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Old 09-12-2012, 12:11 AM
tv43 tv43 is offline
Join Date: Sep 2012
Fire actually can be ionized; via "What exactly is fire?"

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.

ETA: Link to column - --Rico

Last edited by Rico; 09-12-2012 at 01:20 AM.. Reason: add link to column
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Old 09-12-2012, 04:01 AM
aldiboronti aldiboronti is online now
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Originally Posted by tv43 View Post
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.

Last edited by aldiboronti; 09-12-2012 at 04:03 AM..
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Old 09-12-2012, 08:16 PM
John W. Kennedy John W. Kennedy is offline
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Also, “fire” and “ionization” really belong to different universes of discourse.
John W. Kennedy
"The blind rulers of Logres
Nourished the land on a fallacy of rational virtue."
-- Charles Williams. Taliessin through Logres: Prelude
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Old 09-13-2012, 01:10 PM
Qadgop the Mercotan Qadgop the Mercotan is offline
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Originally Posted by aldiboronti View Post
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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Old 09-14-2012, 07:53 PM
jinni73 jinni73 is offline
Join Date: Jul 2011
I assumed fire was the sun
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Old 09-23-2012, 03:48 AM
Derleth Derleth is offline
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Originally Posted by jinni73 View Post
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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Last edited by Derleth; 09-23-2012 at 03:49 AM..
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Old 09-23-2012, 03:58 AM
Derleth Derleth is offline
Join Date: Apr 2000
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.
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