Apologies. I got the impression that the OP was answered and other applications of vacuum to daily life was being posted e.g. pulling vacuum to dry refrigerant paths etc.
No. They expand and contract like other gasses (as Chronos pointed out).
They’re called “noble” because they’re chemically inert and won’t react with any other elements at all – or at least so it was thought until fairly recently, when a few obscure compounds were created with highly reactive elements, like a fluoride of xenon (iirc). For practical purposes though, they’re pretty much inert. Like nobility, they’re standoffish, and won’t fool around with those dirty commoner elements.
SF6 (Sulfur Hexafluoride) was used in the old days because it provided noise insulation. But it’s thermal insulation is worse than air. It is also a bad greenhouse gas.
SF6 is a heavy gas and does the opposite of what Helium does to your voice. (It makes it heavier)
Damn, you’re right, I don’t know what I was thinking. Now, argon has a really low expansion, but it’s actually higher than nitrogen, so what I said is wrong with just that. But, good lord, neon has the highest expansion of anything. So I wasn’t even close to right. Apologies for that, everybody.
I was confused about what you meant when you mentioned the “expansion” of different gasses. Gasses all expand and contract pretty much the same way—in accordance with the ideal gas law.
I think the “expansion” you mention is actually the expansion ratio between a liquid and the gas it becomes when it boils. Is that what you were thinking of?
“Expansion ratio” certainly sounds like it should pertain to how gasses behave, but it only involves the liquid-to-gas phase change. If it’s so cold that the gas between your window panes has condensed into liquid, utility bills are the least of your worries. ![]()
I screwed up the equation regrading “R”. PV=nNRT. “R” varies depending on the gas. My dumb ass thought the position on the periodic table was relevant to “R”. It’s not.
Many incandescent bulbs now use nitrogen or argon. If you point a blowtorch at them, the glass will glow then bulge outward, not inward. PV=nRT and all that. It’s mostly oxygen that causes filament problems, so you can use another gas to prevent that, and not have the bulbs explode like bombs when you drop them. This practice started sometime in the early 1970’s. Some bulbs are probably still vacuum.
What are (maybe only super-duper) platters in hard drives encased in? Something crazy sealed, if not vacuum,right?
They’re just air tight, which is not that hard to do. The “crazy” part is the systems for making sure they are assembled in an absolutely dust free environment.
Never heard drives suck, when opened to save the magnets,
Ordinary hard drives are filled with ordinary air. There’s even a tiny opening to allow the pressure to stay the same as room air pressure.
Note the use of “ordinary”. A few years ago helium filled drives became a thing for high capacity drives. This required quite a bit of tech engineering to achieve since it’s so easy for helium to escape thru tiny pores in the sealing material.
The engineering to produce a vacuum HD would be even trickier. In addition, there might be more heat dissipation issues.
As your link notes, air is required for proper HD function. With inadequate ambient pressure, the read/write head can make contact with the platter, causing damage and data loss.
On a related note, divers in very cold water use gases such as Argon to fill their drysuits for exactly the same reason. It’s noticeably more insulating than plain air or any of the breathing gas mixes and nowadays it’s pretty cheap since its fairly widely used in industry for welding and suchlike.