just a clerk? If he's just an employee, he probably wouldn't care about that phone book, either because it's not his, or he's too busy to care, or what. That's definitely my attitude at work regarding company property!
 * The other patrons refer to him as "Lou", and the place is called "Lou's Cafe", so I'd say he's the owner.
 * ... It's a page from a phone book. Phone books were and are replaced with relative frequency and weren't / aren't exactly rare or difficult to acquire, they usually fall apart quite easily anyway and it's hardly like he's holding up the place or planning the assassination of the president or anything; so who gives a shit?
 * Just because it's going to be replaced eventually doesn't mean that its owner would be perfectly okay with having it torn up by anyone that just happened by. It may be just a phone book that will get replaced in anywhere from a few weeks to a year anyway, but it's still his phone book and it's understandable he'd be annoyed by someone ripping it up if they weren't even going to spend a lousy nickel on a cup of coffee in recompense.
 * How did that bolt of lightning not kill Doc, gloves or no gloves? Not only did he survive, he practically no-sold it-- he simply fell to the ground and got back up after a few seconds.
 * Because the bolt of lightning didn't go through him. Electricity is going to take the path of least resistance, and human bodies are actually pretty resistant. Given the options of going through a human body and through a metal cable explicitly designed and made to move electricity, electricity is going to go through the cable.
 * Sorry but that "path of least resistance" business is a canard. Electricity takes all paths, the available current being divided between the paths, inversely proportional to the relative resistance of each. (e.g. if one path is 50 ohms and the other path 100, then the 50 ohm path gets twice the current of the 100 ohm path.) So even though the cable provided a nice low impedance path to ground, I'd expect some of the current to go through Doc. Funny thing, though: a lot of the people who are struck by lightning every year are not killed. Yes, it's a hella lot of current, but it's also very very brief. They aren't necessarily just fine, though. Mental problems are not uncommon in lightning strike victims.


 * What made Doc change his mind and go to 2015 instead of 2010?
 * He says right then and there that he changed his mind because he felt 30 years was a nice round number.
 * This troper noticed that he didn't "change his mind" so much as had it changed for him. He wanted 25 years in the future before Marty went through time and changed history. Part of the change was informing the past Doc that he is 30 years from the future. They shared a big adventure together and Doc succeeded in his project to get Marty back to the future. Upon seeing the "current" Marty and taking him home he was possibly inspired to have his own 30 year future jump.
 * Why would George want Biff anywhere near his wife and kids? He was a breath away from raping Lorraine the night of the dance. Even ignoring that he's still an asshole who is still physically stronger than him. He could come back anytime and get revenge.
 * George punching out Biff completely changed the power dynamic between the two. In short, after George laid out Biff, Biff was his bitch.
 * In the end of the movie after Doc survives being shot at, he hands Marty's warning note to him and explains that "but then I thought...what the hell?" Ok, do he had that thought and then what? He'd torn up the letter and thrown it way, so how did he get it back?
 * Look back at the scene where Doc tears up the letter. The torn letter never leaves his hands or gets thrown away. He rips up the letter, then covers his ears when Marty starts to tell him about the Libyans. When the tree branch falls and disconnects the wire, Doc yells, "Great Scott!" Doc looks down at the fallen wire, up at the clocktower, and then (quickly) stuffs the letter fragments into his coat pocket right before he runs over to grab some rope. It's a quick sleight of hand, and you need to have a good eye to see it, but it's definitely there.
 * When Marty first enters the 1955 diner in the first film, his digital watch starts beeping and he has to hide it from Lou. So why doesn't he show it to Doc when Doc doesn't believe he's from the future? Doc can dismiss funny clothes, the picture of Marty's family, and Ronald Reagan as the President, but a high tech future watch would be pretty impressive.
 * Why is Marty's watch 35 minutes slow in the beginning of the film, and not just the clocks in Doc's garage? What the heck was he doing going to the garage, anyway? You'd think he'd be more careful about these sorts of things, having been late three days in a row prior to the film.
 * He wasn't careful for the same reason he'd been late the other times. He's a slacker.
 * Just before Strickland catches them, Marty tells Jennifer "This time, it wasn't my fault. The Doc set his clocks 25 minutes slow...." If you look closely, you'll see one clock that shows the time somewhere between 8:15 and 8:20, presumably as a "control" clock for Doc's experiment.
 * I'm not about to do the complicated research necessary (and I can just say "things are different thanks to time travel" anyway), but I just noticed that 35 + 25 = 60, so it's possible that the discrepancy between those two times is the result of a daylight-savings time transition in the trip to 1955.
 * Getting a tad off topic now, but it needs to be said; during the scene where Marty is filming Doc's experiment, he looks at his own watch and shakes it, as if it had stopped. He probably didn't notice that when he was going through Doc's garage earlier in the day.
 * The engineer in Part III tells Marty and the Doc he can get the locomotive up to 50 fairly easily, and that 70 isn't out of the realm of possibility. Why did Doc throw in his doctored logs when the train was only going 20?
 * As Doc pointed out, they were based on a chemical formula designed to "kick in" one by one - presumably their exposure to heat over time starts the chain reaction that increases the boiler pressure sequentially, so throwing them in later would actually be counter-productive as the train wouldn't get up to speed before plunging over the ravine with them both inside the DeLorean. Of more concern is why Marty didn't give the Doc the hoverboard in the first place to prevent him having to make a very dangerous jump from the train to the DeLorean.
 * Perhaps it's also an example of the writing staff showing their work. Many American railroad tracks, in the period which the movie is set, were built hastily and to very low quality standards. Trains often moved slowly not because of technical limitations,but because the track was so poor that they could derail at higher speeds. Doc might have realized that the more time the train spent around 88MPH, the greater the chance that the train would crash and the whole plan would fail.
 * Ah, but once the train hit 88MPH, the time machine (with them in it) would leave that time frame and the fate of the train wouldn't matter. You're just not thinking foutrh-dimensionally.
 * Marty and the Doc end up with a photo of an empty burial plot. So what would happen if Marty or Doc (or someone else) went to the 1955 graveyard and spied on Marty and 1955-Doc digging out the buried DeLorean? What would cause Marty to return to 1885 to save Doc?
 * I presumed Doc set a false tombstone to maintain the timeline.
 * Then the post-ripple photograph would have been the false tombstone, not an empty burial plot. A bigger question is why would the burial plot be empty after 70 years in a cemetary? Wouldn't someone else have been buried there by then?
 * Same reason why Jennifer still has the piece of paper that read "YOU'RE FIRED!" before the timeline changed, and why Marty still has the photo of him and his siblings in the first film: they're immune to the Ripple Effect.
 * Doc at one point says the picture represents what will happen with regards to the confrontation with Tannen. It's essentially become not just a picture of a plot of land, but an artifact representing the potential outcomes of time travel. Thus why it fades out completely when the confrontation is resolved without anyone dying. There might actually be someone buried there now, but the photo didn't need to show it because it's not relevant to what the photo is now.
 * That timeline doesn't exist anymore. The movie doesn't say, but there are an additional timeline: Martys timeline, the one the movie follows. While 1955 Doc and Marty finding the tombstone exists in Martys timeline, spurring him to save 1885 Doc, it doesn't exist in the common timeline. It is pointless to try and figure out what would happen in another timeline as a result, since it doesn't exist, anymore.
 * The DeLorean that Doc came to 1885 in should still be in the cave. right? Surely, there should still be some gas in there. Even if it's all evaporated, you can't leave a note in it that says "Marty, put a can of extra gas in the trunk. Trust me on this. Thanks."?
 * The gas tank also received a nice, big hole in it. Materials and tools for a proper patching job wouldn't be available for decades, and a makeshift one wouldn't be reliable.
 * But even then, there's the gas tank on the DeLorean in the cave that's still good.
 * Doc wouldn't mess with the car in the cave unless there was no other alternative because even the slightest mistake could alter the timeline.
 * Gasoline has a shelf life. Even 1 year old gas will cause lots of problems.
 * And, conveniently, Marty goes back to about nine months after Doc arrives in 1885. By then Doc would have already prepared the DeLorean and buried it in the mine. Even if he had kept the gasoline when he drained it, after nine months stored in an 1885 container it would be ruined as fuel or evaporated, or both.
 * There'd be no gas in the buried DeLorean because, as any gearhead will tell you, when you put a car into long-term storage, you have to drain all fluids from it. Especially gasoline, because it will corrode the tank. Also, in 1955, the 1955 Doc says to Marty "I put gas in the tank", so it was already established that there was no gas in there.
 * Did Marty remember to pick up the pieces of the letter Doc tore up that warned him about the Libyans before taking a passed out Doc Brown home in 1955?
 * In Part I, just after Doc tears up the letter, a limb falls off of the tree and distracts him from tearing it up further because his priorities are shifted to ensuring the cabling is still intact. You see him shove the pieces of the letter into his pocket when this happens.
 * In the Telltale game, if the DeLorean was duplicated when it was hit by lightning and the duplicate was sent to a dystopian 2025 where Griff Tannen momentarily took possession of it, was Doc, who was inside the DeLorean at the time, also duplicated? If so, what happened to the duplicate? Did Griff kill him?
 * One episode is named Double Visions, and in the log in screen to play the game, you clearly see Doc, as the figurehead for that episode. Not that I have been the future or nothing, but I think this will be explained soon.
 * Why would the duplicated DeLorean have been sent to a dystopian 2025?
 * The lightning bolt sent the original seventy years into the past, the duplicate went seventy years into the future.
 * I think the above editor was questioning the "dystopian" part. There's been nothing to indicate that 2025 will be any worse than 2015.
 * One could only assume the future episodes will explain that part. The original 2015 no longer exists as of the end of the third film though either way.
 * I have a feeling that the "dystopian" reality is the one we see in Citizen Brown. I have a feeling that Marty will get help from Doc's duplicate in Double Vision.
 * He didn't. But maybe he'll pull a Past Max in Episode 5.
 * Telltale game again. Episode 3. When Marty finally gets in to see Citizen Brown, the latter shows him a picture from 1931 of Kid Tannen's arrest, and the former points out himself and the "real" Doc together in the gazebo in the background. If everything that's ever been established about photographs and time travel in this series is reliable, Doc if not both of them should have faded from that photograph long before Marty ever saw it!
 * In the Telltale game, the chain of disastrous alterations to the timeline starts with Marty going to the 17-year old Emmett Brown for his rocket drill, but all of that was completely unnecessary. The DeLorean was fully functional at that time, so why did Marty not just hop in and go to whichever point in time he needed to to get the tools to bust Doc out of jail? If there's nothing useful in Doc's lab in 1986, then jumping to 1955 or later and talking to a version of Emmett Brown who's already aware of time travel would be infinitely safer than pestering a teenager who hasn't even really decided to be a scientist yet. I get that this doesn't occur to Marty, who has trouble thinking 4-dimensionally, but why doesn't Doc think of it?
 * And if that opportunity was missed, then Marty could still have avoided involving Edna, effectively ending the game at Episode 2, if he'd just jumped to, say, 1989. Since the Marty of 1989 would be 21, he could just walk into a liquor store and buy the alcohol. This is of course assuming he has a form of ID on him that will work. This troper is not familiar with American liquor stores and the kinds of ID they take.
 * Marty's driver's license would be expired, but it would still have his date of birth on it. If the clerk at the counter was laid back enough he could probably still accept it since it's still proof that he's 21.
 * They're also in the middle of the prohibition. Alcohol is illegal. Other than Young Emmett, Marty's only other option is Kid Tannen.
 * The Marty we see at the beginning of the first film is vastly cooler than anyone else in his family and probably among the top 5% cool kids at school. He plays guitar, fronts a rock band, is an expert skateboarder, is dating someone who looks like Claudia Wells, and all the girls in the aerobics studio wave to him too. Now the running gag through all of the films is that everyone is like their parents and their parents are like their parents, but George and Lorraine are complete losers. How'd Marty-1 escape his destiny, even before he changed his past?
 * The thing he inherited from his father was his lack of drive and refusal to fight for what he thinks is important. Both he and his father are interested in creative works, but refuse to send their work out to companies out of a fear of rejection. As a result, Marty in the original timeline is implied to end up like his dad and take the route of least resistance, working a desk job or something instead of doing what he really wants.
 * How does Doc shift gears when the DeLorean is under RC control? While automatic was an option on the DeLorean, it's fairly well established that the one used for the time machine has a manual transmission seeing as Marty shifts into 5ht gear just before going back to 1955.
 * Close-ups of the shifter show it surrounded by wires. Doc probably rigged it and the clutch with small servos to do the shifting via remote.

Back to the Future: Part II

 * Granted, it would've taken away from the drama, suspense and humor, but in part 2, wouldn't it have been easier to take the Almanac from Biff the day after the dance, or just break into his house when he falls asleep?
 * I think they wanted it to be over with quickly, and probably didn't want to risk spending too much time on the task lest something go wrong (like, for example, Biff becoming onto them and taking greater security measures which would make it more difficult for them). Besides, since they already knew a lot about where Biff would be and what he would be doing during the time frame of the first movie, that gave them some knowledge as vantage ground.
 * It would be too late. Note that Biff took his first serious look at the almanac after the prom, and odds are, he'd be more than obsessive to keep it -- or its valuable information -- in his possession. He could've copied a few pages, hid them, and used them to become rich. It would be a bigger mess to solve if that was the case. It is not the almanac per se that Marty and the Doc need, but to prevent 1955 Biff from gathering too much information from it.


 * Another example that would have taken away even more drama, suspense and humor by never giving 2015 Biff the chance to steal the Delorean in the first place: Marty and Doc could have stopped the police from taking Jennifer "home" to Hilldale; all Marty had to do was claim to be Marty of 2015, his thumbprint scan would have verified it, and surely the police would have left Jennifer in her "husband's" custody.
 * It was risky enough, according to Doc, for them to have been in 2015 at all in the first place, in situations where they might create a paradox by running into their doppelgangers.
 * And it'd be pretty odd for a visibly teenage Marty to just appear out of nowhere and give a thumb scan identifying himself as a 47-year-old man--especially since, if you look closely at Doc's newspaper, there's a bit in the newsline about "thumb bandits" (which are presumably the identity thieves of 2015). The police simply assumed Jennifer had gotten a really good facelift; to see her supposed spouse show up and appear to be the exact same age would raise some big questions.
 * Hold on then...What about Doc getting the procedure to look years younger? If he could do that, why wouldn't the police assume that Jennifer and Marty had both just done the same? Even if it's an expensive procedure that's not common for middle class folk or whatnot, there must still be a lot of people who would be willing to shell out bucks to look younger again.
 * It should be noted that for all Doc's hype about the procedure making him look years younger, he doesn't actually look any different when he finally reveals himself. Presumably the procedure doesn't work that well or is mostly hype; kind of like how skin creams which claim to take "years off" don't make you look incredibly different to how you did before you put them on. In any case, reverting an older man to a (slightly) younger man is different to reverting an older man to a teenager; it's presumably still not good enough to revert a 47 year old man to a point in his life where he was (presumably) still going through the latter stages of puberty.
 * IIRC, by the time Doc and Marty realize that Jennifer's missing, they're pretty much just in time to see the police officers drive off
 * No, you're not remembering correctly. Doc and Marty see the cops find Jennifer, ID her, and drive off with her.
 * It might have made the cops suspect that Marty tranqed her and left her in an alley. Even if he's her husband, that would still qualify as spousal abuse and Marty could be hauled off to jail.
 * But if they suspected that, they shouldn't have just taken her home (except insofar as the new lawyer-free, non-adversarial justice system may somehow disincentivize the cops to actually arrest people). And the suspected abuser showing himself to the cops would probably make him a little less suspicious. Although a hypothetically-abusive Marty might know that the cops would know that an abusive Marty wouldn't do that…
 * If he wasn't there, then they had no reason to suspect that she'd been abused and dumped in that alley for possibly suspicious reasons; they might just assume she'd gotten tanked and fallen asleep in the garbage. Her (much younger than he probably should be) husband suddenly showing up to nervously laugh it off and tell them that it was okay, he knew that his wife was unconscious in the alley for reasons he'd probably be a bit cagey about (since he's hardly going to tell them that they've both just travelled in time and she's been drugged because she was getting a bit too excited about it) is probably going to make them a bit more suspicious as to his intentions. Particularly since if she's unconscious in an alleyway, then he has no real reason to object to them helping her get home that probably isn't at least a little bit suspicious to a police officer.


 * In part 2, Doc gets accidentally set back in time to 1885, he had the power necessary from the bolt, and he had the flux capacitor which was in the DeLorean, but he wasn't moving at 88 MPH ...What gives..?
 * Possibly the car span round so fast that its angular momentum was 88mph. Presumably the wheels didn't have to move that fast as the car was flying.
 * Since we don't know why the 88 miles per hour was necessary, no one can say for sure. Since the timecar always arrives at its destination cold, implying that it can absorb heat as well as direct kinetic energy, maybe the molecular motion of the lightning's heat was enough to make up for the lack of momentum?
 * Word of God says that it spun that fast, and that's why the vapor trails formed the reversed 99.
 * It's actually all explained in Doc's letter in Part III. The flux capacitor already had 1.21 jigowatts stored up, as Doc loaded the fusion generator prior to meeting Marty at the school. The extra power from the lightning caused an overload that scrambled the time circuits and caused the flux capacitor to spontaneously activate.
 * Gigawatt What the hell is a jigowatt?
 * An obscure way of saying gigawatt.
 * Of course, a watt is a unit of power not energy so you can't "store" 1.21 gigawatts. Presumably the capacitor had stored enough energy that it could discharge it at a rate of 1.21 gigawatts for however long is necessary to work it...
 * And that's exactly what Doc Brown has in mind! When he's despairing over where to find the McGuffin electricity, he talks to Edison's photograph: "Tom, how am I gonna generate that kind of power? It can't be done, can it?"


 * Why did Marty have to go to the future to prevent his son from taking part in the robbery? From Marty's point of view, the robbery wouldn't happen for 30 years. All Doc had to do was tell him exactly when it was going to happen, and in 30 years, Marty could prevent it without having to time travel.
 * Of course, Marty would have to remember this for 30 years. But surely he would remember something this important, no? Also, in the next 30 years, he could have just raised his son to be a bit less vulnerable to peer pressure and avoided the whole mess.
 * My theory is that this was all a Xanatos Gambit by Doc to improve Marty's life by having Marty choose to improve himself. Note that Doc doesn't mind actively telling Marty the mistakes his "son" will make, but he refuses to tell him a mistake that Marty will make; i.e., racing Needles because he called him chicken. The end of the third movie implies that once Marty changes, the future becomes a blank slate.
 * The only reason they go into the future to help Marty's kid is because that's how they ended the first one, and the ending was meant to be a joke. When the sequel happened, they had to start with the hook they'd already set up.
 * And of course, kids don't always do as you say. I guess Doc used a more method which would be easier to get result.


 * It surprises me that no one's bought this up yet. Gray's Sports Almanac. It was supposed to have the results of every major sporting event from 1950-2000. Did anyone think that book was just a little too thin to have all that history in there? A book with that much sports history in it would probably be the size of an unabridged dictionary! Plus, each sport would have to have it's own section. Baseball, football, basketball, hockey, boxing, horse races, etc. Never mind the fact that it wouldn't be just the results, there would have to be information such as MVPs, in-game and historical records set (and broken), expansion teams, and so on. Plus, we never really find out if ALL sports are covered in the almanac. Do the Olympics count? What about professional wrestling? MMA? Nascar? And what if some new sport was invented and implemented between 1950 and 2000? There would have to be a whole section on the creation of that sport, and then all the above information (MVPs, records, teams). And then in 1955, old Biff manages to open the page up to the exact game that's playing on the radio. I understand that it was easier to make the book thin so Marty could try and steal it later (and the mistaken identity when Strickland takes it), but couldn't they have come up with something else, like maybe a book that only detailed certain sports for the 50's only? Or certain sports only, like just baseball, football and basketball maybe?
 * The almanac could have been part of set. Marty might have only bought a volume with certain sports, either not realizing there were others or the shop didn't have them.
 * Indeed, only the set could have been organized a different way. The implication of the dialogue does * seem* to be that it's complete, though, and on the commentary track Zemeckis and Gale admit to the absurdity. Really, though, if it just contains the bare, basic statistics, which fill most every page in tiny print and in many columns, using lots of abbreviations, they could probably fit a hell of a lot more in there than it would appear by glancing at the cover and page number.
 * The first draft of the BTTF 2 script mentions that the pages of the almanac are super-thin, and that the almanac is composed of 5000 pages.
 * It's the future. They probably found some technology to make it small.
 * Or holographic in a controllable way, so that it's like several pages in one for each page. Or...something.
 * See, for example, Paul Atreides' copy of the Orange Catholic Bible given to him by Dr. Yueh: about palm-sized, but has thousands of pages. Has its own inbuilt magnifying device.


 * Why does Marty get blamed for the Sports Almanac fiasco? Isn't it at least partly Doc's fault for inventing a time machine that doesn't require keys or a password or at least some sort of security measure, and then leaving it completely unguarded? All Marty did was give Biff the idea.
 * Actually, it'd be more Doc's fault for talking so loudly - that other people can overhear him.
 * Marty didn't get blamed. He just declared that It's All My Fault.
 * It was kind of Marty's fault that Biff was able to steal the DeLorean from Hilldale, as he was supposed to be watching it whilst Doc was retrieving Jennifer, but instead wandered off looking at self-walking dog leashes. A split-second was all Biff needed.
 * Wanders off and leaves the door to the DeLorean wide open. Password be damned, if you walk off and leave your car door open you deserve to have it pinched.
 * Well, that's all in the past.
 * You mean the future.
 * Whatever.
 * Arguably, Marty is more at fault because he had greedy intentions when he bought the Almanac. Doc had more noble intentions when he invented the time machine.


 * If Biff going back to 1955 created another timeline (and that's why going back from the alternative 1985 is useless unless they get things back to normal), how could he get back to his own 2015?
 * There is a deleted scene in which Old Biff fades away the way Marty almost did in the first movie. This suggests that the timeline was in the process of repairing itself to make sense. We know this can't happen instantaneously, or Marty would have started fading the moment he interfered with his parents' encounter. The scene was trimmed however, and we never actually see Old Biff fade away (although he does seem to be in pain upon returning).
 * He returned to the old time line because young Biff has free will, and until he decides to use the almanac the old time line is in place.
 * Time hadn't changed when old Biff left 1985, bit it had changed when he arrived in 2015 and was trying to repair itself.
 * Exactly - a later entry on this page (not mine) says more or less that the ripple effect doesn't fully kick in until a critical event's been reached; old Biff wouldn't be erased from existence until then. By time-traveling forward to 2015, he skips forward past the critical event and into a timeline he's no longer compatible with.
 * Zemeckis and Gale proposed that Biff did indeed return to 2015-A, which we saw on-screen after Biff returned, and which happened to be just that similar to the original 2015 for Marty and Doc to still carry Jennifer out.
 * I figured it was the same reason they could leave Jennifer and Einstein in 1985-A; time transforms around them.
 * You're confusing effects that occur in time with effects that occur in metatime. When Biff used the almanac, and 1985-A overwrote the original 1985, 2015-A also overwrote the original 2015. Timelines aren't "parallel universes": only one version of a given time period exists at a given point in metatime.
 * How do you know how time travel "works"? Maybe there are alternate timelines coexisting, and the only reason Marty started fading out in the first film was that he was in the wrong one.
 * Also, the old Biff could meet the young Biff in 1955 perfectly comfortably, with neither of them falling unconscious or even the Universe imploding. Perhaps it is because the young Biff did not recognize the old Biff as being himself?
 * It's exactly because of that. The young Biff thought of the old Biff as "an old codger with a cane", and nothing more.
 * That, and young Biff was really dumb.
 * Exactly. Essentially a variant on Tricked-Out Time with them avoiding the paradox through the power of dumb.
 * This troper wants to know how in the heck Old Biff knew how to use the DeLorean in the first place? He wasn't around when Doc explained it to Marty in BTTF.
 * Everything is labeled. You see, Doc is an Absent-Minded Professor, so I've no doubt he could lose track of what some of the buttons do.
 * Yeah, but how did he know to turn the time circuits on? And power up Mr. Fusion? And how did he figure out that he had to speed up to 88 mph to travel through time?
 * Maybe there's an Owner's Manual in the glove box.
 * In regards to powering up Mr. Fusion, the device was billed as a "home energy reactor", and probably a common household implement in the BTTF 2015. This doesn't explain how he knew about the other requirements to correctly operate the time machine, though.
 * Doesn't old Biff say something like "So, old doc brown finally made a time machine"? He's worked out it's a time machine, all he has to do is figure out the buttons. The time circuit panel with the date display is labeled, so he probably just kept pushing the buttons until he got it right. Given that he's 'from' the future, he'd know how to fly a hover conversion car.
 * As to knowing to accelerate and all, remember that he remembered seeing the car take off, accelerate, and then disappear back in 1985. He even notes it with "A flying DeLorean! Haven't seen one of those in... thirty years...?", planting the idea he remembers. Doc probably already had the time circuits on and Mr. Fusion powered up a certain amount... all Biff would have to do is punch in the date before flying off and speeding up.
 * And the digital speedometer says "Set to 88," a good indicator of the speed needed to initiate time travel.
 * Um, it's a time machine. He could have taken a month to figure out how to work it as long as he comes back soon after he stole it.


 * In Part II, why are Doc and Marty in such a rush to get the sports almanac back on November 12, 1955? Since both have their past duplicates they have to avoid, it seems rather risky. Since Doc states they need to wait for Old Biff to give Young Biff the almanac, it's obvious they just need to get the almanac back sometime before Biff starts actively using it to bet on horse races, which he can't do until he's 21. Thus, they have several years in which to get it back, so why not wait until even just the next day to attempt to steal back the almanac? This way they wouldn't risk interfering with the events of the first movie.
 * Because Hell Valley Doc had been institutionalized, preventing him from building the time machine in the first place. The fading of the time machine would create a paradox so great that it would no doubt have a catastrophic impact on the universe. The only reason the time machine still existed was because the ripple effect had yet to catch up with it. Doc did not know how long they would have before before the time machine was erased. Every second counted.
 * Biff didn't need to be in possession of the Almanac to bet on sports events: he needed to know the results. If they had waited they were running the risk of him reading the book and memorizing certain results, possibly jotting them down, or even tearing out pages and hiding them somewhere.
 * I think you're giving 1955 Biff a little too much credit, he wasn't smart enough to try anything like that until several years later. Nevertheless it's still important to get that book away from Biff as soon as possible, there's nothing to stop him form placing smaller bets on other sport events illegally until he turns 21.
 * There's two reasons: first, Marty knows from Biff's account to him that their best, if not only, shot at getting the almanac back is very close to the point at which Biff first receives it. And November 12, 1955 is the one point in space and time that Doc and Marty know well enough to be able to predict where Biff's going to be, since they've lived through it several times by now. After that, they're back to guesswork. Also, Old Biff has already told Young Biff to get a safe and keep the almanac safe at all times as soon as he can, and Young Biff is already cottoning onto the almanac's uses even as Marty tries to steal it back. Second, Marty and Doc are trying desperately to ripple 1985-A back into their 1985. The best chance of that is to remove completely the one element that causes the change: the almanac. And the most complete method of removing its influence is to recover it as close as possible to the point in the timestream where it began to affect things. Anything could happen if they don't do so; Biff might win some cash, and though he loses the almanac seven days later, has something else happen. Or, if Marty and Doc intervene (or even make the attempt) on a date other than November 12, 1955, something unpredictable could happen: they could lose the almanac without destroying it. That might erase 1985-A, but odds are on someone else might pick it up and use it, thus creating a "1985-B" -- which from Doc and Marty's point of view is just as bad in that it's completely unfamiliar, completely unpredictable, and could turn out worse than 1985-A.
 * Plus, it's sort of implied that November 12, 1955 has some cosmic significance, at least as far as Marty and Doc are concerned--not only does Doc first envision the flux capacitor on that date, but Marty's parents fall in love at the dance that happened on that same date. Not the most solid explanation in the world, but it's not the worst either.
 * The dance and Doc envisioning the capacitor were not the same date. Marty arrives in 1955 after Doc hits his head, but a solid week before the dance.
 * Because Biff is just as integral to the events of the first film as George, Lorraine, and Marty's other self. If Biff doesn't interfere with Lorraine and Marty's date then George won't punch him, Lorraine and George don't fall in love and we have a major paradox on our hands!
 * If getting the almanac back was so important, why where Marty and Doc sneaking around trying to steal it back without him noticing? Why didn't take, like, a gun and outright coerce him to give the book back? Doc had one at the beginning of the first movie.
 * Doc probably wanted to get the almanac without Biff seeing them, for fear of altering the future. Besides, Doc was very shaky with his pistol; if he tried to hold up Biff with a gun, the odds are good that Biff could've overcome him anyway.
 * And about that: why doesn't Old Biff attempt to stop George from punching Young Biff in the first place, given that he's in 1955 at exactly the right time to do so? Not only would it have allowed him to avert the most humiliating incident of his life, but it would also have had the effect of preventing George from winning Lorraine's love, and taking Marty out of the picture to boot. Instead,.
 * Word of God is that 2015 Biff left 1955 soon after he gave the almanac to his younger self.
 * 2015 Biff is an old codger with a cane and you expect him to prevent a fistfight between two teenagers?
 * 2015 Biff is also a car-detailer who probably hasn't thought the slightest about time-travel before suddenly having a time machine fall into his hands; he probably isn't thinking fourth-dimensionally to this extent. Essentially, he's probably just thinking "If I give this to my younger self, he puts on some bets and mints some serious cash, ka-ching!" and probably isn't interested in considering the timeline for possible past errors he can correct. He probably doesn't even make these connections since he doesn't remember the past timeline. He also probably thinks that punch or not, once he's a however-many-illionaire after winning on his bets Lorraine's going to be attracted to his wealth and leave George for him anyway, further increasing the "ka-ching!" and letting him get his revenge on George that way. Of course, it doesn't work out that way, but he's probably not thinking about it that hard.


 * In the first film, the DeLorean's exterior ices up after each trip through time. Why didn't that happen in the subsequent films?
 * Modifications made in the future, perhaps, although it does ice up in the Telltale game. It could have something to do with the ice not forming when the car is airborne, and it was hot enough in late summer in the Wild West in Part III that the ice wasn't noticeable.
 * Actually it does every time (though it thaws out relatively quickly). It's just not pointed out.
 * Why in the world would Doc have Marty take Jennifer out of the time machine and leave her in an alley? What, was she in his way or something?! Sometimes Doc is the dumbest smart person in the world.
 * She probably was in his way. There's not a ton of room in that car if you watch, Jennifer pretty much has to sit in Marty's lap when all three of them are in there. He probably got her out so that he could get out all the stuff he needed without risking groping his young friend's girlfriend in the process, and didn't think it was worth it to try and wrestle her back in when they only planned to be there for a few minutes anyway.
 * What kind of place must Hill Valley be in 2015 that a gang could assault a teenage boy in a cafeteria without anyone uttering a word of protest?
 * Probably the same sort of place it was in 1955 where they did the same thing? Or the same sort of place New York is today? Most people don't want to step up and defend total strangers. (Especially nerdy white male strangers, who probably rank somewhere just above "big fat hairy bikers" and "people with flattops wearing very fashionable brown uniforms" for generating sympathy from onlookers.)
 * Interesting weather they're having in 1955: Immediately after the DeLorean gets struck by lightning and is seemingly destroyed, the storm ends! And then a few seconds later it starts raining down heavily, with no lightning!
 * That's not completely impossible under ordinary circumstances in real life. Also, in-universe, it may be the case that the storm was sort of "tugged at by causality", a la Rubber Band History, with the purposes of aiding the time travel of both first-movie-Marty and second-movie-Doc.
 * Rainstorms often work like that; it's dry when the thunder and lightning happens, and then the heavens open. On a personal note, it's happening where this editor is currently sitting and writing right now.

Back to the Future: Part III

 * Why was Doc just fine with being left in the 1880s, when he's usually so anal about altering the past? Also, why did he not want to bring Clara along with him into the future/present? She was initially supposed to die, so taking her along wouldn't have messed with anything, in fact it would've actually set things right by taking her out of a timeline where she shouldn't even be alive.
 * He is enough genre savvy to know that Marty ALWAYS mess up the timeline. Although he make friends, none of them seems to be very close. About the Clara part, he met and fell in love with her for a span of four or five days, before Tannen killed him.
 * Well, we know he liked The Wild West anyway, so maybe he just figured that he could live out a quiet life in that era without disturbing anything. (Although he doesn't seem that keen to not disturb anything, befriending all the locals, becoming a major figure in town and all while using his real name.) As for Clara, I agree that that would be the most logical option. I can only assume the Doc's concern was that the culture shock would be too much for her.
 * If you remember, Doc told Clara the whole story and she didn't believe a word of it until she came across the model of the time machine in the stable. He couldn't take her back to the future because she dumped him. Also, on the subject of Doc not wanting to alter the past, III makes it clear that he's had enough of time traveling for personal gain, and has chosen to bury the DeLorean as a selfless act just so Marty can get from 1955 to 1985. When he wrote the letter he was happy living out his retirement in 1885, it wasn't until Marty found out that he got shot days after having written the letter that Marty went back in time and started changing things in a major way.
 * Presumably, Doc was too confused by his conflicted emotions to think straight. If he thought things out more clearly, bringing Clara back with him was the most logical choice (since she wasn't supposed to live in the past anyway). And convincing Clara would've been trivially easy if he had brought Marty and a few future artifacts to her house...
 * With Doc in 1885 you have only one person temporally out of place. With Marty there you have two. Which alters the past more? Which creates more danger of paradoxes?
 * And remember that Doc becomes a little less concerned about the Alteration of History by the end of Part I. That's why he decides to read the note and wear the bulletproof vest.


 * What the hell kind of Westerns did young Brown watch? That was the fruitiest cowboy costume I've ever seen.
 * Given his age, I'd guess black-and-white. The outfit wouldn't have been that bad in B&W (it was the colors that really got to me).
 * He was watching westerns that were made in the 30s, 40s, and early 50s. Check some out some time, and you'll find it easy to see why he thought that outfit would look right.
 * The novelization specifically mentions that his main source for ideas about the old west was Roy Rogers, who was a big T.V. star cowboy in 1955. Take a look at the getup he's wearing in his Wikipedia entry photo for an idea of what Doc had to imagine cowboys wearing.
 * It seems odd that Doc, who loves the Old West so much and is so intelligent, believes that people actually dressed like that back then. Then again, he could have learned all about the Old West after 1955.
 * He is exceptionally intelligent, but that doesn't mean that he has a comprehensive education about everything. The Old West may have been his favorite period of time from the movies he saw and he just liked it for that without ever getting around to doing historical research on it, especially since he was more focused on developing science. He built a time machine but that doesn't mean he's a historian... after all, he sets December 25th in the year 0 as the birthdate of Christ, which if you've studied the history behind theology is probably not the actual date of Christ's birth.
 * I just assumed that, despite knowing they were wrong, those clothes were the best he could get from the theme park at such short notice and he thought they'd have to do.


 * In the third movie Marty and Doc are all in a hurry to get back to the future before Doc gets a bullet in his back, so they come up with the contrived and extremely risky plan of using the boosted locomotive. But when Buford is beaten they suddenly have all the time in the world. Why don't they go back to the drawing board and try to come up with some other way of getting the car to 88mph? Hell, Doc is a genius - given enough time he could probably hack up a steampunk manifold and refine existing gasoline, or some other suitable fluid or gas. But no, they proceed as planned, with all the problems that causes.
 * But after Doc was saved from the bullet, Marty got stuck facing off with Buford in a showdown, so then they had to leave before the showdown. Of course, considering Buford was sent to jail before they left, they could have pulled the plug on the whole thing at that point. Maybe since it was already the day at that point and they had everything lined up, they just thought "Ah... I guess we'll just go through with it".
 * Because Marty was probably getting a bit homesick by then. Time was still passing for him even if it wasn't from his family and girlfriend's perspective. He was also getting older, which would make it hard to go back after a long while without anyone being suspicious. There was also the chance that Marty or Doc would do something that would cause Back to the Future IV. They could easily die from something in the past. Buford could get out of jail seeking revenge. So basically, a lot of very good reasons.
 * At that point, Doc had resigned himself to leaving Clara behind in 1885, and didn't want to torture himself by staying near her any longer than necessary.


 * If Clara Clayton was supposed to fall into the ravine and, thus, have it named after her, how could Doc be survived by his "beloved Clara" in his obituary, unless there's another Clara we don't know about...
 * In the original timeline, Doc went to pick up Clara at the train station, meeting and falling in love with her there. When Doc never showed up because of Marty, Clara rented the buckboard and almost fell into the ravine.
 * This would explain why it was named the Clayton Ravine in the first place, but it seems like once we get a timeline where Doc saves Clara from falling in, it must have some different name. It's not technically a continuity error since Marty knew about the ravine before all this time-traveling happened, but I'm pretty sure I put more thought into this than the writers did.
 * There are three variations here. In one, Clara falls in and they name the ravine after her. In the timeline where Doc dies she didn't fall in, so they maybe kept it "Shonash Ravine". Alternately Clara may have thrown herself in in a bout of grief, so they rename it in her honor anyway. After the third movie it's thought that Marty fell in, so they name it "Eastwood Ravine" after his alias.
 * Yes. In the "original original" timeline where there is no Doc or Marty in 1885 at all, nobody volunteered to take Clara home, thus she had to rent that buckboard, thus she died, thus Clayton Ravine.
 * Word of God is that prior to Marty traveling back and saving Doc, Clara threw herself into the ravine in grief. That's why it remains Clayton Ravine up until the point he travels back in time to save Doc. So it goes like this: No Doc in the past, no Marty in the past, equals buckboard rental and Clayton Ravine. Doc in the past, no Marty in the past, star-crossed lover grief and Clayton Ravine. Doc in the past, Marty in the past, happy and saved Clara, Eastwood Ravine.
 * Except that what Word of God said in the official Gale/Zemeckis FAQ was that Clara might have thrown herself into the ravine, and thus the ravine might be called Clayton in that version of events or it might remain Shonash. They deliberately refrained from showing the name in those parts of the films because they wanted it to be open to interpretation based on people's own theories about time travel.


 * Why Doc and Marty were being so idiotic in the third movie? The previous movies have shown that when you know the future, you can change it. So why didn't they simply leave the town and think about returning to the future with better time? It's not like Tannen would have been ready to follow them to the ends of the earth. Also, it wouldn't have probably taken much persuasion to get the sheriff to arrest his gang at slightest provocation.
 * But wouldn't they need to stay in town since they needed the train and that specific run of tracks to get back to the future? Also, long-distance travel was a lot more difficult in those days AND they have to bring along the DeLorean without letting anyone see it. As for the sheriff, he was clearly already doing everything he could to get Tannen and, I could be wrong, but I don't believe gun dueling was considered a crime in that era.
 * Actually, all they would need would be the flux capacitor, Mr. Fusion, and the time control chip planted on the hood; a rather small package, relatively speaking.
 * To scrap the Delorian Time Machine, put the Flux Capacitor, Mr Fusion and electronics in a rucksack, and flee on a mule... That isn't what people wanted (and paid) to see. But outwitting the most dangerous outlaw in town, helping a mad scientist to find love, stealing a train and pushing it 88 miles per hour to break the boundaries of the 4th dimension... Yeah, perhaps they aren't the sharpest knives, but the ending was worth of EVERYTHING.
 * Given that 'Mad Dog' Tannen had an armed gang and was himself a fast draw and crack shot, the sheriff might simply not have felt able to arrest him. Or Tannen might have been a suspect in many murders but without sufficient evidence (such as surviving witnesses) to actually get a warrant for his arrest on any of them. Or he might have plead self-defense in prior cases (given that his opponent would be armed). Its not like they had CSI teams back then...
 * Gun dueling (any kind of dueling) has in fact been illegal in the United States since it's inception; in fact it was called murder if it went the way it was supposed to go. This did not, however, prevent it from happening, especially in the South, but there is little evidence that the "Showdown at High Noon" happened in the West, apart from one or possibly two notorious incidents. Rather, if you wanted someone dead in the West, you did it the way you wanted it done in modern-day Los Angeles; kick in the door to the bar where he's playing cards and starting spraying. Indeed, a legendary gunfighter whose name escapes me (some Troper will no doubt tack on the right name an the story) was reportedly shot in the back of the head in a bar by his enemy. The enemy confessed, but said "I shot him through the eye, in self defense." The coroner remarked, "If he shot (the gunfighter) in the eye, he was exercising good marksmanship. If he shot him in the back of the head, he was exercising good judgement." So, frankly, the only imaginable way for Buferd Tannen and his gang of crooks to go free men for as long as they did was for the Sheriff to be too afraid of him to think about trying to arrest him. That said, when that sort of thing happened in the West, as would happen today (albeit much faster thanks to telecommunications), that when the law is outgunned by the crooks, U.S. Marshals will be sent in, and if they fail, the Army. (See also: WACO and Ruby Ridge.) Remember, the government doesn't like competition.
 * All of that and, well, in a deleted scene form Part III we see Tannen killing sheriff Strickland outside town before the duel with Marty.
 * That would be Wild Bill Hickok
 * As far as the time machine goes, that's a huge ''wallbanger' for me as well. Why, oh why, for instance, didn't Doc use the stored gasoline from the DeLorean? I can't imagine he'd just throw away that kind of a substance. Even a throwaway line saying he used it in an experiment would have sufficed. And I'm sure Doc "Mad Genius" Emmet Brown could have refined 1885 gasoline into fuel capable of powering the DeLorean. Or even if they had blown out the fuel manifold before thinking to do that, they damn well could have simply taken the time chip, flux Capacitor, and Mr. Fusion, then hopped the next stage or train out of town. With the Doc's brilliance (and possibly using Mr. Fusion as a power supply for incredible and fantastical things,) I can't imagine it would take them very long to establish a stretch of rail track flat (or preferably, on an incline) enough for them to run a specially-built/modified and purpose-purchased locomotive down the track.
 * Except that such a specially-built track probably would not have survived to 1985; it would likely have been dismantled in the meantime, or at least have undergone substantial wear and tear. The DeLorean would indeed emerge in 1985, but possibly in a very inconvenient location.
 * More inconvenient than where it did end up?
 * Absolutely; such as plowing directly into the wall of a building they didn't know had been built where the scrubland had been in the 100 years of expansion of the urban area around Hill Valley. between 1885 and 1985. At 88 miles an hour. With no doubt instant death for the occupants. At least with the bridge they knew the track would still be there with few obstructions; presumably the risk of a train was a risk they felt they'd have to take.
 * For that matter, why the hell, 88 miles an hour? They have the 1.21 gigawatts of energy from Mr. Fusion by feeding it manure. Is there some reason they need to be traveling at 88 miles an hour, relative to the Earth's surface? Does the direction, relative to Earth's rotational spin, and longitude and latitude, or it's position relative to the sun, matter? I can't imagine the last ones do, since the Earth was almost certainly in a SIGNIFICANTLY different location from 1985 to 2015, 1955, and 1885. They would've wound up in space if it did matter, but they always stayed nice and flat on the ground.
 * I don't think such "cheating" could be used considering the time circuits are attached to a vehicle, thus it had to be physically moving.
 * Physically moving relative to what, though? That's the problem -- it's a frame-of-reference thing.
 * Let's not forget that they don't want to change the future in any significant way. If they do, there's a problem in that they don't know what future they'll be returning to. As a result, they had to do everything in as low-key a way as possible (the theft of the train notwithstanding).
 * Admittedly a superficial reason, but Marty would not want to stay in the year 1885 for too long a time. He'd miss his rock and roll, and everything else he liked from the 1980s. As for the gun dueling, you bring up a good point. You'd think murder would always be wrong, but maybe attitudes towards gun dueling were different back then.
 * And don't forget Jennifer is still in 1985!
 * Also, Marty has to get back to the future before too long for one very obvious reason: the longer he stays in the past, the older he gets. If, having left the present at the age of seventeen, he returns to the present at the age of eighteen, or nineteen, or twenty, then everything's screwed up. He can't spend more time in the past than he needs to, because otherwise he won't be able to return to the present.
 * Considering how the incident with Mad Dog had shattered Doc's notion of a "peaceful life" in the Old West, they probably both wanted to get the heck out of there as fast as possible, before anything else could go wrong. Plus, who says Tannen didn't have any other buddies, who'd come looking for some payback for his arrest?


 * In the third movie, when the DeLorean is out of gas in 1885, why don't they take some gas from the earlier time loop version of the car that's still in the mine? (To avoid changing history, they could get some more gas from the future to replace it. Or just take an amount small enough not to be noticed; they only need enough for one trip.)
 * In the novelization Marty EXPLICITLY think about that plan, but Doc said that he had drained the DeLorean to avoid corrosion of the gas tank before storing into the mine. A pity.
 * Better question, why didn't the Doc go to Western Union and make a change to the letter he left, adding something like, "Oh, and bring along an extra jerry can of gas and some duct tape would you?"?
 * Because the letter says "Do not try to come and rescue me. I'm happy here". A letter that ends "PS: I was happy here until you come back here, told me that Bill's grandpa would kill me, and then now are stranded in the past because some stray arrow from an Indian pierced the gas tank. Help!!! Bring Extra Gas and a piece of Duct Tape. PSS: Hey 1955!Marty, I'm 1885 Marty, please, bring some Coke too. I'm thirsty." would be too hilarious and bizarre.
 * Solution: Have a second letter sent to Doc, some time before 1955 Doc sends Marty back to 1985 via the clock tower, but not too soon, saying something like "Marty will come to you at one point with a letter from yourself, and will ask for your help a second time. Make sure he brings extra gas and some duct tape. And do not, under any circumstances, let him know that you received this letter, or indeed that you have received any message from... well, you."
 * But how exactly is Doc supposed to know where to send this to Marty without Young!Doc intercepting it? The only reason the first letter gambit works at all is because Doc happens to know for a definite fact that Marty will be standing in that exact spot at that exact time in order for the postman to deliver it; beyond that, he's got no idea where Marty is going to be or what Marty is going to do. And if he sends the letter to Young!Doc's house, well, Young!Doc is probably going to be there, and is more likely to receive it.
 * Simple-yet-tricky answer to the better question: because he didn't do that. Marty reads the original letter and comes back based on it, so if Doc were to start adding things after that point, it would cause a paradox. In general, Doc's kind of keen on avoiding paradoxes where possible.


 * Doc's chemical bundles cause the locomotive's boiler to explode, yet despite the engine not being under pressure it's still accelerating?
 * Go back and rewatch. What does Doc say about his 'bundles' and the effects they will have on the train?
 * "Make the fire burn hotter, kick up the boiler pressure and make the train go faster" or "Each detination will be accompanied by a sufdden burst of acceleration"? The boiler had just exploded, the steam had escaped, there was no pressure to power the engine. No power, no acceleration.
 * The boiler hadn't yet exploded. It was venting steam like crazy, but you can still have pressure in a leaky container if it builds fast enough.
 * That wasn't the boiler that burst apart, it was the smokebox. The vapors seen escaping are smoke from the burning coal and bundles, not steam, which is why Doc and Clara weren't parbroiled on contact with them.
 * The boiler pops quite a few rivets, venting steam, in addition to losing the smokestack.


 * At the end of Part III we all see that not only is Doc living happily ever after with family, but he also created his very own Time Train. But in order to time travel, he needs a flux capacitor that requires 1.21 gigawatts of electricity. How was he able to create a flux capacitor with resources available only in 1885? He couldn't use the flux capacitor in the Delorean he buried in the mine, or else there wouldn't be a DeLorean in 1955! For that matter, what kind of power source is capable of 1.21 gigawatts of electricity that could be built with resources in 1885?! Even if we assume he got all the futuristic stuff from 2015, he still needed to rig a train that was capable of time traveling in order to reach 2015 in the first place!
 * A. Doc built the Flux Capacitor in the first place. If anyone knows how to build another one, it's him. As for the initial 1.21 gigawatts? Well, Doc might not know exactly when and where lightning's going to strike again, but he's a Mad Scientist. He could rig up a lightning rod and figure out how to channel it into a train at the right time. Also, chill. You're close to going over your daily allotment of exclamation points.
 * We don't know exactly how complicated a device the flux capacitor is - or Mr. Fusion, for that matter. It's possible that Doc could have built one or both from late-1800s components, given enough time (and, based on the ages of his children, it probably took at least a decade). Even if he can't create a fusion reactor, I suppose he could electrically connect the train's wheels to the flux capacitor, and then use a lightning rod to channel electricity into the railroad track. This wouldn't require exact knowledge of when the lightning was going to hit, or exact positioning of the train, as long as the train was traveling along the track at 88 MPH when it did strike. It might take several tries to get it right, but he'd only need to get lucky once.
 * Did you guys already forget he also had the hoverboard with him before Marty went back to 1985? You can never keep a good scientist down with resources like that mo'fo.
 * If it's true that the 88 mph speed is arbitrary, then Doc could have simply removed that, built the machine, attached a lightning rod on top, and waited inside during a thunderstorm. If he set his machine to go to 2015, he could then completely hover-covert it, install Mr. Fusion, etc.
 * It's time travel. He could cannibalize the flux capacitor in the DeLorean for his locomotive time machine...as long as he made sure to put it back (or replace it) before Marty retrieves the Delorean in 1955.
 * And why was everyone yelling in that scene?
 * IIRC, the time-train was making a lot of noise. Plus, Doc and family were standing a good 3-4 feet above the ground, and Marty had already backed a short distance away from the tracks and was too stunned by seeing Doc alive that he didn't think to move closer.
 * Gesturing to the train, Doc explains to Marty and Jennifer, "it runs on steam!"
 * Also, a fairly large flux capacitor can be seen on the train's exterior if you look closely- it's much larger than the one on the Delorean. While it's possible the size of the flux capacitor has to be somehow proportional to the vehicle it's a part of, it might also be that size because Doc made it out of bulky 1800s steampunk components of some sort.
 * The other problem with all these theories is this: the whole reason for the third movie is that Doc explicitly said in his letter that he *isn't* able to fix the time circuits with 1885 components. Since he's in exactly the same situation at the end of the movie (stuck in 1885 with a DeLorean with broken time circuits still in the cave from before), what's different at the end such that he *is* able to figure out how to build another time machine? The fact that he has children when he arrives in 1985 means he had at least five years to work on it, so I suppose it's possible. You just think they'd give a better explanation than "it runs on steam."
 * There are two explanations:
 * Ah) Motivation: First time he ended stranded in wild west, he feels an old man, he likes the wild west, and fixing a Delorean Time Machine would be a huge effort which could end in too many changes in the timeline. But when he sent Marty Back to the Future he has a beautiful wife, a über-positive attitude to life, and the idea of a train to travel. So, when he feels depressed, he has his wife to cheer him up.
 * Bee) Plot: If he could fix the Delorean or make a Time Train when he put a foot in 1885, there would not have been Btt F-3. (Hey! I'm Doc Brown. I will build a Time Train, go to 2015 and buy some replacement parts, then back to 1884 just when I arrived first and give me a letter: "Hey Doc, I'm Doc. I built a steampunk time machine, went to the future and buy this parts for you. Don't forget: go to the future, buy these parts and give them to yourself with a copy of this note and then go back to 1985 for Einstein. I do this to avoid messing with the timeline. Hehehe, we are a pair of genius... PD: Take care of your teeth, I got a caries and it was YOUR fault."
 * Also, Sea) Marty: While we know that it would be possible for Doc to fix the Delorean, he didn't know that for sure. He might have run into a problem that even he couldn't fix, or he might have just died before finishing it, either of which would have left Marty trapped in 1955. 1885!Doc no doubt felt responsible for Marty's predicament, and he knew that 1955!Doc would have a much easier job. He took the option that would give Marty the best chance of getting his hands on a working time machine.
 * The first time Doc is stranded in 1885, he doesn't really mind. He's done with time travelling and thinks life in 1885 is better than life in 1985. Also, suitable replacement parts won't be invented until 1947. He could invent those, but who knows how many early-20th century inventions he needs to do before he can make those? So, he decides that it's easier to stay in 1885. But Marty needs to get home, so he buries it in the mine until 1955. Note that Doc has done some inventions in 1885 to make life easier: he's invented a fridge. By the second time he gets stuck in 1885, this time with Clara, he's realised that 1885 is a dangerous place (Buford Tannen will be released from prison someday, and then what?). Perhaps Clara and the kids would like to see too how 1985 is. So Doc starts building this new time machine, which takes him years, looking at the kids' ages. I guess that after a while, he did get a little homesick about Marty and 1985. So, Doc goes back to the future.
 * There's another explanation, one that is clean and simple, and really doesn't require anything more than what we see in the movie. When Doc said that he couldn't repair the time circuits, he meant that he couldn't do it at a scale such that the DeLorean could actually carry it. Look at what had to be done to the Train to get it to work as a time machine - there's no way that a small car could carry so much. It wasn't until he had the inspiration of using a train to generate the required speed, thanks to the events leading up to Marty's return to 1985, that he realised that there was a way to make time circuits for a time machine in 1885.
 * Another alternative is that the DeLorean had redundancies in its time circuits, in an attempt to prevent being trapped in the wrong time - the redundant circuits were fried along with the originals, unfortunately, but they were both repaired by 1955 Doc. As the DeLorean was to be destroyed upon return, Doc had taken the extra circuits out, in case of some unfortunate accident. Less likely than the size explanation, and requires some extra speculation, but plausible.


 * How could Doc Brown and Clara have a healthy kid at their age, let alone two? In the first film, 1955 Doc even says that he's amazed that he's going to be that old. So how is it possible for that to happen?
 * Men don't stop producing semen due to old age the same way that women undergo menopause. Doc's age is irrelevant-- only Clara's. And she's considerably younger than he is.
 * Not to mention, In Vitro Fertilisation or some other advanced form of fertility aid would have been available in 2015 or whenever they went to the future.


 * Since doc stays in 1885, how does he get away with stealing and wrecking the train?
 * The only witness saw him with a scarf over his face. They didn't exactly have CSI's back in the 19th century to link him to the crime.


 * When 1955 Doc saw his tombstone, how come 1885 Doc didn't remember it?
 * Because that Doc never saw the tombstone, in the same way that the Doc from the start of the first film didn't remember meeting Marty in 1955.


 * So, Doc couldn't repair the time circuits with 1885 components. But he knew how to fix them with 1955 technology; couldn't he build the components he needed? He was able to build a steampunk ice-making machine, would it be that difficult to build 1955 circuits? I don't have knowledge of these things, so probably my question is stupid... but why is it impossible?
 * Because making refrigeration coils is considerably easier than making something to produce a vacuum and thus vacuum tubes, which are clearly a part of the 1955 "microchip"?
 * Pulling a vacuum isn't that tough (see Magdeburg Hemispheres, 1656). But decently working vacuum tubes are tougher than you might think. Glass-to-metal seals (so the connections can get out without letting air in), some fairly exotic alloy coatings on the elements to improve emission from the cathode and reduce secondary emission from the others... even if Doc knew all about that, he wouldn't necessarily have access to the raw materials in a small settlement in the Old West. Then there are other parts like resistors and capacitors... maybe hundreds of feet of magnet wire for transformer windings... all this stuff took a lot of incremental development to get, even to 1955 standards.
 * Okay, Doc has somehow made a refrigerator that fills an entire room. Why is he filling the thing with original Hill Valley water? Surely he can build some filters or an evaporator/condenser into the thing to purify the stuff he drinks. Heck, the thing appears to be steam-powered, so why can't he capture the steam coming off the boiler and drink that?
 * He still has to get the water from somewhere, so he probably figures it's easier to just use the most conveniently available water source. Plus, he probably doesn't want to have to spend ages filtering it, purifying it or collecting every evaporated drop every time he just wants a quick drink. Besides which, he presumably had to live on the local water supply before he got the refrigerator up-and-running, so it's likely he simply got used to the taste, or even likes it.


 * Was anyone else disappointed that Old West Doc hadn't acquired a new dog back then, and named it Newton?

Back to the Future: The Game

 * In the Telltale game, the timeline eventually gets so messed up that the events of the movies never happened, up to and including the part about the time machine having been built in the first place. Shouldn't that cause a major Grandfather Paradox, making that version of the timeline unviable?
 * Delayed Ripple Effect works on time machines as well as time travelers.
 * Couldn't Doc and Marty just kill Edna in 1931 instead of having to go through a long sequence that leads to the planned break-up?
 * Right, because Doc and Marty are cold blooded killers who would be totally fine with straight up murdering someone. That's completely and totally consistent with their characters.
 * The timestream would also take a way bigger hit if they did that.
 * Also, why doesn't Marty just swap Emmett's mind-map with Kid's? Surely Kid must be a "Degenerate Criminal", and Emmett didn't even test Kid's mind-map when the break-up was about to happen. Why go through such a long sequence involving changing smells?
 * Maybe the punch card had some kind of identifier we couldn't make out printed on it. So switching them wouldn't work because Edna would have noticed, being the one to get Emmett to build the thing.
 * If you click on Kid's card, Marty examines it and notes that Kid's name is written on the card. Why you couldn't just get a blank card and punch holes in it to match Kid's is beyond me though.
 * In the third episode, Einstein and Doc disappear from the Delorean wreck and we only see their alternate universe personas. But Marty never changes to his alternate personas throughout the series. Why does this affect Doc and Einstein, but not Marty?
 * Because Doc isn't Doc anymore. By going off with Edna instead of going to see Frankenstein, he is essentially preventing a fundamental aspect of his own Doc-ness. The moment he displays the mind map thing instead of the flying car, he stops being Doc Brown, and starts being First Citizen Brown. It just took until Marty hit 88 for the timeline to catch up to him. Marty didn't disappear because: a.) He didn't put his own existence in jeopardy, and b.) even if he had, it would have taken the timeline longer to catch up to him (due to being the last born), which gives him a chance to undo the damage.

Paradoxes

 * When Marty goes to 2015, how does he meet himself? Think about this: when Einstein (the dog) goes one minute into the future, does he meet up with future Einstein? No, because there is no future Einstein. Einstein just skipped over that minute, and for one minute there was no such thing as Einstein, anywhere in the world, until the DeLorean showed up again. The only way time-traveling Einstein could meet a future version of himself is if he went back in time and then caught up with himself via The Slow Path. Similarly, if Marty jumps to 2015, there should be no future Marty to meet. Logically, Marty went missing back in 1985, and there was an unsuccessful search and eventually he was presumed dead etc. (which would be rather dark, actually...). The only way Marty can meet himself is if he meets a version that has already been to 2015 and back. This brings up an interesting theory: maybe future-Marty knew everything that was happening behind the scenes, but didn't bother involving himself because of the Temporal Paradox or something.
 * This is actually played straight in Flight of the Navigator where a boy is picked up by an alien spaceship and dumped 8 years into his own future by accident. History recorded that he went missing once he was removed from his own timeline. Once he managed to return from the point he left, the timeline continued on as it should have with him in it.
 * Actually all one has to do to explain it all is that Marty could obviously conclude that the future he travels to is part of a current timeline where he did travel back to his own time and lived out his life, thus being able to meet his future self.
 * Regarding both the above plot holes, Robert Zemeckis and Bob Gale have basically admitted that they just fudged it for the sake of convenient storytelling.
 * But they also said that there is a possible explanation, as clearly implied by what Doc says upon seeing the photo of the tombstone change in Part III: that time travel into the future takes you to the likeliest future of the way things are going at the moment when you traveled.
 * Perhaps the timeline "knows" Marty will eventually leave the future and go back to live his life up to that point? Or perhaps this is another facet of the above explanations for why alterations in the timeline don't immediately cause pictures and people to fade sometimes, but do other times.
 * My explanation is that we're seeing an altered timeline already. In the original one, they went to 2015, found out that Marty and Jennifer's older selves weren't present, and returned with disappointment. Then they grow up to become the 2015 Marty and Jennifer we see in the movie, meaning that 1985 Marty and Jennifer are now going to meet them in the altered timeline.
 * The Ripple Effect. We know that it takes a week to catch up to 30 years, but Einstein only went a minute into the future. His disappearance had already caught up with him when he arrived. Marty and Jennifer went 30 years into the future, so they would have had roughly a week before their 47 year old selves faded from 2015.
 * Incidentally, Marty never does meet himself in 2015. Jennifer does, but Marty doesn't.
 * The reason the way things work differently for Einstein is that Einstein is the only person who goes to the future, and DOESN'T go back. There's actually TWO ways a person can meet themselfs/exist twice at the same time; the first, as mentioned above, is to go back in time and meet your past self, OR go to the future meet your future self, then go back in time, ride the slow path to the future, and then meet your time traveling past self. Since Einstein never went back, he really didn't exist during that 1 minute. Also, after BTTF 3 ( Unless the games say otherwise, I haven't played them) Marty lives out his life, and 30 years later Time-traveling!Marty comes does the his stuff, and leaves. Then 2015!Marty doesn't get fired, makes sure that Time-Traveling!Marty did things right, then 2015!Marty has a long heart to heart discussion with Marty Jr. to makes sure nothing like what happens again. BUT! the 2015 marty that we see in the 2nd movie DOESN'T know what is going on ( contrary to the original poster's theory ) because the delayed ripple effect hasn't reached him yet.
 * Here's a totally different possibility then the ones described above. (Or maybe it's the same as one of them, because Timey Wimey stuff is so hard to follow.) The 2015 that we see Jennifer and Marty visit in Part 2 is one in which they hadn't done any time-traveling since 1985; the middle-aged Marty we see had only ever visited 1955 and returned to the modified 1985, while middle-aged Jennifer has never been in the DeLorean at all. The reason this works is that Doc is the one who drives the folks to 2015 and so his perspective is the one that "matters". Here's how it looks from his view: After surviving the bullets with the vest in 1985, Doc decides to go visit the future. He does disappear for thirty years, and time goes on "normally" until 2015. Very shortly after the Doc had left, Marty has the car accident that we see him avoid at the end of Part 3. Sometime after that, it becomes apparent that Doc isn't going to come back, and this further contributes to Marty's psychological issues. In 2015, Marty Jr takes part in the heist and gets arrested. Shortly after that, Doc finally shows up from 1985. He sees the newspaper, grabs it and decides to prevent it. So he goes back to 1985 and picks up Marty and Jennifer, which would have caused an alternate 2015 except the Delayed Ripple Effect doesn't "catch up" then, and only after their arrival in 2015 do any "real" changes happen. As a general principle of BTTF metaphysics, you go to exactly the same future you came from unless your actions are such that there's no way that future could have occured (plus the Delayed Ripple Effect has some kind of complicated weeks-to-years relationship). So old-Biff returns to his original timeline and not the rich-Biff timeline because he left 1955 before the crucial juncture at which either young Biff started getting rich or Marty took back the almanac. I admit that it still doesn't make complete sense to me, though.


 * If Marty prevented Doc from getting shot, that means he never looked at his tombstone, which means he never traveled back in time to save him, which means Doc got shot, which means he did look at his tombstone, which means he traveled back in time to save him, which means...
 * Ripple-Effect-Proof Memory.
 * Doc had plenty of time afterwards to buy a tombstone and put the necessary information to get Marty to come back. The tombstone disappeared at first because it looked like Doc was going to survive and go back to 1985 that day. Ripple-Effect-Proof Memory prevented anything from happening then. When Doc stayed behind for Clara, he would have been able to plant a fake so it would be present in 1955. It's not like Marty and 1955 Doc dug up a body to confirm it.
 * If Marty prevented his son from getting arrested, that means he never got arrested, which means he never traveled forwards in time, which means he got arrested, which means he traveled forwards in time, which means...
 * Most of the stuff in Parts II and III inevitably leads to paradoxes in a "strict" mutable timeline, where subsequent timelines don't have "memory" of what happened "the first time around". One theory that's generally accepted on bttf.com is that in the BTTF-verse, any time traveler's memories from the first time around are transplanted to any subsequent iterations. It doesn't make any reasonable sense, but this assumption helps explain almost everything.
 * We call this Ripple-Effect-Proof Memory.
 * Actually, this isn't a case of Ripple-Effect-Proof Memory. Rather, it's a case of tangent timelines resulting in Doc's previous time travel and observing Marty's son's arrest not being affected, as it occurred prior to the time travel that prevents it. This could be argued to also be why we don't see a second 1985 Doc in 2015 - that Doc didn't travel to the same timeline, just as the 2015 that Marty travelled to doesn't actually get altered by Marty's later personal growth.
 * At the end of Part III, Doc and Marty steal a locomotive. Their getaway plan is to go to 1985, which Marty does... but Doc doesn't, because Clara shows up. So why isn't he arrested for hijacking and destroying a locomotive? Surely the engineer would be able to identify him.
 * Possibly he was. In the Wild West, notorious outlaws were often pardoned in lieu of hanging or imprisonment if the confessed and came along willingly; of course, there was the implication that the hanging would be very prompt and they would never see the inside of a court house if they went back to their thieving, murdering ways. Doc Brown might well have confessed the whole thing, and then, in lieu of payment, went to work for the railway company to pay off his debt. He would have soon paid himself out of debt by using future technology knowledge (we know he knows electrics damn well, and he was turning into a Steampunk Gadgeteer Genius), and that he parlayed into a fortune, which he used to construct the Time Train.
 * How could the engineer recognize him? They both had handkerchiefs over their faces.
 * Everyone probably figured Clint Eastwood and friend had fallen into the ravine.
 * They did, according to Zemeckis and Gale, hence the renaming of the spot as "Eastwood Ravine".
 * I always figured Doc and Clara told everyone some story about how they witnessed "Clint Eastwood" try and stop the hijackers and went down with the train doing so - thus the reason the people chose to name the ravine after him.
 * Which raises further questions as far as the authorities in 1885 are concerned: who in their right mind hi-jacks a train for a "science experiment" and then crashes it off an incomplete stretch of track into a ravine? By the time Marty gets back to the future, Shonash Ravine has in effect been named in honour of someone who went to great lengths to commit suicide a la Thelma and Louise!
 * Yes, and? Most people (including many who've never even seen it) think of that movie precisely because of its ending.
 * Probably the story they told involved hijackers who didn't know that the bridge hadn't been built yet. (Maybe they were from out of town and mixed up one bridge or track with another?) By the time they realized their mistake, it was too late (and possibly they were too busy fist-fighting with Clint Eastwood to even realize the track was ending). Also, the engineer who was told that the hijacking was a "science experiment" decided that that was a ridiculous idea, and concluded that he must have misheard the hijackers.
 * Or that the hijacker was being sarcastic. "Is this a holdup?" "No, idiot, it's a science experiment! Yes, of course it's a holdup, we're pointing guns at you!"
 * An easier explanation is that Clara told everyone about the two hijackers falling into the ravine, while Doc simply stayed hidden at her place. He wouldn't want to confess to anything and risk further altering the future; once the heat died down, he could work on building another flux capacitor (with Clara running interference as needed).


 * The DeLorean's flying circuits are destroyed when it's struck by lightning. So does every thunderstorm in 2015 send cars falling from the sky?
 * Also the Delorean had a solid stainless steel body. For that precise reason it should have been protected from lightning strike. Aircraft are struck by lightning fairly regularly with no real damage due to the electricity flowing around the body and out the other side. This is also why it is safe to be in a car on the ground in an electrical storm, it has nothing to do with the rubber tires as has been so often misreported. Even the slight EMP produced by lightning should be shielded. See Faraday Cage on the other wiki.
 * Presumably, cars that were actually designed to fly have protection against this. The DeLorean was modified to fly, which probably bypassed a number of safety precautions in modern cars. Think of airbags and anti-lock brake systems on cars these days, which are designed to crumple instead of plow through obstacles. It's similar.
 * Except there's a commercial for ground-car conversions in the 2015 segment, suggesting that many cars we see flying around are modified terrestrial vehicles, not originally built to fly.
 * Actually, Doc states that in the future they have a very precise weather altering system. Presumably nobody falls out the sky simply because scientists found a way to make lightning never occur again.
 * It's not a weather altering system, it's a precise weather prediction system. Doc isn't making the rain stop at the beginning of Part II - he's checking the forecast to see the exact moment the rain will naturally stop.
 * Did we ever see anyone flying a car in 2015 during a thunderstorm? Possibly people just keep their wheels down on the pavement when the weather's bad, same as most IRL people avoid driving during a blizzard.
 * We did see cars in 2015 flying during a thunderstorm at the very beginning of Part II. The Delorean jumps from 1985 to 2015, ending up on the wrong side of the skyway.
 * Drivers could be willing to live with the (small) chance of encountering lightning. Slick roads and the risk of a crash don't stop people from driving ground cars during thunderstorms, after all. Plus, we know Doc survived his midair arrival in 1885, so perhaps flying cars have an emergency backup levitation system that brings them down safely if the flying circuits shut down.
 * It's possible that it wasn't just the lightning that destroyed the circuits -- it could have been a combination of being struck by lightning, being propelled to speeds of 88mph+, accidentally travelling through time as a result and what was probably a rather bumpy landing in 1885 before Doc managed to get back in control of things, all of which presumably most 2015 air-motorists wouldn't have to worry about -- but Doc was just over-simplifying to get the point across that the flight circuits were now useless. Alternatively, lightning can still fry most modern electronic devices to the point where they're useless if there's not a good surge protector on the lines, so it could have been something to do with that.


 * As soon as Biff in 1955 gets the Almanac and starts betting on the games, shouldn't that start to change the outcomes of the future sporting events, thereby rendering the Almanac useless eventually? At least once he became a famous, wildly successful gamester, the makeup and playing ability of given sports teams probably would have changed unpredictably.
 * How does one guy making money betting on sports teams change who will end up on those teams and how games will play out? He doesn't own, manage, or coach the teams, and he's not a sportsman himself, so his actions aren't going to change anything.
 * He didn't live in Washington D.C. either, yet Nixon is seeking his 5th term as President in 1985-A. Changes snowball.
 * And even if it was going to change the outcome, don't you remember that every single time the future changes, objects from that future change to reflect it? Marty's brother and sister disappear from the photo in the first one, the picture of the gravestone changes in the third, the fax firing Marty changes once he gets over his Berserk Button, the newspapers about Doc Brown being committed and Marty Jr.'s arrest change when Marty and Doc fix things, and the matchbook that Marty grabs from Biff's casino changes to Biff's auto detailing shop. If the future of sporting events was changed because of Biff's betting, then the Almanac would change too.
 * The imdb goofs page notes that one of the scores mentioned in the movie doesn't match the actual score of the game, suggesting that Biff has played some role in the outcomes of the games. As for how it might do so, who knows? Maybe Biff's massive gambling winnings triggered an investigation which discovered point-shaving that had gone unnoticed in the real timeline.
 * The IMDB goof, which regards the score of the actual Texas A&M/Rice football game on Nov. 12, 1955, could be explained away as the Hill Valley radio station announcer just having incorrect info (which wouldn't be a huge stretch of the imagination in 1955) and Biff being too drunk to notice. It would be waaaay too soon for Biff to start changing the future in any significant way.
 * Because of the ripple effects of time travel and the book's status as an object from the future, any sports scores until 2001 would always be correct.
 * Biff's insane wealth caused the Vietnam War to last longer than it should've. Pretty sure if his money influenced something like global politics, it most definitely affected sporting events. Although, wasn't it said that Biff got his million dollars from just one horse race? If he got it all in one go, it wouldn't matter what the almanac said after that, considering he doesn't rely on it. Even if he, like it's been said, anything that changed the future would change the almanac. As long as he didn't do something crazy like change it so often the publishing company who printed the almanac never did it, and then the almanac fades from existance entirely. Not like it'd matter, by that time Biff would be filthy rich.
 * No, it says he won his first million on that one horse race, and then kept on winning and winning.
 * He presumably didn't bet on every single game or race, however; he presumably picks and chooses his victories. We don't learn how long his winning streak was.
 * Good old-fashioned corruption and match-fixing. The more money 1985A Biff has, the more he has to spend on match-fixing, bribery, etc, thus ensuring favourable outcomes book or no book.
 * Even if the almanac only works for the first few games, Biff can still get rich off of it. He becomes a millionaire on his first day of betting. Over the next couple months, he uses that million in more bets and makes more money. Let's say that at this point, For Want of a Nail, the book starts making mistakes. But what does it matter? Biff's already a multi-millionaire now. He can put his money into investments or whatever, so he keeps getting richer.
 * And even at the beginning he might be making bets infrequently enough that the almanac has time to catch up to any changes. He bets on a horse race in late March 1958; if the next thing he bet on was, say, the '58 World Cup (June), the almanac would have long since updated itself. If we assume he can get, say, a 75% return for each bet he makes, he's got about $50 million (which would be $170-180 million in 1985 money) after only seven additional wagers after the first, which could easily be accomplished by, say, the mid-1960s, after which he "parlayed that winning streak into the vast empire called Biffco" and had no need to make additional money by gambling.


 * Presumably there's a version of Marty who grew up with an assertive father. What happens to him?
 * Um... went to the past, of course. In the first movie, we see the version of Marty who grew up in the altered timeline briefly when the "original" Marty arrives a few minutes later to save Doc.
 * Many many moons ago, Starlog magazine published an outline of their theory on the LP-TP timeline dichotomy ("Twin Pines" and "Lone Pine", respectively; Marty's from the Twin Pines Mall timeline, and ends up in the "Lone Pine" timeline after running over one pine in 1955). According to their theory, in the LP timeline, Doc is a bit more cautious (as evidenced by the bulletproof vest), and loads extra plutonium. Marty, having his own car in this timeline, is a better driver. He arrives back in 1955, and avoids hitting the tree, then immediately returns to 1985 with the spare plutonium as soon as he makes it to a good road. Things are a good deal bleaker for him, according to the theory: Doc's dead for real, his dad's a giant pussy, etc.
 * Why would LP!Marty change history? TP!Marty exists in his past and would still do all the stuff he did normally, so going by the above explanation the only change would be that a car briefly appeared then disappeared in the middle of nowhere during 1955. This should have little to no effect on the future, especially since history is pretty elastic in the series.
 * You assume that LP!Marty went back to the same time point as TP!Marty did. If LP!Marty went back to earlier, it's possible that LP!Marty in some way caused the "original" TP timeline to play out as it did. Thus forming a Stable Time Loop. In fact, given the remarkable strength of the genetics, perhaps he travelled much further into the past, and ended up starting the entire McFly family line, then "returned" to the 1985 TP timeline.
 * Lorrayne and George just love to tell the story about how did they end in love. And Doc had a lot of time to think about implications of time travel (he had experimented them!) So, while TP!Marty comes back to reality, LP!Marty will end stranded in the past without extra plutonium, just as Doc had planned; he will try to follow 1955!George as TP!Marty did, and would rush to save him from being hit by the car, as TP!Marty did. Then he would wake up and be called "Calvin Claine". He just had to put two and two together, remember the story that their fathers said for many years, and play the lines his fathers have been telling him since he was born. The only thing that would change is a "WTF" for LP!Marty part.
 * Except this theory is Jossed by Parts II and III. We're thus to believe that no "alternating timeline loop" occurred.
 * Not that we got to see. Doesn't mean they didn't exist, though.
 * My theory is that the two Marty's just merged - and, eventually, Marty remembered both the Wimp!George past and the Confident!George past.
 * I don't think so. My biggest bit of Fridge Logic is how Marty intends to not look like a body snatcher. He's essentially traveled to a parallel universe where everyone (including Doc) has led a different life than he thinks they did.
 * It wasn't a different universe, it was a different timeline. I think, within time, Marty's new memories would catch up with him.
 * Marty seems a lot more confidant in parts 2 and 3 than he did in 1. I always believed that it was because he became the Marty of the new timeline. Shortly after part 1 he looses his old memories and only has memories of the new Marty's life (notice how part 2 treats the altered timeline as the original).
 * I always assumed that Marty was less vulnerable to his environment than his siblings, thus he turned out okay even with the unhappy family. So that the change in family background didn't effect him much (just all his memories).
 * This makes no sense. For all intents and purposes, the Marty raised in the LP timeline should replace the Marty raised in the TP timeline in the "next iteration". As for why he had the memories of the original timeline, there are different theories, from "time travelers in BTTF undergo memory replacement when they travel to the past" to "we're viewing the intermediate timeline, not the final timeline where the changed Marty returns to the future".
 * We're probably never going to come to any conclusive agreement. There are all different theories one can go with. I believe that LP Marty went back to 1955 and became TP Marty. After returning to 1985, TP Marty and LP Marty become one and the same. To me, the "memory replacement theory" makes the most sense.
 * Recall that all through the first movie, Marty's own history is gradually disappearing (as seen in the photo), and that he actually starts feeling physical discomfort toward the end. This seems to back up the "Merging Timeline/Memory Replacement" idea.
 * Inherent plot hole of nearly any story where the main characters have Ripple-Effect-Proof Memory.
 * Okay, here's my theory. When George kissed Lorraine it caused the photo to fade back, creating the LP timeline. At that moment, TP Marty was fading out. Thus, when he faded back, he became the LP Marty. BUT he has Ripple-Effect-Proof Memory, so now he's LP Marty with the memories of TP Marty. Consider the implications: When Marty met Doc after the dance, that Doc would now have the memories of interacting with the LP Marty and not the TP Marty or even the LP Marty with the memories of the TP timeline. Also, when we see the original Marty of 1955 in Part II, he would have the memories of the LP timeline up until the school dance. As far as the LP timeline is concerned, Marty's memories spontaneously changed at the moment George and Lorraine kissed.
 * I still think, at the end, Marty would remember his past from both both timelines. During the week in 1955, though, there is only Marty with TP memories. To have him ever be LP Marty during that week would mess with the events seen in the film. I also really don't like the idea of everyone that LP Marty has known suddenly losing the Marty they knew and loved forever. Also, in the novel of the third film, there is an indication that Doc 1985 in 1885 would suddenly remember dressing Marty up in the outfit - even though he didn't, at first. I know the novels aren't entirely canon with the films, but that's another thing to consider.
 * My opinion's always been that LP Marty is the one who hates being called chicken. TP Marty, with low-self-esteem inherited from his father, wouldn't get worked up over it. Further details on the Wild Mass Guessing page.
 * Of course, you also have to realize that during 1955, Marty is still the TP version, and is theoretically outside of the main time stream (seeing as how he hasn't been born yet), and upon his return to LP 1985, "skipped" the 30 years to arrive back at the mall when the LP version of Marty travels back to 1955 (thus making the TP Marty the LP Marty the moment he travels back through time).
 * My insane theory is that the Marty we see go back in time at the end of Part I is the same Marty we see in the background of 1955 in Part II. That Marty returned directly to the repaired 1985 and eventually grew into the Marty we see in 2015. That Marty grew up with messed-up kids and never made the trip to 1885. When POV (Point-of-View) Marty declines the race with Needles at the end of Part III, he causes 2015 Marty to fade out of the future, which is why the "You're Fired!" fax fades out as well. By the end of Part III, LP Marty was erased from existence.
 * Here's my take on it: TP Marty goes to 1955 and unknowingly "fixes" George's confidence. We now have a new LP timeline. When TP Marty leaves 1955 to go back to 1985, we now have an LP Marty, who has lived a life with a confident father, a Doc who's not telling him he's wearing a bullet proof vest, that left to go back to 1955. However, even though the new LP timeline has replaced the old TP timeline, it has only been replaced AFTER the fight with Biff and the kiss. WHY? Because George still needs "a friend" to push him to be confident, which doesn't happen until the dance. Before that, he's still a wimpy Peeping Tom UNTIL Marty arrives, saves and interacts with him. Never in George's life has he ever developed confidence on his own without Marty's help. So George's life before the dance is identical to the original TP timeline. In a nutshell, ever since the TP Marty returned from 1955, there will now always be a Marty going back to 1955 to do the same thing. The only difference is the LP Marty will see a much bigger contrast than TP Marty did between his father's behavior in 1955 and his father in 1985. So, just like the skateboard, the Mayor, and Johnny B. Goode, George Mcfly's confidence (as well as Old Man Peabody's pine!) has now become a Stable Time Loop.
 * Speaking of Time Loops, in the BTTF universe, Marty has and always will be the inventor of the skateboard, inspiring Chuck Berry, and convincing Goldie Wilson to run for Mayor. Since all these things existed for TP Marty, this means that Marty will always travel back in time. It is interesting to note that TP Marty lived with a wimpy father in contrast to LP Marty, who lived with a confident father, which was created due to TP Marty's actions. So, under the Stable Time Loop theory, there WAS a Marty before TP Marty that went back in time to 1955, invented the skateboard, and inspired Chuck Berry and Goldie Wilson; but unlike TP Marty, he never saved his father from getting hit by the car nor did he push him to be confident (and he dodged the pine!). So my question is, why did Time decide to give TP Marty, in his leap back to 1955, a different pattern of thought to save his father and make him confident, in order to create the LP timeline?
 * If Doc is more careful and planning in the Lone Pine timeline, it's possible he mused through all this beforehand. He had thirty years to think it over, after all. He could have altered things like the amount of fuel in the gas tank and the date the time machine was set for slightly, so that Lone Pine Marty would still run into his father, save him from being hit by the car, and thus setting off the necessity of going through all the same events. The differences between the two would probably be negligible. Indeed, none of Marty's family is surprised by the way he dresses or his habits ("Sleep in your clothes again?") other than his being surprised at them, so the two may simply be different in extremely minor ways through whatever coincidence of events, meaning that the only difference in the two would be their early experiences upon arriving in 1955.
 * In all actuality, with the alternate time line, the Michael J. Fox version of Marty and his siblings, as he knows them at least, probably shouldn't exist. The genetic information that makes up an individual is decided in great deal due to both parents' DNA, but there is some randomness such as exactly which sperm, containing Father's genetic information, interacts with which egg, containing the mother's. This is why if you are a boy and have two brothers, you don't all look identical. Therefore, unless in the "alternate" time line Marty and his siblings were conceived at the exact same date and exact same time, down to an instant (doubtful), and unless the inherent randomness in transferring genetic information, such as which specific sperm fertilized the egg, is completely preserved in this alternate time line (also doubtful), even if the "new" Marty was still named Marty, by all accounts he should probably look at least slightly, but still noticeably, different. So, if time-traveling Marty has offset his parents' sex life by even 15 seconds, the chances of having the exact same looking children are slim-to-none.
 * Marty, at least, has to be conceived in exactly the same way or else there's a paradox. If "Marty" is different from the one we all know, then he may be unsuccessful in getting his parents together or may not travel back to 1955 at all. Marty has to be conceived (and live a relatively similar life) in order for the Stable Time Loop that, in the new timeline, causes his conception to occur. Otherwise the entire universe gets destroyed... or it might be localized to our own galaxy.
 * Or, maybe this is exactly why Marty no longer looks like Eric Stolz?...
 * What is with all the above Epileptic Trees? Look, folks, it's as simple as this: the past Marty that Protagonist Marty witnessed shout "You bastards!", get into the car, and go back in time was the same Marty. It's called a Duplication Paradox. (It is to be assumed that not all paradoxes endanger the whole space-time continuum, since Doc would surely be aware that time travel automatically creates paradoxes just by being time travel.) It happens all over the second movie. If you traveled back in time, you would theoretically be able to watch yourself doing something in the past as well. Would that mean that you're automatically a different you from the one you're seeing do what you very well remember doing yourself? It's just a loop.
 * No, it's not that simple. See, at the end of Part I, Marty is surprised by all the changes in the world, and his family was surprised at his surprise. So, in lets say September 1985, there was a Marty walking around who had always grown up with an assertive father etc.. Our Marty, however, never had that childhood, which is why he is surprised at all the changes. Two different Martys had two different childhoods. So it's something more than simple duplication.
 * There never was a Marty growing up with an assertive father. The Marty in Lone Pine Mall is the original Marty, from the beginning of the film, but the ripple-effects of timetravelling is only just catching up with the timeline. Time is literally changing around him. By the next morning, everything is in place, except for his memories of the new 1985, but they should catch up with him soon enough.
 * My thought is that it happens chronologically. Marty never loses the memory of his trip to 1955 regardless of which timeline he's from because those memories first existed in 1955. Using Btt F's timeline theory, the first point at which Marty exists is on November 5th 1995, and although his personality and circumstances change with the altering timeline because Marty himself existed before that point in his own life, the memories of his old life will remain intact because they were created earlier in the time stream: Marty can change his parents' lives and the lives they affect, but the sequence of events that created those memories remains intact. (The Telltale game has a couple of scenes in the beginning that show Marty appreciating his father even more for it)


 * Okay, in 1985-A, Doc was sent to an insane asylum. This means that the DeLorean time machine would never have been invented and that Marty would never have gone back to 1955. Therefore, when the Part II Marty goes back to 1955, the Part I Marty shouldn't exist there anymore. At least not until the almanac is burned, at which point the Part I Marty would be restored to 1955 via the ripple effect.
 * This is simple inconsistency. Without time machine invented through all 30 years (ALL 30, this timeline must not differ from others) and Great Night (what LP Marty had seen at the end of part 1) Marty-2 and Doc-2 must be erased and fade out. However, they have a whole week, while the events of Hell Valley happen just one night. P. S. This page need to be named The Movies for Noodlebakers.
 * Actually, since the time machine was never invented, it would undo all the previous trips through time, including the current one, creating a very convoluted paradox. The only way to get around this is to suppose that somehow, the time machine was still invented in the A timeline, and Marty still went to 1955 and back to 1985 and then to 2015. Actually, he's the Marty we're supposed to be following in 1985-A, since Word of God says (and it's consistent with other portrayals of time travel) says that he departed from 2015-A. We are, after all, dealing with Ripple-Effect-Proof Memory.
 * And a Ripple Effect Proof time machine. Once it (and its passengers) enter a time period, they become part of it (until they fade out, of course).
 * It appears from the films that the ripple effect doesn't occur unless the events that lead to what would be affected irrevocably changed, Doc and Marty had a working Time Machine so the ripple effect would not affect them in 1985-A, because they CAN change the events that lead to that timeline. This is also why Marty began disappearing at the dance, why Old Biff faded away when the Time Machine left, and why all but two photographs change instantly. Notably, the two exceptions have an affected event that wasn't going to happen until a week later. It's not so much metatime as the law of probability.
 * I didn't get a real good look at that newspaper (can you even * see* the date on it?) but I don't know of it saying that the committal happened in 1985.
 * I'm assuming he was committed at some point after creating time travel (which, since Marty already met him in 1955 and him aware, he may have gotten a head start on in Part I's alternate 1955-85). Keep in mind that if Biff had the Doc committed before the time machine was made, Alt85 wouldn't exist, because Biff would have no way to influence himself in '55.
 * However, even if Doc Brown was committed after inventing the flux capacitor, Marty has been shipped off to Switzerland for boarding school, so he wouldn't have traveled to 2015 to allow Biff to steal the DeLorean anyway. Damn these movies...
 * Only in 1985-A would the time machine probably not be invented. Not in 1985-original. Better that way: having two time machines from different timelines about would just open up too many new and mind-screwy cans of worms....
 * By 1900 or so, judging by Clara's dress and the age of his sons, Doc Brown has a steam locomotive that can fly, probably runs on phlebotinum and some sort of super-efficient steam engine in order to actually lift all that weight, and can travel through time. Even without bringing the time travel aspect into it, this is a hell of a departure from the technological state in our own turn-of-the-19th-century era. For comparisons, the Wright Brothers made their first flight in 1904 and air travel as a whole didn't really get started until WWI. This is such a drastic technological shift that by the time Doc goes forward to 1985, it should not be the same 1985 as Marty's. Doc couldn't built the new time machine in secret-- he could have been able to get away with building or procuring a steam locomotive (it takes more than 1 person just to operate a conventional one!) and all the scaled-up-in-size parts and fuels to build the time machine part of it without someone to help him. Something about the project would have leaked out. If a sports almanac can change 2015 so drastically, antigravity should render Doc's 1985 completely unrecognizable from Marty's.
 * The Wild West don't have those meddling reporters, and during the victorian years there was still many superstitions. It wouldn't too far-fetched that the Time Train could be even the same original train that pushed the Delorean, salvaged to the extreme (Any given train would need to be almost completly reconstructed, so working with some unclaimed remains would be still plausible) With some rebuilds, the controls mostly automaticed and Doc's Chemical Log you don't need many people to operate it, and hidding the big thing in a Doc-Cave, he could still be "That odd old Smith-inventor", and his greatest secret would be Clara's secret pie recipe.
 * I'm not talking about whether or not Doc has the technical knowhow to work on a steam locomotive--he built the time machine to begin with, and there are some hints that he likes trains sprinkled through the series. What I'm talking about is the simple fact that since a steam locomotive is much bigger than a car. Because of the size different alone--not to mention the challenges of finding all the materials for the Time Train and its modifications--Doc would have had to had some help building the time train. One man can lift a car wheel and many of its other parts himself, for example, but there's no way in hell he could manage a 5 foot or bigger wheel made of solid metal. Therefore, by implication, there are other people who know about the project, and the timeline Doc and his family end up in should be very different.
 * Don't forget that the derelict train would be a memento of Marty. Extra motivation to work, indeed!

Fading

 * Speaking of fading, why could the characters notice the fading? Marty might have been able to remember his brother and sister having been in the photo, but what sense does them gradually fading bit by bit have? They could have had more realistic changes, that could have actually happened without the effect of time travel, had things simply gone differently. Marty could have still felt ill as he had, simply without fading, maybe it get worse and all of a sudden it stops and he's now got a Lone Pine ID card or something in his wallet next to the photo (which would then contain his siblings again). The individual siblings disappearing could be handwaved as the time stream trying to keep George and Lorraine together, it just takes longer and loger and they have fewer kids every time something doesn't change, but really, why would Marty have been born the same age, with one hand, and the ability to play the guitar, had his parents not kissed at the right point in time? (summed up well in this comic). I've asked before, but the last time I mentioned it I got yelled of the forum for it not being relevant, mere days before the comic was put on the web. Please take it seriously.
 * This one has to be chalked up to rule of Plot Purposes. If Marty faded out, or things changed overly dramatically (he suddenly didn't have siblings) then he would have failed in his mission to leave history unchanged. In essence, he would have killed his brother and sister. There's absolutely no reason for time travel to work the way it does in the movie unless you consider that changes are a wave that slowly travel forward in time from the point of change (in other words, a change in 1955 takes three days to fully register in 1985), and that doesn't make any sense. But since we're dealing with hypothetical situations that can never really occur, it pretty much happens because Word Of God says it happens that way. It's a cop-out explanation, but a scientific or realistic answer is impossible.
 * I took the picture as being "readjusted" to fit with the new timeline, where his brother (his sister, and later himself) wasn't born, but had to work through the Time Travelers Immunity that the photo possessed so this process took a while.
 * My pet theory is that the picture is a quantum superposition of all possible pictures, so that the net effect is that the viewer sees the most probable outcome. So Lorraine and George might still get together without Marty's help, but perhaps not in time for Dave to be born. As events progress, it becomes increasingly less likely that Lorraine and George will hook up at all, so the picture gradually fades to blankness. When Lorraine and George kiss, the probability of Dave, Linda, and Marty all being born on time snaps back to 100%. (This also explains how and why the YOU'RE FIRED fax faded away, but it does imply that "facts" as recorded in Gray's Sports Almanac keep fading in and out.)
 * There's evidence supporting this in Part III: when "Mad Dog" Tannen arrives at the saloon and calls out Marty for their showdown, Marty hesitates and looks at the photograph of the tombstone. The tombstone was previously blank, but the name "Clint Eastwood" (Marty's alias) begins to fade into view, indicating that he will die if he goes out.
 * The picture is between depictions of alternate situations because reality itself is that way. That may raise more questions than it answers, but there you have it. The situation of whether Marty and his siblings will ever be born wasn't nixed entirely when he prevented George from being hit by the car, as the climactic events of the movie in question prove. Therefore the closer the situation got to the point where Marty and his siblings would never be born, the closer they got to fading from the picture, and for some reason (probably either the same one or just for dramatic purposes, Rule of Cool) Marty himself started to fade as well. When it became certain again that the three kids would be born, Marty and his siblings were firmly reestablished once more. Still, one wonders why that photo would have been taken without them in it.
 * Presumably in that instance the photo would itself fade away shortly after Marty did, there being no reason for it to have been taken (or it would have been replaced by whatever photo had actually been taken on that particular filmstrip in the new timeline). Similarly with Marty's clothes, which I believe were also fading (and if they weren't, they probably would shortly after Marty).

Relationships

 * I never noticed this until another website (cracked.com?) made a point of it. At the end of the first movie, George is an assertive, fulfilled guy, and Biff's a submissive blowhard, no longer any kind of threat. All well and good, but even under those circumstances I'd be a bit leery about the guy who tried to rape my wife back in high school having unfettered access to my home and car, no matter how defeated he may be.
 * It's never told what all happens in the 30 years after The Punch, but that is a great deal of time for even someone like Biff to completely reform and prove it to the McFlys, as he clearly has done at the end. Maybe some people are never willing to forgive even after all that time, but George and Lorraine are likely good-hearted people who truly see the change in Biff. It's actually a nice Aesop.
 * As well as the above, in the new timeline, New Assertive George McFly has already kicked Biff Tannen's ass once before, and by the end of the movie doesn't seem to be willing to take any crap from the other high school bullies who used to push him around. 30 years is plenty of time for George to make it pretty clear to Biff that if he tries anything of that nature again, he's going down hard.
 * Factor in some values dissonance, probably. Back then, rape... or even attempted rape... didn't occupy the place in public conscience it does now. Lorraine and George may have been raised so that they considered Biff's actions just a sign of immaturity... not a good thing, but a "young people just do stupid stuff" sort of thing. By the time rape, even attempted rape, became acknowledged as the unforgivable act it's considered today, they probably would have already gotten over it, forgiven him, and so on. What would they do, decide to get themselves all riled up and hate him again just because society was now open about the fact they were supposed to?
 * Also see UsefulNotes/TheFifties. Even if Biff had raped her, society might not have considered it Biff's fault.


 * At the end of the first movie, Marty tells Lorraine his real name. Lorraine clearly likes the name, implying she will eventually call her child that. The only thing... Marty was not her firstborn son. So why didn't Dave end up being called Marty and Marty end up being called something else?
 * Maybe she liked the name Dave even more.
 * Dave was her previous fling (she sure seemed to have no trouble throwing herself at a stranger, which implies she wasn't exactly unfamiliar with that kind of situation)
 * She certainly had at least one boyfriend prior to Marty, given that she said "it's not like I've never parked before."
 * Maybe the father chose the name of the firstborn son. Then Lorraine chose it for the second son.
 * Additionally, the pop-up trivia information on one of the DVD's of Part III says that Marty's having an ancestor by his own name is an indication that he was likely named Martin partially after that guy as well.


 * How come Marty doesn't have any ancestors who look like George, Dave or Linda?
 * He probably did, but we just didn't happen to meet them over the movies.
 * How come Shamus, Marty Jr., Marty's daughter and William McFly (as seen in the old photograph in the library) all look like Marty, yet George looks nothing like any of them?
 * Real Life answer? Crispin Glover wanted more money than the studios would pony up, or so I hear...
 * The Telltale game has Artie McFly, Marty's grandfather/George's father, look and sound roughly like Crispin Glover.
 * George never found it just a bit strange that Marty grew up to look perfectly identical to Lorraine's old fling?
 * Unless George has photographic memory, he's probably not going to remember very well what a guy he knew for a week thirty years ago looked like.
 * In that case how come Lorraine didn't notice it?
 * Same deal as with George: she knew him for a week thirty years ago, and we have no evidence that Lorraine's memory is any more photographic than George's.
 * Ok, but here's the thing about that. George and Lorraine are both pretty smart, Biff was pretty dense, so how come George and Lorraine don't realize that their youngest child looks like Lorraine's ex from 30 years ago, but Biff, who only saw the DeLorean once for a few seconds at the end of BTTF, remembers it 30 years later as old Biff in BTTF 2?
 * I think a DeLorean that actually took off, flew and disappeared in a flash of light is going stick in one's mind quite clearly.
 * Memory isn't entirely about how smart you are, and whilst a disappearing flying Delorean is the kind of thing that you're going to remember, the exact facial appearance of someone you knew for a week decades ago isn't.
 * Specifically addressed on cracked.com: 'now we don't claim to know exactly what first enters the mind of a married man when his wife births a child who looks identical to their old high school boyfriend, but we're guessing it's not "time travel conspiracy"'.
 * We know that Marty and Doc had their picture taken back in 1885 with the new clock set to be installed in the new city hall. It would stand to reason that Seamus and Maggie McFly - who were at the same dance - had a similar photo taken. That photo would become something of an heirloom and pass down through the family. Thirty years later, George and Lorraine, having stumbled upon the hundred year old photo in some box, could have marveled at how much their son looks like his great-great-grandfather. The memory of some guy who was around for a week would pale next to a photograph of gramps. Of course, Lorraine's resemblance to Maggie would be truly remarkable.
 * There's no reason to assume Seamus and Maggie had a picture taken. Photography at the time was not as quick and simple as it is today; the photographer might've charged a lot for a picture, which Doc could afford but Seamus couldn't (or Maggie would dismiss as a frivolous waste of money).
 * This troper has just received some Fridge Brilliance and realized something. George's book is called " A Match Made in Space" and the alien on the cover looks like it's wearing a radiation suit. On top of that, Marty's solo at the prom must have sounded a bit like the music "Darth Vader" played to get him to ask Lorraine out. Conclusion, George thinks "Calvin Klein" is an alien.
 * The game briefly addresses this point, as Marty spends a few days over the course of a year with a young Emmet Brown. Near the end Doc arrives to pick Marty up and while he's just about figured out that "Sonny Crockett" was really Marty he clearly wasn't quite sure and admits that his memory has played tricks on him - he remembered Sonny as being taller. If the inventor of time travel had difficulty making the connection then two people who don't even know time travel exists are going to have a much harder time.


 * In the original timeline, there would have been an obstacle to George and Lorraine's relationship: Biff's bullying George. Since Biff wants to make Lorraine his girl, it would be out of character for him to react to the George/Lorraine relationship in any other way than by ordering George to stop dating her. And since Original Timeline!George was incapable of standing up to Biff, he would have caved in and they never would have gotten married. I suppose, though, that if Biff moved away from Hill Valley after high school, then George could have dated and married Lorraine without being disturbed, and once they were married, it would be too late for even that level of bullying to break them up.
 * Maybe Lorraine did all the standing up to Biff. Either way, I think it should be noted that Biff wanting to marry Lorraine is a Ret Con made by Part II. In the first film, he didn't seem to have any particular interest in her other than wanting to get in her pants.
 * Maybe that's what Biff meant, and we only see Biff marry Lorraine in 1985A merely because he was envious of George?
 * Also, I'm sure that Biff did harass other girls - besides Lorraine. I think part of why he marries Lorraine, in 1985A, is because of how she ended up marrying his former target. Remember that he had resentment issues towards George, too.
 * Simple: Original!Lorainne falls for Original!George. Biff no longer wants her, coz he's a cool guy and why go for a girl with such poor tastes in men? It reflects badly on him. LP!Lorraine dates LP!George, who is now cooler, running for class president, and later a successful author. She is thus still attractive to Biff coz she has pizzaz. It's worth it then to murder George and take his wife, she's no blemish on Biff's reputation.
 * The potential answers to many of the above are on the DVD box set documentaries. In it, the writers mention how their original idea is that there was some time-governing entity that had limited power in regulating events. It had a general outline (i.e. George and Lorraine get married and have their three children) and otherwise manipulated events to maintain this.
 * In Spite of a Nail covers it quite well. In the BTTF universe, unless something happens to prevent an event from occurring as it did in the unaltered line, it happens. Slightly modified in detail, perhaps, but close enough for jazz rock and roll.
 * That concept seems to be contradicted by other things in the series that show large future changes from relatively trivial changes to the past. For example, Marty's family at the end of the first movie seem to have radically different personalities, jobs, etc., apparently all because Marty's dad punched a bully in 1955. It seems likely that they could have found ways to be losers if that was really what they were "fated" for and some entity was pushing them in that direction.
 * Actually, this is answered by basic rules of the universe. Matter can neither be created nor destroyed, but pretty much anything else goes. If, barring extreme alteration, George and Lorraine were meant to have three children, then the actual personality, nature, and ultimate outcome of those three children is immaterial. Look at it this way... suppose you have an area with a cube that has thirty grams of matter in it. The universe doesn't care if this matter is cube-shaped, spherical, painted red, painted green, rendered into a dense cloud of particles, or is a very cute squeaky mouse, so long as there is thirty grams of matter there. Barring some serious fuxing of the laws of existence, all it cares about is the amount of matter, not the state.
 * That won't work; by the same token, the universe doesn't care whether the matter comes together in the form of three children or not. The matter that makes up the children came from the food that Lorraine ate during her pregnancies, and that the children ate after birth. If the children had never been born, that matter wouldn't be destroyed; it would have been eaten by someone else, or rotted.
 * Going by the summary above, according to the writers, someone or something in-universe does care. Which puts this into the realm of Deus Ex Machina and/or A Wizard Did It.
 * Chronal inertia. The "small change" of George belting Biff had 30 years to snowball into the different personalities (and decor, and jobs, and cars).
 * In the altered timeline created by Old Biff going back in time in Part II, why did Lorraine marry Biff?
 * I figure that it was due to George McFly being murdered and Lorraine being stuck with three kids who she had trouble supporting. Even though Biff is a Complete Monster, Lorraine probably married him so that both she and her kids could be secure (and she probably wasn't aware that it was Biff who killed her husband). Notice in Part II when Lorraine threatens to leave that Biff threatens to cut off her kids, at which point she backs down.

Technical Details

 * Doc in 1955 must have had a bad case of Plot Induced Stupidity. His plan was based on reaching 1885 directly from 1955, which could've been (and indeed was) a bad idea: driving the Delorean on dirt damaged the fuel line, and subsequently, filling the fuel tank with alcohol destroyed it completely, thus forcing 1985 Doc to elaborate a contrived plan, involving the hijacking of a locomotive, to let Marty return home. To me, it looks like 1955 Doc forgot that a time machine can reach any point in time, so a more sensible plan to save Doc could've been made:
 * 1) replace the blown microchip with 1955 components
 * 2) reach 1985
 * 3) buy a replacement microchip
 * 4) remove the 1955 components and solder the working microchip to the circuit board
 * 5) reach 2015
 * 6) have the Delorean hover-converted again
 * 7) reach 1885 with a fully functional flying Delorean
 * 8) save Doc
 * For one thing, having the flying circuits repaired would require taking the DeLorean to an auto shop, where a mechanic might get curious about the time circuits (Doc did the first conversion himself, but there's no way Marty has that kind of technical skill). But more importantly, Doc had already decided to dismantle the time machine after resolving the sports almanac debacle. He knew that time travel is inherently dangerous, and he only risked helping Marty get back to 1985 because his presence in 1955 posed a greater threat to the timeline.
 * And you forgot to stop for gas.
 * 1985 Doc decided that; 1955 Doc didn't, and in fact can't, because the entire timeline of the movies depends on his spending the next thirty years building it. But by the same token, 1955 Doc hasn't had the same experience of time travel as 1985 Doc, and decided the direct route was simplest.
 * Nor does 1955 Doc know anything about integrated circuits, much less 21st century technology like the hover conversion or Mr. Fusion. He could quickly learn, of course, but it'd start seriously screwing up the timeline if he did so (remember, this is a version of Doc in the past, and the more time he spends helping Marty, the more it's going to screw up 1985 Doc's memories and personality). Plus, Doc's a friendly neighborhood Mad Scientist: it seems in-character for him to think out the most direct route and not really consider the consequences. That's how his trouble with the Libyans began in the first movie.
 * Also, it wasn't the terrain that broke the fuel line but a wayward arrow. How was Doc supposed to see that coming? Without that, the DeLorean would have had plenty of fuel, meaning that the plan should have worked fine.
 * A car's fuel line is on the bottom of the car (note where the fuel is leaking out of). The arrow was just stuck in the side. Unless Marty was making the car do barrel rolls in some deleted scene, it was the rough terrain that did it.
 * Clearly Native American aiming skills were so accomplished that they could masterfully "bend" an arrow shot from their bows to penetrate the underside of Marty's car. That, and they knew enough about cars to know that it was a smart thing to do.
 * Actually a puncture through the side would still make fuel appear to pour out from underneath. The fuel tank side wall is not the fender of the car so fuel would not pour out the hole the arrow made in the sheet metal. It would come out the side of the fuel tank, run down the side of the tank between the plastic tank and the metal inner fender and pour out the bottom of the car. Plus if the fuel line had been broken Marty would have only been able to drive the car about 10 yards farther since the gas would not have been reaching the engine with sufficient pressure to run a fuel injection system. However this does raise another problem. Even if it was a hole in the side of the tank the gas should only drain out to the level of the hole. Unless the arrow penetrated all the way through on a downward angle to the bottom all of the gas should not have drained out.
 * Well, except for the fact that on the DeLorean, the gas tank is in front of the driver's side dashboard, under the trunk hood.
 * Another thing to remember is that even though Marty is traveling through time, he's still aging at a normal rate. The longer he stays away from his original year (1985) the harder it will be to go back. Suppose that whole plan laid out above takes a year or two to fully complete. In a year Marty (considering he's technically still in high school) will look very different. That will lead to a lot of awkward questions from his family.


 * If Plutonium/Mr. Fusion is only used to power the actual time travel components of the DeLorean, why did it keep shorting out during the first movie?
 * Truth in Television. One of the main reasons why DeLoreans were unsuccessful as cars was that they had incredibly unreliable ignition.
 * For that matter, why is plutonium/Mr. Fusion relegated to powering time travel in the third movie, when Doc specifically says in the first that the car itself is electric?
 * No, he says that the time travel circuits are electric, but need such a huge electric charge that plutonium is the only way to generate it. The car itself is clearly gas-powered.


 * At one point, Doc sets the time circuits to the year "0000", which doesn't exist (Jesus was born in 1 AD, and the year before that was 1 BC). What would happen if the DeLorean had tried to travel to that time?
 * Presumably, it would extrapolate the year from its dating system and thus arrive in 1 BC.
 * Historically, the year of Jesus' birth isn't known, but was most likely around 3-5 BC. The modern Gregorian calendar isn't too precise that far back.
 * This troper remembers hearing on the commentary that that was a joke.
 * Wikipedia tells me that "astronomical year numbering" has a year 0 (what we would call 1 BC), and then it counts -1, -2 etc.. Maybe the Delorean is set to astronomical time. Or whatever.
 * Doc wasn't actually going there, he was illustrating an example...slightly dumbed down for the audience, of course. This is particularly the case given Jesus wasn't born on December 25, which is the date Doc typed in.
 * As I mention on the WMG page, I would estimate that if you had to travel to B.C.E. years, the four-digit display would just change color. And there technically was a year zero, it just wasn't called that.
 * Also, as the DeLorean only travels through time and not space, even if the Doc was able to travel back to December 25, 0000 to witness the birth of Jesus Christ, he would have arrived in the land which would one day become California, and would have had no means to travel to that stable in Bethlehem in time to witness the birth in the first place! For this troper, this headscratcher overrides all ideas of the year 0000 not existing.
 * He'd have had a means of travel --- the Delorean can fly. But he wouldn't do it, because I can't think of anything that would do more damage to the timeline. That said, I now have the urge to write a Fanfic where the star that the three wise men followed turns out to be the Delorean.
 * The DeLorean was not hover-converted until the end of Part 1. Doc was probably just goofing off anyway.
 * He was just giving Marty some examples you could travel to with a time machine, like the Declaration of Independence or the birth of Christ. Doc doesn't seem to be kind of guy to know much about religious history, and just thought "Christ was born on Christmas Day, at the beginning of the calendar dating", thus December 25, 0000. As for the wrong location, I just can't picture him saying: "Or witness the birth of Christ?" *sets digits to DEC 25 0000* "Of course, you'd have to travel all the way to Bethlehem first, because the DeLorean can only travel in time, not in space, you know." He was just giving some quick examples.
 * The time circuits are clearly limited to four-digit years. So what would happen if you went to 11:59 p.m. on December 31, 9999 and waited one minute?
 * The Y10K bug strands you in a post-apocalyptic wasteland...obviously.
 * Maybe 9999.12.31.23.59 would actually result in a BC year if the computer is running with signed integers.
 * In one Fanfic I read once, Emmett mentioned that the vehicle COULD go back further than a year with four digits; he just figured that not many people would want to do it.
 * If the time circuits measure time in minutes after 0000-01-01 00:00 (assuming a proleptic Gregorian calendar with no 4000-year rule), then the smallest amount of memory that could be used to express all values from then until 9999-12-31 23:59 would be 33 bits (unsigned). This would actually cover it until approximately the beginning of April 16332, but you might have trouble seeing it on the Present Time display. If they measured time in seconds following 0000-01-01 00:00, you'd need at least a 39-bit unsigned integer, which would cover you until roughly mid-January 17421.
 * I don't think Doc ever planned to travel that far in time. The machine may have been intentionally built not to be capable of it, or he may have had some technical solution, or been able to think one up, if he changed his mind.
 * If he didn't stop at four-digits, how many was he going to stop at? Five? Six? 34? 24187? It probably would have been a bit mind-boggling even for the Doc to travel to build the Delorean with the ability to travel to infinity and beyond.
 * Besides, a 4-digit year is a good cut-off point as that can theoretically get a person back as far as the Late Stone Age.
 * I don't think he'd ever deliberately go that far into the future. Traveling 30 years into the future is risky enough. Who would have the slightest idea what to expect in the 100th century? The Earth might have been rendered completely uninhabitable due to nuclear war or something.


 * The DeLorean obviously travels through time, but how does it also travel through space? Consider this: the Earth is tearing through space at fantastic speeds. Even when Doc sent Einstein on a just one-minute trip, the Earth still will have moved quite a bit. If Einstein's coordinates only move through time, and not space, shouldn't he pop out in outer space, where the Earth was one minute ago?
 * See Time and Relative Dimensions In Space.
 * Perhaps the Flux Capacitor locks itself onto a gravity well


 * So, does the DeLorean need to be going at 88 MPH or does it just need to achieve that speed? Put another way, if you were going at 89 MPH and you turned on the time circuits, would you go back in time or would have to drop down to 88?
 * My guess is that you have to accelerate to 88 miles per hour with the time circuits already on. But what about flying? Is 88 miles per hour the ground or air speed? What about flying against (or with) the wind?
 * Probably it's relative to the speed (and direction? maybe?) at which you turn on the time circuits, so that's why they mostly start from a dead stop to simplify gauging the speed.
 * More than once the car time travels from the air onscreen.
 * Also, why has it to be 88 MPH anyway? Is it just an arbitrary setting by the Doc? If so, he probably could have changed it when they were stranded in 1885 to a lower speed, perhaps the speed they could reach and maintain using the horses... So this can't be it...
 * Probably has something to do with how the Flux Capacitor works. Chalk it up to some weird law of science, like the speeds of light and sound.
 * To quote Doc: "The way I see it, if you're gonna build a time machine into a car, why not do it with some style?" If someone like Doc is to create time machine, why not to put some obstacles to remind the time traveler that this deal is not just playing in the sandbox? You need to think many times to dare to interact with time. While you accelerate, you can think again.
 * I figured that Doc programmed the time circuits that way. He could have had the Flux Capacitor calibrated to activate at any speed. When the lightning strike fried the time circuit control chip and sent him to 1885, the technology to reprogram it didn't exist.
 * Willing Suspension of Disbelief and Rule of Cool.
 * In the DVD commentary, the filmmakers state that they chose this particular number because it's easy to remember. If you're looking for an in-universe explanation, I got nothing.
 * It cannot be a gag because, contrary to popular belief, the Delorean's speedometer does not go up to 85. It goes to 95.
 * It's probably 88 MPH due to this number, when displayed on a two-digit digital readout like the one in the film, uses all 14 light-able segments.
 * It's been said that one reason for the 88 MPH requirement was to serve as a Shout-Out to The Adventures of Buckaroo Banzai Across the Eighth Dimension -- the 88 LED display resembles the logo for the Banzai Institute.
 * Not to mention it makes for a far more gripping climax for the first and third films if Marty has to gun the engine up to eighty-eight. How boring would it have been if you only needed to get to three miles an hour? The third movie would have been over in a third of the time.
 * Perhaps Doc picked this number to avoid having accidental activation of the time machine. 88 is faster than highway and residential speeds, so if Doc is driving the DeLorean somewhere and accidentally turns on the Flux capacitor and time circuits (due to malfunction or something), he doesn't risk zipping off to the crucifixion in the middle of I-90.
 * Since "flux capacitor" is a mish-mash of electromagnetic terms, and Doc said that the DeLorean's steel frame is important, I'd guess it has to create a powerful electromagnetic field to trigger the time jump. A moving electric charge creates a magnetic field and vice versa, so Doc's apparently either charging or magnetizing the DeLorean's exterior, and then speeding the car up to generate a strong enough EM field. 88 mph just happens to be the magic number.
 * Doc calibrated the time circuits to 88 MPH because it's a speed one is unlikely to reach simply driving around to the store to get some milk. Thus by accelerating up to that speed means that you are deliberately attempting to travel though time and not setting the damn thing off accidentally. It seems that as long as a destination date is punched in as soon as you hit 88 mph the time circuits activate and away you go, and since there is ALWAYS a destination date displayed the car is always "active." It's a machine that he designed for the express purpose of moving through time. The reason why it's a car is because you want it to go places and the reason it's a DeLorean is because the stainless steel skin optimizes flux dispersal.
 * I think I've got it. It's a little joke by Doc Brown. To travel through time, you must (on Einsteinian theory) exceed lightspeed. Exceeding lightspeed in theory means your mass goes beyond infinity, yes? Which is unbelievable on its own, but you must then somehow catch up and reassemble the infinite number of photons that have spun out since the moment you want to go back to. That would be a task in the order of double infinity, yes? Turn the number "88" sideways and tell me what you see.
 * Four boobs?
 * I always assumed it was an issue of assisting the flux capacitor, under the assumption that time travel works by creating excessive amounts of energy (hence a lightning-bolt's worth of electricity run through a fancy capacitor), and that 88 mph was just an additional way of adding further energy to the DeLorean (in the form of kinetic energy). 1.21 Gigawatts + Capacitor + 88 mph of velocity together met that energy requirement.
 * I might be thinking on the same track as you with this. You see those crazy sparks that appear in front of the DeLorean as it accelerates? I'm thinking that those sparks have to be traveling somewhere between 87 and 88 miles per hour. When the DeLorean runs into those sparks, they've created sort of a portal through time, that's even what it looks like when we see Marty's first trip through time from the inside of the thing.
 * That may actually be the best of all of the explanations - the flux capacitor sends out energy in such a way that, in order to latch onto the same location on the earth's surface in both times, it must actually emit forwards along the earth from the capacitor itself at 88 miles per hour. The car must be travelling at the same speed in order to actually be within the resulting portal.

Other
"Marty: What about all that talk -- about screwing up future events, the space-time continuum? Doc: Well, I figured, what the hell."
 * Perhaps this is a stupid question, but did bulletproof vests that could protect you from several 7.62 rounds fired at relatively close range, exist in the 80s? I've been investigating a bit, and from what I read the standard issue back then in the US military was the PASGT vest, which was only Level II (meaning it could stop most handgun rounds, but not rifle rounds), and even modern day armor will only save you from an AK if you are wearing ballistic inserts underneath the vest.
 * It's already been discussed above. I think general consensus is that Doc Mad Scienced the vest to beef it up.
 * We know from the newspaper clippings seen in the opening that Brown Mansion burned down and that Doc subsequently moved into his garage, selling the rest of the land to developers. However, the scene where Marty leaves the garage in 1985 shows that these developments have resulted in Doc having his residence in the middle of what is clearly a commercial district. Would any kind of zoning commission allow this?
 * Zoning changes over time. Since Doc Brown needed the money from the developers, he wouldn't have spoken out against changing the area around his home from residential to commercial. He probably would have supported it since it would have helped in the sale.
 * Yeah, but would the city allow him to continue living there?
 * If he made it a condition of the sale, and they wanted the land badly enough to put up with that condition being in the contract...
 * Could be that the building is technically identified as a commercial building (i.e. it's his workshop or something) but he keeps a bed and just happens to sleep there; kind of like all those movie private investigators who seem to basically live in their offices.
 * What were a couple of Libyan terrorists doing in Hill Valley, which seems to be an at least somewhat obscure place, anyway? Did they deliberately seek out the Doc knowing that he could build them a bomb?
 * Doc probably previously contacted them as an attempt to get some Plutonium, chances are he told them if they could get him some we would use it to make a bomb. This obviously wasn't in Hill Valley at the time, as he hadn't expected them to track him back there.
 * Also, if I were a terrorist, I'd be a lot happier with a time machine than a bomb...
 * Also, if I were anyone, I'd be a lot happier with a time machine than a bomb...
 * It is perfectly clear that they didn't * know* about the time machine. That was part of Doc's ruse. And yes, Doc may have contacted them, or they may have heard of him and contacted * him* instead (he may have had impressive past accomplishments that the derisive natives of Hill Valley don't know about, don't care about, or disbelieve; Gale and Zemeckis said that they think of him as having probably worked on the Manhattan Project).
 * People who have suspicious and illegal transactions to make would probably prefer the more obscure, the better. As such, if you're arranging to acquire some stolen plutonium for a terrorist plot, then why not some quiet, obscure little town where no one's really going to be on the lookout for that kind of thing?
 * Biff Tannen. How does someone with obvious homicidal/sociopathic tendencies get to run around free as a bird without any kind of recourse? Young Biff was willing to run over another human being in full view of the public, as well as trying to run the same human being into a tunnel wall with his car a few nights later. He was also tried to rape another student. Older Biff was an unapologetic drunk driver. Why is he not in a sanitarium for the criminally insane?
 * It was The Fifties. Stuff like that happened a lot.
 * He didn't * succeed* at those crimes, so he couldn't be charged with them. Maybe with attempting them, but that wouldn't automatically land him in a sanitarium (he clearly isn't insane), and even if it did he might be out of it even more quickly than in prison. It's not like someone is likely to go to prison for life just for * attempted* murder or rape, and those who witnessed it might have been too afraid of him to come forth with it. The direct victims seem not to have pressed charges.
 * Considering that in the movie, half the time young Biff's intended victim was Marty, who couldn't press charges because (1) he wasn't supposed to exist (what would he do if the police or judge asked him for ID?), and (2) Doc wouldn't have allowed him to, as it would screw up the timeline (not to mention that, after the first manure-truck crash, if Marty had pressed charges, the trial would probably be scheduled after Marty would have to hit the lightning bolt at the clock tower to go back to the future).
 * And maybe he did spend the night in jail after crashing into the manure truck, and his grandmother had to come bail him out. It could explain why she always sounds so grumpy whenever she asks him where he's going ("BIFF! Where ya going this time?!?").
 * Isn't he implied to be a high school football star? Cops have certainly cut corners for guys like that in real life small towns, it wouldn't surprise me if it was the same there.
 * Not really a JBM, but merely an observation: if my calculations are correct, there are no less than four DeLoreans in Hill Valley'on November 12, 1955:
 * 1) Marty's DeLorean he brought back from 1985 to 1955;
 * 2) The DeLorean stolen by Biff and brought back to 1955;
 * 3) The DeLorean stored away in the Delgado mine in 1885 and recovered in 1955; and
 * 4) The DeLorean Doc and Marty used to get to 1955 from 1985-A.
 * Not so fast. From the audience's (and black hat Marty's) POV, the Delgado DeLorean wouldn't be in the mine yet, because 1985 Doc hadn't been struck by lightning yet. Simple cause-and-effect. The very moment Doc was accidentally sent back to January 1, 1885, the ripple effect kicked in, and the DeLorean would have been in the mine. Thus, only three DeLoreans in 1955. (Except if Marty does some retrospective thinking later on. He's gonna be stuck trying to figure out that ripple effect for a LONG time to come.)
 * This one does bug me, though: in the first film, before he heads off to make his run back to the future (heh heh), Marty tells his parents that if they ever have kids and if one of them when he's eight years old accidentally sets fire to the living room rug, to go easy on him. The implication is that Marty's referring to himself. Only problem: if, as is implied, Marty does retain his memories of the TP timeline only, and doesn't gain the memories of the LP timeline, how can this make the slightest bit of difference to his own life? I realise it's more in there for a joke, but it doesn't make sense. More to the point, why the hell, having just barely avoided fading out from his own messing around with the timeline, having been warned repeatedly by Doc that he's not to interact unnecessarily with people from his own past, would he then consciously do something which could potentially start the damn problem all over again?
 * Marty wouldn't actually know at that point how the memory thing works. As for way he'd do something that would risk messing up the timeline... well, Rule of Funny, I guess.
 * This troper actually has a point. Lets say that at first either George, and/or Lorraine didn't want children at all, and that Dave was an accident, but they decided they loved being parents and had two more children. Marty bringing up their future kids could have brought up in the conversation that George or Lorraine or even both didn't want children, which could have led to an argument, causing them to break up, thus, no more Marty!
 * Like all fallible characters (and all fallible people) Marty does dumbass things sometimes, and this is, if anything, one of the more understandable instances of it. Remember that his total incomprehension of all the time travel logic Doc tells him about is a repeatedly made point. He's just a kid who doesn't really understand all this timey wimey bullshit, and he was acting in the moment on a natural impulse that anyone might have. Plus it made for a hell of a gag. Far less clever people than Marty have endangered themselves with greater obliviousness before, both in fiction and Real Life.
 * Something I discussed over (quite a few) pints really ended up bothering me. So on Doc's "personal timeline" he ends with a time machine (the locomotive) and pretty much full knowledge of the events of the movies. And he's shown himself to be sort of Doctor Who-ish in his ability to trust other "versions" of himself. Why not just use the train to go back and let himself know at various parts what he has to do to ensure the "ideal" future. He could have just traveled to 2009, printed off this page, delivered it to himself in 1985 and saved Universal millions making the the movies.
 * Why would he want to do that? Didn't everything pretty much work out perfectly in the end. Why would he want to risk messing that up?
 * Because he already did it at least once: he heeded Marty's letter warning him of his own death, and took steps to prevent it, way back in the first movie:

""We at the Hill Valley Preservation Society feel it should be preserved exactly as it is.""
 * But in that case he actually had something to prevent, namely his own death. As of the end of Part III, what would he want to prevent? George's success? Biff's comeuppance? Marty avoiding the auto accident? I don't think so. He wouldn't change anything because there's nothing to change. Everything is already perfect.
 * For this to work, the Doc would have to travel through time talking to other versions of himself. In II he makes it quite clear that he and Marty should not be interacting with their older selves, and goes to great lengths to avoid his older self seeing his face in the Square (although really he should have had the sense to avoid that area entirely). Also, doing all this could have created a paradox where he never ends up in 1885, and thus never gets the chance to create the train time machine.
 * To be fair, he probably couldn't avoid that area entirely if he wanted to get to where he was going without delay; the town square is usually named so for a reason, it's often the main central thoroughfare for the community -- and certainly would have been so back in 1955, when the town was much smaller. Chances are, it would have either been impossible or impractically time-consuming to get from A to B without passing through the square, so he's got little choice but to risk it.
 * At the end of Part 3, how the heck does the railroad crossing gate know to come down when the only train that's coming is coming from god-knows-how-many-decades in the future?
 * Isn't that standard? Where I live, crossing gates come down quite a bit before the train shows up.
 * But that's presumably through a motion detector or something. The crossing gates in the film came down before the train arrived in 1985 when there was nothing to detect.
 * Sorry, got confused. Thought you meant the first train, that destroyed the Delorean.
 * Obviously, the sensors that lowered the gates because of the Delorean-destroying train aren't right at the crossing, but some distance away. This makes sense, as you'd want the gates to close early enough that idiots won't be tempted to slip past the oncoming train.
 * Rule of Cool.
 * Doc traveled to 1985 away from Marty's field of view, triggered the crossing gates, traveled to some arbitrary point in time, went to the railway crossing, then traveled back to 1985 precisely as the crossing gates he had already triggered came down. In short, he went through a hell of a lot of effort just to make an entrance (but what an entrance!). *** It could just be a fluke or a malfunction, or maybe the disturbance from the time travel or the appearance of the DeLorean set off the motion detectors (or even caused a malfunction).
 * This has always bugged me too, but the way I look at it is simply that the level crossing had a random glitch that just happened to coincide with Doc's arrival. Level crossing malfunction is actually more common than you'd think. It wouldn't be impossible for the crossing to activate randomly based on malfunction or a dispatcher pressing a wrong button or something like that. As noted above, it's mainly for dramatic purposes, but for an in-universe response, either of these are probably the best you're going to get.
 * Judging by the popping sounds, the time machines may partially integrate back into the physical world before they actually appear, thus setting off sonic booms... not solid enough to hit objects, but solid enough to cause air displacement and thus the pops, and then the big displacement that blows stuff back when they get all the way there. But that still might be solid enough to trigger the railroad gates' motion detectors.
 * Also, since it was a 100-year jump, the longest the DeLorean had ever made (that we know about, at least), the sonic booms were far enough apart that, and this is a stretch, the gates could have been triggered manually by an operator (likely with Plot Induced Stupidity). Compare the last jump to the first one with Einstein, which was only a minute, and thus, sounded more like three firecrackers going off in quick succession.
 * Perhaps traveling through time creates local electromagnetic disturbances several seconds before the visible/audible pyrotechnics.
 * So when Marty pretends to be Darth Vader hailing from the planet Vulcan to scare George into going out with Lorraine, that inspires George to write a story about it later. However, after seeing the Star Wars and Star Trek franchise used two things that he would have used in the story does he ever wonder if they too were visited by the same alien? if so, would he try to get in contact with the creator of that franchise to talk to them about that only to be laughed at?
 * Vulcan is a Roman god, so the name would be likely to be used for a planet anyway. Star Wars came out twenty-two years after 1955. If you heard a name once, would you remember it after twenty-two years? Okay, maybe if the person who told you it was an "alien" invading your bedroom, but it's still conceivable George forgot the exact name.
 * And before anyone asks: no, the Vulcan salute wouldn't give it away, either. Leonard Nimoy drew on his Jewish background and the hand gestures used by rabbis in synagogue ceremonies to incorporate that into the character of Spock. The gesture, in other words, is common, not specific to Darth Vader from Planet Vulcan.
 * To add to this, there was a minor craze in science fiction in the early-mid twentieth century in imagining a tenth planet in the solar system, and given the tendency for naming planets after Roman Gods 'Vulcan' more or less stuck; Star Trek is the obvious example, but Doctor Who also featured this idea a few times around the same time (one of them being the first story Patrick Troughton appears as the Doctor, incidentally), and I think there were a few other examples floating around; point being, George McFly being the sort of sci-fi nerd he was, would probably be aware of this and not think anything was out of the ordinary; he'd if anything just assume that they were based around an actual planet called Vulcan.
 * By the time George has published the science fiction story which is (presumably) based on his 1955 experience, Star Wars has already been out for almost ten years. It's quite possible that he was saving the Darth Vader name for that, but then when Star Wars came out he thought "Dang it, some one else used it first" and changed it.
 * It's even possible that George no longer believes the thing really happened, but still considers it a fine yarn on which to base a novel.
 * Perhaps George waited so long to write the book because he was afraid that Darth Vader the Vulcan would be pissed if he blabbed about his "encounter", and only did so because other writers had successfully used those names without interplanetary repercussions?
 * I like to think that sci-fi writing George McFly thinks that George Lucas encountered the same alien and used the Darth Vader name himself.
 * Or George as a science fiction writer himself might have befriended both Marvin Roddenberry and Marvin Lucas and helped their struggling cousins out with their own series by providing the names of Darth Vader and Vulcan.
 * Ok, so Doc couldn't change the letter he sent to Marty otherwise it might create a paradox. But why didn't they think to get themselves the supplies they needed AFTER they escape 1885 a la Bill and Ted? I mean, they have a time machine. All they have to do is, say, open that cupboard over there and, hey, a full gas can and new fuel line! Now, all they have to do use those to get back to 1985, buy a gas can and fuel line, then travel back to 1885 and leave those things for their convenience. Simple! Of course, there goes the plot...
 * They could only put that into effect after they got back to 1985 and if they're already back anyway, what's the point?
 * And it would * still* involve a paradox. Like I said above, though, all time travel into the past necessarily seems to by definition anyway, but that's another story....
 * No, it's not a real paradox. It's a causal loop (i.e. A causes B, which causes A), which is weird, but logically consistent. Basically this would be invoking Retroactive Preparation.
 * Obviously, Bill and Ted trump Doc and Marty when it comes to time travel jujitsu. "Excellent!"
 * In seriousness… Retroactive Preparation only works if it worked if it will work, and it doesn't if it doesn't if it doesn't. Characters in time travel stories don't need to be able to literally cause their own future selves to save their lives at any moment merely by hoping they will. Would it really be that "mysterious" if a character in a time travel story says "I strongly intend to eventually travel back to now and put a million dollars cash into this briefcase!", then opens the briefcase and sees that it's empty? Obviously, the briefcase being full or empty is the writer's prerogative, but there's a pretty good argument that "full" is less likely (and real-life experience certainly attests to that!). Of course, that could have been an interesting thing for the characters in the movie to try, but there's no reason to assume it would work.
 * I'm bothered by the "Save the Clock Tower" foundation. It was struck by lightning, a natural accident. How does that make it worth keeping broken?
 * I believe the Mayor was planning to replace it with an entirely new clock. Since the old one had been around for 100 years, some people just wanted to keep it for the sake of tradition.
 * Meh, people create activist groups for all sorts of silly reasons. Do we really need a campaign for English spelling reform?
 * Yes.
 * Wy dose we hav to spel good?
 * From what I remember, in one of the old scripts it said they were religious fundamentalists who didn't want the clocktower changed because God struck it with lightning and wanted it broken, or something like that.
 * It's a local historical point-of-interest. Granted, a point of interest to maybe only a small handful of people, but people have organized protest over smaller things.
 * It is important to preserve historical artifacts for the sake of preserving historical knowledge and for the understanding and viewing of future generations. Besides, it was probably the closest thing to a tourist attraction the town had.
 * It hadn't just been broken -- it had been broken for 30 years. No one probably would have cared if they had tried to replace it back in 1955. As for why they didn't fix it in 1955, we'll have to suppose that either the city had budget problems, the plans got lost in committees, or no one thought it was especially important at the time.
 * Or nobody who had the authority to fix or replace it noticed.
 * I thought that the protest foundation were trying to get the clock fixed so that it would work again, not just preserve it in the same broken state it's been in for 30 years.
 * No, they wanted to keep it broken.


 * This is not unheard of in Real Life. The old Christchurch Railway Station's clock (well, one of them) has been left to read 4:35 as a reminder of their earthquake.
 * How on earth does Doc control his height and altitude in the hover-converted DeLorean? Surely we should see him doing more than merely turning the steering wheel—that should only turn him left or right. Shouldn't there be an extra lever or something somewhere?
 * maybe by additional foot pedals?
 * Or pressure pads in the steering wheel that act sort of like a non-obtrusive version of the wingflap controls on a model plane remote control?
 * Here's one: why is Doc suddenly in such a rush to destroy the time machine after the rather minor incident in 2015 with Jennifer? I would understand his reasoning if he'd made the decision after seeing the horrors of 1985-A, but the Jennifer incident? That was the nail in the coffin for all time travel?
 * Doc Brown is a pretty smart guy. I'm sure after the "Jennifer incident" he immediately realized the full, horrifying implications of meddling with the timeline.
 * Don't forget that Doc spent quite a bit of time in the future before returning to 1985 to get Marty and Jennifer, so there's no telling what adventures he had. This troper recalls a Fanfic that details Doc running into some trouble with a gang in the future over his stockpile of plutonium from 1985.
 * Doc was probably just finally accepting what he already knew (or thought he knew) in his heart. It took more straws than one on the camel's back to make that happen. I mean, he did invest thirty years of his life in the thing, you know.
 * It was the first time any of the dangers he'd run into resulted in a situation that he thought might have placed the entire space-time continuum in mortal danger. If that isn't reason enough, I don't know what is. (Of course, all time travel by definition entails paradoxes, so I guess some of them are more dangerous than others...?)
 * Christopher Lloyd went from JIM IGNATOWSKI to Doc Brown. That is all.
 * There's an episode that shows what Iggy was like in college. Maybe in the BTTF universe, he was never introduced to drugs.
 * In the Gale/Zemeckis FAQ for the trilogy, one of four possible answers they propose for Doc acting like he's forgotten many details in 1985 that he learned from Marty and other things in 1955 is that he experienced a memory loss in the years between from all the hard drugs he took as Reverend Jim.
 * Why do the Libyan Nationalists have a hippy van?
 * Because it was cheap and they could pay cash for it.
 * It's a Volkswagen! Those things are reliable. Just like AK series rifles. Oh, wait...
 * Reverend Jim will provide.
 * The terrorists are hippies. =)
 * If The Punch back in 1955 caused Biff to become a nice guy/complete wimp in 1985, why did he become, well, like his teenaged self again in 2015? Y'know, treating "Marty Jr." the way he treated George as a teenager and trying to alter history to make himself rich and powerful and all that.
 * It was 60 years later. He went from a teenage bully to a wimp, probably getting bitter over the years. He also knows that most people, like Marty Jr., aren't going to fight back when he bonks them with his cane. He's 77, fer cryin' out loud. Screw Politeness, I'm a Senior! and all that.
 * It was probably just George that he was ridiculously nice to, he's probably scared of him because he knows he packs a mean punch when backed into a corner and/or he could well report him to the police for his attempted rape. Anyone but George (even his grandson) is fair game however. Not to mention the fact that he's probably seen Marty Jr. around town, and his worried that he's going the same way that George before he manned up, or the same way Marty Sr. has gone, so giving him a bit of friendly advice is for his own good.
 * Supported briefly at the end of Part III when Marty goes to get his truck (so he can drive to Jennifer's house and awaken her). Biff starts to yell at him as a "butthead," but quickly falls back into the meek submissive role once he recognizes it's Marty.
 * Did the clock tower in the original movie have a second hand? If not, how did they know the exact time the lightning would strike the clock tower? It seems to me that Doc and Marty would have had to have figured out a way to make the DeLorean hit the wire and remain attached to it for around sixty seconds. Otherwise, the lightning would strike too soon or too late to do any good.
 * You know... If you need to do that, you should put a metallic grid over the DeLorean, like the bumper cars have, connect the grid to the clock tower, and have Marty run for a time at 88MpH until lightning strucks and it's powers is chanelled to the grid, and from the grid to the DeLorean. But that would spoil the awesomeness
 * The flyer said the lightning struck the clock tower at precisely 10:04 pm. That is, 10:04:00 pm. Yeah, a Contrived Coincidence, but there it is.
 * A car traveling at 88 MPH equates to a speed of 129 feet per second. That would mean that Marty would have to be really, really precise.
 * In the defense of this theory, the producers mentioned a being that controlled space and time. And if that were the case, the being would have made things line up perfectly so that Marty reached the clock tower at the precise moment lightning struck it. Note that had he started going when the timer went off, he would have been late.
 * Maybe that wire that the DeLorean hit was more than just a simple wire. Maybe Doc had rigged some fancy gadget on the side so it would (somehow) continue to hold electricity for a second or two, and thus the timing didn't need to be perfect.
 * Also, lightning actively seeks out the most conductive available pathway between ground and clouds. Even if the timing wasn't absolutely perfect, and it had to jump a gap between the hanging cable and the hook on the DeLorean, it'd do so as long as that was a cleaner conductive pathway than going straight through the clock tower's superstructure.
 * Hmmm. Another thought. At the end of the first movie, Marty makes it back to 1985, watches Doc get shot, and then watches himself go backwards in time. We'll call the one who watches himself the TP Marty, and his counterpart the LP Marty. Anyway, the implication is that TP Marty has now arrived at the far end of a Stable Time Loop. But logically that can't be so, since the future TP Marty has arrived back to is different from that of his counterpart - the ripple effect has made his life great, and his father always stood up to Biff in this timeline. So what past does the LP Marty wind up in? Does LP Marty just hang with Doc for 7 days and then make a perfect run back to the future? And when he does, does he replace the TP Marty? My head! Argh!
 * This was already covered above with the question "Presumably there's a version of Marty who grew up with an assertive father. What happens to him?"
 * How come we don't see cops all over the railroad tracks at the end of the third movie? The engineer whose train ran over the Delorean would've surely radioed in about the collision, so there ought to have been an immediate police response to determine if anyone had died. And even though no bodies would be found, a criminal investigation should've followed, to arrest the idiot who was driving on the tracks and risking a catastrophic train derailment.
 * The engineer couldn't have seen Marty well enough to recognize him in a line-up. What's he going to report? "Some kid in a cowboy outfit"?
 * Then the VIN on the broken-up DeLorean's parts should led the police to Doc, not Marty. Which is even worse, because Doc's disappeared, and Marty's the only person in 1985 he spends much time with, so he could come under suspicion of having killed Doc Brown and destroyed the DeLorean to get rid of evidence. A broken wrist could be the least of the problems Marty still has to avoid, if Doc's returned to 1885...
 * What possible reason would the police have to suspect Marty of murdering Doc? There's no motive and no evidence. A lawyer from the mall could rip that accusation to shreds.
 * Even Doc could be in trouble if the police investigate the train collision. Could there still be any traces of radiation on the car's pieces, from the plutonium and/or Mr. Fusion? Did he make references to his dealings with the Libyans in his research notes? If Doc ever shows himself in 1985 again, he could find himself branded a nuclear terrorist!
 * Authority figures don't seem to exist in BttF. This seems to be the case in a fair number of 80s movies -- The Karate Kid is another one that comes to mind. I imagine there's a trope for this, but I don't know the name.
 * Police Are Useless (or just plain Adults Are Useless).
 * RE: points 3 and 4; remember, Doc has business to conclude in 1985, which is partly why he shows up at the end -- he has to collect his dog and give Marty the picture for a start. Chances are, he's probably smart enough to learn of / anticipate both these issues and make suitable arrangements for them. To cast suspicion off Marty, all he has to do is plant something (a note in his handwriting or a video will or something) which reveals he's leaving town and gets Marty off the hook for any suspicions of that nature. As for being branded an international terrorist -- well, that's in 1985, and he's not going to be living in 1985 any more (or any one time, it seems), so what difference does it make?
 * It bugs me, but how in the world would have Doc and Marty known one another in the first place? They are not exactly what one would call similar. One is a Musician, the other is an Eccentric Scientist Who Travels in time. What would they ever have in common? Or maybe I am just forgetting some important detail I can't seem to find anywhere in the movies?
 * An early version of the screenplay explained the Doc originally hired Marty to work for him as an after-school job. The filmmakers cut this because they had a lot of exposition to get through in the first film and didn't think that bit of information was especially important. And they reasoned that kids are naturally drawn to eccentric people anyway.
 * Word of God has also said that the fact that Doc has a super awesome human-sized guitar amplifier at his place provides a plausible reason for a wannabe rock god like Marty to befriend him.
 * Well, at least in the modified timeline Doc has a reason for seeking Marty out, and the guitar amplifier might have just been a way of forging a friendship between them. Maybe the reason they became friends orginally was because the timeline needed them to.
 * This troper remembers a fanfic that said he met Marty then he crashed into his trashcans after he lost his grip on a car.
 * Simply because Doc knows he'll have to befrend Marty at some point from meeting him in 1955. Doc is probably the one who sought Marty out, so that there would be no major paradoxes.
 * Word of God is right here. Turns out that Marty was just a curious kid circa 1981, and wanted to see this crazy inventor who everyone told him to avoid. Doc found Marty's curiosity to be heartwarming, and hired the lad on as a part-time lab assistant.
 * As a side note, for many years there were rumors of a script for a prequel TV movie called Back to the Beginning, which would have shown how Marty met Doc.
 * When Marty writes the letter to Doc in the first film, why does he write "Do no open until 1985" on the envelope? First, there wouldn't have been anything wrong with Doc opening the letter right after Marty had left anyway and secondly, all it did was tell Doc that Marty was trying to tell him about the future, prompting him to tear it up.
 * Because (1) he wants to make sure Doc doesn't forget any important details, and (2) he's being a dolt.
 * If Doc had read the letter before 1985, he would've known that terrorists were going to shoot him, and it may have prompted him to never initiate contact with the Libyans, which would've screwed up the timeline. Marty should have gone further and should have written "Do not open until October 19, 1985," keeping the timeline intact until that point but still giving Doc a week to procure a bulletproof vest.
 * Did the letter say he was going to be shot? If so, I don't think it said the shots would all be in the chest. Doc was really taking a chance by wearing the vest. Even if they didn't shoot him in the head, they could have shot him in the arms, groin, or legs, which may have still resulted in his death or serious injuries.
 * The AK-47 assault rifle on full auto kicks like a mule on amphetamines. The terrorist had it pointed at Doc Brown while set to full auto. Hence, he aimed for the biggest part of the body: the chest.
 * Few people ever shoot at such small targets. Everyone who knows how to use a gun knows to shoot at an object's center mass. Of course, there's still the chance that they'll miss and hit his head. But anyone who would knowingly design and build a machine that could theoretically create situations where a conceivably universe-ending paradox is possible has got to be more than a little reckless.
 * I'm not sure I know what you mean. As a person who has seen what bullets do to human flesh, I don't think I would entrust my life to a vest when someone is firing an assault rifle at me. Some people fire at "6 o'clock mast." You aim tends to creep upward at night. Also, an AK-47 has significant recoil, which causes the barrel to climb. Firing from a moving vehicle is erratic and unpredictable. I'm just saying that if I'm a six-foot-tall man, I'm not going to trust my life to a single piece of protection that covers around one-third of my entire body. Plus, Marty didn't see what happened after he goes back in time. How does he know the terrorists wouldn't go back and light Doc on fire? In summary, Marty's warning was vague and Doc's precautionary measures were too limited.
 * Guys. It doesn't matter. No 1985-era concealable body armor vest could have possibly stopped a full magazine of AK-47 rounds from thirty feet. Even a fully-reinforced 2000s era SAPI rig would have problems with that. If the Libyan has been firing an Uzi (with its much lighter ammo), maybe...but its clear that the Libyan is firing a much longer assault rifle, at point blank range. (Cracked even snarked this exact scene.
 * Concealable under normal clothes, maybe. Doc was wearing a bulky, baggy radiation suit and didn't need to be doing a lot of dextrous maneuvers. He might have put multiple steel plates in the thing (or lead plates, to help with radiation shielding while he was at it).
 * You're also not a character in a movie.
 * This is Doc Emmet Brown we're talking about though. He's got this letter in his possession for at least thirty years, easily time for him to spruce up an ordinary bulletproof vest with something with a little more staying power.
 * Why don't the fire tracks left by the Delorean in the beginning of Part 1 burn Marty and Doc when they're standing right in them? Are they supposed to be in the same spatial location, but a different time? If so, how come 1955 Doc specifically avoids them once he's sent Marty back to 1985?
 * I'm guessing that the only reason they appeared to be standing almost right in the midst of the flames was a Special Effects Failure.
 * It could also be because that wasn't actually fire. 1955 Doc thinks this, and avoides them, but this is because they look like fire. They could infact be holes in the space-fabric left by the DeLorean. Of course, this is only speculation on my part.
 * It probably isn't fire. When Doc gets sent back to 1985, the "fire" is actually visible in the air for a few seconds.


 * Didn't George ever wonder why his son bore such an uncanny resemblance to his wife's ex-boyfriend? Or that "Calvin Klein" would become one of the most well-known names in the fashion industry? Or for that matter, how both Gene Roddenberry and George Lucas somehow managed to borrow ideas from his private notebooks?
 * Obviously, George would assume that the same alien visited Roddenberry and Lucas.
 * His wife's ex-boyfriends tell them that tey will have a children that at eight years old would burn their carpet. THEN they knowed the truth!! But teenagers just need their space and live their lifes.
 * His wife's ex-boyfriend was someone she had only known for a week, neither of them would have ever seen any sign of him after that, and Marty was born more than 10 years later, after two other kids. Maybe it would look like a bizarre coincidence, but anything more than a coincidence would be just as implausible.
 * Marty returns to 1985 ten minutes before he left. He had to run at least two miles in those ten minutes to reach the "Lone Pine Mall" when Marty goes back in time. How did he do that? Sure, he was breathing hard...
 * If there's something very important waiting for you at the end of those two miles (such as saving your friend's life), then it's not impossible that you'd run fast to get there; adrenaline would probably get you through it.


 * Why oh why did no one, over the course of five years, among any of the thousands of people involved with the trilogy, ever inform Gale & Zemeckis or any of the actors of the correct pronunciation of "gigawatt"?
 * People probably didn't know at the time. They probably thought it was a derivative word from "gigantic."
 * Most people know the correct pronunciation today either because they heard how Back to the Future mispronounced it, or because the term "gigabyte" has become widely known due to the advancements of modern computers in the last decade or two.
 * "In the film Back To The Future the term is pronounced "jiggawatt" in reference to the 1.21 GW of electricity needed to power the fictional Delorean time machine. Though obscure, the "j" sound is still an accepted pronunciation. -- The Other Wiki
 * The movie's science adviser had the habit of pronouncing it "jiggowatt" (which, as noted, is technically acceptable). Nobody in the case or crew realized that the science adviser was using an obscure pronunciation.
 * A number of questions related to the first film, brought up by comedians Chris Hardwick, Mike Phirman, and Matt Mira, between two Internet articles and a podcast:
 * Why does Marty only set the time machine to give himself ten minutes to save Doc's life upon returning to 1985?
 * Because Marty figured he'd be able to drive over there and warn him. But that would have caused a time paradox, which is exactly why the DeLorean failed. That, and Truth in Television.
 * It was Marty, however, who made the choice as to how far back he'd travel. Why not an hour? Why not a day? Ten minutes is not nearly enough time; even if he had made it there in time to see Doc (and his other self, and there's a time paradox for you), it's not like he could have expected Doc to simply have a bulletproof vest on hand.
 * Two miles in ten minutes to drive somewhere and shout "Doc, in a few minutes you're gonna get shot, get out of here now!!" is easy if you're in a rather fast car in the early hours of the morning with little traffic to impede you -- he's not expecting the car to break down, remember. A day or an hour, and he risks bumping into himself or hanging around and losing track of time somehow, and although he's not exactly the sharpest stick when it comes to thinking fourth-dimensionally he's probably had enough time travel-related headaches in the past week to decide to make this particular instance as simple and painless as possible.
 * What experiment is Doc conducting where he's elated that the clocks are running 25 minutes slow? Is he just messing with Marty? How does he know Marty would be there anyway?
 * How it is possible to (change time on the clock) for all clocks simultaneously, even from another place with remote? Doc tried it and it worked.
 * Wild Mass Guessing: Doc's been doing test firings of the flux capacitor in the room to see how it affects the spacetime continuum in a very localised way. If the clocks hadn't all gone off at the same time, he'd have known the flux capacitor itself was damaging spacetime in some way, since he'd very precisely attuned all of them to go off at once.
 * The vagueness is intentional. They're establishing Doc as a mysterious, possibly kooky fellow whose experiments don't seem to make a whole lot of sense. As long as it foreshadows that some time-related experiments are going on, nothing more is needed. I think it's probably best if we don't always know what's going through that strange old man's head.
 * I haven't been able to check it, yet... but is it possible that Marty inadvertently walked into an experiment that stopped time locally? It would explain the 25 minute disparity in the clocks, and why Marty managed to end up 25 minutes late despite only spending a few minutes there and having a watch. It would also explain why Marty's watch is wrong along with the others, and fits perfectly into Doc's field of experiments, as stopping time would be as interesting to him as travelling through it.
 * Why does George McFly dye his hair in the original, more pathetic timeline, but not in the improved timeline where he's a writer?
 * In the original timeline he's so self-conscious about his age and his lost years of amounting to nothing that he dyes his hair to avoid dealing with the fact it's greying. In the improved timeline he's a successful writer, at peace with himself and self-confident, so he doesn't feel the need to dye his hair at all.
 * How did Doc get into contact with the Libyan terrorists?
 * The terrorists probably sought him out. There can't be many people in a place like Hill Valley who have the know-how to build a nuclear bomb.
 * Gale and Zemeckis say in the DVD materials for the box set that they thought of Doc as having probably worked on the Manhattan Project. If the Libyans did their homework then they would likely have heard of him, so either they sought him out and he took advantage of the opportunity or he used his credentials to his advantage and sought them ought with his hoax already in mind.
 * Why does Lorraine's father (Marty's grandfather) complain that another teenager threw himself in front of the car? Has this happened before?
 * Yes. It's an Oh, No, Not Again gag.
 * I thought it was a sneaky comment about horny boys eying his daughter as she changed.
 * This has happened before. Lorraine met all of her previous boyfriends because they were trying to look through her bedroom window and got hit by her father's car. This also helps explain why Lorraine is so taken with Marty: she assumes he was looking at her as she dressed (and apparently she doesn't find this creepy; maybe she even sets it up on purpose) and therefore she assumes that Marty is already attracted to her. In fact...we can further suppose that Lorraine's father suspects that this is the case. Therefore, he tends to hit these boys with his car on purpose (not too hard, mind you) as a way of saying "stop being a peeping tom". He further describes Marty as "an idiot" at the dinner table, because he thinks Marty was peeping.
 * Why does the family just have Biff, who attempted to rape Lorraine, hang around and do auto detailing work for them (as asked earlier on this page)? Furthermore, why didn't they get him sent to jail?
 * It was The Fifties at the time, with different societal attitudes. Also, time heals a lot of wounds I guess (see Watchmen for details). And when Biff was polishing the car, the Mc Flys weren't at home. They were out playing tennis. Biff himself is also a changed man: possibly he's even apologised to Lorraine for the attempted rape.
 * In the new 1985, why is Dave in a suit and going to the office on a Saturday? If he has an office job that requires a suit, how come he still shares a car with his parents (as implied by his anger when Marty claims the car was wrecked)?
 * Maybe the people at his office carpool. And maybe he's working on the weekend because he has a Pointy-Haired Boss.
 * As asked above on this page, does George McFly eventually suffer mental breakdowns when he sees "Darth Vader" on Star Wars, the Vulcan salute on Star Trek, and hear the music of Van Halen? Or does he just believe the alien visited the creators of those works, too?
 * This question has been addressed above twice.
 * The Power of Love is great and the song with that title used in the first Back To The Future is great too. But how exactly does the content of the song relate in any way to the plot of Back To The Future?
 * Does every song in any movie have to relate back directly to it's subject matter? It's a catchy, up-beat song to set the tone for Marty's character
 * No, but wasn't the song written specifically for the film? You'd think if someone went to all the trouble of writing a song for a movie, they would make it relate to the plot at least vaguely.
 * You're thinking of "Back in Time", the other Huey Lewis song on the Back to the Future soundtrack, which plays on the radio when Marty wakes up at the end of Part I, over the end credits, and as the theme song for Back to the Future: The Animated Series.
 * The Power of Love is strong enough to seep through time and make Lorraine realize that she feels awkward kissing her future son (even though she doesn't know its him) and this allows Marty to escape his bind with her. It is through The Power of Love that Marty and Doc manage to stumble on the way to get Marty back to 1985 and save his and his siblings' entire existence, when his appeal to Doc by showing him Jennifer's message of love ends up accidentally revealing the way. It is through The Power of Love that George ends up finding his courage--twice--and sealing his entire family's fate, and his and Lorraine's love ends up drastically affecting the future of everyone. "It might just save your life." I'd say the song is extremely relevant.
 * Plus, this is a movie from the 1980s we're dealing with; you couldn't swing a cat in Hollywood without hitting a movie which had at least one catchy pop song with bugger-all relevance to the actual movie on the soundtrack during that decade.
 * Doesn't it kind of deal with the plot since each movie contains a love story of some sort. In the first movie it had to do between Marty, George, and Lorraine and was the entire plot for what they were doing it 1955. In the second movie it was Biff, Lorraine, and George. Although George was dead Marty still loved him and his mother enough to change things back to where they are supposed to be. As for the 3rd movie, i mean come on. It was the entire reason that Doc didn't come back to 1985 with Marty. It was the reason that "Eastwood Ravine" was never named "Clayton Ravine." I mean come on, how can you not say that "The Power of Love" wasn't relavent?
 * So the "old" McFlys from Part III are George's ancestors, and unless we admit a massive Squick moment, we are assuming that George and Lorraine are not related in any way, shape, or form...so why does George's ancestor look exactly like his wife? ** shivers**
 * Word of God is that McFly men are just predisposed to be attracted to women that look like Lea Thompson.
 * Yes, Claudia Wells could pass for Lea Thompson if you squint really hard...
 * Elizabeth Shue, on the other hand...
 * Biff saw the flying DeLorean in 1955!!!
 * And the hoverboard. Other than freaking him out though, I don't see how that's Fridge Logic, more like Fridge Brilliance. Are you watching closely? His incredibly disturbed reaction to seeing the DeLorean in 1985 ("What the hell is going on here?") probably made him remember that he saw it in 1955. He has a good memory even when old, as evidenced by 2015 Biff ("The manure! I remember that!"). By 2015, when he sees it for a third time and eavesdrops on the Marty/Doc conversation he finally has the solution to a sixty year old problem: how he was able to see a flying DeLorean, an unusual car even without the hover conversion, on three seperate occasions in his life ("So Doc Brown invented a time machine"). Of course you could argue that 1955 Biff only saw the DeLorean after Marty and Doc travelled back to retrieve the Almanac and hadn't seen it at the start of the movie when only Marty went back to 1955, but even so; he saw it in 1985 and again in 2015 before any serious changes were made to the timeline, creating 1985-A by having 2015 Biff travel back to 1955. Seems like he would have come to the same conclusion either way. If that isn't Character Development I don't know what is; he goes from a dumb kid in 1955 to an Evil Genius old man in 2015.
 * The Biff we see at the beginning of Part II isn't a part of a Stable Time Loop...he's only merely freaked out by seeing a DeLorean fly into the air and explode. Remember, in this trilogy, things happen from Marty's (and the audience's) POV; ergo, this Biff doesn't have memories of a flying DeLorean in 1955 (or, for that matter, a second manure truck crash) because those things haven't happened yet.
 * Watch the tunnel scene again. 1955 Biff does not get a very good look at the DeLorean. He's looking up for exactly four seconds, during which time the POV shot shows us something unidentifiable as a DeLorean (especially since the car hadn't been invented yet) and looking not so much like a car as an air-roving Hunter-Killer from the Terminator movies (although they hadn't come out yet either). It's possible that 1985 Biff remembers seeing that irritating Calvin Klein kid get pulled up into some weird aircraft or spaceship, but he doesn't have any way of knowing it's the same vehicle he sees for a longer moment, from the front, in broad daylight, thirty years later. And if he doesn't recognize Marty as looking like Calvin Klein (which he theoretically might--just because he hasn't said anything doesn't mean that he doesn't--but let's apply the principle of conservatism here), then chances are he doesn't remember the Doc Brown voice (which had shouted only about three words) very clearly either.
 * The only headscratcher here is: In the span of a week, Biff went to being the King of the Valley, to see as a foreigner with funny clothes that Pwned him, then the same guy befriended the local Butt Monkey and made him a confident and assertive man that punched him KO. and THEN the same guy with funny clothes robbed him from a magical Sports Almanac, who was incidentally using a flying board, and finally he was helped by what looked as a frigging 'SPACESHIP'. And then, the guy dissapeared and never was seen again. HOW is that Biff didn't commited himself to an asylum? How is that he remained in Hill Valley and didn't hid himself in a cave for the rest of his life, for fear of "Aliens with a Lifesaver Vest"?
 * The first few things are demoralizing, perhaps, but not really the kind of thing that intensive psychiatric therapy is called for. The "aliens with a lifesaver vest" thing is a bit more of a potentially destabilizing thing, to be true, but the very fact that 1985!Biff ends up a completely spineless wimp is perhaps indicative that his experiences did indeed take a bit of a toll on him, but thirty years is also a pretty long time -- time enough to more or less come to terms with things, at least.
 * Rule of Cool of Flying Car overrides Fridge Logic perhaps, but when Doc went in to have a hover conversion fitted to the DeLorean, presumably a very extensive modification judging by the amount Goldie Wilson III says it costs, did no future mechanic notice the flux capacitor, time circuits switch and the huge LCD readout panel mounted to the dash with the labels "DESTINATION TIME", "PRESENT TIME" and "LAST TIME DEPARTED" - not to mention the converted nuclear fission reactor on the back?
 * I always assumed Doc made the hover conversion himself. He did the same for an entire freaking train engine in 1885...
 * IN A CAVE! WITH A BOX OF SCRAPS! *cough*
 * No, he went to the future before appearing to Marty. He had the hover conversion done then. Although that leaves the question of why the train time machine still runs on steam.
 * He could have done it himself in the future, after learning how from future people. The two things are not mutually exclusive, folks.
 * Rule of Cool.
 * Fridge Brilliance, again. The only thing needed for a steam powered engine is something to burn, like say wood, something that would be plentiful in any time period.
 * Doc installed all the time-travel stuff into the car in the first place. If he needed somebody else to perform the hover conversion, he could probably just take out all the time-travel stuff, get the car converted as if it were a normal car, and then re-instal the time-stuff himself.
 * Possibly he told the mechanics who did the conversion that the car was needed as a prop for an upcoming scifi/comedy movie about a time machine. Don't touch those fake dials and gizmos, please, the prop department worked really hard making those look like old antiques from the '80s.
 * Here's something I've always wondered, and I'm surprised it's never been mentioned yet. Why does 1955 Doc have such a colossal freak-out at the end of Btt F 2/beginning of Btt F 3 upon seeing Marty again right after sending the past Marty back to 1985? He knows all about the time machine by this point, so why would seeing another future version of Marty cause him to go into shock, pass out, and then act in denial of Marty's existance until he shows him the letter from his future self?
 * He had just spent a whole week wrapped up in that scheme, only for it to come to naught (as far as he can see) the very moment it had succeeded. Anyone would be tempted to be in denial after that. Besides, Doc is an excitable fellow.
 * After the time machine was destroyed in Part III, one would think that eventually someone would come by to see if there were any bodies in the rubble, and to clean up the scene. The problem is, there are several parts of the time machine that were either unique to it (the flux capacitor and time circuits) or were borrowed future technology (Mr. Fusion and the destroyed flying circuits). Does it stand to reason that someone may have found, say, the Mr. Fusion device, and reverse-engineered it to become the "new" creator of the Mr. Fusion? Kind of like what happened in The Terminator or Star Trek IV the Voyage Home.
 * Marty and Jennifer probably picked up the most important pieces before they left the scene.
 * What are the odds of someone who would know what to do with such an elaborate kind of mechanism chancing to come across the rubble before it was cleared? Or that the pieces would be in any condition to help them?
 * I don't know enough about science to answer this myself, but I've always wondered: can a single lightning bolt generate 1,210,000,000 watts of electricity? Or can the small amount of plutonium seen in the first film? I wouldn't know, but it sounds like an awful lot....
 * According to The Other Wiki, it could send hundreds of Deloreans Back To The Future. "The average peak power output of a single lightning stroke is about one trillion watts — one "terawatt" (1012 W), and the stroke lasts for about 30 millionths of a second — 30 "microseconds"."
 * Fissioning one kilogram of plutonium can produce 20000 megatons of energy, which is about 100 petajoules. So, in theory, it could keep on producing 1.21 gigawatts of power for about 3000 years.
 * Uh, no. Try 18.5 hours, if we're assuming pure Pu-239 and fissioning 100% of it (in reality, some of it would be transmuted into heavier isotopes and some would remain Pu-239 after the reactor has gone subcritical due to fuel depletion).
 * Why does Doc Brown need a disguise for showing himself to Marty? Marty has seen him younger and thus would recognize Doc 30 years younger, so that seems kinda pointless?
 * It was a handwave. Christopher Lloyd, when the first film came out, looked like Doc Brown in 1955. They put make-up on him for his 1985 scenes to make him look older. When it came time to do the sequels, he didn't want to be put in make-up to look older for he whole time, so they did the "rejuvenation therapy" excuse to make him look young again, and threw in the 'disguise' bit as a Lampshade Hanging. Honestly, though, I always thought the joke was that he looks exactly the same regardless.
 * Ditto. If there was makeup involved, it was too subtle for This Troper to notice.
 * I also felt that this was more of a "just in case" choice by Doc Brown. He almost always takes extra steps to prevent catatrophic events due to the effects of his time travel, so this always seemed like Doc taking every available precaution, whether or not the risk was very high.
 * Rule of Funny -- as noted above, the joke is that even after having thirty-or-so years of his life rejuvenated Doc looks exactly the same as he ever did.
 * Doc explicitly says to Marty that he's wearing the mask because he wants to avoid the surprise and confusion of older Doc disappear one day and younger Doc show up the next and all the resulting questions this would raise (such as "Doc? How come you look thirty years younger now?!") and ease Marty into accepting this when he feels they have some time. Of course, the effort turns out to be pointless because he looks exactly the same, but the logic's there.
 * Why are we 5 years out from the events of the 2nd film and still without hoverboard and flying cars? Seriously, Mattel needs to step it up.
 * We're getting there.
 * We destabilised the space-time continuum when fax machines fell out of popularity. Without the amazing development of having a fax machine in your cupboard, scientists have been unable to replicate the technology for flying cars, hoverboards, self-lacing shoes, and self-drying clothes. Some suspect this to be an conspiracy on the part of moviegoers in order to prevent the making of fifteen more Jaws films.
 * Well then said fax machines must have prevented the advent of such technologies as cell phones, which are surprisingly absent from BTTF's 2015. Either that, or in five years none of us will use them anymore.
 * Yeah, if it depicted the now modern world accurately then everyone wouldn't be driving in flying cars but instead constantly yapping on their cell phones in ordinary ones. Which to be fair is no less dangerous.
 * Also, the Weather Channel has a lot of catching up to do...
 * And Princess Diana is obviously never coming to become queen now, unless there is somehow such a thing as a posthumous coronation. The version of 2015 featured in the movie is, however, like all futures the Delorean can take you to, only "[the space-time continuum's] logical extrapolation of the events of [the moment you left from], [i.e.] the likeliest future of the time you left" according to the official Gale-Zemeckis FAQ (quoted from memory), and therefore not necessarily the way things will be. Marty already altered at least part of it at the end of Part III, and other parts may have been altered by other actions since, or that same action may have created a butterfly effect.
 * My personal theory is that Marty's actions after we see 2015 (so, his meddling in 1955, 1885 and possibly 1931) created some kind of butterfly effect that changes events in the most random places. So, by 2015 after the events of the 3rd movie, it'll be just like 2015 in Real Life. The flying locomotive probably came from a very far future, and the hoverboard is now a relic of a time that never happened. Or, Marty's and Doc's constant meddling with the Timey Wimey Ball caused random changes in time, causing the 2010s as we know it.
 * One of the statements directly above has brought up something that has always bothered me: why does the 2015 McFly family have a functional, turned-on fax machine in their closet (not their cupboard, although that would be an equally weird place)?
 * how do you know they dont have one in the cupboard? I think thats one of the jokes. BTTF films are not comedies but do have humour sprinkled in each of them. The second act of part II (1985 A) has virtually no humour aside from the line "they must have hit you hard this time". The 1995 part has slightly more with biff being at his dumbest but 2015 has by far the most mostly with some of the silly fads/technology.
 * I don't get the joke.
 * It's basically about technology becoming so common that it's absolutely everywhere. A big joke during parts of the eighties and nineties was that you could invent something new and sell a ton of them by simply taking an already existing product and sticking a digital clock in it. Like digital clocks were appearing everywhere, the writers were extrapolating that faxes would be everywhere. (And they're kind of right, since most "all-in-one" style printers can be used as fax machines if they're set up to do so.) The joke is that when they're saying they'd be everywhere, that they'd be everywhere... including in the closet.
 * Why did Doc Brown get so upset with Marty over buying the Grays Sports Almanac, when in the first film he said he planned to get the results of the next 25 World Series?
 * He wasn't upset that he just purchased it, he was mad that he was concealing it because he was clearly planning to use it to make money. I don't think Doc Brown ever said he wanted to know the World Series results for that reason.
 * I think he was upset even at the purchase since he knows Marty too well and even possession of the book can lead to trouble (as the film proves), but yes, he never said in the first film that he intended either to gamble on any world series nor to bring back any future records or evidence of who would win them, only that he was interested in knowing, as I suppose many baseball fans would be.
 * I always assumed by that line, that Doc Brown was planning on watching the next 25 world series in person rather than looking up the results.
 * Also, at this point Doc doesn't have much experience in the ways of time travel. By the time he tells off Marty, he's lived through the first movie's chronological shenanigans and apparently had a few adventures besides. He knows what the consequences could be.
 * Or, he's telling off Marty but he's actually cross at himself for putting the idea in the boy's head to start with with that '25 World Series' bit.
 * When Doc is drunk in 1885 and explaining the concept of the automobile or "horseless carriage" to the other bar patrons, they express pure disbelief and act like he's crazy. But would people from 1885 really react this way? It's not the middle ages; they're used to locomotives, and it's not much of a stretch to imagine a locomotive that can work without a track. And besides, in 1885 people like Karl Benz were already designing and tinkering with the first production cars. This is like someone from 2095 going back in time to 1995 and heralding the invention of...the DVD. Most people would say "yeah I could see VHS tapes becoming obsolete soon," not "oh you crazy mad scientist and your wacky impossible ideas!"
 * The other patrons only think he's drunk, but still, that's their perception, so it's less "Oh you crazy mad scientist and your wacky impossible ideas!" and more "Oh that drunk guy is rambling about the future." Also, just because some people were designing and tinkering with prototypes doesn't mean a buncha cowboys out on the frontier are going to know anything about it. And the VHS to DVD thing is faulty, since technology has progressed much faster in the last 20 years than it has in previous eras of history, so that someone in the 1990s would have more expectation of one technology replacing another than a bunch of drunken frontier cowboys in 1885 would expect something they've never heard of or seen becoming so commonplace.
 * And even if a bunch of bar flies did know about the prototype automobiles being built back east, there was still serious doubt in the late 1800s about whether the concept would ever really get off the ground.
 * In the first movie when Doc and Marty are loading the plutonium into the Delorean, they are wearing radiation suits to protect themselves from the plutonium. However, less than 10 seconds later after Doc and Marty have taken off their headgear, Doc opens up the chest FULL of plutonium to put them empty jar back, exposing himself to a severe, if not lethal dose of radiation. All of this happens IN THE SAME SHOT. How could the filmmakers have missed this?!
 * The plutonium was in a tube like thing in the glass jar. When he loaded the plutonium, it was removed from the jar. The jar contained some sort of liquid, which I assume it protects the handler from radiation. If you notice, the liquid is still in the jar after the plutonium is inserted into the car. It was only during the transfer that there would be possible exposure.
 * We know that the DeLorean becomes very cold immediately after traveling through time. And vacuum tubes need to be warm to operate properly. In BTTF 3, Doc built the time circuit control tubes right on the hood of the car, and specifically said they were "warmed up" before sending Marty off. Shouldn't the tubes have shattered from the rapid temperature change immediately after Marty went back to 1885, especially with all the vibration from the off-road conditions at high speeds?
 * Dunno about the vibrations, but the "time travel freezes the car" thing is something the deliberately downplayed and dropped over the course of the series, presumably so they wouldn't have to spend time/money frosting up the car all the time.
 * It's true that they downplayed it, but it still happens. If you look closely at the DeLorean right after Marty is transported back to 1885 (just before he shouts "Indians!") you can see some frost on the car.
 * You can also see it in Part II after Marty and Doc travel back to 1955.
 * I have a theory that the only bits that get cold are the stainless steel shell of the DeLorean (having to do with the stainless steel helping the flux dispersal or whatever) and NOT the various electronic bits or other automobile parts. 1985!Doc probably knew this and figured the vacuum tubes would be safe. (I'd also wager that his 1955 counterpart packed the trunk with extra tubes and parts just in case).
 * Since time travel is precisely what is involved, there's no reason to assume the temperature change happens "instantaneously" even though it appears that way to the driver. Maybe, from the tubes' frame of reference, Marty (or whoever is driving) moves extremely slowly "during" the trip (which, after all, does last a hundred years, in a way).
 * After the events of the first movie, Marty, Linda and Dave ALL should have ceased to exist. The odds that Confident George and Lorraine would have sex at the same times as their counterparts in the Twin Pines universe, so that the same ova and sperm meet to create the same individuals, are astronomically improbable
 * Answer: It's a movie. (However, the original script for Part II sort of addressed this by having Marty in 1967 trying to make sure his parents went through with his conception.)
 * It's not as improbable as you may think when you consider the logic of time travel. As overzealous as Doc may be with his theories about perceived possible dangers in grandfather paradoxes, none ever occur throughout the entire trilogy, and Bob & Bob's FAQ presents as a possibility the theory that since, logically, a grandfather paradox cannot happen, therefore the time-space continuum has some kind of built-in mechanism that ensures it's always prevented one way or another. However much Marty may fade and the picture may change, they're doing that only because they're caught in a no man's land in terms of established reality. Long story short, it is logically impossible for Marty to prevent his own conception (talk about a nifty instance of justified Plot Armor!) so he must be conceived as the person he already was physiologically.
 * 1985 Doc holds Albert Einstein in high enough esteem to name his dog after him. At the beginning of part III, however, as Doc is reading his letter he says something like "Please take care of Einstein for me." pause "Einstein?" Then Marty tells him its what he calls his dog in 1985. Doc gives this look that suggests he thinks it is a silly name. Why would 1955 Doc's opinion of Albert Einstein be so low?
 * My interpretation of that was different: upon first reading this (without scanning ahead to the next sentence), Doc thinks his future self used the time machine to bring the actual Albert Einstein to 1985. Naturally he would be rather surprised at that.
 * Yeah, that's pretty much exactly what's meant by that. Hell, if you want to get into WMG territory, the 1955 section takes place in October of 1955. Einstein died in April of that same year. For those few seconds, Doc is probably thinking, "He didn't die, I brought him to the future!" The look isn't that he thinks it's a silly name, it's that Doc is somewhat disappointed that he won't be hanging out with what's likely one of his idols.
 * Heck, forget idols, could have been one of his friends. It's implied in places that Doc worked on the Manhattan Project, he may have named his dog not after some far-off idol but a good buddy he'd been missing for awhile.
 * In the first film, Doc rigs up an alarm clock on the dashboard of the DeLorean and tells Marty to "hit the gas" when it goes off, so he'll reach the conducting wire at exactly the right moment. Not only were his calculations off (the car stalls until a few seconds after the alarm rings, yet Marty still hits the wire at the correct time), but it wouldn't even be possible for the calculations to be correct. It might have been possible to figure this out if the DeLorean had an automatic transmission, but we can clearly see from the first chase scene that it has a stick shift. Unless Marty is planning to get to 88 MPH in first gear, he can't just "hit the gas" and keep going. He has to momentarily release the gas to upshift - and this makes the run impossible to time with any degree of repeatable accuracy.
 * Actually, Doc's calculations may not have been incorrect. We see the Present Time on the time circuits reading 10:03pm a few seconds before the clock tower ticks over, therefore it is apparent that the clock tower was slow, meaning that the lightning did not strike at precisely 10:04pm. If Doc had used his own correctly timed watch to plan his calculations, his calculations would have given him a few seconds off owing to the difference between clock times.
 * How would Doc know how a car from thirty years in the future works? Given that Marty hits 88 miles per hour before he hits the wire (you can see the bottom of the car light on fire like it does when it time travels), then it's likely that Doc didn't know what the DeLorean was capable of.
 * What sort of experiment causes all of your clocks to run twenty five minutes slow? Before you answer that, I point out that this was before the first run of the time machine.
 * The whole series revolves around time travel, and you have to ask this? That was the first run of the DeLorean, but you don't think Doc Brown would've, you know, tested the mechanism before sticking his dog into it?
 * If this were a time travel experiment, shouldn't he actually be paying attention to it? It's kind of important you don't mess those ones up, what with the universe exploding when you do. He's seemingly let the experiment run unattended over the entire week, if what Marty says is true.
 * Depending on the details of the experiment, Doc may not have wanted to be around so that he wouldn't be affected by whatever effect was happening. There are some experiments and procedures where one step amounts to "Let it sit for a while and check after a few hours/days/weeks." Besides, it's not like he didn't have other things to do, like modifying the DeLorean and ripping off the Libyans.
 * I think it's meant to be left to our imaginations beyond hinting at the time travel theme. It's just a Noodle Incident.
 * This troper once read an interesting Epileptic Tree on a BTTF fansite that hypothesised that the Doc had been converting his clocks from sidereal time to solar time. It even had some math to back it up, and it guessed that Doc would eventually go home to reset his clocks to the correct time.
 * Many fans do not live at USA at the first place, nor they live in the small Pasadena-like towns. Is there something special in lifestyle of this towns, that foreign Btt F fans can miss because they are not acquainted with US? First question: what's population of Hill Vallley? 20k? 10k? 5k? Second question: how can other parts of the town be called? Hills&Mills? Pine View?
 * Neither of those questions really would have an impact on one's understaning the movies. But here are a few Useful Notes. The centerpiece of Hill Valley is the Courthouse Square which, in many small towns, was the center of business activity. You will notice that the square is a lot dirtier in 1985. By that time, many small town squares were no longer important because (like Hill Valley) large malls had been built on the outskirts, usually former farmland. Availability of cars meant that more people lived in planned suburban developments (like Lyon Estates and Hilldale) and drove to work. Of course, the films are loaded with more cultural references than could fit here.
 * There's probably always stuff you miss when a film or TV show is set in a country you've never lived in. The best stories, though--like this one--render that more or less irrelevant to the enjoyment factor.
 * Just a minor thing that bugs me about that distant world of the future. Why would there be a thumb reader on both sides of the door, as shown when young Jeniffer can't get out because "there's no doorknob"? (unlike RL devices we have now, which usually have finger scanner on the outside and regular knob on the inside) Isn't that just a little weird that you need authorization to get out?
 * Not really. Similar safety measures have been implemented in stable facilities and suggested for mobile facilities and vehicles in Real Life. it prevents anyone who does manage to get in from jumping and running at the first sign of trouble, since they'd have to work their way through the security from the inside (assuming they hadn't simply blasted through the window or door or stolen the owner's finger).
 * It still seems odd for there to be one on a private house, though. Dangerous, too, if you think about fire safety.
 * Maybe everything's fireproof in 2015, or the system automatically lets people out if it detects a fire.
 * At the end of the first movie, why is Doc in such a hurry to get Marty and Jennifer back to the future to save their children? Chill out Doc, it's not gonna happen for another 30 years.
 * Currently Marty looks exactly like his son. Since he's 17, he's still maturing quite rapidly at that point. Doc doesn't know if Marty would be able to pass exactly for his son further down the line.
 * It can't have waited a few hours though?
 * Doc might have got himself locked into a 'San Dimas Time' way of thinking (i.e. the clock is always ticking and I have to get this done right away!); perhaps not rational, seeing as San Dimas Time doesn't seem to operate in the BTTF universe, but he's perhaps running on adrenaline a bit given the nature of the crisis and not really thinking straight.
 * Doc's watch is set to the precise 10/21/2015 time, and he's calculated all the events down to the moment. Remember when he looks at his watch when the weather changes, and remember how its alarm goes off when it's time to go intercept Marty Jr.? Doc imposed San Dimas Time on himself.
 * I know I know, Berserk Button and probably not thinking straight, but Marty is still a massive idiot for letting Griff get to him from being called chicken in 2015. The insult was meant for Marty Jr., so why does Marty even care? Or could he be taking the insult as a means of saying "nobody calls my son chicken!" ?
 * Pride is rarely rational. A personal example: When I was in drama club in high school I was never comfortable playing buffoonish, doltish, or silly characters because I had a very hard time separating myself from the character I was portraying. So when the audience would laugh at something I did on stage it felt like they were actually laughing at me rather than at the buffoonish character I was portraying. No matter how many times the cold and logical side of my brain told me that they were laughing at my character and not at me, it took me a long time to learn how to get over my pride and stop taking their laughter personally. The same thing is probably going on with Marty. Even though he knows Griff is technically insulting Marty Jr., Marty Sr.'s pride causes him to take it personally all the same.
 * Leaving Jennifer on a porch in 1985-A, with nothing but Doc's guess/hope that history will shift around her and she'll end up where she's supposed to. I understand why it was done from a story perspective - the ending of Part I forced them to bring her along, but they couldn't just leave her in the back of the DeLorean in a coma for all of Part II and III - but every other fictional treatment of time travel This Troper has seen says that she would have been lost in a timeline that's no longer accessible/doesn't exist. You don't switch time-tracks without a time machine, period. Since they were already re-shooting the ending to substitute Shue for Wells and add Biff's reaction, they should have just left her standing at the curb and saved a lot of trouble.
 * Possibly the act of travelling in a time machine renders her a certain level of immunity to The Ripple Effect, just as Marty and Doc are. That immunity is enough "chronological protection" to leave her asleep in an alternate timeline because God, The Dark Tower, or Peewee Herman will hold that timeline in existence long enough for Marty and Doc to try and shift it back from 1985-A.
 * Doc is confident, and being the guy who invented the time machine he knows enough about what will very likely happen that he doesn't have to guess or hope. Besides, it's the way things always work in these movies, the timeline changing around a person from another timeline. He's just reasonably predicting that to stay consistent.
 * The best thing I can say is that she was left in her porch in 1985. So when they changed the past, she woke in a safer 1985. Whatever misventures she could suffer in Hell Valley were erased. They are so lucky that the Delorean don't work like the Petrelli Time Travel with Caitlin!
 * Biff in 2015 plans to steal the sports almanac and give it to his 1955 self. Fine, young Biff has the sports results and bets on winning games... but how long would that last? Eventually the change in history, even minor, will ripple out. We know that Biff eventually made real money but a change to time could result in games eventually being played differently, making the entire almanac useless, and cutting into Biff's fortune if he bets on a game and the altering of time changes the results. That's not getting into the possibility that Biff could be investigated for winning a lot of bets in a row... sure, the book could make some easy money early on but the change that Biff would become that wealthy would be a slim one.
 * Why would the book not change when we're explicitly shown every single other piece of future documentation change when the relevant facts to it change in the past? The photos in the first and third film, the newspaper in the second, the fax from the second that changes in the third...Every single time something changes in the past, artifacts from the future change to reflect it.