How much does it cost to fill a zeppelin with it?

Where's it all come from? You can't get helium from the atmosphere. When helium is released into the air it floats up and eventually dissipates into space. We get helium from alpha particles emitted by radioactive decay.

Because it disappears for ever when released, the US government decided to store helium. They figured it was useful for atomic research, and anything that needs to be really really cold. It sounds a little cold war dr strangelovish, but the stock pile is still in a bunker in Texas. all 3 billion cubic feet of it. Thats a lot of balloons.

So it turns out that the price of helium in 1986 was 37.50 per 1000 ft3 now-a-days? who knows... But the helium stock pile is all for sale!

BTW:

Total Gas Capacity of the Hindenburg: 7,062,100 cubic feet, at the prices in 86, I think it would cost about 1/4 million to fill it with helium.

joelf, is it true if you suck in too much helium, you die? And then you become a floaty zombie?

sasshat: yes, it was on Mythbusters recently. And, if the Mythbusters said it, it's irrefutable.

And, from another irrefutable source: Wikipedia!

Those floating zombies are a bitch, man. Of course, if you hit one just right it slams back into the horde of earthbound zombies who are advancing towards you, so, with careful planning and the correct weaponry, you can turn the floating zombies to your own advantage.