And is that strength enough to put vacuum airships back on the menu?
Just imagine the energy savings!
Like a blimp but with a rigid balloon filled (ha ha) with vacuum instead of a light gas.
The article is saying it's a polymer so I'm guessing it doesn't have the right rigidity, ie, the stronger than steel bit must be with respect to a different strength measure
A helium balloon makes sense, it's lighter than air so it floats, duh.
Well, what's lighter than that? Nothing (vacuum)! It's such a dumb, but correct answer that I had a hard time wrapping my head around it.
Yup, theoretically a vacuum would be extremely buoyant if we could put it in a light enough structure.
And there's the problem.
Containing a gas with pressure equivalent to the outside air requires just a membrane. Storing a vacuum requires a container that can resist external pressure of ~ 14 psi. It scales very badly.
This also creates an insane amount of stored energy in the stress on the shell. Here's a couple of videos of vacuum crushing steel tanker railroad cars [0] [1]. Of course that size doesn't even begin to scale up to the level of vacuum that would be required to buoyancy in the earth's atmosphere.
[0] https://www.youtube.com/watch?v=VS6IckF1CM0 [1] https://www.youtube.com/watch?v=yBq5uapC-e0
I'd think the only way to do it might be to have many small hollow spheres contained in a net or something, but the trick would be for each one to be light enough to be positively buoyant...