2mo ago

How long would your hair have to be for it to work as a parachute?

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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You know that pull you feel as your parachute opens and you slow down drastically?
Put all that force on your neck vertebre
- 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.
  
  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.
  
  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.
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.
- 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.
  
  Yeah the math checks out, but real hair would be even worse since individual strands create less drag than a solid surface - you'd need something like 20+ feet of afro diameter to slow down enuf, and the weight of that much hair would probably snap your neck before you even jumped lol.
- 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.
  
  Technically, while wind currents do play a part, spiders don’t fly; they use the earth’s magnetic field to float. Different mechanics.
Fun experiment. Seems like a good type of question for an AI, but if we imagine that there is no turbulence (laminar flow/fall), then hair would just raise straight up with little extra resistance beyond your own air-resistance. But in normal atmosphere, the hair would start to oscillate and create eddies and stuff (like a flag/flame), which would hold you back a little. However, I think that would be like hanging from a series of torn parachutes that also went turbulent (flapping) all the way down - exciting but deadly I presume ?
Without knowing it for sure, I think the weight from the hair it self would quickly overtake the minimal drag force at the edge between hair turbulence/atmosphere. I don't think you can survive in any way, but there is likely a sweet-spot where it helps the 'most'. 25m. ?
The inspired question could perhaps be: 'How much Hair do I need to weave a Parachute ?', 'how do I grow a HUMONGOUS Afro hair ..fast ?', or 'how much Hair do I need to land on if I want to survive without a Parachute ?' ;-)
That is a question I would send to XKCD. They need something to feed their pool of "What if?" Questions.
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.
- 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!
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.
- 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.
  
  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).
Hahahaha, love the question!
Thanks OP, for posting something very interesting today.
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.
- Incredible, thank you. Where did you get the 8.7% number?
  
  https://www.theweek.in/news/sports/2024/08/09/do-hair-and-outfits-really-slow-down-athletes-study-reveals.html
  Imma be real with you though, I didn't actually read the study
What about in an afro form factor?
- 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.

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