Journal Quietlife2k's Journal: Lighter than air ? 2
Question : What is lighter than any known gas ?
Answer : Vacuum
Question : Can we make a rigid "balloon" sufficient to withstand a high enough level of vacuum so as to be lighter than air?
Thinking carbon60 or carbon nanotubes here....
Answer : ?????
With the new materials it just might be possible (Score:1)
Build it in space and then drop it. It will achieve 'neutral buoyancy' somewhere along the way down... the trick is to prevent it from burning up on reentry...
The answer is "maybe" (Score:2)
People have been thinking about it since 1670. [wikipedia.org]
The problem is that it has to resist one atmosphere of pressure from the outside, and the construction required to do that is extremely difficult (perfect sphere) and/or heavy (reinforced). As it rises, the pressure outside decreases, but so does its buoyancy since the air is thinner. If it could expand as it rose and the pressure decreased, that could help, but the larger surface could end up with a larger total force.