A thought just struck me that from Back to the Future II onwards, Doc was quite adamant of the need to destroy the DeLorean, not because it was a bad car or anything, but because the risk of time travel was too dangerous. Yet, at the end of Back to the Future III, we see Doc has created another time machine in the form of a train!

Why did Doc create another time machine after being set on destroying the DeLorean because of the dangers of time travel?

  • 22
    "Well, I figured, what the hell."
    – Hypnosifl
    Aug 17, 2015 at 3:59
  • 3
    "You can't keep a good scientist down." Really. This is a guy who is smart enough to build a time machine. His wife knows he's from the future. Do you really think that family is going to just sit around in the 1800's?
    – phantom42
    Aug 17, 2015 at 4:41
  • 6
    Yes, and being as curious as he is, he's likely to get a bit of scientific and historical wanderlust. Add in his wife and kids who would likely want to know about all the things that came true from all of Jules Verne's stories and the like. I seriously can't see Doc staying put in the past for very long.
    – phantom42
    Aug 17, 2015 at 4:44
  • 8
    He also says (possibly slightly tongue-in-cheek) that he needed to pick up Einstein.
    – phantom42
    Aug 17, 2015 at 4:50
  • 6
    Doc has been known to change his mind over such things. He ripped apart the letter about the terrorists but still ended up taping the pieces together and reading it anyway
    – user13267
    Oct 15, 2015 at 9:18

2 Answers 2


Although it's never really discussed in the movies, there's really one big event to convince him to destroy the DeLorean.

Namely, a bumbling aged idiot named Biff was able to figure out how to steal it and work it inside a day, destroying everything Doc had in the process. It's easy to use nature was it's danger - power like that never should have slipped out of Doc's hands.

I agree with comments and the answer from Charles that a quieter life and family gave him the distance and time to rethink it. He had really invented a wondrous thing - properly controlled, and kept safe in the right hands, it could be done right. My own thinking is that this led to his new design. It's a lot harder to steal a train, he had experience with that. We never see the inside of the thing, but I imagine a steampunkish design with physical locks that only he would know how to operate. It would be a far cry from a hop in and go vehicle that a car represents.

  • 1
    Plus there's that whole "the future is what you make of it" speech, which presumably represents his philosophy at the point when he makes it.
    – user867
    Oct 30, 2015 at 3:18

I agree with "you can't keep a good scientist down". The DeLorean time travel experience was a continuous, rolling catastrophe that required full time focus from Doc and Marty, so it was no wonder Doc had a meltdown or two about time travel. With the advent of Clara and his two sons, and a little bucolic quietude in his life for awhile, Doc dreamed of trying it again - and this time he could get replacement parts - or make them - in his new 1885 home. Also, he now had a nice big cockpit for the rig, so he could show his whole family the wonders of the past and future. (Since the new steam machine could fly, no tracks necessary in the Jurassic)

  • If Doc could not get the necessary details to fix the DeLorean in 1885 then how did he manage to build a time machine inside a train? May 26, 2017 at 3:44

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