Thinker"What Is Fire? Exploring the 4th State of Matter

In summary: Each material has a different pressure-volume relationship, different heat capacity, and different free energy. They're not all the same, they're all different states of matter.
  • #1
wirefree
105
21
If every thing is either 'solid', 'liquid' or 'gas' then what is fire?


wirefree
 
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  • #2
What would your answer be?

Looks to be a combination of either solid+gas (solid fire) or liquid+gas (liquid fire). Depends on what fuel material is burning:

http://en.wikipedia.org/wiki/Fire

Remember the fire triangle -- heat, fuel, oxygen.
 
  • #3
First, everything is not solid, liquid, or gas. There are many other forms of matter, such a plasma. The flame you see is, in fact, a partial plasma. It's composed of gas atoms, some of which have electrons stripped from them. The recombination of these free electrons with the atoms is what produces the visible light.

- Warren
 
  • #4
Oh, good point! I spaced the plasma part of it. Kind of like your avatar...:biggrin:
 
  • #5
chroot said:
First, everything is not solid, liquid, or gas. There are many other forms of matter, such a plasma.

I know about solids, liquids, gasses and plasmas. What other forms of matter exist?
 
  • #7
Einstein-Bose condensates, degenerate matter (such as in a neutron star)... but I'm not sure if they're really considered 'states' in the official sense of the term.

edit: Holy cats, Chroot. That list is making my eyes hurt.
 
  • #8
Danger said:
Einstein-Bose condensates, degenerate matter (such as in a neutron star)... but I'm not sure if they're really considered 'states' in the official sense of the term.

Of course they are. Even simple things like their pressure-volume relationships are distinctly different than 'ordinary' states like gas and liquid.

- Warren
 
  • #9
chroot said:
First, everything is not solid, liquid, or gas. There are many other forms of matter, such a plasma. The flame you see is, in fact, a partial plasma. It's composed of gas atoms, some of which have electrons stripped from them. The recombination of these free electrons with the atoms is what produces the visible light.

- Warren

Just don't remember being taught that in school. :grumpy:

Appreciate that, chroot!
 
  • #10
Wow I have a feeling most people here know about the things on the list, but just didn't consider them to be categorized as their own state of matter! Thats definitely what i thought of Amorphous solids.
 
  • #11
It's not a very useful question - it's a bit like "how many seas are there".
I would say that there are solids,liquids,gases.
Once you start adding Bose-Einstein condensates etc then you have to pretty much have a different state for each material. A metal is different from a glass so are they different states of matter?
I would argue that even plasma is just a charged gas - it behaves differently to a gas but then so does a magnetised solid.
 
  • #12
Again, plasma is a distinct state of matter, because several physical quantities (like heat capacity) change abruptly when moving from the gas state to the plasma state. Futhermore, there's a jump in free energy between a gas and a plasma -- you have to add energy to dissociate the atoms.

- Warren
 
  • #13
There's also a pretty impressive change when helium goes superfluid!
I don't know if plasma is more fundamental jus because it was discovered earlier.

My point was that 'states of matter' is not as useful a distinction as it used to be now that we know about macroscopic quantum effects.
It's a bit like the 'number of planets' question - do you count every rock, is Pluto a planet - arguing about where the boundary lies doesn't really tell you much about orbital mechanics.
 

1. What is the 4th state of matter?

The 4th state of matter is called plasma. It is a highly energized state of matter that is formed when gas is heated to extremely high temperatures or exposed to strong electromagnetic fields.

2. How is plasma different from gas?

Plasma and gas are both made up of atoms and molecules, but in plasma, the atoms and molecules are highly ionized, meaning they have lost or gained electrons. This gives plasma unique properties, such as the ability to conduct electricity and respond to magnetic fields.

3. How is plasma created in nature?

Plasma can be found in nature in the form of lightning, the sun, and other stars. It is also created during certain natural disasters, such as volcanic eruptions and lightning strikes.

4. How is plasma used in technology?

Plasma has many important technological applications, including in plasma televisions, fluorescent lights, and fusion energy research. It is also used in industrial processes such as cutting, welding, and etching.

5. Is plasma dangerous?

Plasma can be dangerous if not handled properly, as it is highly reactive and can cause burns and damage to cells. However, in controlled environments and applications, plasma is not typically harmful to humans.

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