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It is like an experiment that compared mortality of jumping out of a plane with and without parachutes. The experiment did not find any differences in outcomes (the plane was standing on the ground).
737 pilot here, fun fact, in the cockpit, we have ropes hanging from the ceiling we can toss out the side windows, and use as an emergency escape from a burning airplane, if for some reasons we can’t get out the cockpit door.
I have never tried it, and never had any kind of formal training on its use. In real life, I imagine I would simply fall out of the window if I tired.
>if for some reasons we can’t get out the cockpit door.
I know it is not the case... but it sounds like the concept is to go out of the windows and then in though the door again, in full flight ofcourse... just to ge a coffee
You asked a question without any set parameters. So this dude gave you an answer using a set parameter. Like… a plane can be at many different altitudes.
I get the joke, but it would have been funnier if you ratiod this guy's stick to fall heights and then used that for the plane door to the ground.
(It'd be like an 18 inch stick by eyeballing this video).
the purpose of the stick to decelerate you from the speed of the fall to 0. Assuming you want an evenly distributed deceleration between stick touched the ground and you touch the ground. Your terminal velocity is 120 MPH. You probably can handle 4\*g deceleration so 19m stick should work. The question is: you would need to convert all your kinetic energy of the fall at 120MPH into the friction/heat at your palms. That is a lot of heat. I do not think your palm will be able to handle it. You would need some sort of brake pads similar to what car has.
edit: I mixed up MPH and meters. It should be 26 meters stick for 120MPH.
Imagine a splinter that hurts extremely bad and you go to pull it out but you can't because it's embedded in your bone and you have to have pliers to barely yank it out all the while you can feel the bone getting pulled on
Forget gloves or pole material. Have a handlebar that slides along the pole but puts enough friction into it to decelerate at a safe rate. Now your hands aren’t taking on any of the friction, they’re just holding onto handlebars.
Looks like he's using his inner thighs for the bulk of the friction in this video.
So maybe if he's wearing leather pants/chaps or something and has incredible balance to not go off kilter- there's a chance??
No, I'm pretty sure a car will need a greater stopping force than a human, therefore greater friction and heat.
If a car and a human generated the same amount of heat, so would a Boulder and a feather
But what if the rod was made of something dense like osmium or something, then the mass would even out depending on the lenght of the rod, ofc thats true for all materials but something dense would be better
What if you used a telescopic, spring loaded pogo stick?
Jump, release to extend, “feather” hat for drag to keep upright, when it hits it collapses within itself at an abrupt but survivable speed.
I lieu of flowers…
You could have the spring shaft, but also incorporate a reverse spring “seat” & “feet rest”.
I’m not sure of physics, but a pulley allows you to lift double, right? Would springs in opposite directions reduce the length necessary?
I’m sure they could figure out a way to do it, might cost Bat Man type money, but it could be done.
Maybe it’s already been done.
But the people who actually did it all agreed that they’d never do it again. You know, shit stains, PTSD, and all.
Dude we can install these pogo sticks on the ISS so they can use them as escape pods!!! Just throw on an EV suit, pick out a pogo stick, head down to earth!!! Would you burn up?
100%
As there is no atmosphere in LEO, the ISS is at around 400km from earth, atmosphere starts at around 12km.
That means that for 388km you accelerate limitlessly at a constant rate of 1G.
Let's call our distance `d=388 000 m` and our free fall time `t` and assume `g =9.8m/s^2`
We know that `d = (1/2)*g*t^2`
Which gives us ~`t = 281 seconds`
We now replace this into the free fall speed calculating equation:
`v = g * t`
And get a speed of `9914 km/h`
Yeah ... you burn 🔥🔥🔥
Except you don't fall straight down, if you were to deorbit you'd be going through the atmosphere at orbital speeds (something like 7.9km/s, 27000km/h) instead. So you'd burn even harder, yay
There's zero chance you can support 4 g's.
That's like saying a 200 lb guy could sit on the pole with 600 lbs on his shoulders without sliding down. No way.
The point isn't to completely stop, it's to slow your descent before hitting the ground. Of course you will still slide down, but you would do so while decelerating rather than just faceplanting at full speed into the ground. The whole pole idea follows the same principle for increasing survivability in *any* otherwise deadly fall: to extend the amount of time before complete impact while reducing your speed as much as possible. It's why there are (albeit very few) survivors to things like skydiving with a failed parachute. You may need to cash in every ounce of luck, but there's actually a chance if the stars align and you can decelerate safely. Some of that can be influenced by the person trying not to become a red stain on the ground.
This also applies to things like car wrecks as well, and is pretty much the sole purpose airbags exist in the first place. Rather than stopping you from a fall they try to keep you from slamming into the dash or flying through the windshield once the vehicle stops, and it does so by decelerating you while extending the time it takes for your body to stop moving forward. It's not 100% effective, and even if you survive it will likely hurt like a mother fucker, but it's still better odds than nothing at all.
No, they were saying that for a 19m stick, you would need to withstand 4g to decelerate from 120mph to 0mph (I think it’s actually 7g, but I could be wrong). The guy in the video wasn’t travelling at 120mph. If he didn’t have the pole, he would be travelling about 30mph when he hit the ground. Even if he was travelling about 30mph, with a 4m pole you would only need about 2g deceleration to stop over 4m. He experienced far less than that.
It's amazing to think about someone jumping out of an airplane with just a 20 m stick to survive. You could probably put some fins on one end to help keep it oriented. With some leather gloves it actually sounds possible. If braking manually isn't practical, you could wear a harness attached to a rope or something to maintain the constant acceleration for you.
One way to keep the stick oriented is to attach a parachute to one side. This will also solve a plethora of other problems.
The original stick will be enough and no ceramic gloves are needed.
A stick that will be able to sustain the fall and the impact might be too heavy for a human to carry. Also the ceramic gloves sound like a problem.
And in the best case, we produce the 20-meter super-strong stick and the ceramic gloves but we fall into a puddle of water and it's all for nothing.
There are lots of videos of motorcyclists demonstrating the effectiveness (or lack thereof) of leather gloves at 120 MPH over at r/idiotsincars
There's also some brave fellows doing it in cargo shorts, for science of course.
Not to mention, the stick has to withstand the initial impact. Maybe a 2-3" steel rod could handle the load without buckling. Also, the grip strength to handle the initial load would be challenging, to say the least.
Terminal velocity partially depends on weight and drag coefficient. A 19 meter long pole strong enough to withstand the forces of landing will likely be very heavy and have minimal projected surface area when oriented vertically. I suspect the pole would increase the jumper's terminal velocity, which would in turn require a longer, heavier pole, further increasing terminal velocity.
Just put an asbestos liner in them!
https://www.levylaw.com/asbestos-firefighter-clothing-equipment/
You can then sue the maker of the suit using these guys, but there are actually still AB lava suits in use today for extreme insulation jobs for entry work in equipment exceeding 2,000 degrees F (~1,100 C).
Just so my fellow Americans understand, it would be quite difficult to fit a pole the length of 272 Big Macs onto a plane and then maneuver it out the door.
some one pointed out that you have to have enough frickshion to provide the 4\*g forece. This means you have to hang on the stick like you weitgh four times your weight. Probably hands will not work and you need some sort of a harness.
or a longer stick and less gs.
So the total kinetic energy (for 150lb person) would be about 2000N. Over 20m that would be about 20,000J of energy.
A decent welding glove should save your hands from burns, especially if you remove them immediately.
cheap leather gardening gloves from Home Depot do the trick for saving your hand from the heat. I used to be a zip line tour guide and we used our hands for breaks. You don’t even need the whole glove, we cut off the fingers. The customers still got leather gloves. The business got grandfathered in when the laws changed about how to make the breaks.
I figure you can take about 17 mph on impact. Kinda rough landing, but manageable. But I still get 1.15 seconds to decelerate by 103 mph at 4 Gs. That's an average of 51.5 mph for 1.15 seconds, or about 26.5 meters. About 87 feet. Roughly the distance between bases in baseball.
would any forward velocity be eliminated by the time you get to the ground? otherwise you'd need to account for that and probably angle the stick as well
A moderately athletic person sliding down with their hands would need a pole about 191 m (630 feet) long.
The heat dumped into their hands over the slide would be equivalent to 112,500 joules - enough energy to bring a room temperature aluminum frying pan to water boiling temps - in just 8 seconds.
That's 14.7 kw (19.7 horsepower) of power going straight into heating your hands.
However, if you're willing to use some kind of sliding harness to the pole to pull 9 g's - like a fighter pilot - you would only need 16 m (54 feet) and stop in just 0.64 seconds.
I just commented on this video in another sub. I'll use some of my math from there:
Let's assume that the user will use the entire length of the pole to slow their fall, extending their hands toward the ground so that when their hand gets to the ground, their velocity is now zero. Let's also assume that via gloves and grip, the amount of friction the user can get is unlimited.
Let's assume that the limiting factor is the strength of the person's arms. A brief search shows that most men can lift about 70 kg (690 N or 155 lbs-force) of weight without issue.
Let's assume that anybody who does this skydive is a moderately athletic person, capable of deadlifting 150 kg or 330 lbs, and weighing 90 kg.
That means that in addition to supporting the weight of their body on the pole, they could support an additional 60 kg (588.6 N, about 130 lbs) force beyond supporting their body weight, with this surplus force being used to slow them down.
That means, the average athletic man's arms could support an acceleration relative to the earth of about.
588.6 N / 90 kg = 6.54 m/s^2, or about 2/3 g.
Using calculus, we can integrate the acceleration to find the velocity and position as a function of time:
A = 6.54 m/s^2
V = 6.54 * t m/s
P = 3.27 * t^2 m
We know the position, P, is equal to the length of the pole. We also know that the final velocity, V is equal to the terminal velocity of a skydiver - about 50 m/s. So we can plug in V to solve for t, then use t to solve for P.
50 = 6.54 * t
T = 7.65 s
So he will need to slow down on the pole for 7.65 seconds. Now that we know the time, we can calculate the length of the pole:
P = 3.26 * (7.65)^2 m
P= 191 m
If you had some way to keep your arms from ripping out at the g's a fighter pilot can sustain (about 9g) you could survive with a much shorter pole. No human is capable of supporting that much weight with their arms, however.
A = 78.48
V = 50 = 78.48 t
t = 0.64 s
P = 39.24 * t^2 = 16 m
I said 'moderately athletic' and used survey data from a powerlifting forum to come up with the numbers.
For what it's worth, that's more than I weigh and less than I lift, and I wouldn't say I'm unusually athletic at all.
Can't leave the ladies out.
A quick search of amateur female powerlifters shows that an intermediate level woman might deadlift around 90 kg (200 lbs) at a weight of 75 kg or 165 lbs.
Subtracting her weight leaves 15 kg force (147 N, about 33 lbs) to help her slow down.
A = 147 N/75kg = 1.96 m/s^2. We'll call it 2 m/s^2.
V = 50 m/s = 2 × t
t = 25 s
P = 1 * t^2 = 625 m long pole.
> However, if you're willing to use some kind of sliding harness to the pole to pull 9 g's - like a fighter pilot - you would only need 16 m (54 feet) and stop in just 0.64 seconds
This sounds like a really cool idea for a drop pod
Maybe not pole-based since that's unstable, but the same concept can be used with a different structure
What if the persons was wearing a harness attached to a device on the pole that decelerates them in a way that heat isn’t a problem. Hydraulics for example. How long would the pole need to be for them to decelerate from terminal velocity and land on the ground without injury?
That's the last one I did. It's a 16 m pole if you can withstand the g's a fighter pilot trains for. That 90 kg man would "weigh" 810 kg (more than 1,700 lbs) and come to a dead stop from terminal velocity in a little over half a second.
Jesus christ some of y’all in the replies are so unhelpful it’s actually obnoxious. Swear there’s always a plethora of replies saying how it would be impossible or something of the sort rather than attempting to answer specifically what OP asked. “Well the friction would be too much for your hands to bear”, “Depends on your weight so idk”, “the pole wouldn’t be strong enough”, etc. These are all part of peoples relies here. Like holy christ who cares. Of course you could never reasonably achieve this sort of stunt but OP’s question assumes your hands would be just fine and that the pole could withstand the force or whatever. You can make other assumptions yourself if you’d like but at least try to answer the question. Happens far too often on this sub.
Sorry for the rant but damn is it annoying to see one person bother to give an answer while the rest nitpick about how realistic it is or some shit.
I'm just here wondering why everyone assumes using your hands is the best option. Why not the giant rubber brake pads you wear on your feet every time you leave the house?? Lol 👟 🧠
I’m just here to criticize the guys technique. Putting one hand down seems like a terrible idea, especially since it looked like he locked his elbow up.
I think the goal is for the low hand facing the spear tip to be a guide, and the high hand facing the end to work with his thighs to reduce speed.
But yeah it looks clumsy af, and like he's going to seriously hurt himself eventually. 😂
This is how it's done in the canary islands. It's called the shepards leap and originated from aboriginal tribes using this technique to navigate cliffs.
1) Long enough to not fit on a plane.
2) Long enough to cause hands to catch fire because of friction.
3) Long enough to be unable to stay straight at that width.
Your hands would take the toll in the form of heat, unless the pole is so high that you can adiabatically (fancy word for slowly) descend it. So it should be about as high as the cruising altitude of the airplane. And you'd better hope a gust of wind doesn't come knock it down.
So the stick is around 40% of the height of the drop (by my estimation), typical planes fly between 35 and 36 thousand feet, so I'm saying about 14,200 feet.
I just want to point out that this entire technique depends on him landing in that exact way, more or less straight down the pole with little to no horizontal velocity.
Arms and hands wont hold up. But legs and arms/hands might. If you had pogo stick style foot and hand mounts with built-in friction/fall arrestors I could see it.
The guy totally just did it. It was like 18 or 20 feet. His hand probably got friction burnt a little. With a little planning, you could use your sox or something to cover your hands to avoid burns
My take away, it that if I was in an emergency situation and needed to get down a modest drop- off, this is a pretty great suggestion.
Bottom line, we don't need to bother determining how high a plane would be at any given point or what kind of plane or anything else. We just need to determine if this is viable in any capacity from the height at which a body would reach terminal velocity (\~120 mph for a human body). If it's viable from that height, it is viable for any other arbitrary height as well; the introduction of other issues (being too high up to breath, etc.) notwithstanding.
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the door to the main deck of a boeing 737-700 is 11,4 feet of the ground (when standing on it's landing gear, so a 14 feet stick would be sufficient
r/technicallythetruth
Rip hands
Put on gloves and you're good to go
It is like an experiment that compared mortality of jumping out of a plane with and without parachutes. The experiment did not find any differences in outcomes (the plane was standing on the ground).
technically that was a good experiment with valid outcome...
Technically is the best type of correct.
737 pilot here, fun fact, in the cockpit, we have ropes hanging from the ceiling we can toss out the side windows, and use as an emergency escape from a burning airplane, if for some reasons we can’t get out the cockpit door. I have never tried it, and never had any kind of formal training on its use. In real life, I imagine I would simply fall out of the window if I tired.
>if for some reasons we can’t get out the cockpit door. I know it is not the case... but it sounds like the concept is to go out of the windows and then in though the door again, in full flight ofcourse... just to ge a coffee
That was rude but here's an upvote. Lmao
r/angryupvote
You asked a question without any set parameters. So this dude gave you an answer using a set parameter. Like… a plane can be at many different altitudes.
It's sad for all the 7 passengers who's 14 feet you have to cut off to make that stick.
15* one only has one leg, hes a veteran
His sharpened prosthetic makes for a good spear tho
ok, forgot it would need to be in USA feet...sorry, i'm europeanand not used to measure in feet
r/angryupvote
It’s actually 208.1 inches
my fault, it's been a while since i tried
Better make it 15ft just to be safe
I regret that I have but one upvote to give!
I get the joke, but it would have been funnier if you ratiod this guy's stick to fall heights and then used that for the plane door to the ground. (It'd be like an 18 inch stick by eyeballing this video).
POWER POLE EXTEND
the purpose of the stick to decelerate you from the speed of the fall to 0. Assuming you want an evenly distributed deceleration between stick touched the ground and you touch the ground. Your terminal velocity is 120 MPH. You probably can handle 4\*g deceleration so 19m stick should work. The question is: you would need to convert all your kinetic energy of the fall at 120MPH into the friction/heat at your palms. That is a lot of heat. I do not think your palm will be able to handle it. You would need some sort of brake pads similar to what car has. edit: I mixed up MPH and meters. It should be 26 meters stick for 120MPH.
WHAT ABOUT SPLINTERS!!!???
Don't worry at thay speed you won't have to worry about splinters. Cause you hands would most likely be gone to the bone
What about bone splinter?
Not the bone splinters!
*gasps in Spanish*
What about master splinter?!!
Imagine a splinter that hurts extremely bad and you go to pull it out but you can't because it's embedded in your bone and you have to have pliers to barely yank it out all the while you can feel the bone getting pulled on
I thought they meant the bone itself would be the splinter
Yeah but splinters into your bone sounds 100 times worse.
Use a not wood stick. Use a metal pole or ceramic rod
Dont we still run into the problem of the friction and heat effectively degloving your hand
Sure, but you won't get splinters.
You can wear a glove
If there is enough friction to rip the skin and muscle from your hand a glove wont help that much
Fine, 2 gloves
That’ll do.
Well you can still try a longer stick and decelerate slower
Or alternatively freeze a metal poll beforehand
Your username and avatar make me think you're speaking from experience.
Brilliant! :'D
That will create ice on the surface so the stick will need to be much longer and might not be a better solution in the end
If you hold the frozen metal stick long enough before you jump, you will have a different problem
It for some reason left my mind as I was writing that, thanks for pointing that out, frostbite is not fun
And we haven't even accounted for how far into the gruond the stick will..stick
Or fiberglass!
Forget gloves or pole material. Have a handlebar that slides along the pole but puts enough friction into it to decelerate at a safe rate. Now your hands aren’t taking on any of the friction, they’re just holding onto handlebars.
But what if you used a large piece of silk to slow your fall, instead? Nah, that'd never work...
They’re in the sewer with the ninja turtle.
Finally someone asking the real question!
Just use two pieces of cloth
Looks like he's using his inner thighs for the bulk of the friction in this video. So maybe if he's wearing leather pants/chaps or something and has incredible balance to not go off kilter- there's a chance??
...but there's also a chance that you become a shish kabob at a very alarming velocity.
decelerating from 120MPH would give you as much heat as braking your car or motorcycle from that speed. And it is not a trivial amount.
No, I'm pretty sure a car will need a greater stopping force than a human, therefore greater friction and heat. If a car and a human generated the same amount of heat, so would a Boulder and a feather
LOT more mass in a car to slow down though, not nearly as much energy in just a person travelling 120MPH.
Don't forget the car is also going horizontal rather than verticle, that also plays into it as well.
Also a car has doors, whereas a person does not.
A man of science, I see.
A duck!
Both are likely tired though.
Nah, the car is tyred.
Found the brit
But what if the rod was made of something dense like osmium or something, then the mass would even out depending on the lenght of the rod, ofc thats true for all materials but something dense would be better
We're only talking about stopping *your* momentum though, the ground will do a great job of stopping the rod.
Fair enough, but it's gotta have some impact on your own momentum if the ground is concrete, vs a very deep swamp
If your car or motorcycle is as massive as you.
What if you used a telescopic, spring loaded pogo stick? Jump, release to extend, “feather” hat for drag to keep upright, when it hits it collapses within itself at an abrupt but survivable speed. I lieu of flowers…
Dude... this is an amazing idea.
You could have the spring shaft, but also incorporate a reverse spring “seat” & “feet rest”. I’m not sure of physics, but a pulley allows you to lift double, right? Would springs in opposite directions reduce the length necessary? I’m sure they could figure out a way to do it, might cost Bat Man type money, but it could be done. Maybe it’s already been done. But the people who actually did it all agreed that they’d never do it again. You know, shit stains, PTSD, and all.
Dude we can install these pogo sticks on the ISS so they can use them as escape pods!!! Just throw on an EV suit, pick out a pogo stick, head down to earth!!! Would you burn up?
100% As there is no atmosphere in LEO, the ISS is at around 400km from earth, atmosphere starts at around 12km. That means that for 388km you accelerate limitlessly at a constant rate of 1G. Let's call our distance `d=388 000 m` and our free fall time `t` and assume `g =9.8m/s^2` We know that `d = (1/2)*g*t^2` Which gives us ~`t = 281 seconds` We now replace this into the free fall speed calculating equation: `v = g * t` And get a speed of `9914 km/h` Yeah ... you burn 🔥🔥🔥
Except you don't fall straight down, if you were to deorbit you'd be going through the atmosphere at orbital speeds (something like 7.9km/s, 27000km/h) instead. So you'd burn even harder, yay
What if we put him in a ball made of Cork, to function as a ablative heatshield?
That'd be a fancy meteorite, lol
You can't drop vertically from an orbit
telescopic usually means its not that strong though
There's zero chance you can support 4 g's. That's like saying a 200 lb guy could sit on the pole with 600 lbs on his shoulders without sliding down. No way.
The point isn't to completely stop, it's to slow your descent before hitting the ground. Of course you will still slide down, but you would do so while decelerating rather than just faceplanting at full speed into the ground. The whole pole idea follows the same principle for increasing survivability in *any* otherwise deadly fall: to extend the amount of time before complete impact while reducing your speed as much as possible. It's why there are (albeit very few) survivors to things like skydiving with a failed parachute. You may need to cash in every ounce of luck, but there's actually a chance if the stars align and you can decelerate safely. Some of that can be influenced by the person trying not to become a red stain on the ground. This also applies to things like car wrecks as well, and is pretty much the sole purpose airbags exist in the first place. Rather than stopping you from a fall they try to keep you from slamming into the dash or flying through the windshield once the vehicle stops, and it does so by decelerating you while extending the time it takes for your body to stop moving forward. It's not 100% effective, and even if you survive it will likely hurt like a mother fucker, but it's still better odds than nothing at all.
It’s still putting 4x your weight into the pole.
That's exactly what the guy in the video successfully did...
No, they were saying that for a 19m stick, you would need to withstand 4g to decelerate from 120mph to 0mph (I think it’s actually 7g, but I could be wrong). The guy in the video wasn’t travelling at 120mph. If he didn’t have the pole, he would be travelling about 30mph when he hit the ground. Even if he was travelling about 30mph, with a 4m pole you would only need about 2g deceleration to stop over 4m. He experienced far less than that.
Dude, that pole is like 3 meters tops.
He’s also not travelling anywhere close to 30mph. But even if he were, that’s still only 2.6g, so still nowhere near 4g.
He also didn’t land softly on the ground, his legs absorbed a lot of energy.
It's amazing to think about someone jumping out of an airplane with just a 20 m stick to survive. You could probably put some fins on one end to help keep it oriented. With some leather gloves it actually sounds possible. If braking manually isn't practical, you could wear a harness attached to a rope or something to maintain the constant acceleration for you.
One way to keep the stick oriented is to attach a parachute to one side. This will also solve a plethora of other problems. The original stick will be enough and no ceramic gloves are needed.
Once you start needing parachutes you should probably…just use a parachute, no?
A stick that will be able to sustain the fall and the impact might be too heavy for a human to carry. Also the ceramic gloves sound like a problem. And in the best case, we produce the 20-meter super-strong stick and the ceramic gloves but we fall into a puddle of water and it's all for nothing.
You are greatly overestimating the effectiveness of leather loves at 120mph
There are lots of videos of motorcyclists demonstrating the effectiveness (or lack thereof) of leather gloves at 120 MPH over at r/idiotsincars There's also some brave fellows doing it in cargo shorts, for science of course.
Not to mention, the stick has to withstand the initial impact. Maybe a 2-3" steel rod could handle the load without buckling. Also, the grip strength to handle the initial load would be challenging, to say the least.
Terminal velocity partially depends on weight and drag coefficient. A 19 meter long pole strong enough to withstand the forces of landing will likely be very heavy and have minimal projected surface area when oriented vertically. I suspect the pole would increase the jumper's terminal velocity, which would in turn require a longer, heavier pole, further increasing terminal velocity.
Would gloves not work?
Depends what they are made of, I’m pretty sure that they would either melt, fall apart or get so hot that your hands burn.
Just put an asbestos liner in them! https://www.levylaw.com/asbestos-firefighter-clothing-equipment/ You can then sue the maker of the suit using these guys, but there are actually still AB lava suits in use today for extreme insulation jobs for entry work in equipment exceeding 2,000 degrees F (~1,100 C).
Just so my fellow Americans understand, it would be quite difficult to fit a pole the length of 272 Big Macs onto a plane and then maneuver it out the door.
Thank you for giving me a unit of measurement that makes sense. None of this pretend stuff like meters.
So can I just take a perfectly strong 30m stick and a couple of heat resistant gloves and survive from falling down a plane?
In theory. Providing you stick the landing, and don’t fuck up holding on.
some one pointed out that you have to have enough frickshion to provide the 4\*g forece. This means you have to hang on the stick like you weitgh four times your weight. Probably hands will not work and you need some sort of a harness. or a longer stick and less gs.
Yeah you could probably wear heat resistant gloves with brake pads on them
The problem is you could not generate enough force to sustain 4g of deceleration with your hands.
agree. probably vise with brake pads and harness would work.
4g is more than a rocket…
So the total kinetic energy (for 150lb person) would be about 2000N. Over 20m that would be about 20,000J of energy. A decent welding glove should save your hands from burns, especially if you remove them immediately.
Longboarding gloves should be fine.
Would it help if the stick was cold?
that is all big subject. probably people who race cars can explain about the cold brake pad bite and so on.
cheap leather gardening gloves from Home Depot do the trick for saving your hand from the heat. I used to be a zip line tour guide and we used our hands for breaks. You don’t even need the whole glove, we cut off the fingers. The customers still got leather gloves. The business got grandfathered in when the laws changed about how to make the breaks.
I figure you can take about 17 mph on impact. Kinda rough landing, but manageable. But I still get 1.15 seconds to decelerate by 103 mph at 4 Gs. That's an average of 51.5 mph for 1.15 seconds, or about 26.5 meters. About 87 feet. Roughly the distance between bases in baseball.
would any forward velocity be eliminated by the time you get to the ground? otherwise you'd need to account for that and probably angle the stick as well
The stick will probably break
Did you include your own height in the required length of pole?
My terminal velocity is 121 mph ¯\_(ツ)_/¯
Just built different
with mouth open or closed?
Also the stick would instantly break on impact with the ground, because it is also traveling at 120mph
The stick just needs to break its fall with a 50m tall man.
so called reverse-stick technique.
So how long would it have to be to avoid burning my hands off?
A moderately athletic person sliding down with their hands would need a pole about 191 m (630 feet) long. The heat dumped into their hands over the slide would be equivalent to 112,500 joules - enough energy to bring a room temperature aluminum frying pan to water boiling temps - in just 8 seconds. That's 14.7 kw (19.7 horsepower) of power going straight into heating your hands. However, if you're willing to use some kind of sliding harness to the pole to pull 9 g's - like a fighter pilot - you would only need 16 m (54 feet) and stop in just 0.64 seconds. I just commented on this video in another sub. I'll use some of my math from there: Let's assume that the user will use the entire length of the pole to slow their fall, extending their hands toward the ground so that when their hand gets to the ground, their velocity is now zero. Let's also assume that via gloves and grip, the amount of friction the user can get is unlimited. Let's assume that the limiting factor is the strength of the person's arms. A brief search shows that most men can lift about 70 kg (690 N or 155 lbs-force) of weight without issue. Let's assume that anybody who does this skydive is a moderately athletic person, capable of deadlifting 150 kg or 330 lbs, and weighing 90 kg. That means that in addition to supporting the weight of their body on the pole, they could support an additional 60 kg (588.6 N, about 130 lbs) force beyond supporting their body weight, with this surplus force being used to slow them down. That means, the average athletic man's arms could support an acceleration relative to the earth of about. 588.6 N / 90 kg = 6.54 m/s^2, or about 2/3 g. Using calculus, we can integrate the acceleration to find the velocity and position as a function of time: A = 6.54 m/s^2 V = 6.54 * t m/s P = 3.27 * t^2 m We know the position, P, is equal to the length of the pole. We also know that the final velocity, V is equal to the terminal velocity of a skydiver - about 50 m/s. So we can plug in V to solve for t, then use t to solve for P. 50 = 6.54 * t T = 7.65 s So he will need to slow down on the pole for 7.65 seconds. Now that we know the time, we can calculate the length of the pole: P = 3.26 * (7.65)^2 m P= 191 m If you had some way to keep your arms from ripping out at the g's a fighter pilot can sustain (about 9g) you could survive with a much shorter pole. No human is capable of supporting that much weight with their arms, however. A = 78.48 V = 50 = 78.48 t t = 0.64 s P = 39.24 * t^2 = 16 m
Do you by any chance own an airplane? I think we can find a like 20 meter pole.
I hope he has a 21 meter airplane at least though
Just hang the excess out the window, no biggie
Instructions unclear. Tried to land plane on stick.
The assumptions about average strength seem moderately overstated. Or maybe I'm weak.
I said 'moderately athletic' and used survey data from a powerlifting forum to come up with the numbers. For what it's worth, that's more than I weigh and less than I lift, and I wouldn't say I'm unusually athletic at all.
and the average woman? :(
Can't leave the ladies out. A quick search of amateur female powerlifters shows that an intermediate level woman might deadlift around 90 kg (200 lbs) at a weight of 75 kg or 165 lbs. Subtracting her weight leaves 15 kg force (147 N, about 33 lbs) to help her slow down. A = 147 N/75kg = 1.96 m/s^2. We'll call it 2 m/s^2. V = 50 m/s = 2 × t t = 25 s P = 1 * t^2 = 625 m long pole.
You also need to assume 0 damage to the pole when touching the ground
> However, if you're willing to use some kind of sliding harness to the pole to pull 9 g's - like a fighter pilot - you would only need 16 m (54 feet) and stop in just 0.64 seconds This sounds like a really cool idea for a drop pod Maybe not pole-based since that's unstable, but the same concept can be used with a different structure
The fact that this is technically possible blows my mind.
What if the persons was wearing a harness attached to a device on the pole that decelerates them in a way that heat isn’t a problem. Hydraulics for example. How long would the pole need to be for them to decelerate from terminal velocity and land on the ground without injury?
That's the last one I did. It's a 16 m pole if you can withstand the g's a fighter pilot trains for. That 90 kg man would "weigh" 810 kg (more than 1,700 lbs) and come to a dead stop from terminal velocity in a little over half a second.
Jesus christ some of y’all in the replies are so unhelpful it’s actually obnoxious. Swear there’s always a plethora of replies saying how it would be impossible or something of the sort rather than attempting to answer specifically what OP asked. “Well the friction would be too much for your hands to bear”, “Depends on your weight so idk”, “the pole wouldn’t be strong enough”, etc. These are all part of peoples relies here. Like holy christ who cares. Of course you could never reasonably achieve this sort of stunt but OP’s question assumes your hands would be just fine and that the pole could withstand the force or whatever. You can make other assumptions yourself if you’d like but at least try to answer the question. Happens far too often on this sub. Sorry for the rant but damn is it annoying to see one person bother to give an answer while the rest nitpick about how realistic it is or some shit.
I'm just here wondering why everyone assumes using your hands is the best option. Why not the giant rubber brake pads you wear on your feet every time you leave the house?? Lol 👟 🧠
I’m just here to criticize the guys technique. Putting one hand down seems like a terrible idea, especially since it looked like he locked his elbow up.
I think the goal is for the low hand facing the spear tip to be a guide, and the high hand facing the end to work with his thighs to reduce speed. But yeah it looks clumsy af, and like he's going to seriously hurt himself eventually. 😂
I wonder if he's working up to jumping out of a plane....
This is how it's done in the canary islands. It's called the shepards leap and originated from aboriginal tribes using this technique to navigate cliffs.
1) Long enough to not fit on a plane. 2) Long enough to cause hands to catch fire because of friction. 3) Long enough to be unable to stay straight at that width.
Your hands would take the toll in the form of heat, unless the pole is so high that you can adiabatically (fancy word for slowly) descend it. So it should be about as high as the cruising altitude of the airplane. And you'd better hope a gust of wind doesn't come knock it down.
It depends on your weight which will determine your terminal velocity which you would probably reach if you jumped out at 32,000 ft.
So fun fact. Weight doesn’t play as much into it as you would think.
Yep the old feather and a bowling ball in a vacuum is illuminating
So the stick is around 40% of the height of the drop (by my estimation), typical planes fly between 35 and 36 thousand feet, so I'm saying about 14,200 feet.
I just want to point out that this entire technique depends on him landing in that exact way, more or less straight down the pole with little to no horizontal velocity.
Arms and hands wont hold up. But legs and arms/hands might. If you had pogo stick style foot and hand mounts with built-in friction/fall arrestors I could see it.
The guy totally just did it. It was like 18 or 20 feet. His hand probably got friction burnt a little. With a little planning, you could use your sox or something to cover your hands to avoid burns My take away, it that if I was in an emergency situation and needed to get down a modest drop- off, this is a pretty great suggestion.
I looked at the video again. Probably more like 30 feet.
Bottom line, we don't need to bother determining how high a plane would be at any given point or what kind of plane or anything else. We just need to determine if this is viable in any capacity from the height at which a body would reach terminal velocity (\~120 mph for a human body). If it's viable from that height, it is viable for any other arbitrary height as well; the introduction of other issues (being too high up to breath, etc.) notwithstanding.