Forums > Technical Discussion > What is Fire?

Posted: 2nd Feb 2005
the colour of fire is caused by the burning of oxygen.eg if you burn an aqueous solution of boric acid you get a green flame due to thhe position of boron in the spectrum.other examples are [Co(H2O)6]2+ is pink,CoCO3 is purple.most copperr complexes are blue.alll this is due to the numberr of d electrons,absorbing or reflecting the light to produce colours.

Posted: 2nd Feb 2005

Written by: DoktorSkell

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What type of energy is it?

does it have mass?

what causes its orange glow?

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light and heat.

no.

the type of fuel you're burning (and the amount of oxygen supplied to keep it going).



we used to confuse ourselves talking about what flames were and why they burnt like they do - like 'what temperature/size does a flame have to be before it starts flickering?' and so on





cole. x

"i see you at 'dis cafe.
i come to 'dis cafe quite a lot myself.
they do porridge."
- tim westwood

Posted: 2nd Feb 2005
Its exothemic combustion.

*buts goes with Coles answers*

Posted: 2nd Feb 2005
i wonder how fire would burn in zero g?

it would be like a baknket of floating death!

or a true ball as teh liquid qould form together!

as for fire, its just that fire, the oxidiastion of the fuel source, giving rise to the stored enegry becommin, heat and light, and sound enegry

there is also some given off as kenetic enegry in the movment of teh flames

all in all its a poo enegry source, just as electrisity is

now if you wnat a realy stupid question...what is electrisity, mass? size?

none of the above, its all a flow of electrons, and thus is weightless and life less!

Step (el-nombrie)

Posted: 2nd Feb 2005
Apparently candles won't burn in zero g - you need the convection caused by hot air rising to bring in new oxygenated air to keep the flame going. So in zero g it uses up the oxygen near it and then goes out.

monkeys ate my brain

Posted: 2nd Feb 2005
watch the movie red planet for a demonstration of someone with far too much time on their hands accuratly rendering zero-gravity fire. the movie sucked, but the weightless fire bubbles were quite accurate.

Lights dancing off my skin as chains wrap round it.
Pain is in a little box and I'm so glad I found it.

Posted: 2nd Feb 2005
i would love to see fire in zero g

it would be so lush

obviously till i died but lush!

Step (el-nombrie)

Posted: 2nd Feb 2005
Mo-seph is correct. fire in zero G would not last long - as there would be little or no convection, meaning all the oxygen in the area of the flame would be quickly used up, and no up draft (heat only rises because of gravity) to bring in fresh air. so explosions are possible, and perhaps quick flas fires, but not sustained flames or really even embers, unless you have an oxygen souce directly feeding the flame (as per an acetylene torch for example)

So really, accurately rendering a flame in zero G is complete BS, just like the rest of the movie "Red Planet" - that movie doesn't even qualify as science fiction - just fiction (maybe "space fiction"?), because there is pretty much no (even vaguely) accurate science in it.

and to be technically correct ,you aren't really burning oxygen - rather burning is the process of rapidly oxidizing a substance in a exothermic reaction. the flame you see is actually elctrons that have been ecited by the heat of the reaction into a higher energy state falling back to their ground level. as they do so, they emit the energy in the form of light (in a flame much of that light is infrared light - also known as heat to the lay person). If you are burning a substance other than carbon (which gives the yellow/orange), the different electron orbital configurations lead to the electrons falling back to ground states with a different amount of energy released than for carbon, and since light color is is energy dependant, that means your flame will be a different color

for example, the energy difference between the first exited state for electrons orbiting a boron atom is greater than for a carbon atom - thus buring boric acid gives a green flame, which has a higher energy content than the yellow flame of carbon. this does not mean the boric acid neccisarly burns seemingly hotter though - just that more energy is contained in the green light. The amout of infrared heat (which is what you will feeel as heat directly) may actually be less, depending on this and other variables.

-v-

Wiederstand ist Zwecklos!

Posted: 2nd Feb 2005
geek.

who wants a peek at my favourites directory...?

https://exploration.grc.nasa.gov/combustion/web/video_collection.htm




cole. x

"i see you at 'dis cafe.
i come to 'dis cafe quite a lot myself.
they do porridge."
- tim westwood

Posted: 2nd Feb 2005
cool - thanks Cole!

-v-

Wiederstand ist Zwecklos!

Posted: 2nd Feb 2005
Lovely. There goes my afternoon.

monkeys ate my brain

Posted: 2nd Feb 2005
"geek"

Seconded.

Getting to the other side

Posted: 2nd Feb 2005
Wow.. I found that really interesting Vanize!

Never pick up a duck in a dungeon...

Posted: 2nd Feb 2005

Written by: Pink...?

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Wow.. I found that really interesting Vanize!

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Geek!

monkeys ate my brain

Posted: 2nd Feb 2005
er... you know, at last count, there were well over 16,000 geeks registered on HoP....

-v-

Wiederstand ist Zwecklos!

Posted: 2nd Feb 2005
i thought a few of those 16,000 were hippies no?




cole. x

"i see you at 'dis cafe.
i come to 'dis cafe quite a lot myself.
they do porridge."
- tim westwood

Posted: 2nd Feb 2005
yeah, there are a few hippie geeks and a few techno geeks, but they(er, we...) are all geeks - we are all on a internet discussion forum basically talking about pyromania for pete's sake - what more do you want?

YOU ARE ALL GEEKS!!!!

(me too)

-v-

Wiederstand ist Zwecklos!

Posted: 2nd Feb 2005
who ever said you can't be both!? (not that i am, i'm just a geek. geeks are the coolest people ever!) a hippie geek would just be somebody who runs his/her comp on solar!

-James

"How do you know if you're happy or sad without a mask? Or angry? Or ready for dessert?"

Posted: 2nd Feb 2005

Written by: vanize

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YOU ARE ALL GEEKS!!!!

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Shhh... Don't burst my liquid membrane wholly enclosing a volume of gas.

monkeys ate my brain

Posted: 2nd Feb 2005
Aww, bless. You're all lovely anyways

Getting to the other side

Posted: 2nd Feb 2005
fire is also something that exists in some people's hearts, and keeps them going

We are the music makers, We are the dreamers of dreams,
Wandering by lone sea-breakers, And sitting by desolate streams;
World-losers and world-forsakers, On whom the pale moon gleams;
We are the movers and shakers of the world for ever, it seems.

Posted: 7th Feb 2005
Im a gippy... Geek + Hippy
Or a Heek?

ohmygodlaserbeamspewpewpew!

Posted: 7th Feb 2005
or a swat/hippy.,...
swippy or a hipwat.

Posted: 6th Apr 2005
'the colour of fire is caused by the burning of oxygen'

no it isn't: it's caused by carbon emitting light. that's why the gas in your boiler burns with a BLUE flame (complete combustion, you see)

and you can get a fire going in zero G. they actually performed this experiment; the flame forms a thin blue shell around the head of the combusting material. convection currents are sufficient to sustain the fire. although whoever it was ^^[?] was right to suggest that fires in zero g won't do much.

ture na sig