this post was submitted on 21 May 2025
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I got to thinking last night that theoretically, with enough hair, the air resistance would slow you down so that your terminal velocity would be low enough to land unharmed. How long would it need to be? How would one go about calculating this?

I assume you need some kind of drag coefficient and a density for hair to start with. Not sure where to find that information.

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[–] Treczoks@lemmy.world 8 points 1 day ago

That is a question I would send to XKCD. They need something to feed their pool of "What if?" Questions.

[–] ThrowawayPermanente@sh.itjust.works 3 points 1 day ago* (last edited 1 day ago) (1 children)

They did a study and found that long, curly hair increases drag by 8.7%. I'm going to assume that's for 1m of hair and that drag increases linearly with hair length. To decrease terminal velocity by a factor of 2 I think we need to increase drag by a factor of 4, which would mean adding a total of 34m of hair the first time, 172m the second time, and 356m the third time. I think that would probably be enough to get you down to a survivable terminal velocity.

[–] LibertyLizard@slrpnk.net 1 points 1 day ago (1 children)

Incredible, thank you. Where did you get the 8.7% number?

[–] Onomatopoeia@lemmy.cafe 5 points 1 day ago

Hahahaha, love the question!

Thanks OP, for posting something very interesting today.

[–] MyPornViewingAccount@lemmy.world 21 points 2 days ago (1 children)

You know that pull you feel as your parachute opens and you slow down drastically?

Put all that force on your neck vertebre

[–] LibertyLizard@slrpnk.net 15 points 2 days ago (2 children)

Well first no since I've never used one lol. But also this is deceleration from a speed you would never reach so I don't think that means it would necessarily be a problem.

I was wondering about this issue as well though. Can people survive being lifted by their hair? I'm unsure.

[–] otter@lemmy.ca 15 points 2 days ago* (last edited 2 days ago) (1 children)

Can people survive being lifted by their hair? I'm unsure.

Coincidentally, I saw this from a few days ago

https://www.guinnessworldrecords.com/news/2025/5/circus-performer-hangs-by-her-hair-for-over-25-minutes-to-take-decade-old-record

A circus performer with seriously strong locks has broken a hair-hanging record that went unchallenged for more than a decade.

In the picturesque setting of Redwood National and State Parks in California, USA, Leila Noone spent 25 min 11.30 sec hanging by her ponytail to claim the record for longest time suspended by the hair.

The American took on the challenge in June 2024, breaking the previous record of 23 min 19 sec, that had been set by Suthakaran Sivagnanathurai (Australia) all the way back in 2011.

[–] pennomi@lemmy.world 8 points 2 days ago

For what it’s worth, if you don’t train for this you can get some nasty scalp separation injuries.

[–] MyPornViewingAccount@lemmy.world 6 points 2 days ago (1 children)

The point of the dropping the floor out when hanging someone wasnt to choke them to death, it was meant to break their neck, so my vote is no, you would survive rapid deceleration from the neck.

[–] adespoton@lemmy.ca 7 points 2 days ago

He had a valid point though; hair would not cause rapid deceleration. The bigger question is whether it affects your terminal velocity enough that you would survive the fall.

But even that has too many assumptions. People have survived falls from airplanes flying at 30,000 feet. Was it because of their hair? The displacement of their body and clothing? The surface they landed on?

Probably all of the above plus other uncalculated factors. But I doubt that hair drag played a big part; after all, there’s a reason we deploy 70lbs of horizontal airtight fabric instead of 70lbs of thread when skydiving.

[–] CarbonatedPastaSauce@lemmy.world 20 points 2 days ago (2 children)

I’m no physicist, but I doubt that’s possible. Even with super long hair it’s still only going to create a giant streamer the size of your skull which will not slow you down enough.

Also I have no idea what I’m talking about.

[–] knightly@pawb.social 9 points 2 days ago* (last edited 2 days ago)

Tried looking it up but I'm not finding any academic research on the drag coefficient of hair as a property of its length.

I do know that drag scales with cross sectional area, but I imagine it would require a very voluminous afro to function as a parachute.

Solving the drag equation for velocity and assuming* a drag coefficient around .5, then for a 80kg person to be slowed to a 7m/s parachute landing speed they'd need a 'fro roughly 10.5 feet in diameter.

*this assumption is most definitely wrong, but close enough for humorous purposes.

[–] LibertyLizard@slrpnk.net 2 points 2 days ago (1 children)

Spiders fly on a strand of silk, so I think it should work. A streamer is still creating friction as the air flows by it, though you’re right that it’s narrow shape is certainly not ideal for maximizing drag.

[–] Seleni@lemmy.world 6 points 2 days ago (1 children)

Technically, while wind currents do play a part, spiders don’t fly; they use the earth’s magnetic field to float. Different mechanics.

[–] Onomatopoeia@lemmy.cafe 3 points 1 day ago

Whoa.

That's some stuff right out of science fiction. Very cool.

[–] rowinxavier@lemmy.world 8 points 2 days ago (1 children)

This would be a perfect question for That's Absurd Please Elaborate.

https://thatsabsurdshow.com/ask

You should also ask if this could solve anything.

[–] Mister_Feeny@fedia.io 4 points 2 days ago (1 children)

I feel like this question would also fit well in xkcd's what if section.

https://what-if.xkcd.com/

Yeah, as he's already done one which touches on the material properties of hair, this seems right up his alley!

[–] Vanth@reddthat.com 7 points 2 days ago (1 children)

Like, long enough to spread out into effectively a parachute? It would have to knot together into some sort of canopy. Bc just streaming loose above you won't be enough. Surface area normal to airflow is needed, not parallel to it, like loose, streaming hair would be.

Google it for proper formatting, but the equation is: Fd=21ρv2CdA, where Fd is the drag force, ρ is the air density, v is the velocity of the object, Cd is the drag coefficient, and A is the reference area of the object (as in reference with respect to the plane of drag).

Just because I happen to have this trivia in my brain: Terminal velocity in "skydiver" posture: stomach down, arms outstretched to max drag, is around 120 mph. Pulling in to minimize area (and therefore drag), one can get to around 180mph.

[–] LibertyLizard@slrpnk.net 3 points 2 days ago (1 children)

I was thinking just freely streaming behind you. I am not sure how this equation accounts for an object that’s incredibly long and thin but I feel confident that the longer it gets, the more drag there is, even if not much more.

I realize the answer might require impossibly long hair but that’s part of why I asked. I want to know just how impossible.

[–] Onomatopoeia@lemmy.cafe 2 points 1 day ago (1 children)

Long and thin may not necessarily have any more drag. It depends on shape, how the airflow follows the body.

A long thin shape with an idealized nose will keep airflow smooth along it's length, reducing drag.

A shorter shape with the same nose will create low-pressure, turbulent areas just behind the nose, inducing more drag because the air doesn't flow smoothly along the body.

(I am not an engineer, these are presented simplistically, I'm sure more knowledgeable folks can explain it better).

[–] LibertyLizard@slrpnk.net 1 points 1 day ago* (last edited 1 day ago) (1 children)

I feel like this wouldn’t apply to hair because it billows but that’s interesting.

[–] Onomatopoeia@lemmy.cafe 1 points 1 day ago (1 children)

Er, wut?

It doesn't matter what the object is, fluid dynamics always applies.

[–] LibertyLizard@slrpnk.net 1 points 1 day ago* (last edited 1 day ago)

Typo, I meant hair. Basically, the surface will be much less smooth due to the hair’s motion. So there might be a lot more drag than like a rocket or something.

[–] ToaLanjiao@lemmy.world 2 points 2 days ago (1 children)

What about in an afro form factor?

[–] catloaf@lemm.ee 3 points 2 days ago

I think this would actually be better than long straight hair. The large area would have greater drag, and the low density would mean it's lighter than any shaped straight hair.