How small can a fire be?

Hmm… it might be best to explain this question by way of example:

If I was to come across a burning house and decided to grab a 2x4 and shove the end of it into the fire for a few minutes and then pull it out, the end would probably be burning merrily along. Ok? Now, if I was to shrunk to 2mm in height and came across a burning match and grabbed a tiny wood splinter and shoved the end in, it would turn to ash pretty much instantly, am I right? Is it possible to make a fire on a very tiny scale? If I was but a millimeter tall and wanted to make a campfire that was to scale with me, would I be out of luck? I realize that If you stick a large flame next to a small piece of wood, the wood will burn down quickly and that holding a match to a sliver of wood is like turning a flamethrower onto a small tree branch, but could I make a fire small enough that it didn’t consume the wood any faster than “normal”? How about other products?

i know what you mean, and i was wondering the same thing. it came up when i started thinking about the smurfs having campfires. they always lasted like regular fires, but i think they should have burned up quickly.

Well, I do not have a scientific background, but I think using a little critical thinking, I can answer this for you.

Fire needs three things (heat, fuel, and oxygen) to survive. If it loses one of those things, then it will die. Now I believe that a “normal” fire, i.e. wood, uses these three elemnts at a constant rate, no matter how much of each elemnt there is. So since the fire uses these elemnts at a constant rate, it will burn at a constant rate. So if a pine wood burns at a rate of 1 square foot a minute, then 5 square feet will take 5 minutes to burn. (I am making these numbers up, but I think you can see what I am trying to say) So then if we take your match, which is probably about a 1/100th of a square foot, then it will take 1/100th of a minute to burn. Now I think this would only apply if there are abundant resources. If I restrict the oxygen supply and put the fire in a cold enviroment, then you could probably slow the burn rate down so that your match would not be consumed as quickly. But in STP (standard temperature and pressure) with standard oxygen, your match would be gone in a second.

I hope that was clear enough. I really stink at explaining things. :frowning:


If you were 2 mm tall, would your perception of time be the same as it is now?

I don’t see why not. There is no equivalent to relativity based upon size. A fly, or a very small camera, sees things at the same rate you would.

everyone knows smurfs are 3 apples high, not 2 mm tall.

3 apples? I always imagined them as at most 1.5 apples. Perhaps Gargamel was smaller than I had thought.

Rather than matches, let’s think of a gas flame. Below a certain rate it will not maintain enough temperature for combustion.

True. Fire does burn at a constant rate, as the oxidation reaction that makes up fire happens at a constant rate. That’s why sawdust explodes when it hits flame: All those little pieces burn very fast all at once, making for a small burst of flame.

Smurfs’s lore (what they say on the tv show) has them down as 3 apples high, but if they were really that big they’d kick the crap out of that cat in no time. I’m sure a small gang of them with sharp sticks could take down Gargamel too, but that would kinda kill the fun of the show.

why is that? are you telling me that gargamel and azrael can’t be slightly larger than what we humans expect them to be? oh, of course not. that would be ridiculous. but little blue men is perfectly acceptable.

don’t try to use your logic in the land of the smurfs. you will lose.

I remember the ol’ “heat, fuel, oxygen” combo from fifth grade science and fire prevention classes.

Even then I wondered, Heat? Really?

I realize a fire sort of makes its own heat, but if you were able to control the conditions – as in a laboratory --could you really “freeze a fire out” while the fuel and oxygen remained constant?

Little blue dudes with sharpened sticks…scary thought. Like midgit muppets on acid. They might begin to throw Molotov cocktails made of little drops of propane and engine grease in those little bottles of liquor sold in hotels, using kleenexes as the flaming rags. That would bring this little excursion right back to the OP in a rather interesting way.

Oh I think I will, even if Gargy and Azrael were larger than what we’re used to the size of an apple, as portrayed in the Smurf world, (you’re assuming I was talking about our apples) is still too large for any of them to be 3 apples high.

i don’t understand what you’re saying.

i assume nothing.

all i am saying is that the smurfs can be 3 apples high. there is no proof otherwise.

so there.

Sorry, I should preview my posts more often. Here’s why smurfs aren’t three apples high:

  1. The smurfs TV show has shown apples.

  2. The smurfs TV show says smurfs are three apples high.

  3. If you measure a smurf-world apple and a smurf you can plainly see that smurfs do not equal 3 apples.

Your assumption is that I’m comparing our real-world apples to cartoon smurfs, that’s just not true.

please provide the evidence showing that smurfs don’t equal 3 smurf land apples.

Naww I’ll let you watch the hours of mind-numbing reruns looking for the elusive smurf apple. Though there is a raging smurf height debate here.

Yes, you can put out a fire by cooling it off, without removing the fuel, or oxygen. Try it. Take a spool of heavy copper wire, coil it around a pencil for about an inch. Leave a long uncoiled portion to hold on to. Stretch it out a bit, to leave room for air to pass through, and lower it over a candle flame. Snuff.

Small fires won’t self sustain if they are not able to generate enough heat to raise the fuel to the ignition temperature. That varies some with the fuel, and the geometry of the fire. Very small fires are not able to heat enough fuel unless it is directly in the convection path. If it is, then it will heat the fuel enough to increase the rate of burn, and the fire will grow. That can be controlled, such as in a pilot light on a stove. The limits are still there, though.


i don’t want to hijack this thread anymore, but i went to that link. their arguments are based on silly logic much like your own.

smurfs can be 3 apples high.

anyway. i’ll let this thread go back to it’s original purpose.