It's tasteless, colorless, and odorless. It doesn't mix well with other chemicals. In fact it's lack of reactivity is one of its greatest virtues. The other is that it is so light. And that, besides being a virtue, could be its downfall.
While my brother Bernell was visit a few days ago, he and our son Steve got into an interesting discussion about how long helium (I'm sure you guessed that was the mystery chemical by now) will be among us. I had heard some speculation about that problem but hadn't heard it in terms of doomsday dates until that discussion. I think Bernell threw out the date 2015 but I could be wrong and Steve was talking in terms of a decade or so. Wow, I thought, another inconvenient truth we're not talking about.
You see, although helium is the second most abundant element in the universe (hydrogen being most abundant) helium is rather rare on the earth because it has this habit of escaping from the caves or pockets in the earth where it develops to the atmosphere and then boiling off the outside of our atmosphere and wandering around the universe. Its production by radioactive breakdown primarily of uranium and thorium is a slow process, slower unfortunately than the evaporation of helium from our atmosphere.
Now scientists like Steve are worried about the loss of helium because it is used in scuba diving. Oh, it is also used in low temperature research. Adequate replacements have not been found yet and the clock is ticking.
Me, I'm worried about buying balloons for my grandkids that will float up and away from them when they let go. I mean you don't get the same effect from a mylar balloon on a stick.
No, you don't get the same "up, up and away," but then you don't get the accompanying litter when up comes down, either.
ReplyDeleteI don't think we will ever completely run out of the stuff, but the price will become much, much higher.
ReplyDeleteHelium-3 sells for about $1500/g which is admittedly very high, but that is enough for about 8 liters at STP. Very expensive yes, but consider that it is made from the decay of tritium (hydrogen-3) which is generally just used in making thermonuclear bombs.
Helium-4 (The standard stuff we use) could probably be collected from above nuclear waste at reactors. It will be very expensive, but I suspect it's price will stay below the current cost of Helium-3.
So when it hits $100/g the economy of helium will be different. Divers and scientists will pay higher costs and invest in recycling units. And balloons will be restricted to those who want to pay $100 for 8 helium balloons.
I wasn't too worried with applications calling for gaseous helium, but those that require liquid. I couldn't (read: didn't take the time) to find the expansion factor of helium, but nitrogen (another very common lab gas) is 683. This means one liter of liquid nitrogen expands to 683 liters of gas. I would expect the factor for helium to be even larger.
ReplyDeleteSo you have to compress a lot of gas to get enough liquid helium. We use it for cooling superconducting magnets. Our NMR (nuclear magnetic resonance) machines use superconducting coils to create high field strength magnets. These metals need to be at 4 Kelvin to act as a superconductor; otherwise they become very powerful resistors and get very hot (this quenching evaporates all the liquid helium they are in seconds, but that could be another story). This is also the same technology used in MRI machines. The discounted price for 100 L of liquid helium is $550, and the pesky stuff keeps disappearing out of the machine.
I love my nerdy family!
ReplyDeleteSo do I. But I think I'll need to invent an emoticon that signifies "poetic license taken" so I can stray from the literal truth without being written up for it. After all, I'm not getting any smarter and don't have the inclination to do significant research.
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