This question is prompted by the new television show, but I'm open to any sources for explanation.

With reference to this particular scene from the season's trailer, The Flash saves a person from being hit by a car by running up and pulling them out of the way.

However, this doesn't seem like a great idea to me. Written satirically, let's examine what could be going on in Flash's mind:

Oh--Look over there! There's a person who's about to get hit by a car traveling ~40mph. If a car impacts them at that speed, they're nearly certainly dead. So, I'm going to run at least 10 times faster, and whisk them out of the way so fast they will die from internal injuries and whiplash-like effects instead!

Basically, my question is as follows: Given that the rapid acceleration of organs (and the resulting force) is typically what kills people in high-speed impacts, why doesn't The Flash end up killing all the people he's trying to help?

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    I'm not adding this as an answer because I'm not familiar enough with Flash lore to know if they use this device, but many superpower universes include ancillary, related powers to help explain this sort of thing. A shapeshifter also needs the ability to perfectly remember what someone looks like, a flier needs to be able to breathe at high altitude, a time traveler needs to be able to teleport to account for the rotation of the Earth, etc. Flash's Speed Force Aura sounds like a similar thing: minor abilities which help to facilitate the primary. Its a useful concept for this sort of question.
    – Nerrolken
    Oct 9, 2014 at 22:09
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    Yeah I always wondered about a somewhat similar thing that flying superheroes do in movies - when they save someone from falling from a tall building by horizontally intercepting them right before they hit the ground. Seems like the falling guy stops just as fast as if he hit the ground. And he falls, what, like 4 feet less than he would have otherwise. But always seems to be entirely ok, not even injured.
    – Misha R
    Nov 1, 2014 at 7:23
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    Yeah, I imagine that grabbing someone by the arm at this speed would only succeed in tearing it off and leaving the rest of their body to be run over. Nov 6, 2014 at 15:20

3 Answers 3


If they are holding to canon, the people the Flash rescues are not affected by his speed. He technically stops running (or slows down if they are in motion). Grabs them and accelerates again. They are then protected from his powers by his speed force aura.

  • The Flash's body is surrounded by what he calls his "speed force aura". This aura protects him and anyone who is running with him or carried by him, from the effects of using his speed.

  • This includes friction and airborne particulate matter. It also protects him from injury from high speed impacts such as punches he delivers and receives from his opponents.

  • With this aura, he is able to absorb kinetic energy. He possesses a level of superhuman resistance to injury which at times does extend far past normal physical interactions, as received from normal combat.

NOTE: This Flash has been dialed back from his canon comic version who is significantly more powerful and capable.

  • His access to the Speed Force appears to give him the ability to reach the speed of sound, move people he interacts with at super-speed without them being damaged by his use of said speed, and allows him, if injured to recover due to his enhanced metabolism.

  • Wally West, when he took up the mantle of the Flash was powered down to about the same level. This is a successful adaptation for the TV show, allowing the Flash to be visually interesting but not so powerful he can't be challenged.

See SFSE Article for amplifying information: What is the best scientific explanation for how THE FLASH moves so fast without issue, or is it just “magic?”

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    FYI: I have rejected this edit (scifi.stackexchange.com/review/suggested-edits/38371) because it clashes with @Thaddeus' normal formatting techniques.
    – Möoz
    Oct 9, 2014 at 22:19
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    +1 for the speed fource aura. I remember the issue in which this was "discovered"...
    – keshlam
    Oct 10, 2014 at 0:20
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    Assuming that is the case and he and his passengers are protected by the aura, why does Flash have to wear his special material suit and why do I remember the 90s Flash series when he picked up Tina and ran while carrying her and all her outer clothes were ripped to shreds?? Obviously I remember because I was a teenager at the time, but the only in universe explanation would be that Barry wanted it to happen?? Because out of universe the production wanted to provide eyecandy for us nerds watching....
    – BMWurm
    Oct 10, 2014 at 6:02
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    @PointlessSpike with great power comes great respo... oh wait, wrong franchise, go ahead.
    – Rob Church
    Oct 10, 2014 at 10:06
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    @BЈовић in the pre New-52 comics both Wally West and Bart Allen (and presumably Barry Allen) can "lend" and "steal" momentum with people and objects through the Speed Force. When they do this, they don't need to be in direct contact, but they do need to be in very close proximity.
    – Monty129
    Nov 1, 2014 at 14:06

You're right that looking at scenes like this, and applying physics indicates that Flash is a monster who runs around killing people with speed. However, comics have built up ways to explain this.

In the comics, this can be assumed to be a result of The Flash's source of power: The Speed Force. The Speed Force grants the various speedsters the ability to move themselves fast, but it also enables them to move and accelerate other things (and people) safely. The Speed Force was mentioned by name at the end of S1E11, The Sound and the Fury, so it's present in the TV show as well.

In addition, we frequently see The Flash do a super-human job of managing his momentum. In the example from the question, he would travel to the accident victim quickly, but then slow himself to match the victim's speed so as he handles the victim, he doesn't do damage. At this point, he can then easily manipulate the victim's momentum just as he does his own, via the Speed Force.


The Flash's ability to control his power has always been rather haphazard but this especially holds true now since he has only just gotten his abilities. Eventually he will be able to fire concussive blast of air, time travel and even move through solid objects... But even after he learns to manipulate his Speed Force Aura at those levels it is not indestructible. Despite the aura operating subconsciously to an extent, if he is impacted with enough force or distracted he can and will take damage... If you recall even on the new CW show his mind wondered back to his mother's death before the super speed mishap that lead to his broken arm.

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