Absolute zero? So is there an absolute <insert high temperature here>?

Question

I've always wondered this. I understand how the concept of an absolute zero works. But isn't it possible for the molecules of something to move too fast? For example, what if a substance was heated up so much that the speed of the molecules approached the speed of light?

Answer 1

You almost answered your own question.
According to Einstein, moving mass at the speed of light is not possible because it would take infinite energy to do so.
Unless you have an infinite energy supply handy, you just defined the theoretical temperature limit.
No matter how you address the question, there is no practical absolute maximum temperature, but limits are implicit in physics.
How do you contain a molecule to direct energy to it if it is too hot to be contained?
Nuclear particle accelerators using magnetic fields may help but the limits for other situations must be acknowledged.
Who knows what the future holds in the field of particle physics?

Answer 2

There is no limit on kinetic energy, since the momentum of a particle can increase indefinitely, even under relativity - the kinetic energy of a particle under relativity is given by:
E = mc^2/(1-c^2/v^2) - mc^2
As v asymptotically approaches c, E approaches infinity. So, relativity does not limit temperature in that sense.

The highest theoretical temperature is usually given to be the "Planck temperature", 1.42x10^32 K. At this temperature, particles are moving so fast that they collapse into a black hole. That is to say, our existing physics can't tell us anything beyond this point.

Answer 3

The temperature scales are defined so that temperature increases as a linear function of added heat. If added heat can approach infinity, so can temperature. So there is no absolute hot.

Answer 4

Absolute Zero (Absolute Minimum ?).
Think of the molecules in the sun and their temperature, I doubt if there's any upper limit like 'Absolute Maximum'...!!??

Good question though.

Answer 5

Good question! I think if temperature reaches such a high level it will cause fusion to take place, in order to go higher the force of a gravitational field would be needed to generate more heat.