Maximum temperature?

[thelordemperor]

The coldest somethign can get, AFAIK is 0ºK.

So how hot can somethign be? Is there a limit or a point at which the atoms just become energy? Or something else?

 

[AyashiKaibutsu]

Coldness isn't really something it's just a measure of the lack of heat. There is no limit to heat. Well for there to be a limit, you'd have to assume the total amount of energy in the universe is constant (seems likely) and bring it all together to get the maximum temperture.

 

[silverpig]

As you heat up a solid it will liquify, then boil. Then the atoms will have enough energy that they will knock off their electrons thermally. You'll have a soup of electrons and nuclei floating around with nothing really bound to anything else. This is a plasma.

You can go even hotter and the nuclei will split up and the protons and neutrons will actually break apart as well into a soup of gluons and quarks. There is some difficult physics to explain this gluonic-quark state, and I'm quite sure no one could tell you exactly what happens. This only occurs at temperatures of hundreds of billions of degrees. After that no one really knows. Right now I can't think of a reason why there would be an upper bound theoretically. Physically though there wouldn't be enough energy to accelerate the particles any further so yeah, there is a physical max temperature. There may be some more physics that comes into play later that we just don't know yet (around 10^18 GeV something interesting should happen as that's where gravity is supposed to unify with the other forces... so maybe we'd have a graviton soup?).

 

[TuxDave]

Hmm... I'm beginning to see what you're getting at. So if we introduce enough energy into an atom, we should be able to start breaking bonds. I guess you're asking, how much energy and how many bonds must we break before there's no more that we know of?

 

[Geniere]

In nature, and after the Big Bang, I think only neutron star formation can achieve temperatures in the billions of degrees. Free quarks may exist shortly after the collapse.

 

[Chaotic42]

Originally posted by: silverpig
As you heat up a solid it will liquify, then boil. Then the atoms will have enough energy that they will knock off their electrons thermally. You'll have a soup of electrons and nuclei floating around with nothing really bound to anything else. This is a plasma.

You can go even hotter and the nuclei will split up and the protons and neutrons will actually break apart as well into a soup of gluons and quarks. There is some difficult physics to explain this gluonic-quark state, and I'm quite sure no one could tell you exactly what happens. This only occurs at temperatures of hundreds of billions of degrees. After that no one really knows. Right now I can't think of a reason why there would be an upper bound theoretically.

Wouldn't there be a limit as the speed of non-zero mass particles approaches c?

 

[glugglug]

Temperature is a measure of KE per molecule. So at any given temperature, lighter molecules are moving faster than heavier ones.

As the speed of the molecules approaches c, their relativistic mass increases. The infinite mass per molecule will allow infinite temperature.

 

[imported_StormGod]

I sat in on a lecture given by one of the physicists who got the Large Hadron Super Collider built in upstate NY. It was on quark-gluon plasma, which existed for the first 100,000 years after the Big Bang (assuming our models are correct, huge assumption). After 100,000 years the universe cooled enough for protons, neutrons, and electrons to form. There is only so much energy in the universe, so bringing it all together into an infinitely small space would result in infinite temperature.

Regarding the first comment on the coldest temperature, yes by definition the "coldest" something can get is absolute zero. As correctly mentioned, there is no such thing as ?cold?, only a lack of heat. To achieve absolute zero, 0K (don't use degrees with Kelvin, scientists don't) requires a complete lack of both heat and entropy which is basically disorder. Therefore, a material at 0K would have no atomic motion and be in a perfect crystalline state. This, however, violates the Heisenberg uncertainty principle which states that one cannot know both the position and velocity of an object simultaneously. We have gotten down to 10^-9 K in labs with lasers. This creates an interesting sixth state of matter called a Bose-Einstein condensate (the other five being solid, liquid, gas, plasma, and filaments).

 

[imported_Sasha]

Originally posted by: thelordemperor
The coldest somethign can get, AFAIK is 0ºK.

So how hot can somethign be? Is there a limit or a point at which the atoms just become energy? Or something else?

There is no 'degrees' Kelvin. Its just 0K.

Any answer that is offered on how hot something can get will be limited by the tools, and knowledge, of our time.

 

[Witling]

Silverpig, a small correction to your generalization that, "s you heat up a solid it will liquify, then boil." Toss some flour or an egg into a pan and heat it up. No boiling! Some things liquify. Some things don't. Some things, like carbon dioxide, liquify only under special conditions not found at the surface of the earth.

 

[imported_StormGod]

Witling is correct, some materials sublimate. Sublimation is the transition from solid phase directly to gaseous phase without first becoming a liquid. This can occur when a solid at a pressure below its triple point is heated at constant pressure (isobaric heating) or when a solid at a temperature below its triple point experiences a constant temperature decrease in pressure (isothermal expansion). This sort of thing is covered in thermodynamics or physical chemistry courses. Sublimation can be brought about in a more complicated manner but these two simple examples seem to be sufficient here. Helium is another material that will not liquefy under most circumstances. It needs to be cooled to around 10K and pressurized to several hundred atmospheres in order to liquefy. When it does it forms a very interesting material called a superfluid. Superfluids have viscosities of 0, meaning they have no resistance to flow.

 

[DrPizza]

If you want to read about something really really cool (no pun intended) and exotic, read about superfluids and check out the pics..
here's one source

 

[silverpig]

Originally posted by: StormGod
Witling is correct, some materials sublimate. Sublimation is the transition from solid phase directly to gaseous phase without first becoming a liquid. This can occur when a solid at a pressure below its triple point is heated at constant pressure (isobaric heating) or when a solid at a temperature below its triple point experiences a constant temperature decrease in pressure (isothermal expansion). This sort of thing is covered in thermodynamics or physical chemistry courses. Sublimation can be brought about in a more complicated manner but these two simple examples seem to be sufficient here. Helium is another material that will not liquefy under most circumstances. It needs to be cooled to around 10K and pressurized to several hundred atmospheres in order to liquefy. When it does it forms a very interesting material called a superfluid. Superfluids have viscosities of 0, meaning they have no resistance to flow.

He was talking more about complex molecular compounds breaking down before melting. Regardless, these are both side points. I was just illustrating where plasmas and gluon-quark states sit in relation to solids, liquids and gases.

 

[imported_StormGod]

Originally posted by: DrPizza
If you want to read about something really really cool (no pun intended) and exotic, read about superfluids and check out the pics..
here's one source

Cool link!

 

[jagec]

Originally posted by: DrPizza
If you want to read about something really really cool (no pun intended) and exotic, read about superfluids and check out the pics..
here's one source

heh, yeah, back when they were first starting to liquify helium, the first science group to do it (IIRC) accidentally "discovered" superfluids...they lost all their helium through some tiny crack or something in the equipment.

At least, that's what my prof told me.

 

[willfreund]

When it starts melting you have a problem. For computer parts every things is plated and alot is alloys .So you have to look at the box

 

[BespinReactorShaft]

Originally posted by: StormGod
sixth state of matter called a Bose-Einstein condensate (the other five being solid, liquid, gas, plasma, and filaments).

What exactly is this "filaments" state?

 

[silverpig]

Originally posted by: ming2020

Originally posted by: StormGod
sixth state of matter called a Bose-Einstein condensate (the other five being solid, liquid, gas, plasma, and filaments).

What exactly is this "filaments" state?

I've not heard of it either, but I do know of a gluon-quark state. And I'm pretty sure there's another state way down on the temperature scale where some things aren't quite liquids but aren't quite solids either.

 

[kkeennyy]

I think maximum temperature is limited by the available energy in (the system of) the universe less the energy required to constiture the matter being heated. Perhaps a little less for the process or heating, and the agent if applicable, etc.

 

[biostud]

I think I once heard that when the particles reaches the speed of light maximum temperature is reached.

 

[silverpig]

Originally posted by: biostud666
I think I once heard that when the particles reaches the speed of light maximum temperature is reached.

No.

1. they can't actually reach the speed of light
2. you can always add more energy to the particle and give it more kinetic energy.

 

[imported_StormGod]

Particles (with mass) can't reach the speed of light that requires infinite energy. This has already been pretty well covered here so I won't waste anyone's time with the details, but accelerating an electron to the speed of light requires more energy than there is in the universe.

Also temperature isn't a real thing its purely artificial and for our convience. A single particle does not have a temperature you need collisions to have temperature. We should be careful not to confuse temperature and energy which are very different things. This distinction was covered very breifly in my graduate-level thermo class and was not discussed at all in my undergraduate-level thermo classes or p-chem classes so I really don't expect many of the readers here to have already known this.

 

[DainBrammage]

The hotest something can get? My money is on a supernova, were talking a sun fusing hydrogen (3billion plus degrees F) to begin with and then fusing all available fuel (elements) until Iron is reached on the periodic chart. with each tracnsformation the sun gets more and more dense and then when all the fuel is spent and nothing but Iron remains a catclysmic explosion takes place thea simutaneouly fuses the iron and in a chain reacton produces every element on the periodic table.

 

[glugglug]

THinking about it some more, I take back what I said about infinite temperature being possible. At a certain point, due to relativistic mass increase and size contraction, the individual atomic nuclei will become micro-singularities (black holes).

 

[Chaotic42]

1.4e32K is the Planck Temperature, which is the temperature of the universe at one Planck Second (5.4e-44s) after the big bang.

I suppose that would make it the largest meaningful temperature.