[fatsdomino001]

We can theoretically do vacuum zeppelins, which is of course lighter than helium and unlimited tho it has its own problems too.

[bentcorner]

I was curious about this and it looks like it's currently impossible to have a material that is both strong enough and light enough to support a vacuum balloon:

https://physics.stackexchange.com/questions/71027/is-it-poss...