> We loved reading the thread a couple weeks ago about hydrogen vs. helium for blimps
Say it takes 1000 m3 hydrogen to lift 1 m3 concrete. Image a pyramid shaped cone 4000 meter long with a bottom 4 m3. Now imagine a balloon with a diameter of 8000 meters.
Clearly much to big to build [for now]. We pump the hydrogen out of it. How much extra lift does that generate before the balloon implodes? What other materials can we use? Would it be possible to make it smaller than a km?
I really have no idea how to do it properly. I was thinking a wedge shape 2000 m long with 2 m height difference would be 1 m thick on average. Then one can build a circle out of those. With a pyramid you could build a sphere (kind of).
It was originally a napkin calculation from someone who did. The pun [if you like] is that a flying city is doable but one has to think much much bigger.
Say it takes 1000 m3 hydrogen to lift 1 m3 concrete. Image a pyramid shaped cone 4000 meter long with a bottom 4 m3. Now imagine a balloon with a diameter of 8000 meters.
Clearly much to big to build [for now]. We pump the hydrogen out of it. How much extra lift does that generate before the balloon implodes? What other materials can we use? Would it be possible to make it smaller than a km?