# Fire actually can be ionized; via "What exactly is fire?"

**URL:** https://boards.straightdope.com/t/fire-actually-can-be-ionized-via-what-exactly-is-fire/634472
**Category:** Cecil's Columns/Staff Reports
**Created:** [September 12, 2012, 5:11am UTC](https://boards.straightdope.com/t/fire-actually-can-be-ionized-via-what-exactly-is-fire/634472 "2012-09-12T05:11:00Z")
**Posts on this page:** 7
**Page:** 1

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### Author: ![tv43](https://avatars.discourse-cdn.com/v4/letter/t/7ba0ec/32.png) [@tv43](https://boards.straightdope.com/u/tv43)
#### Post date: [September 12, 2012, 5:11am UTC](https://boards.straightdope.com/t/fire-actually-can-be-ionized-via-what-exactly-is-fire/634472/1 "2012-09-12T05:11:00Z")

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In “What exactly is fire?”, part of Wenhsingyu’s question is:

> [@](#):
>
> Can it [fire] be ionized?

Cecil answers:

> [@](#):
>
> Can fire be ionized? Is it affected by magnetism? Not so’s you’d notice. You’re thinking of plasma, which is ionized (and thus electromagnetically reactive) gas, often described as the fourth state of matter. You see it in welding arcs, lightning bolts, and the sun. Ordinary fire isn’t plasma.

While almost all of Cecil’s answer is correct as usual, fire _can_ be ionized, and used as both a rectifier and an amplifier with the addition of electrodes. Flame rectifiers even make use of electrodes coated with salt in order to inject additional ions into the flame.  
Source:

> **[Flame Triode With Gain.](http://www.sparkbangbuzz.com/flame-amp/flameamp.htm)**

_ETA: Link to column - [What exactly is fire? - The Straight Dope](http://www.straightdope.com/columns/read/2425/what-exactly-is-fire) --Rico_

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### Author: ![aldiboronti](https://avatars.discourse-cdn.com/v4/letter/a/9fc348/32.png) [@aldiboronti](https://boards.straightdope.com/u/aldiboronti)
#### Post date: [September 12, 2012, 9:01am UTC](https://boards.straightdope.com/t/fire-actually-can-be-ionized-via-what-exactly-is-fire/634472/2 "2012-09-12T09:01:05Z")

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> [@tv43](#):
>
> While almost all of Cecil’s answer is correct as usual, fire _can_ be ionized …

So which is the incorrect part? Note that Cecil does not assert that fire cannot be ionized, he simply says ‘not so’s you’d notice’, which is true.

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### Author: ![John\_W.Kennedy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_w.kennedy/32/1031_2.png) [@John\_W.Kennedy](https://boards.straightdope.com/u/John_W.Kennedy)
#### Post date: [September 13, 2012, 1:16am UTC](https://boards.straightdope.com/t/fire-actually-can-be-ionized-via-what-exactly-is-fire/634472/3 "2012-09-13T01:16:34Z")

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Also, “fire” and “ionization” really belong to different universes of discourse.

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### Author: ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)
#### Post date: [September 13, 2012, 6:10pm UTC](https://boards.straightdope.com/t/fire-actually-can-be-ionized-via-what-exactly-is-fire/634472/4 "2012-09-13T18:10:46Z")

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> [@aldiboronti](#):
>
> So which is the incorrect part? Note that Cecil does not assert that fire cannot be ionized, he simply says ‘not so’s you’d notice’, which is true.

Yeah, you don’t have too many ions in the fire.

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### Author: ![jinni73](https://avatars.discourse-cdn.com/v4/letter/j/ad7895/32.png) [@jinni73](https://boards.straightdope.com/u/jinni73)
#### Post date: [September 15, 2012, 12:53am UTC](https://boards.straightdope.com/t/fire-actually-can-be-ionized-via-what-exactly-is-fire/634472/5 "2012-09-15T00:53:03Z")

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I assumed fire was the sun

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### Author: ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)
#### Post date: [September 23, 2012, 8:48am UTC](https://boards.straightdope.com/t/fire-actually-can-be-ionized-via-what-exactly-is-fire/634472/6 "2012-09-23T08:48:34Z")

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> [@jinni73](#):
>
> I assumed fire was the sun

No, the Sun is a miasma of incandescent plasma.

Fire, on the other hand, is a kind of exothermic oxidation reaction.

The reaction that makes the Sun bright is _nuclear_: It involves atomic nuclei physically slamming together at extremely high speeds and liberating massive amounts of energy. This destroys atoms and creates new ones.

The reaction you see when a candle burns is _chemical_: It involves valence shell electrons jumping from atom to atom and liberating rather small amounts of energy in the process. The atoms themselves are largely unchanged.

I like to think of atoms as small stones surrounded by cotton candy: The cotton candy is the electron cloud, the small stone is the nucleus. A chemical reaction is all about the edges of the ‘cotton candy’ of two or more atoms touching, whereas a nuclear reaction involves the little stones changing in some fashion.

(Fun fact: Most of what you think of as solid matter is really empty space. Very little of the volume of an atom is filled by the nucleus, leaving the electrons as tiny little particles buzzing around in a relatively huge empty volume. How empty? Well, the nuclear reactions in the Sun produce tiny little electrically neutral particles called ‘neutrinos’; approximately 65 billion of the little buggers pass straight through every square centimeter of the side of the Earth facing the Sun every second, like they were peas being shot through a thin fog. The majority of them never interact with anything.)

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### Author: ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)
#### Post date: [September 23, 2012, 8:58am UTC](https://boards.straightdope.com/t/fire-actually-can-be-ionized-via-what-exactly-is-fire/634472/7 "2012-09-23T08:58:29Z")

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Of course, since most of the neutrinos never interact with anything, they come right out the other side of the Earth, so they pass through the side of the Earth facing directly away from the Sun at very, very close to the same rate.

Also: Neutrinos have mass. They have to, or else we can’t explain how many we actually observe the Sun producing. So this isn’t quite the same as radio waves passing through; it’s tiny little hunks of matter finding a path right in between the solid parts of all of your atoms, all of the Earth’s atoms, and so on.
