4
$\begingroup$

Magical fire is often depicted as flames. To get fire and flames the right mixture of oxygen, fuel and heat is needed. Assuming that the magic only provides the heat, there are only two chemical reactions that could explain the flames. The nitrogen in the air reacts with oxygen to form nitric oxide:

$$\mathrm{N}_2 + \mathrm{O}_2 \to 2\mathrm{NO}$$

and nitrogen dioxide:

$$\mathrm{N}_2 + 2\mathrm{O}_2 \to 2\mathrm{NO}_2$$

Judging by the fact that we're all still alive, it must be quite hard to get these reactions started. What does this tell us us about fire magic with flames? How hot is it? What color would the flames have? Is the reaction endo- or exothermic?

$\endgroup$
  • $\begingroup$ A flame is just very hot air, nothing more. $\endgroup$ – AlexP Jan 2 at 0:08
  • $\begingroup$ If it IS a chemical reaction in the atmosphere between nitrogen and oxygen, it pretty much has to be endothermic. If it's exothermic, it'll be self-sustaining and will spread across the entire world and kill everyone. $\endgroup$ – Ryan_L Jan 5 at 1:52
6
$\begingroup$

You don't necessarily need a chemical reaction to have visible flames. Most of the light released by fire is due to black body radiation, the heat given off by anything hot. The color of black body radiation depends on exactly how hot the material is. Red is cool, blue is hot. This is true regardless of what the material is. Iron glows the same color as sodium and as helium if all 3 are at 1000 degrees. The common shape and motion of flames is just due to convection currents. Again, all you need is heat, regardless whether it comes from a chemical reaction, a laser, or magic.

Some chemical reactions do produce their own colors, but I can't help you there. Maybe someone else can.

|improve this answer|||||
$\endgroup$
2
$\begingroup$

Magical fire could be “simpler” in concept. Magic takes oxygen and sunders it into 8 hydrogen atoms. That process itself takes magical energy from the caster. But one you have free hydrogen (H) atoms, science takes over: the hydrogen atoms react with the remaining oxygen (O2) almost instantly to produce a huge dump of energy and water (H2O) as a byproduct.

Hydrogen burning in air burns at about 2000 deg Celsius (very exothermic). Hydrogen burns with a pale blue flame that is nearly invisible in daylight. The flame may appear colored if there are impurities in the air.

https://en.wikipedia.org/wiki/Hydrogen_fuel

|improve this answer|||||
$\endgroup$
  • $\begingroup$ Why not use the massive amount of energy required to split the oxygen atoms and use it directly to heat the air? The energy released by a chemical reaction is vastly inferior to the energy required to break the oxygen nucleus. $\endgroup$ – AlexP Jan 1 at 22:50
  • $\begingroup$ @AlexP I assume magic does things science can’t, like cheap fission. Like some sort of mechanical advantage. My usual approach to questions like these is to identify the physical effect that magic contributes that science cannot that does what the questioner wants. In this case, produce realistic flame from non-flammable source in a way consistent with chemistry. $\endgroup$ – SRM Jan 1 at 23:45
  • $\begingroup$ @AlexP put another way: science needs lots of energy to split atoms. Magic doesn’t cost that much to do the same, for whatever reason. $\endgroup$ – SRM Jan 1 at 23:47
  • $\begingroup$ All I'm saying is that a very small fraction of the amount of energy required to split oxygen nuclei would do quite well to heat the air to the temperature of a flame... A flame is just very hot air, after all. $\endgroup$ – AlexP Jan 2 at 0:07
  • $\begingroup$ @AlexP But what I’m saying is the caster doesn’t have enough energy to split an atom. Sure, if they had that energy, use it directly. But that’s an immense amount of energy. Magic subs that out. Some small amount of magic — cantrip level — is all that is needed to create flame. $\endgroup$ – SRM Jan 2 at 1:34
0
$\begingroup$

I am always interested in sciences related to magic in modern media. I actually read a book where the author demonstrated physical laws inherent in engineering and how the magic of the world seems to go against those basic rules and no one knows why. Though I will kind of say that you may not need a chemical reaction for fire magic, the movie the Sorcerer’s Apprentice demonstrated fire magic as the result of friction. I will say I think that line of thinking could open up a whole host of possibilities like sticking to the walls like Spider-Man, or have your enemies fail and fall like their trying to walk on an ice skating rink, just some food for thought. As for how hot magic fire can go, sorry as I can tell that always depends on how much juice you put into it. Hope the answers you get keep The creative juices flowing.

|improve this answer|||||
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.