In the Season 4 Episode 15 Barry very likely "runs" the fastest so far in the TV series. Basically half the episode plays while a

nuclear bomb is in the early stages of exploding.

While Barry doesn't move as far as calculated here, he moves half the episode at Flash time. Is there any way to establish a ballpark of how fast he is moving? Or is moving not the correct concept at all?

With a nuclear explosion expanding at about 12,000,000 m/s and the explosion expanding about two meters (my guesstimate) during half the episode that part of the episode takes place in about 1.6x10-7 seconds. Yet the time is portrayed in regular speed (1s to 1s (1:1)) while indicating ~ 1.6x10-7s:1,200s (20 minutes) or 1.38x10-10:1

1 Answer 1


The thing to remember is that however fast the Flashes are going for most of the episode, there are moments where they're going ever faster. They are talking to each other, standing "still" for a great deal of time, but all that time they're moving, reacting, etc at an insane speed. But then they start running.

So when Jesse runs off to Earth 3 to get Jay, or they all speed up to fling lightning bolts, they're going even faster than whatever speed they're at to be able to get so much done in the micro-instants between "ka" and "boom"

There's a lot of moments in the episode that require hand-waving. Barry's statements imply that taking someone into "Flash-time" is a new power only he has, a side-effect of his return from the speed force. But Jesse tries it like it's no big thing, and is surprised that it doesn't work, likely assuming that she can't because she's starting to slow down.

Then there's the fact that they're traveling so fast, presumably faster than lightning—they shouldn't have HAD to toss three bolts at once—Barry could have just set three of them going himself, and the micro-moments between their arrival shouldn't have made any difference at all.

Then there's the whole "Oh, neither you nor the Quark Sphere are trapped in the Speed Force any more, but I'm sure that'll be just fine"

  • To be fair, the issue of the Quark Sphere was raised between Barry and Jay, and they figured out there was no way of knowing what the reaction of the Speed Force would be, so they'd just have to deal with it if and when it comes, and until then there was no point worrying about it. Mar 7, 2018 at 20:45
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    Which flies in the face of how important it was for Barry to remain trapped in the force to prevent it getting all unstable from the finale of last season, and why they had to build the decoy in the first place. When something goes from Terribly Important to "Eh, it'll be fine", it tends to annoy me. It's possible it'll come back as part of The Thinker's plan, but even that would annoy me. This whole season has been a bit too hand-wavey for even me, and I accept a guy who can run at light speed. Mar 7, 2018 at 20:52

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