In the Back to the Future universe, we know what is needed for time travel: a flux capacitor, 1.21 gigawatts and a travel speed of 88 miles per hour (I know there are more requirements than that but I do not want to get bogged down by tiny details).

If any one of these three things is absent, per the story's logic, time travel will not occur.

Here is my problem. Doc was hovering in the DeLorean when it was struck by lightning, sending him back to 1885. How? He was not traveling 88 mph, he was traveling 0mph. Did the filmmakers just overlook this glaringly obvious problem, or is there an in-universe explanation?

  • We know the 88 mph is important, but we don't know precisely how. Speed could help stabilize jumps, through gyroscopic...stuff, with 88 mph being the safety threshold Doc chose. – Gaultheria Jun 17 '17 at 18:26
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    "Q. *How could the DeLorean travel through time when it gets struck by lightning if it isn't going 88 miles per hour? Bob Gale: The sudden rotation of the DeLorean from the lightning hit accelerates it to 88 miles per hour when it spins."; BTTF FAQ – Valorum Jun 17 '17 at 18:39
  • This is an excellent idea, and well worth exploring. Having said that, the third movie seems to suggest that 88mph is a necessary requirement rather than a safety threshold the Doc set. In the third movie, they had Mr.Fusion (capable of producing immense power), but the damage to the DeLoren's exhaust manifold meant that they could not reach 88mph. If their lives were on the line (as the Doc's was), then I am sure they would throw caution to the wind and just overcharge the flux capacitor again. – Magikarp Master Jun 17 '17 at 18:41