/sci/ - Science & Math

[Anonymous No.9683389]

Minimum achievable temperature. Is it possible to prove that a specific temperature is impossible to achieve for a given system? Would the minimum temperature be given by planck's constant divided by boltzman constant?

[Miniature Spacecraft No.9683397]

>>9683389
Temperature = agitation

No agitation = minimum achievable temperature

[Anonymous No.9683402]

>>9683397
But the smallest amount of allowed energy is given by planck's constant right? So what would it mean for the energy spacing to be less than this. For example I have found the energy spacing for a particle in a 3d box to be on the order of 10^-42 for states near the ground state.

[Anonymous No.9683444]

>>9683389
>Is it possible to prove that a specific temperature is impossible to achieve for a given system
Yes, 0 K

[Anonymous No.9683475]

>>9683402
Energy is directly related to heat. Temperature is a different concept altogether

[Anonymous No.9683492]

>>9683397
But it's physically impossible to have a system with no molecular agitation

[Miniature Spacecraft No.9683548]

>>9683492
>impossible
for now

[Anonymous No.9683565]

>>9683389
You guys need to take some thermodynamics
It's totally possible to remove all the "agitation" from a system - just remove all the atoms.
The problem then depends on how you define temperature.
Say you want to know the "temperature" of a single atom. What are you making reference to? If you say the speed of the atom, then your temperature isn't Lorentz invariant, it could be absolute 0 in some frame.
If you remove as much energy as possible from a system of fermions, you will still be left with at least the Fermi energy of the system, which is determined by the number of particles. This can be related to Planck's constant. (>>9683402
) However, the energy of a system is not the same as the temperature.

If you want a good definition of temperature, use enthalpy and entropy. Absolute zero is defined as the state where entropy and enthalpy is the absolute minimum it could be. At absolute zero, fundamental particles have minimum energy. That doesn't mean they have no energy, they are just in their zero-point energy state. Absolute zero is an achievable temperature, although it has not yet been measured or produced because it's extremely difficult. For example, if you have a state at absolute zero, how do you observe it? A photon could end up exciting the state of the particle, putting it in a higher energy state.

Technically, there are ways to achieve negative temperatures (below absolute 0) through processes involving systems which continue to emit energy after they have technically reached their lowest energy potential. This means you need to have a slightly different understanding of temperature than you're probably used to. This is probably too complicated to explain in a post on 4chan, but if you want look it up, it was done at the University of Munich.

[Anonymous No.9684347]

>>9683389
simply put, 0 degrees kelvin
(-459,67 Fahrenheit for imperial fags out there)
is impossible

Heat is basically the movement of the individual atoms in a substance

Due to the wave particle duality of all matter at the quantum the current position and future position cannot be known at the same time, therefore when reaching absolute zero there will always be some movement and thus heat

[Anonymous No.9684365]

>>9683565
if you remove all the atoms from a region, you're still left with a photon gas (that has a nonzero temperature)