is candle flame a plasma? (what even is plasma?)
i’ve always wanted to know what really is a flame… is it plasma? is it magic?
what is it? i know it’s a chemical reaction with the oxygen in the air.
In: 201
Some good answers on “what is a flame”, but if you really want to see plasma look up videos of Tesla coils or a Jacob’s ladder or one of those electric balls where you touch it and the electricity arcs to your hand (or if you’re lucky and live near a Science museum you may be able to go see them in person).
The glowy filaments you’re seeing aren’t electricity itself, it’s the air turning to plasma as electricity passes through it. In a similar vein, a lightning bolt while caused by electricity isn’t really electricity: the visible bit is plasma created from huge amounts of electricity passing through the sky
There are a lot of incorrect answers here.
A plasma is an ionized quasineutral gas. There is some level of background ionization in basically all gasses, and as you heat any gas, a larger and larger portion of electrons leave their nuclei. In gas in the atmosphere the ionization fraction is so low that quasi neutrality does not occur, and thus we don’t call those gases a plasma.
People think that plasmas have to be hot, but there are ways to manipulate gases with electric fields such that the gas temperature is room temperature while the electrons are preferentially heated. This is used in the manufacture of computer chips commonly.
Flames are technically plasmas, but they have very low ionization rates (much less than 1%). If you place a candle flame in a very strong magnetic field you can bend the flame or even extinguish it.
Source: had a homework assignment on this topic in a plasma course in graduate school.
The flame is the light and heat emitted from the chemical reaction. Oxygen combines with Hydrocarbons (Carbon and Hydrogen) to make Carbon Dioxide and Water, light and heat. The flame is the area where the reaction happens, and is hot and emits light making it visible.
> (what even is plasma?)
Well, the first thing to ask is what do people mean when they say ‘liquid’ or ‘gas’. And here the definitions you learned in elementary school are probably correct. When you say ‘gas’ what you mean is a bunch of material that follows the ‘rules’ for a gas. So you can predict how a specific gas by applying the general gas rules. ‘Plasma’ is a new state because it no longer follows ‘gas’ rules.
More specifically a plasma is a ‘gas’ where a sufficiently large number of ions exist to cause significant interactions with electromagnetic fields. Because of this new mode of interaction a lot of assumptions that are made for ‘gas’ don’t hold true for ‘plasmas’.
For example, bits of plasma can interact with each other at ‘long’ distances.
Imagine you wanted to predict the behavior of say a big cloud of helium gas on the atomic scale on a computer. You could arrive at a pretty decent solution by treating each helium atom as a ball, and just simulating those balls bouncing off each other when they ‘hit’. The nice thing about this is when you’re trying to simulate each atom you only need to worry about the handful of other atoms that are close enough to trigger a collision.
Now lets say you ionize some of those helium atoms to make an helium plasma. Now you have a mix that includes free electrons (e-) and helium ions He+. These are still going to ‘bounce’ the same way the neutral atoms did, but there is a significant complication. When you take an ion and cause it change direction/speed you create an EM field. EM fields will also interact with ions that are traveling in them. So now, when your He+ ion bounces off something you can’t just look at the few closes atoms to see what effect it has, you would need to look at how it effects all the ions in your simulation.
Similarly a ‘gas’ will not respond to an externally applied field, but a plasma will. This allows a plasma to conduct electricity. It also means that it’s possible for two plasmas to ‘couple’ at non-trivial distances (e.g. two plasmas can have significant effects on each other beyond ‘touching’ distance by shooting EM fields at each other).
I’m not a scientist or anything, but as my username applies I work at a shipyard and operate their nc plasma cutting equipment. Because I’m not knowledgeable on the actual science of it, I always see it as superheating a gas mixture via electricity to create a beam of plasma.
A flame is just the photons that you see, which are given off by hot gas and/or plasma. So in general, you could say that a flame is just hot gas and/or plasma that’s so hot that it starts emitting photons in the visible part of the spectrum. There are multiple ways to get a gas and/or plasma that hot, one of which is to combust something with oxygen in the air. This releases heat which then continues the combustion without any further intervention.
Apart from solid-state plasmas, such as those in metallic crystals, plasmas do not usually occur naturally at the surface of the Earth. For laboratory experiments and technological applications, plasmas therefore must be produced artificially. So no a flame is not a plasma. Fun Fact: In advanced semiconductor production they are now using EUV light to expose wafers. They have to generate that light by producing a plasma from liquid tin and hitting it with a laser.
Fire is a chemical reaction propagated through air, producing heart and light.
The colour of the flame is based on the temperature and also what’s burning.
I can burn propane and produce a yellow flame (lower energy) or if I mix it with oxygen (like in an oxy-propane torch) or could go bright blue and emit enough energy to give you arc eye.
Plasma, as previously said, is shed electrons. Normal fire , isn’t.
Source.. Fire trainer. UK fire service
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