52

Biff didn't actually have to use the same plutonium-driven Delorean that Marty had to use in the 1st part. He used the Delorean that Doc had modified based on 2015 technology, which didn't need the high energy of plutonium to operate anymore rather than just garbage (nor did it need any roads either). We see this in the beginning of the film, where Doc just ...


37

The Doc Brown in 1955 is younger than the Doc Brown in 1885, by 30 years. The Doc Brown in 1955 will still live for another 30 years before traveling back to 1885 and being shot by Buford.


36

Speculation: Old Biff returns to the changed 2015 (designated 2015A). Doc and Marty "transitioned" to 2015A without noticing. Why didn't they notice? Maybe because they were out on the street when it happened and Hilldale looks the same in 2015A. BTW, time travelers "transitioning" between changed timelines is implied by Doc Brow when he tells Marty not to ...


21

In all the Back to the Future movies, a major component of the plot is reality taking time to catch up to events. Typically, this is represented as pictures with gradually changing features, which the protagonists are trying to prevent from changing. Marty's family photo in the first movie, and the tombstone in the third are examples of this. From this ...


15

Maybe, but the Post Office wasn't involved. The package wasn't delivered by the United States Postal Service, it was delivered by Western Union, a private company. Speaking as a former postal employee, I would expect the US Postal Service to lose the letter sometime in that 70 years. They may eventually find it... but find it and deliver it on time? Not ...


11

He appears to have inherited it. When explaining to Marty where the flux capacitor came from I had a revelation! A vision! A picture in my head! A picture of this! This is what makes time travel possible: the flux capacitor! It's taken me nearly thirty years and my entire family fortune to realize the vision of that day


9

I explained something similar to this over on the Sci-fi/Fantasy site, but this one is actually easier to answer. If the change you made in time affects the future you have to wait for it to catch up to you. An example of this is when Marty saves his dad he alters history but it takes about a week to catch up to his present and erase him from time. Even if ...


6

The ripple effect of 1955 takes weeks in the year 1955. This is because in those weeks there is still a finite probability that the mess can get corrected. (and it does). The photo and Martin that are disappearing are in 1955. Had there been a way to fast forward to 1968, there would be no slow fading ripple effect in 1968 In the same way, the doc sending ...


6

I think the most simple answer is that this is what the characters did at the end of the original film. Bob's Zemekis and Gale never had any intention of producing a sequel and never originally considered crossing that bridge story wise - even the famous pre- credit 'To be continued...' frame was only added as a joke to the original home video releases. ...


5

It's not the worst plan ever. Firstly, the Marty of 1985 is arguably more grounded than his 2015 self. Although there are plenty of ways that Marty could just try to keep his son from getting involved with Griff, the Doc might have not got great faith in Marty's parenting abilities given what a "Loser" he has become. Besides, he would have to explain the ...


4

I believe that 'Back to the Future 2' follows the same logic as the 2005 movie 'A Sound of Thunder' based on the Ray Bradbury story. In 'A Sound of Thunder' (the movie) when someone went back to the time of the dinosaurs and they made even the smallest change, and then returned to their own time, then sometime later timewaves would catch up to the present ...


3

If someone went and killed an incarnation of Doc, present at that point in the timestream, it would have a ripple effect on the future. Killing a fully grown adult Doc, not at his fully-grown point in time, but rather killing a Doc who was never in a time period, who is only visiting that time, would not have implications on any Doc, because the death of ...


3

In Back to the Future Part II, how could old Biff have made it back to 2015? Answers most of your question, but the other part is simply that changes to the time stream in BTTF are not instant. The characters have enough time to affect the changes before they are erased from existence. Paradox averted.


3

The fact that old Biff made it back to his own timeline should have been an indication to him that his plans didn't work out in the end. There were effectively two timelines old Biff created when he gave the almanac to his younger self.However, once Marty got the almanac back in the alternate 1985, there was then no longer an alternate 2015. The alternate ...


2

(Yes, I know this topic was started over an year ago) I didn't know about Biff's deleted scene where he fades out of existence. Because of that, this has become my point of view: In BTTF1, Marty traveled back to 1955-A and changed his future, thus creating a 1985-B where he didn't exist. The future took some time to change, but since he was 30 years in the ...


2

When old Biff goes back to 1955 and creates a timeline B (which is reality now), he started to fade in 1955 of timeline A after handing the magazine to his younger self. Maybe this is because he doesn't live to be that old in timeline A after he makes his younger self a billionaire. Maybe it gets him killed before he can get past 1985 and that old. In fact, ...


2

There is another explanation, which is a dark, uncanon theory: Marty actually dies and doc finds it out later and goes back in time to rescue him. And perhaps that's not even the first time that happens either! Remember when Biff points a gun to Marty in 1985A? Marty jumps off the building and stands over the flying DeLorean. Maybe he died once. How did Doc ...


1

Then according to the timeline ripples, Doc will never be present in 1955. By that logic, no one would ever be able to travel into the past unless they would be able to naturally live out their life to come back to the point in time they travelled from. If you had 50 years of natural life left, you then wouldn't be able to travel 51 years into the past. ...


1

There's a lot of information regarding backstory in the newspaper clippings that cover Doc's walls in the opening credit sequence of the first film. Pretty sure there were clues there as well as Doc's reference to his family fortune. You'll need a big TV though!


1

Old Biff lest 1955 before young Biff had started to use the Almanac, or even realize its potential, so old Biff was ale to beat the ripple effect in the time machine to 2015. Remember that in the first movie, it took about a week for Marty's accidental change to the timeline to catch up with him, and that was thirty years of "new time". Now Biff has effected ...


1

No, the dog in the original Back to the Future was named O.J. I did a Tree Top apple juice commercial with him when I was 13.


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