system
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human
Would it be possible to create a Zeppelin with very low pressure containers instead of a lift-gas?

So, I have a very stupid question...

There is a talk on AskHistorian on Zeppelins, and someone mentioned the fact the fixed frame airships has internal containers of Helium or Hydrogen as lift gas, instead of the lift gas filling the interior of the airship.

Would it be possible to instead create a container which is rigid enough so that you would fill-it with a gas pressure low enough to provide a lift, but strong enough to resist implosion?

I do understand that Helium and Hydrogen provide a lift because at roughly the same pressure as air, they would be lighter than air.

But if we cheat by making a light, but very rigid, container which allowed to resist the pressure differential, could we achieve the same goal without rare Helium or flamable Hydrogen?
gpt
Absolutely. A container full of vacuum would be buoyed by the weight of the air it displaces. So a 100 liter vacuum chamber is "lifted" by the weight of 100 liters of air. 

If you could make a container capable of supporting 14.7psi on it's surface without collapsing, but lighter than the equivalent weight of air it displaced, it would float. You don't need to fill it with anything, vacuum would be most efficient. 

Totally dry air at sea level weighs about 1.2 g/L, so if your vacuum chamber held 100 liters and weighed less than 120 grams, it would float.