What is the Highest Temperature Possible?

[WoodenPupa]

I know there is absolute zero for the coldest temperature. What physical laws govern the upper limits of temperature? Or is there a limit at all? The fate of the moon might depend on an accurate answer so I need info fast!

 

[unipidity]

I have no idea what the upper temperature is, but there is one... relativistic effects are going to ensure that as you keep pumping heat into a medium, the velocity/temperature rise gets less and less.

v = root(3RT/M)

T = M * v^2 / (3R)

M/3R about equal to one. Hence T is about v^2. So 9^16 K?

Of course, this is a classical formula. So that probably doesnt really work at all. But its my best guess.

 

[bobsmith1492]

Originally posted by: WoodenPupa
The fate of the moon might depend on an accurate answer so I need info fast!

 

[cquark]

Originally posted by: WoodenPupa
I know there is absolute zero for the coldest temperature. What physical laws govern the upper limits of temperature? Or is there a limit at all? The fate of the moon might depend on an accurate answer so I need info fast!

There's no upper limit. For practical high temperatures, the Sun's core is about 15 million K and a supernova starts at around 5 billion K.

 

[onix]

This train of thought might lead to the right answer.

Another related question is, what is the temperature of a photon?

Originally posted by: unipidity
I have no idea what the upper temperature is, but there is one... relativistic effects are going to ensure that as you keep pumping heat into a medium, the velocity/temperature rise gets less and less.

v = root(3RT/M)

T = M * v^2 / (3R)

M/3R about equal to one. Hence T is about v^2. So 9^16 K?

Of course, this is a classical formula. So that probably doesnt really work at all. But its my best guess.

 

[DrPizza]

Originally posted by: WoodenPupa
I know there is absolute zero for the coldest temperature. What physical laws govern the upper limits of temperature? Or is there a limit at all? The fate of the moon might depend on an accurate answer so I need info fast!

Oddly, you're correct about the fate of the moon. When our wonderful sun eventually becomes a supernova, it's going to destroy the moon.

My question: Why are you concerned about the moon and not the earth??

edit: except the "info fast!" part isn't accurate. It's going to be at least a dozen years or so.

 

[f95toli]

It all depends on how you define temperature, and there are several possible definitions. In classical physics temperature is a parameter used to calculate probability distributions and you can relate it to the kinectic energy of particles. However, this does not really work in modern physics but the concept of temperature is still used.

When people talk about the temperature of a photon they can mean two different things: The temperature of the surface that emitted the photon (a 300K surface will emit 300K photons, you can relate the temperature of the surface to the emitted energy using Stefan-Boltzmanns law which tells us that the energy is proportional to T^4)
OR the energy carried by the photon which depends on the frequency, the energy will be of the order of T=h*f/kb, h Planck's constant and, f frequency and kb Boltzmann's constant.

 

[cquark]

Originally posted by: DrPizza

Originally posted by: WoodenPupa
I know there is absolute zero for the coldest temperature. What physical laws govern the upper limits of temperature? Or is there a limit at all? The fate of the moon might depend on an accurate answer so I need info fast!

Oddly, you're correct about the fate of the moon. When our wonderful sun eventually becomes a supernova, it's going to destroy the moon.

The Sun doesn't have enough mass to attain temperatures above the 100 million K required for helium fusion, so there won't be a supernova. However, during helium fusion, it will become a red giant with a radius near that of the Earth's orbit, so the Earth/Moon system may be consumed in that event.

 

[ggjb]

In regards to the temperature of photons.

Note that photons do have a specific amount of energy associated with them, depending on the frequency and wavelength of the electromagnetic wave.

After doing a little research through Google, I found this this.

In regards to the OP.

There doesn't appear to be any feasible limit, although in reality there is obviously a defined limit.

 

[WoodenPupa]

"Oddly, you're correct about the fate of the moon. When our wonderful sun eventually becomes a supernova, it's going to destroy the moon. "

True, quite true.

"My question: Why are you concerned about the moon and not the earth??"

Ah, but why *on Earth* do you assume I'm not concerned about the Earth, old boy! You see, I've got the Earth all figured out, so my plans for it are already in order. Not enough attention has been paid to our sweet satellite the last couple of decades and now I'm personally paying the price!

"edit: except the "info fast!" part isn't accurate. It's going to be at least a dozen years or so. "


Oh. Cool, I've got time for my tinfoil idea then. Or at least to vaccuum the poor thing.

Wait a minute, is our sun definitely going to supernova? I thought it wasn't big enough.

 

[WoodenPupa]

The Sun doesn't have enough mass to attain temperatures above the 100 million K required for helium fusion, so there won't be a supernova. However, during helium fusion, it will become a red giant with a radius near that of the Earth's orbit, so the Earth/Moon system may be consumed in that event.[/quote]

Oh okay, that's what I thought. Dr. Pizza had me worried!

 

[DrPizza]

Originally posted by: cquark

Originally posted by: DrPizza

Originally posted by: WoodenPupa
I know there is absolute zero for the coldest temperature. What physical laws govern the upper limits of temperature? Or is there a limit at all? The fate of the moon might depend on an accurate answer so I need info fast!

Oddly, you're correct about the fate of the moon. When our wonderful sun eventually becomes a supernova, it's going to destroy the moon.

The Sun doesn't have enough mass to attain temperatures above the 100 million K required for helium fusion, so there won't be a supernova. However, during helium fusion, it will become a red giant with a radius near that of the Earth's orbit, so the Earth/Moon system may be consumed in that event.

You're right. Brain fart for a second. But, regardless, earth is going to get "gobbled up" by the sun.

 

[onix]

You may not need a supernova to create the high temps of fusions. Sonoluminescence anyone?

http://www.nytimes.com/2005/03/15/science/15soni.html?

Originally posted by: WoodenPupa

The Sun doesn't have enough mass to attain temperatures above the 100 million K required for helium fusion, so there won't be a supernova. However, during helium fusion, it will become a red giant with a radius near that of the Earth's orbit, so the Earth/Moon system may be consumed in that event.

Oh okay, that's what I thought. Dr. Pizza had me worried!

[/quote]

 

[TuxDave]

Originally posted by: DrPizza

Originally posted by: cquark

Originally posted by: DrPizza

Originally posted by: WoodenPupa
I know there is absolute zero for the coldest temperature. What physical laws govern the upper limits of temperature? Or is there a limit at all? The fate of the moon might depend on an accurate answer so I need info fast!

Oddly, you're correct about the fate of the moon. When our wonderful sun eventually becomes a supernova, it's going to destroy the moon.

The Sun doesn't have enough mass to attain temperatures above the 100 million K required for helium fusion, so there won't be a supernova. However, during helium fusion, it will become a red giant with a radius near that of the Earth's orbit, so the Earth/Moon system may be consumed in that event.

You're right. Brain fart for a second. But, regardless, earth is going to get "gobbled up" by the sun.

That's why we gotta bulid lots of really big rockets to push the earth away!

 

[WoodenPupa]

Well 9^16 K is a pretty gigantic temperature unipidity. I wonder what that would do to a star system.

Now a related question is, isn't the universe in a state of "cooling off" since the big bang? I mean, what was the temperature of the big bang? Or is that even a relevant question, as explosive power may not be related to temperature?

 

[everman]

Maybe a star that is so massive that it is right on the edge of collapsing into a black hole?

 

[thunderroller]

there is not limit for energy to be stored in a point.so no limit of temp

 

[bobsmith1492]

At some point, for particles to have any more energy, wouldn't they have to be moving faster than the speed of light? So in essence, isn't the speed of light a limiting factor?

 

[Emultra]

Originally posted by: WoodenPupa
Well 9^16 K is a pretty gigantic temperature unipidity. I wonder what that would do to a star system.

Now a related question is, isn't the universe in a state of "cooling off" since the big bang? I mean, what was the temperature of the big bang? Or is that even a relevant question, as explosive power may not be related to temperature?

I read an article about the temperature a fraction of a second after the Big Bang. It was zillions of zillions.

 

[BitByBit]

Intense concentrations of energy can tear space-time.
This is what happens when a star colapses under the strain of its own gravitational field, causing a black hole.
Since heat is a form of energy, I'd expect the same thing to occur.

 

[WoodenPupa]

Originally posted by: bobsmith1492
At some point, for particles to have any more energy, wouldn't they have to be moving faster than the speed of light? So in essence, isn't the speed of light a limiting factor?

I still don't have a solid answer to the question. Some people are saying there is no limit, some are talking about photon temperature, some are saying there is definitely a limit. Surely we can't exceed the temperature of the big bang can we?

 

[f95toli]

AS I have already written: It depends on you definition of temperatures.

There are MANY possible ways to define temperature, some will definitions give you a "maximal temperature" and some won't.

So the question is meaningless unless you specify what you mean.

 

[zugzoog]

Originally posted by: bobsmith1492
At some point, for particles to have any more energy, wouldn't they have to be moving faster than the speed of light? So in essence, isn't the speed of light a limiting factor?

As a particle approaches the speed of light relative to anothe object , its mass (and hence energy) increases according to the Lorentz transformation. Translated; as the particle approaches the speed of light its energy approaches infinity.

So the particle does not have to exceed the speed of light to acheive infinte temperature.

 

[bobsmith1492]

Thanks zugzoog; I didn't know that.

 

[f95toli]

Originally posted by: zugzoog
So the particle does not have to exceed the speed of light to acheive infinte temperature.

So? Again, what definition of temperature are you using?
If you just do a direct "translation" between energy and temperature (by dividing by kb) then this is true, however in many other cases (statistics) temperature is more related to the speed of the particles and then there is a maximum temperature set by c.