Most folks don't realise all the helium we have is all the helium we have!
Couldn't you use less helium by heating it?
Problem with using a vacuum structure is that the structure weighs more that the air it is displacing and thus it won't float on air which is what Hydrogen and Helium do.
Joule-Thomson appear to disagree with you...http://en.wikipedia.org/wiki/Joule%E2%80%93Thomson_effectI have first-hand knowledge that escaping hydrogen can ignite in the way I've described.
Operative word there is "can".
And yet for years and years people have been able to avoid just that problem.
A hydrogen atom is smaller than a helium atom, so you would expect hydrogen to have a very high leakage rate. But like nitrogen or oxygen, hydrogen molecules exist only as a pair of hydrogen atoms stuck together, and so are much larger than a helium atom.
Commercial production of Helium is done by distilling natural gas, which can contain up to 5-7% helium. It is result of natural radioactive decay so it is also found in uranium ore in higher concentrations. So as long as we have natural gas we will have Helium. Furthermore by the time we go to the moon again it will be one of the main export products of the moon.
Quote from: GoForSmoke on Oct 20, 2012, 02:37 amOperative word there is "can".You are wrong. The operative words are "first hand knowledge".QuoteAnd yet for years and years people have been able to avoid just that problem. Wrong again.
And yes, people -have- been filling balloons big and small for a long, long time with hydrogen and not getting burned or blown up, they have avoided that exact problem. Sorry you didn't share their experience, happy they didn't share yours!
Just so we know, CodingBadly, how did you loose your eyebrows with hydrogen?