Where do we get the helium to put in tanks and balloons and such? If itâ€™s lighter than air, wouldnâ€™t all of the helium on earth just float to the top of the atmosphere?
According to Wikipedia, â€œOn Earth it is created by the radioactive decay of much heavier elements (alpha particles are helium-4 nuclei produced by alpha-decay). After its creation, part of it is trapped with natural gas in concentrations up to 7% by volume.â€
Roland’s data is, it seems, technically correct. But it’s only half the story!
Helium is the second-most-abundant element in the universe. Most of the helium on Earth is helium-4 (which, as Roland states, is produced by radioactive decay). However, most of the helium in the universe is helium-3, which is produced by nuclear fusion in the heart of a star.
(interesting aside: if we take the long view, eventually (trillions and quadrillions of years from now) there won’t be any hydrogen left in the universe to form stars and burn. Helium will be the new hydrogen. Of course, trillions of years later the lowest element around will be something like iron, and iron can’t fuse, so the stars will go out. Huh.)
Like Roland says, most of the helium that we harvest (the United States is, in fact, the top helium producing country in the world) comes from natural gas deposits. The helium is removed via the liquification of all the other gasses in the mix. Helium has an extremely high boiling point, so, as the temperature drops, all the other gasses in the mix liquify before the helium and can be simply poured away.
But what happens to the helium that isn’t stored in the crust of the planet? Well, some of it gets stuck in the very top of the atmosphere. But the rest of it “escapes into space”.
Now, if I escaped into space, I’d do more than just lolligag around, enjoying the emptiness. Helium feels the same way.
Helium goes to Mars!
That’s right, all the helium that escapes the Earth goes to Mars and visits the city it was named for; Helium. Helium (the city) is the main bastion of civilization on Mars, and is the home city of John Carter from the Edgar Rice Burroughs stories. Helium (the element) likes to visit Helium (the city) and wreak havoc in serious conversations by slipping in to people’s lungs and making them sound silly.
(another aside: There is another non-poisonous gas called sulfur hexafluoride that has the opposite effect; when you inhale it, your voice gets really LOW. Weird, eh?)
In any case, that’s the story on helium. Remember, don’t inhale helium from pressurized cylinders, because that could explode you. Also, don’t inhale too much helium, because the breathing mechanism is triggered by too much carbon dioxide, not missing oxygen, so it’s easy to asphyxiate. Cheers!