Absolute Zero - No Entropy -Quantum Jiggles?

In summary: Zero-point energy does not necessarily mean that quantum jitters aren't occurring. In fact, it could be argued that the quantum jitters are what allow things to move at absolute zero. Additionally, the presence of zero-point energy in noble gases results in an increase in their specific heat.
  • #1
Quantum Bum
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0
When something is frozen fully, and the temperature is absolute zero -there is no entropy - but does that mean the "quantum jitters" are not occurring?
 
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  • #2
What are quantum jitters exactly?
 
  • #3
Stuff at absolute zero still have zero-point energy, if that's what you're asking.
 
  • #4
Drakkith said:
What are quantum jitters exactly?

I'd assume he or she means that all motion ceases, down to quantum level, violating the HUP, and maybe a host of other quantum phenomenon that are often lumped together. Probably a good explanation of why you never CAN get to AZ.
 
  • #5
What that means is that you cannot have something at "absolute zero". Absolute zero means no motion at all. As long as you sure the object whose temperature you are lowering is in the same building with you Heisenberg uncertainty means the speed of the atoms making up the object cannot be 0.
 
  • #6
HallsofIvy said:
What that means is that you cannot have something at "absolute zero". Absolute zero means no motion at all. As long as you sure the object whose temperature you are lowering is in the same building with you Heisenberg uncertainty means the speed of the atoms making up the object cannot be 0.

Unfortunately, that statement is interpretation-dependent. In the de Broglie-Bohm interpretation (experimentally equivalent to orthodox QM), the zero-point energy is a 'quantum potential energy' (source: Holland's deBB textbook 'The Quantum Theory of Motion'). For a zero-angular momentum stationary state at absolute zero, the particles really do come to a dead stop, with zero kinetic energy. This doesn't violate the Heisenberg uncertainty principle because that principle only refers to ensembles of identically prepared systems. Over the ensemble, there is a distribution of positions in space in which the particles come to a dead stop which obeys the HUP, but for any individual system they are nevertheless stationary.
 
  • #7
HallsofIvy said:
What that means is that you cannot have something at "absolute zero". Absolute zero means no motion at all. As long as you sure the object whose temperature you are lowering is in the same building with you Heisenberg uncertainty means the speed of the atoms making up the object cannot be 0.

This is -as Camboy has already mentioned- not quite correct. According to what I would consider to be "mainstream" QM things DO move even at absolute zero.
See e.g. Gardiner's book on Quantum Noise (as far as I remember there is even a calculation in there showing how fast an electron would move due to ZPE random-walk motion, a very small but non-zero number)
 
  • #8
f95toli said:
This is -as Camboy has already mentioned- not quite correct. According to what I would consider to be "mainstream" QM things DO move even at absolute zero.
See e.g. Gardiner's book on Quantum Noise (as far as I remember there is even a calculation in there showing how fast an electron would move due to ZPE random-walk motion, a very small but non-zero number)

So quantum zero-point motion -vibrations, or are you saying more then this?
 
  • #9
Quantum Bum said:
So quantum zero-point motion -vibrations, or are you saying more then this?

In quantum harmonic oscillator, the LOWEST possible level has an energy of [itex]1/2 \hbar \omega[/itex]. So it isn't zero.

Furthermore, in the deBoer effect for noble gasses, the specific heat actually increases as one gets closer to absolute zero, which is a direct consequence of the presence of zero-point energy/uncertainty principle.

Zz.
 

1. What is absolute zero?

Absolute zero is the lowest possible temperature that can be reached, at which point a thermodynamic system has no thermal energy and all molecular motion stops.

2. How is absolute zero related to entropy?

Entropy is a measure of the disorder or randomness in a system. At absolute zero, there is no thermal energy to drive molecular motion, resulting in a state of zero entropy.

3. What are "quantum jiggles"?

Quantum jiggles, also known as zero-point energy, are small fluctuations in energy that occur even at absolute zero due to the laws of quantum mechanics.

4. Can absolute zero ever be reached?

Absolute zero is considered an idealized limit and cannot be reached in a physical sense. However, scientists have been able to reach temperatures very close to absolute zero in laboratory settings.

5. What are the applications of studying absolute zero and zero entropy?

Studying absolute zero and zero entropy helps us understand the fundamental laws of thermodynamics and quantum mechanics. It also has practical applications in fields such as cryogenics, superconductivity, and quantum computing.

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