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Bubblechute

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Flying over ocean in a rickety aircraft and don't want to strap into a bulky parachute? No worries, just pack a bubblechute instead.

Bubblechute is a canister (a bomb really) filled with compressed air. As you jump out of your plane you grab a bubblechute along. You chuck it ahead of you just before you impact water. Bubblechute explodes under the surface releasing a huge swarm of air bubbles that break water surface tension and let you settle into the ocean as if it was a fluffy bed.

Warning: improper throwing technique or incorrect timing side effects include: mild headache, bruising and death.

ixnaum, Aug 21 2021

High dive records https://en.wikipedi...d_record_high_dives
[a1, Aug 23 2021]

Survival of high-velocity free falls in water https://www.faa.gov...s/media/AM65-12.pdf
FAA,1965 [a1, Aug 23 2021]

Micro-Softie Parachute https://www.aircraf...tie_parachutes2.php
A little smaller than the “mini-softie” but doesn’t have as many colour choises [a1, Aug 25 2021]

Diving Pool Bubbles https://www.google....4AscQ4dUDCAg&uact=5
The theory is sound. [neutrinos_shadow, Aug 26 2021]


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       Bun, but tried throwing things while skydiving at terminal velocity? I suspect its more difficult than you think.
RayfordSteele, Aug 21 2021
  

       It needs autodeployment, human reflexes and strength just aren't up to it.
Voice, Aug 21 2021
  

       Have the cannister attached to you by a long string (length predetermined by various factors...) and suitably streamlined so its terminal velocity is greater than yours. So it will hit the water before you & do its bubbling.
neutrinos_shadow, Aug 21 2021
  

       Personally at this depth... I'm going to have to charge you double.   

       ...   

       Get it? 'cause depth charge and, stuff.
Hello.
Is this thing on? Turn off those lights so I can see if everyone is at lunch and I need to get a rain-cheque on the audition.
  

       hello...   

       Someone check these calculations, but if a person if going 120mph (terminal velocity) and decelerate at a constant 5 G's (adjust for max short term acceleration without blacking out or having the air forced from your lungs), it will take 1.1 seconds to stop, during which time the user will travel 190 feet. I recommend designing this explosion to make a column of bubbly water 190 feet tall so that the user stops near sea level rather than 190 feet underwater.
scad mientist, Aug 21 2021
  

       From the title I thought this might be the idea of a type of super polymer based chewing gum that you blow out into a bubble when needed which becomes parachute sized on the way down.
xenzag, Aug 21 2021
  

       // I suspect its more difficult than you think.//   

       Meh, you have the rest of your life to figure it out and get it right.
AusCan531, Aug 23 2021
  

       //decelerate at a constant 5 G's//   

       I know physicists that spew sentences like this while rapidly calculating stuff on paper. It gets my goat, you can't start feeding demonstrably wrong stuff into a calculation without being sure of getting wrong stuff out of it. If you fire a bullet into water it won't make 190ft down, well, maybe the fragments will sink that far.   

       Nothing in fluid like this is linear. I suspect the graph curves hard at both axes, where very low velocities will decelerate at almost 0, and high velocities at almost infinity. Calculations with 0 & infinity in them are hard.   

       I imagine falling from any kind of aircraft-normal height into water is going to be lethal. Especially since you're going to need to be conscious and in reasonable physical shape to stay afloat.
bs0u0155, Aug 23 2021
  

       // I imagine falling from any kind of aircraft-normal height into water is going to be lethal. //   

       I imagine you mean using this bubbly idea. Having done it correctly - with a parachute and proper training - I can assure you it isn't always fatal. Wikipedia listing (linked) for high dive records shows some non-parachute survivals as well.   

       An FAA study (also linked) explains why a high-diver knifing into the water has a better chance of survival than a belly- flopper. File that bit under "obvious" but other parts of the study are interesting and may help develop [ixnaum]'s idea.
a1, Aug 23 2021
  

       Thanks for that. I find some of the most nuts/interesting stuff comes out of peak cold war era military studies.
bs0u0155, Aug 23 2021
  

       Nuts, interesting, from the peak cold war era? I m not sure if I should be flattered or insulted.
a1, Aug 24 2021
  

       Heh, take it as a compliment. I'm more than a little jealous of some of those who lived through the period. It seems things happened, fast. If you were in science/technology, it was "here's the money, have at it". I read a study a while ago, I was trying to get some kind of handle on what fraction of human energy is lost as heat through breathing. I found one source from a late 50's/early 60's Air Force study. Essentially it went: "We don't know how much heat humans loose while breathing in harsh conditions, so, we took 25 volunteers and made them dig trenches in Greenland to find out".   

       There's tons like it: "We don't know what g-forces do to people, so we strapped this guy to this thing we invented called a rocket sled, to find out". "We don't know how nuclear reactors behave in the air, so we took this B-36..."   

       In my area, things were the same, 80% of the drugs in use today were developed 1940-1970.   

       Having met people, it's the stories created by living in a fast-moving era that my generation can't compete with. My ex-girlfriend's dad: "I cut through the boot floor & through the top of the fuel tank, she managed to curl up in there under the boot carpet and spare wheel and I just drove us out of Poland. Problem was, I had to rig up the windscreen washer bottle as a makeshift fuel tank, I had to stop every 10-15 miles to top it up all the way through Europe".
bs0u0155, Aug 24 2021
  

       Wish I could brag, but nothing I did back in the 60s or 70s was especially interesting.
a1, Aug 24 2021
  

       We need to learn how to do science again. It's not about papers, acronyms after names, and peer review. Our dearly departed knew that and served as excellent examples of how science should be done.
Voice, Aug 25 2021
  

       A missile that deploys a series of weapons could do it. Throw out thirty or so explosive devices timed to foam the water and for the shockwaves to mostly disperse before the user hits. She can sink into a progressively lower series of foamed water and dead fish.
Voice, Aug 25 2021
  

       Maybe a sizable depth charge, such that the waterspout would rise up to meet the falling flyer, would do the trick, and would generate many bubbles.
sninctown, Aug 25 2021
  

       As [bs0] pointed out directly hitting a waterspout would be a rather unpleasant experience. But maybe if the waterspout were timed to start falling before the user, such that it would be falling when met, but somewhat slower...?
Voice, Aug 25 2021
  

       As the original audience for this idea was anyone who didn’t want to strap on a “bulky” parachute, I have to inquire about the size & weight of the bubble-chute system. One example of a compact parachute (linked) weighs 14 lbs and pack bulk is only 22x13x2.25 inches. I like how they spec’d the thickness in fractions of an inch - and the slightly larger model comes in lots of colours (I want the red one!). Competition in that market space must be fierce.   

       If you can’t make it smaller than that - and offer it in more colours - I’m not interested.
a1, Aug 25 2021
  

       //Flying over ocean in a rickety aircraft// Solving the rickety part might be the best solution.
pocmloc, Aug 25 2021
  

       // I know physicists that spew sentences like this while rapidly calculating stuff on paper. It gets my goat, you can't start feeding demonstrably wrong stuff into a calculation without being sure of getting wrong stuff out of it. If you fire a bullet into water it won't make 190ft down ... //   

       Sorry for stealing your goat, but while a bullet obviously won't go through 190 feet of water, and a person traveling at 120mph will go though even less un-aerated water, my point is that if the water was aerated enough to slow down a person at a reasonable rate of deceleration, they would end up that deep.
scad mientist, Aug 26 2021
  

       //they would end up that deep.//   

       Would they? Even aerated water would be strongly velocity sensitive. How far down is the aeration? Making bubbles at 190ft down would need a lot of pressure & therefore air. Those bubbles would represent a fraction of the water by volume, but that fraction would be heavily dependent on the depth related pressure. My point is, it's a very tricky calculation full of non-linearities and unknowns. I suspect it would be easier to do the experiment.
bs0u0155, Aug 26 2021
  

       Of course it's nonlinear. To have a constant 5G deceleration you'd need a nonlinear distribution of bubbles. If you couldn't control the bubbles that precisely and you wanted to keep deceleration less than 5G, then you'd need to design it to have deceleration of 5G or less, so the user would have to go even deeper than 190 feet. 190 feet is the best case with max 5G deceleration. Now we may find that deceleration greater than 5G for less than a second won't cause black out, or it will be a short enough black out that the person will wake before inhaling water. But still even if we can cut the distance by half, 95 feet under water is an issue that needs addressing. I threw out the idea of a 190 foot tall column of aerated water. It's not a trivial problem...   

       Side note: This idea is completely worthless in the real world and it seems that only a very remotely related variant of this idea could ever have a practical use. This is the half-bakery, so I'm suspending disbelief and attempting to point out an issue that hadn't been addressed yet, and proposing a possible work-around. I think the fundamental core of this idea (aerating water to soften the impact) is true to some extent, and interesting, which is why I bothered to comment. When I first read the idea (// let you settle into the ocean as if it was a fluffy bed //), I pictured a 10 foot deep pillow of aerated water. But then I decided to do a reality check on that and discovered it would have to be a lot deeper. I figured I'd share my results. Are my results useful? Absolutely not. As you implied, there's no known way to generate a 190 foot column of aerated water (either above or below the water surface) by dropping any sort of bomb on the surface, let alone a column that has the proper gradient of aeration to provide constant deceleration. That seems fairly obvious to me.
scad mientist, Aug 26 2021
  

       //the fundamental core of this idea (aerating water to soften the impact) is true to some extent//
It's absolutely true. See linky for diving aeration systems.
neutrinos_shadow, Aug 26 2021
  

       Interesting. I didn't realize this was commonly used for diving training.
scad mientist, Aug 27 2021
  

       A skydiving school could feature a large pool of aerated water for this purpose. Or a small one if you're feeling lucky.
Voice, Aug 28 2021
  

       Yes, this idea came up while watching diving practice. The coach would press a button to release bubbles just before the dive.
ixnaum, Sep 01 2021
  

       Yes, this idea came up while watching diving practice. The coach would press a button to release bubbles just before the dive.
ixnaum, Sep 01 2021
  

       Yes, this idea came up while watching diving practice. The coach would press a button to release bubbles just before the dive.
ixnaum, Sep 01 2021
  

       A triple back-flip jack-knife with a two-and-a-half twist!   

       <the crowd goes wild>   

       Actually a density gradient will arise naturally in the bubble/water column with the bubbles expanding as they rise - but it’s going to be linear density/depth, you might prefer it to be non-linear proportional to d^2. All the same- propelling your depth-charge 190 feet under water, as you fall, is going to be a challenge. Having the capacity to do anything at all in free- fall takes a lot of training!
Frankx, Sep 05 2021
  

       So really Bubbleshoot.
wjt, Sep 08 2021
  


 

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