The reaction propagation is always from the ignition source to the media, so the 'fire' is always on the outside. Even if the inside is in the process of quickly becoming the outside.
By itself in a vacuum, no. Under gas pressure, when contacted by water it will react from the point of contact until all reactants are complete. I wouldn't consider the reaction to be 'fire' though. At least not personally. Drop some hydrocarbons in the mix and you'll get a fire as the oxygen produced gets something to react with.
Yes, that is how rockets get to space, for example. Earth's atmo is ~21% Oxygen. So that is giving flames a boost. Careful not conflate "burn" with the presence of flames. In a vacuum, the flame could only exist briefly because there isnt the available Oxygen from the air. The reaction will (or might?) still happen, but without the oxygen to produce a flame.
BTW, this has been studied in microgravity aboard the ISS.
Also, just found out that the red and yellow "flames" are actually heated soot that's glowing, like metal glows when heated. That's why "hotter" fires glow blue, that's actually the chemical of the gasses burning and less soot is being produced. That's why it's counter intuitive why colder flames glow brighter than hotter ones.
Is fire even a thing or just, like, a symptom? Like shadow and cold don't actually exist, they just describe the absence of light and heat respectively. 🤔
23 Comments
OpenStars@piefed.social · 16 pts · 290d
Air is on fire.
...
Unless the fire was in space I suppose - which can't happen, so yeah, air is always on top of fire.
Edit: nope, I was wrong. Air is not always on top of fire :-P.
HikingVet@lemmy.ca · 9 pts · 290d
What about chemicals that create their own oxygen source when burning?
Skyrmir@lemmy.world · 6 pts · 290d
The reaction propagation is always from the ignition source to the media, so the 'fire' is always on the outside. Even if the inside is in the process of quickly becoming the outside.
HikingVet@lemmy.ca · 5 pts · 290d
No, I get that. Not why I asked the question.
If you have a compound like potassium super oxide chatch light in a vacuum, does it still burn because it has it's own oxidizer?
Skyrmir@lemmy.world · 4 pts · 290d
By itself in a vacuum, no. Under gas pressure, when contacted by water it will react from the point of contact until all reactants are complete. I wouldn't consider the reaction to be 'fire' though. At least not personally. Drop some hydrocarbons in the mix and you'll get a fire as the oxygen produced gets something to react with.
HikingVet@lemmy.ca · 3 pts · 290d
Speaking from experience with Potassium Superoxide, once it goes up the flames are impressive in atmosphere.
Skyrmir@lemmy.world · 1 pts · 290d
I would absolutely expect that to be true. Generate enough oxygen, and damn near everything suddenly wants to be a gas that's paired with it.
higgsboson@piefed.social · 1 pts · 290d
obligatory at this point:
https://www.science.org/content/blog-post/things-i-won-t-work-dioxygen-difluoride
higgsboson@piefed.social · 3 pts · 290d
Yes, that is how rockets get to space, for example. Earth's atmo is ~21% Oxygen. So that is giving flames a boost. Careful not conflate "burn" with the presence of flames. In a vacuum, the flame could only exist briefly because there isnt the available Oxygen from the air. The reaction will (or might?) still happen, but without the oxygen to produce a flame.
BTW, this has been studied in microgravity aboard the ISS.
OpenStars@piefed.social · 3 pts · 290d
Excellent point. I edited my comment to say that air is not always on top of fire:-D.
danekrae@lemmy.world · 12 pts · 290d
That's nothing, in Scandinavia it's "there is fire in things".
huppakee@piefed.social · 2 pts · 290d
Maybe the dutch partly learned from the vikings because we do it the other way around: "The thing is in fire!"
SupremeDonut@lemmy.ml · 5 pts · 290d
Fire is the energy emitted from converting the molecules to carbon
chuckleslord@lemmy.world · 3 pts · 290d
Converting the hydrocarbons to CO2 and H2O, yes.
Also, just found out that the red and yellow "flames" are actually heated soot that's glowing, like metal glows when heated. That's why "hotter" fires glow blue, that's actually the chemical of the gasses burning and less soot is being produced. That's why it's counter intuitive why colder flames glow brighter than hotter ones.
sirico@feddit.uk · 2 pts · 290d
My mum says I'm fire
CarbonIceDragon@pawb.social · 2 pts · 290d
A hot air balloon is kind of on fire, at least when the burner is running
LifeInMultipleChoice@lemmy.world · 2 pts · 290d
Yeah but then where is shorty fire burning?
BowtiesAreCool@lemmy.world · 1 pts · 290d
Fire blanket, it’s briefly “on” fire, until it isn’t anymore. Or until fire is on it too. Fire blankets are the liminal spaces of fire.
ILikeBoobies@lemmy.ca · 1 pts · 290d
If fire is on my ass hair then isn’t my ass on fire?
Kolanaki@pawb.social · 1 pts · 290d
Is fire even a thing or just, like, a symptom? Like shadow and cold don't actually exist, they just describe the absence of light and heat respectively. 🤔
Kacarott@aussie.zone · 2 pts · 289d
Fire is essentially a name for a chemical reaction. So it's probably more accurate to say "thing is undergoing fire"
Venat0r@lemmy.world · 1 pts · 288d
I think it would make more sense to say "thing is firing", similar to how we say "thing is freezing" or "thing is falling"