What exactly is fire? I know it’s combustion of fuel, blah, blah…but what is it exactly? Is it purely energy? What state of matter is it? I suspect it’s highly energetic gases, whose energy state is so high that they emit light, and thus we see flame, with the hotter flames being higher in electromagnetic energy. But I’ve never seen any source explaining exactly what fire is. Can it be ionized? Can it be affected by magnetism? Gravity? –Wenhsingyu
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This letter shows why the world needs me. The explanations of fire in most standard reference works (not to put too fine a point on it) suck. The Encyclopaedia Britannica, for example, takes the following ineffectual stab: “rapid burning of combustible material with the evolution of heat and usually accompanied by flame.” No wonder people have lost faith in science. Time to let a professional show how it’s done. We’ll start by reviewing the defects of the EB definition.
(3) Evolution of heat. I don’t know what this is supposed to mean either.
(3) Body of incandescent gas. Flame defined. Most encyclopedia and dictionary definitions blow past this entirely, allowing persons such as yourself to imagine that fire is “pure energy” or similar nonsense. We say “body” because the gas has a characteristic structure and composition. We say “incandescent” because (a) it sounds scientific, (b) it means “luminous with intense heat,” precisely what we are attempting to convey, and (c) if the Teeming Millions are going to learn one vocabulary word today, by God “incandescent” should be it.
Is fire affected by gravity? Of course–gas has mass. Flame is shaped by convection, a function of gravity (hot air rises). In low- or zero-G environments, fire looks way different: a candle flame on the space shuttle isn’t yellow and tapered but blue and nearly spherical (see www3.cosmiverse.com/news/space/0802/space08220205.html).
