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you laugh but i've always thought it would be great to carry a kilo of pure hydrogen in my backpack - just burn it to obtain like 5 litres of water ... I mean w

you laugh but i've always thought it would be great to carry a kilo of pure hydrogen in my backpack - just burn it to obtain like 5 litres of water ... I mean why are we carrying all that oxygen in our backpacks when he atmosphere has a plentiful supply of it...

dylan604 3y ago
Have you ever actually seen a canister of hydrogen? Specifically, have you ever felt the weight of that canister? I'd rather just carry the 8lbs of a gallon of water. At least it gets lighter as the water is depleted
- whatshisface 3y ago
  Carbon is lighter than oxygen, so their plan would work if they brought fully saturated hydrocarbons including ones so long-chain that they were solid at room temperature.
  - dylan604 3y ago
    You just described coal. So, you're suggesting taking coal on a backpacking trip along with a very heavy canister of hydrogen. To make water? Anything else you want to do to help destroy the environment you're backpacking through? You realize this whole thread started with the concept of dehydrated water, right?
    - whatshisface 3y ago
      Saturated hydrocarbons contain hydrogen. That is what the carbon is saturated with. Coal is not saturated.
  - deleted 3y ago
    [deleted]
- Filligree 3y ago
  Well, the same amount of hydrogen (as in 1kg of water) in the form of methane only weighs ~450g though. And methane, conveniently, turns into H2O when burned. So in principle you could carry a bottle of methane and burn that to get water. ;-)
  - dylan604 3y ago
    roughly half the weight, plus the weight of the burner equipment. again, that weight still remains even after the supply of fuel to make water is depleted. a just of water gets lighter. by the end of the hike, this is very much a nice quality
    - Aachen 3y ago
      Where do you find 550g lighters? Surely a pocket lighter to save half a kilogram of water is worth it
      - dylan604 3y ago
        What do you expect to do, open the valve, flick a Bic, and the water is going to start flowing? Come on. This was a fun nonsensical thread, and you're now trying to turn it into a magic trick rather than goofy science. You have to capture the flame's exhaust, pressurize it, and whatever other sciencey stuff to get the waste into a liquid
        marcosdumay 3y ago
        > pressurize it You "just" have to capture and cool it down. I mean, it's completely outside of viability, but it's not breaking ground science. You could do it perfectly well in a lab (if you had any reason to).
        dylan604 3y ago
        There's a lot of things that can be done in a lab, but bringing it to the real world is totally different. Nevermind fitting this in the original concept of backpacking
- sp332 3y ago
  Just put the hydrogen in a balloon and it will carry itself.
  - dylan604 3y ago
    Just remember, the flame from hydrogen is clear and very hard to see until it catches other things on fire. At that point, it's well past too late
    - toast0 3y ago
      Just need a longer string for the balloon and it'll be ok. And hike in places with less trees (although, after a few mishaps, the trails you frequent will have less trees, too).
- deleted 3y ago
  [deleted]
solardev 3y ago
Maybe we need mini packblimps that can not only carry fuel, but part of the pack, the dog, the kid, etc. It could have AI assisted propeller machetes to hack away at wayward branches, geofenced to protect endangered flora of course. Then if you add some condensing coils and a transparent roof, you could also just leave the backpacking food in there and it'll slowly get moist and solar cook. After a twelve hour hike you'd get lukewarm edible mud, mmm. Explosions are a minor risk, but if you can make water out of the hydrogen anyway, surely you can put out any resultant wildfires. Cyberpunk Smokey would be proud.
- dylan604 3y ago
  would this not be considered a drone? drones are not legal in national parks. can only imagine each state following suit for state parks.
  - solardev 3y ago
    Guess we have to get rid of the props and just tether it to the pack like a balloon. Seriously though, I've often wondered if a weather balloon style lifter tethered to a backpack could help it be lighter. Probably with a less flammable gas, and only in sparsely forested areas.
    - dylan604 3y ago
      Less flammable would be Helium. It just so happens that the US is looking to sell the strategic helium reserve. So you just need to find a VC and you can get your backpacker's assistant idea off the ground. hehe as far as helium balloon, it would have to be a balloon of such enormous size to be of any benefit. To launch a couple pounds of payload to 90k feet required a balloon 8' in diameter on the ground.
      - namibj 3y ago
        A kilogram of lift per cubic meter of helium. At sea level; if you let it expand it only goes bigger at altitude, without needing more helium.

dylan604 3y ago

Have you ever actually seen a canister of hydrogen? Specifically, have you ever felt the weight of that canister? I'd rather just carry the 8lbs of a gallon of water. At least it gets lighter as the water is depleted

whatshisface 3y ago
Carbon is lighter than oxygen, so their plan would work if they brought fully saturated hydrocarbons including ones so long-chain that they were solid at room temperature.
- dylan604 3y ago
  You just described coal. So, you're suggesting taking coal on a backpacking trip along with a very heavy canister of hydrogen. To make water? Anything else you want to do to help destroy the environment you're backpacking through? You realize this whole thread started with the concept of dehydrated water, right?
  - whatshisface 3y ago
    Saturated hydrocarbons contain hydrogen. That is what the carbon is saturated with. Coal is not saturated.
- deleted 3y ago
  [deleted]
Filligree 3y ago
Well, the same amount of hydrogen (as in 1kg of water) in the form of methane only weighs ~450g though. And methane, conveniently, turns into H2O when burned. So in principle you could carry a bottle of methane and burn that to get water. ;-)
- dylan604 3y ago
  roughly half the weight, plus the weight of the burner equipment. again, that weight still remains even after the supply of fuel to make water is depleted. a just of water gets lighter. by the end of the hike, this is very much a nice quality
  - Aachen 3y ago
    Where do you find 550g lighters? Surely a pocket lighter to save half a kilogram of water is worth it
    - dylan604 3y ago
      What do you expect to do, open the valve, flick a Bic, and the water is going to start flowing? Come on. This was a fun nonsensical thread, and you're now trying to turn it into a magic trick rather than goofy science. You have to capture the flame's exhaust, pressurize it, and whatever other sciencey stuff to get the waste into a liquid
      - marcosdumay 3y ago
        > pressurize it You "just" have to capture and cool it down. I mean, it's completely outside of viability, but it's not breaking ground science. You could do it perfectly well in a lab (if you had any reason to).
        dylan604 3y ago
        There's a lot of things that can be done in a lab, but bringing it to the real world is totally different. Nevermind fitting this in the original concept of backpacking
sp332 3y ago
Just put the hydrogen in a balloon and it will carry itself.
- dylan604 3y ago
  Just remember, the flame from hydrogen is clear and very hard to see until it catches other things on fire. At that point, it's well past too late
  - toast0 3y ago
    Just need a longer string for the balloon and it'll be ok. And hike in places with less trees (although, after a few mishaps, the trails you frequent will have less trees, too).
deleted 3y ago
[deleted]

solardev 3y ago

Maybe we need mini packblimps that can not only carry fuel, but part of the pack, the dog, the kid, etc. It could have AI assisted propeller machetes to hack away at wayward branches, geofenced to protect endangered flora of course. Then if you add some condensing coils and a transparent roof, you could also just leave the backpacking food in there and it'll slowly get moist and solar cook. After a twelve hour hike you'd get lukewarm edible mud, mmm. Explosions are a minor risk, but if you can make water out of the hydrogen anyway, surely you can put out any resultant wildfires. Cyberpunk Smokey would be proud.

dylan604 3y ago
would this not be considered a drone? drones are not legal in national parks. can only imagine each state following suit for state parks.
- solardev 3y ago
  Guess we have to get rid of the props and just tether it to the pack like a balloon. Seriously though, I've often wondered if a weather balloon style lifter tethered to a backpack could help it be lighter. Probably with a less flammable gas, and only in sparsely forested areas.
  - dylan604 3y ago
    Less flammable would be Helium. It just so happens that the US is looking to sell the strategic helium reserve. So you just need to find a VC and you can get your backpacker's assistant idea off the ground. hehe as far as helium balloon, it would have to be a balloon of such enormous size to be of any benefit. To launch a couple pounds of payload to 90k feet required a balloon 8' in diameter on the ground.
    - namibj 3y ago
      A kilogram of lift per cubic meter of helium. At sea level; if you let it expand it only goes bigger at altitude, without needing more helium.