Skip to main content

back to the future - Why did Doc need to use a moving car to achieve 88mph?


88mph is an important speed to screw the space-time continuum. But, motion is relative...


Hey doc, can you please explain 88mph relative to what?


What we see in the movie: it was the speedometer reading which matters. So, place the car on a conveyor belt moving in opposite direction of the car having the car's speed and acceleration. The car will reach 88mph without resultant displacement and will go time warp.


To confirm, the speedometer was normal without any modification to record absolute speed (which is impossible). You can see in the first time travel (of Einstein) that the remote-controlled car was slipping on road initially but still Doc was recording increasing speed.


This means it's clear that the time circuit needed only a revolving thing in space with a tangential speed of 88mph (w.r.t. the axel which is, at rest, relative to the time circuit). In the case of the flying car from 2015, a similar setup in rocket exhaust can be assumed (motion is relative, after all).



My question: why didn't Doc use a time machine at rest with revolving parts? It would be less risky. (Note: Marty crashed twice.) Plus... instead of pushing the car with a steam train, the revolving parts could be revolved easily with a steam engine.



Answer



One theory is that the flux capacitor generated a portal through which the De Lorean traveled, and it could only remain open for a brief moment with the power available; by Doc's calculations, the length of that moment was exactly the amount of time it took for a De Lorean to travel its own length at 88 mph (that is, to enter the portal completely). A stationary machine would be able to generate the portal, but not enter it.


Comments

Popular posts from this blog

harry potter - Did Dolores Umbridge Have Any Association with Voldemort (or Death Eaters) before His Return?

I noticed that Dolores Umbridge was born during the first Wizarding War, so it's very likely she wasn't a Death Eater then (but she is pretty evil -- who knows?). After that Voldemort was not around in a way that could affect many people, and most wouldn't know he was planning to rise again. During that time, and up through Voldemort's return (in Goblet of Fire ), did Umbridge have any connection with the Death Eaters or with Voldemort? Was she doing what she did on her own, or was it because of an association with Voldemort or his allies? Answer Dolores Umbridge was definitely not a good person. However, as Sirius points out, "the world isn't split into good people and Death Eaters". Remember that he also says that he doesn't believe Umbridge to be a Death Eater, but that she's evil enough (or something like that). I think there are two strong reasons to believe that: Umbridge was proud to do everything according to the law, except when she trie...

What is the etymology of Doctor Who?

I recently decided to watch Doctor Who, and started viewing the 2005 version. I have the first two episodes from the first season, and I can't help but wonder what is the etymology of the name "Doctor Who"? And why does the protagonist call himself "the Doctor" (or is it "the doctor")? Answer In the very first episode of Doctor Who (way back in 1963), the Doctor has a granddaughter going by the name "Susan Foreman", and the junkyard where the TARDIS is has the sign "I.M. Foreman". Barbara, who becomes one of the Doctor's companions, calls him "Doctor Foreman" (probably assuming that is his name given his relationship to Susan), and Ian (another early companion) does the same in the second episode, to which the Doctor says: Eh? Doctor who? What's he talking about? "Foreman" is most likely selected as a convenient surname for Susan to use because it happened to be on display near where the TARDIS landed....

story identification - Animation: floating island, flying pests

At least 20 years ago I watched a short animated film which stuck in my mind. The whole thing was wordless, possibly European, and I'm pretty sure I didn't imagine it... It featured a flying island which was inhabited by some creatures who (in my memory) reminded me of the Moomins. The island was frequently bothered by large winged animals who swooped around, although I don't think they did any actual damage. At the end one of the moomin creatures suddenly gets a weird feeling, feels forced to climb to the top of the island and then plunges down a shaft right through the centre - only to emerge at the bottom as one of the flyers. Answer Skywhales from 1983. The story begins with a man warning the tribe of approaching skywhales. The drummers then warn everybody of the hunt as everyone get prepared to set "sail". Except one man is found in his home sleeping as the noise wake him up. He then gets ready and is about to take his weapon as he hesitates then decides ...