If this has been answered somewhere else, blame the search engine and the timeout feature. It couldn’t have been me.
**How did Doc Brown get back to 1985 at the end of BTTF 3? **
I will give him the fact that a locomotive could do 88 mph or better, but where did he get the circuits to build the flux capacitor? They did not exist, and would not until Nikola Tesla came along. Oops…maybe that’s the plot for BTTF 4…
We’re led to believe that Doc Brown is capable of designing a huge breadboard circuit to replace a 1985 integrated circuit (using only currently-available 1955 tech, apparently based on a 30-year-old memory). Why shouldn’t he be capable of bootstrapping himself into electronics? The raw materials of circuits aren’t particularly hard to come by—metal, glass, silicon—the important part is the knowledge and processes.
Wasn’t he in 1885 with Mary Steenburgen? Genius or not, building a flying time-travelling train with 1885 tech is pretty impressive.
He likely, once he got the prototype working with whatever he could scrounge from the 1885 Old West, traveled into the future and upgraded a lot of things, including the levitation device-which of course may have used some of the Phlebotinum from the hover board they used to escape the doomed train. The hover board may have let him shortcut a lot of corners in fact.
He must have built the time travel part in 1885, but the flying part he added in the future (like 2015 or so) before he jumped back to 1985 to meet Marty. Personally, I’m looking forward to those flying skateboards, which should be on the market any time now.
cf. “Already been there.” – Dr. Emmet (Doc) Brown
Huh. All this time I thought the time circuits in the DeLorean had somehow taken them and the train to the future, and then Doc fixed up the train there.
Crud. I mis-explained that. I meant I thought the DeLorean somehow made the train capable of traveling through time. I much prefer a non-magical explanation.
Well, Doc Brown did have the hoverboard with him. I’m sure the tech from that helped him cook up another time travelling gizmo.
And yes, at the end of the movie when Marty asks him if they’re going to the future now, Doc Brown replies with “we’ve already been to the future” and then the train takes off, so that’s where they got the train fitted with flight capabilities.
Yep, just five more years.
I also can’t wait to get my car hover converted.
As fun as that sounds, it’s the Mr. Fusion that will change the world.
I’d be happy with dust proof paper and shoes that auto-tie.
I am personally dreading the return to dominance of the fax machine though.
Yeah, one in every room does seem a bit excessive.
“I am attempting to construct a temporal manipulation circuit, using stone knives and bear skins.”
Roger Sherman Hoar, writing under the name Ralph Milne Farley, produced the books The Radio Man and its sequels, all John-Carter-of-Mars-esque stories about Myles Cabot, who gets transported to Venus. He has to produce radio equipment from scratch to survive, and Hoar/Farley describes his doing it in some detail (the first story dates from 1924).
Interesting stuff. If I were stranded on an alien planet, I doubt that I could do anything like this – But I do think it possible to produce a limited radio receiver set. Not at all easy, and the production would be incredibly time-consuming.
Read L. Sprague de Camp’s Lest Darkness Fall or Larry Niven and David Gerrold’s The Flying Sorcerors for a picture of how difficult even technically non-demanding projects could be in a primitive society. I think Hank Morgan would’ve had a hard time doing all that Mark Twain demanded of him in A Connecticut Yankee. And I suspect Doc Brown would’ve died of old age before he got his Time Traveling Locomotive running.
Remember there are actually two Deloreans in the old west. One was the one that Doc originally took back there, and hid in the mine for future Marty to pick up. Then there was the one that future Marty took, and that’s the one Marty eventually used to return to the present. But the one Doc originally took back there should still be there, so he could go through the same train shenanigans all over again and warp to the future.
The question is, if Doc took his original Delorean back to the future, if he didn’t eventually put it back in the old west mine for future Marty to find, would that cause a paradox?
The train that was pushing the DeLorean that might have had some timey-wimey stuff transferred to it went all explodey when it flew off into open air and fell down into Clayton/Eastwood revine.
I guess the Doc could have gone down into the revine later and picked up some pieces and put them on another train.
I’ve never really thought about this before but I like Yumblie’s explanation.
Personally I can’t wait for the self-fitting auto-drying clothes. I’d be playing out in the rain all the time.
I can’t wait to have a Tab.
You can’t have a Tab until you order something!
I was referring to a different Doc.
The version of Doc that’s in 1885 is the 1985 version who’s sent back to 1885. In his letter (delivered to Marty at the beginning of BTTF3), he mentions that the car/time machine is inoperable and unfixable using current tech, so he has stowed it in the cave, and provided a schematic for replacement parts using 1955 technology. In the scene where the 1955 Doc is fixing up the car, he holds up a huge plank full of big clunky electronics that’s meant to replace a little integrated circuit in the car. 1955 Doc looks at the fried IC and says something about “Made in Japan. No wonder it broke.” and Marty says “What are you talking about; all the best stuff’s made in Japan.”
So, without notes or references, 1985 doc (in 1885) designed a replacement for a modern integrated circuit, not just using technology that’s 30 years out of date, but using his 30-year-old memory of what that technology was. And it worked on the first try.
I like Yumblie’s explanation, too. As long as the Doc puts the DeLorean back in the cave prior to 1955, it all works. Although I wonder how well it fits the timeline. It’s been 10 or so years between Marty’s departure from 1885 and Doc’s train-arrival in 1985.