5 ms·
Closer to home you can get similar things when you grind metals for instance. The sparks are at extremely high temperatures, but won't typically start fires or
by kadoban 1y ago
Closer to home you can get similar things when you grind metals for instance. The sparks are at extremely high temperatures, but won't typically start fires or cause burns (it depends) because they're just too small to impart much actual energy to anything they touch.
You only get fire risks when the things they touch are themselves tiny (like dust), so they're unable to absorb and spread the heat.
A similar thing happens when you bake with tinfoil. The foil will be at like 350 F, but you can still touch it basically immediately if you're willing to gamble that nothing with thermal mass is stuck to it where you can't see. It just doesn't have enough thermal mass on its own to burn you, but if there's a good-sized glob of cheese or water or something on the other side you can really be in for a nasty surprise.
- chasil 1y agoI wonder if actual tin foil would behave differently from the aluminum foil that we are all now using. https://en.wikipedia.org/wiki/Tin_foil https://en.wikipedia.org/wiki/Tin_foil
- toast0 1y agoTin foil and aluminum foil do have generally different properties. For instance, tin foil can disrupt mind control and aluminum foil can't, and corrosion effects are likely at least different. But any thin metal foil isn't going to be able to hold much heat, because there's just not that much material.
- chasil 1y agoI do not think that you are correct. "The thermal conductivity of aluminum is 237 W/mK, and that of tin is only 66.6 W/mK, so the thermal conductivity of aluminum foil is much better than that of tin foil. Due to its high thermal conductivity, aluminum foil is often used in cooking, for example, to wrap food to promote even heating and grilling, and to make heat sinks to facilitate rapid heat conduction and cooling." https://www.chalcoaluminum.com/blog/aluminum-foil-tin-foil/ https://www.chalcoaluminum.com/blog/aluminum-foil-tin-foil/
- piker 1y agoIf it rounds to zero, then perhaps 4x'ing it won't make a difference?
- kardos 1y agoWell, heat capacity and thermal conductivity are not the same thing
- adastra22 1y agoThat’s the part of the comment you took issue with? Lol.
- chasil 1y agoThe things that you can measure are science. The things that you can't measure are... not.
- haneul 1y ago> tin foil can disrupt mind control You're not weaponizing Gell-Mann amnesia against us are you?
- toast0 1y agoNot at all. Just doing my part to point out, whenever it's topical, that tin foil hats work and aluminum foil hats don't. There's a reason they want you to call aluminum foil by the wrong name.
- PantaloonFlames 1y agoCommitted to the bit. Kudos
- aydyn 1y agoMind control waves are pure magnetic fields as opposed to traditional EM waves. So although aluminum can act as a Faraday cage, its not a magnetic shield and hence not capable of stopping mind control.
- dtgriscom 1y agoOoooh! I get to share my favorite Stack Exchange answer! https://physics.stackexchange.com/a/208520/82798 https://physics.stackexchange.com/a/208520/82798
- ahazred8ta 1y agoThe anti mind control tinfoil hat was invented in 1926 by SciFi author Julian Huxley, brother of Aldous.
- Schweigerose 1y agoWell, I guess Germans are in for a nasty surprise since they call that garment an "Aluhut" in the respective circles where such things are required for street cred ...
- hinkley 1y agoTin foil keeps the illuminati out of your brain. That's why they cancelled it. And I have proof!
- kosievdmerwe 1y agoThe other thing that helps you is that you're made mostly of water, which is one of the substances with the highest heat capacity. So it's hard to heat up or cool.
- HPsquared 1y agoI think similar of radiant heaters. The heating elements are clearly very hot, glowing even, but you never reach equilibrium with it: your leg will not get that hot. This is because your leg is cooled by conduction and convection (which is basically conduction again) and possibly a little evaporation.
- kadoban 1y agoYeah, radiative cooling/heating is actually super slow compared to any other type. This is why it's so hard to cool anything in space, it's your only option and it kind of sucks at its job.
- BobaFloutist 1y agoWouldn't the other option be ejecting heat "ballast"? I'm sure that would lead to other issues (sure, ejecting it would move you, but you could just always eject it in the opposite of the direction you want to go, which is how spaceships work in the first place), but what if you had super-cooled ice in a thermos-like enclosure, and as you needed to cool you pulled some out, let it melt, then vaporized it, then superheated the steam, then vented that out the back?
- kadoban 1y agoI think you could do that, but mass in space is kind of hard to come by. If it wasn't (like if you're on the moon) you could just use the mass for conduction anyway. If you have to ship it up and consume it like that, that's expensive and limiting. I'm not sure you can practically superheat the ballast without just causing more heat that you have to deal with. Maybe a heat pump works? Something about that feels vaguely wrong.
- HPsquared 1y agoIf you're about to generate super high temperatures (via a heat pump), might as well use a radiator again. Radiative heat transfer rate scales with temperature to the fourth power. Any such system requires energy, however.
- rayiner 1y agoGreat examples!
- hinkley 1y agoAlec Steele (youtube blacksmith) installed a particulate filter into his grinding room before he branched off into exotic metals. He also started keeping his shop floor a lot cleaner. Both because you probably shouldn't breathe that shit in, and also magnesium and titanium dust are very enthusiastic about combusting. Everyone knows about magnesium but nobody knows titanium is almost as surly.
- jimmaswell 1y ago> magnesium and titanium dust are very enthusiastic about combusting Iron dust too. Make sure to keep it away from your pre-lit candles: https://youtu.be/vZ3Pi1QBAlQ https://youtu.be/vZ3Pi1QBAlQ
- hinkley 1y agoDon't let your rust and aluminum filings mix too well either. It's bad.
- IAmBroom 1y agoOK, this has gotten silly. Almost ANY small particle in a light-density air suspension (dust cloud) will ignite. Certainly anything that oxidizes is prone to going WHOOF! around flames. This includes non-dairy creamers, paint spray, insecticide sprays (canned or pumped), and sawdust tossed over a fire.
- hinkley 1y agoCorn silos know about this intimately. I was referring to thermite though.
- kadoban 1y agoTrue, dust of combustable stuff can be very dangerous if it accumulates, and the things that will combust as dust are not terribly predictable. Eg, flour is a _serious_ explosion risk if it's mixed with the right amount of air.
- euroderf 1y ago> if there's a good-sized glob of cheese or water or something on the other side you can really be in for a nasty surprise. My next band will be named Velveeta Disfigurement. The stuff never unmelts.