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Q & A: vacuum balloons

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Most recent answer: 10/22/2007
Q:
I have been told that if you could create a perfect vacuum you could achieve lift much like a helium filled balloon. Assuming this is correct or at least partly do you have to have a perfect vacuum?
- Anonymous
A:
Sure, a vacuum is even lighter than helium gas. There's no reason it would have to be a perfect vacuum, or even a very good one. The last 1% of the gas molecules only have 1% of the total weight. The reason that vacuum balloons aren't used is that the outside pressure would make them collapse unless they have very sturdy walls. Sturdy walls are not practical for something you want to have be lighter than air.

Mike W.

(published on 10/22/2007)

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