I know we’ve been through this before, but there were lots of qualifications and hemming and hawing and whatnot, so I’ll simplify matters.
Is there anywhere on earth cold enough that a cigarette could not maintain its combustion, and would just go out as soon as I walked outside (or very shortly thereafter)?
danke schoen,
jb
Well, the record coldest place on earth I have heard of is Vostok Antarctica (sp?) I recall the record there being set as -128 Celcius and some decimal change…, which is colder than dry ice if I recall correctly… That’s just nutty…
If you were outside there and then, I doubt you would be wishing to have a cigarette. More like a shelter of some sort.
Er… My ex… she could extinguish the flames of Hell!
I don’t think that the temp. has anything to do with maintaining combustion. Burning things need oxygen. Now anywhere that is cold enoough for oxygen to liquify is a place that I don’t want to be.
I don’t know about a cigarettes, but I have a buddy who’s a fire control/suppression consultant. He’s currently working on a system to be installed in one of the laboratories in Anarctica. So, we at least know that fire is a pretty serious concern. But, like I said, I have no idea how, or if, that could apply to something as small as a a smokey treat.
Uh… isn’t the sun on fire?
Things burn in outer space. That’s how they weld space stations together, y’know?
So, if fire can burn in space (where it’s pretty freakin’ cold) I would imagine it would burn wherever there is fuel.
Yes, they can weld in space, but with an oxy/aceteline torch, the oxygen is provided by a tank. Also, arc welding doesn’t require a flame at all.
I don’t think the sun would count as a fire, but as a big-ole nuclear explosion, which occurs at an atomic level, not a molecular, so it doesn’t need oxygen.
Back to the OP, my WAG would be that once combustion was initiated, it could last until the fuel was exhausted. In extreme cold, it may take more initial energy to start it.
Or something like that.
The Sun is essentially a fusion reactor. It doesn’t burn, it turns hydrogen into helium.
Things don’t burn in outer space unless there is both a fuel and an oxidizer. Rocket engines carry both.
andyman, you missed my point.
I was ignoring the oxygen question and simply addressing the relevance of the concept of ambient temperature to combustion.
**sdimbert wrote:
Uh… isn’t the sun on fire?**
No. The sun, and all other stars are powered by nuclear fusion. Standard chemical combustion (fire) is a totally different process.
Standard chemical combustion is the rapid oxidation of a fuel, with the result of heat and waste gases. Nuclear fusion is the combining of 4 protons into one helium nucleus with the result of one helium nucleus and LOTS of gamma radiation.
In order for something to burn, three things are needed: Heat, Oxygen, and Fuel. Take away any one of these three things, and the burning will cease.
No, NO, NO!!!
I did not mean to suggest that the sun combusts. :sigh:
RTFP,P. I said:
What I meant is that ambient temperature does not seem to prevent combustion.
It isn’t how cold it is outside, it is what was put into the cigarette to maintain combustion without it being drawn on. You’ll notice if you set down a cigar or a pipe in an ashtray it will soon go out all by itself. Set a cigarette down in an ashtray and it will continue to burn until it is all the way down to the filter. This seems to indicate that an accellerant(sp?) has been added to the tobacco or the cigarette paper to “aid in burning”. Since the manufacturers aren’t required to tell you what they adulterate their product with, they won’t. Not to say that any of the tobacco products aren’t carcinogenic, but why was lung cancer almost unknown prior to the 1930s a decade after cigarettes became popular?
Sorry, sdimbert! Yes, I would agree that ambient temperature does not seem to prevent combustion. Well, the only time I see it really being a problem is when it gets cold enough for oxygen to liquify. Like Stupendousman, you need heat, oxygen and fuel to sustain flame.
hardhead365, I don’t think the reason the cigarettes keep burning are because there are additives, but because they are less densely packed than cigars, therefore more air can pass through them. Cigars are wrapped in much thicker actual tobacco leaves aren’t they?
sure, torches burn is space, what with all that oxyacteline (sp?). but would a cigarette go out in the cold of space? not if there was enough oxygen. However, we have a nicely constant ratio of oxygen to nitrogen to everything else here on earth. I have a feeling that a cigarette would go out if it were cold enough (and not at absolute zero, either (not to imply it wouldn’t stop burning at 0 K, just giving the wiseasses one less weasling point)).
The question is, can it be that cold on earth? Or, is my feeling wrong?
jb
This was one of the thorniest topics I ever debated here at the SDMB. I think I’ll stay out of it this time, though.
My contention was basically that any fire with fuel and O2 was self-sustaining – heat was not a requirement (thus, no, you could not snuff a fire with just cold). But there were many valuable contributors who felt otherwise. The topic, in my opinion, was never definatively settled.
Here’s the old thread. Check it out:
http://boards.straightdope.com/sdmb/showthread.php?threadid=27102
(You have to wade past all the Smurf crap, toward the bottom of the thread to read the discussion about heat and fire.)
Yes. Oxygen liquefies somewhere slightly above the temperature of liquid nitrogen (about 77 K, or -196 degrees Celsius). It is often that cold on Earth in laboratories, in small spaces.
However, it is never that cold on Earth, ambient. Therefore there’s always oxygen in the air to keep your cigarette lit. Given oxygen and fuel, the fire will never go out, no matter the ambient temperature, because the cigarette itself will still be hot!
LL
No, I don’t think that heat is needed to burn something. Heat is a by-product of something that is burning. What you do need is a catalyst to start the combustion, and it doesn’t need to be heat.
Actually American cigarettes do have an additive to keep them burning. European cigarettes do not. This URL about fire safe cigarettes, mentions it.
Things on Earth are oxidizing all the time, it’s just going to slowly for us to see them. The reaction that makes paper turn yellow over time is the same oxidation that makes it burn when you hold a flame to it, it’s just going alot slower. What we call ‘burning’ is an oxidation reation that has reached a high-enough tempature to continue in a chain reaction. So for a cigarette to stay lit, assuming that it has enought fuel and oxygen, it’s cherry needs to remain hot enough to spontanously combust. I guess that if it were cold enough out, the air would absorb enough heat energy that the cigarette would no longer be able to sustain combustion. However, given the amount of heat produced and to poor thermal conductivity of air, I don’t see this happening.