>>1217044Regardless of the precise cost, the point remains: there is a relatively large amount coming out of this pipe, while only trace amounts exist in the air...a small fraction of a percent. I've not researched the other noble gases, but I work with helium every day. $4/cubic meter adds up pretty fast when filling up a blimp. Look at this hangar filled with helium aerostats... know what we do to recapture the helium if they pop or leak? Nothing. Something may be possible, doesn't make it reasonable to make the Herculean effort for miniscule returns. The implication that we can simply stick a helium-scooper out the window to replenish the stock is not realistic.
