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As far as I understand, helium is a non-renewable fossil resource. So a sustainable airship design should be using hydrogen instead. The challenge is to make it

by kozak 4y ago

As far as I understand, helium is a non-renewable fossil resource. So a sustainable airship design should be using hydrogen instead. The challenge is to make it safe.

shreyshnaccount 4y ago
You just need a sun
chrisseaton 4y ago
> As far as I understand, helium is a non-renewable fossil resource. No it's a by-product of decay of heavier radioactive elements. It's often found dissolved into fossil gas deposits, but it's not a fossil resource.
sampo 4y ago
> As far as I understand, helium is a non-renewable fossil resource. Helium deposits don't originate form organic matter, so they're not fossil.
marksbrown 4y ago
Vacuum is the ideal. Taking the molar mass of air at 28.8g/mol at STP we can see a density of air at about 1.225 kg per metre cubed. Combined with the volume of the bag we have the uplift. We quickly find that empty flexible bags collapse with nothing to provide an atmosphere of pressure back out thus the compromise of low mass gasses. These still add weight to our vessel diminishing our carrying capacity. Therefore the best solution is hot hydrogen.
- i5heu 4y ago
  There is no light and strong enough Material that can keep a vacuum in the size needed for a Zeppelin on earth so it could fly. On mars this could work. The brain confusion that a room of vacuum is lighter then air and will therefore have a lift is amusing.
  - jfim 4y ago
    I think you misinterpreted what the parent is saying. He's saying that a bag that contains only vacuum would be the lightest, but as it contains nothing, it would just collapse into having no volume due to the atmospheric pressure. That would obviously provide no lift. As such, you need something in the bag that will fill the space.
throwaway744678 4y ago
I reckon helium is not "consumed" by using it in the airship. Eventually, it may leak to the atmosphere, but it is not destroyed or lost.
- jillesvangurp 4y ago
  The point of helium is that it is light. So, any helium that escapes, goes up and eventually leaves out atmosphere.
  - stackbutterflow 4y ago
    How did it end up on earth in the first place?
    - __s 4y ago
      Radioactive decay

by kozak 4y ago

As far as I understand, helium is a non-renewable fossil resource. So a sustainable airship design should be using hydrogen instead. The challenge is to make it safe.

shreyshnaccount 4y ago

You just need a sun

chrisseaton 4y ago

> As far as I understand, helium is a non-renewable fossil resource. No it's a by-product of decay of heavier radioactive elements. It's often found dissolved into fossil gas deposits, but it's not a fossil resource.

sampo 4y ago

> As far as I understand, helium is a non-renewable fossil resource. Helium deposits don't originate form organic matter, so they're not fossil.

marksbrown 4y ago

Vacuum is the ideal. Taking the molar mass of air at 28.8g/mol at STP we can see a density of air at about 1.225 kg per metre cubed. Combined with the volume of the bag we have the uplift. We quickly find that empty flexible bags collapse with nothing to provide an atmosphere of pressure back out thus the compromise of low mass gasses. These still add weight to our vessel diminishing our carrying capacity. Therefore the best solution is hot hydrogen.

i5heu 4y ago
There is no light and strong enough Material that can keep a vacuum in the size needed for a Zeppelin on earth so it could fly. On mars this could work. The brain confusion that a room of vacuum is lighter then air and will therefore have a lift is amusing.
- jfim 4y ago
  I think you misinterpreted what the parent is saying. He's saying that a bag that contains only vacuum would be the lightest, but as it contains nothing, it would just collapse into having no volume due to the atmospheric pressure. That would obviously provide no lift. As such, you need something in the bag that will fill the space.

throwaway744678 4y ago

I reckon helium is not "consumed" by using it in the airship. Eventually, it may leak to the atmosphere, but it is not destroyed or lost.

jillesvangurp 4y ago
The point of helium is that it is light. So, any helium that escapes, goes up and eventually leaves out atmosphere.
- stackbutterflow 4y ago
  How did it end up on earth in the first place?
  - __s 4y ago
    Radioactive decay