I challenge the world , bring it on!

[james blunt]

@Sustainer , you survive Sunday?

I am still online my friend at the moment, not been disconnected yet .

 

[james blunt]

I am fairly sure that all Stat. TD tells you is that at T=0 every element of the ensemble, in all its degrees of freedom, has fallen back into the respective ground states.

This may shock you, I would be fairly sure myself and have to agree with you that T=0 is the constant ground state.

My reason for this would be a logical thought,

In imagination, in a void if there was one individual binary particle only, there would be no mechanism for a change of the particles entropy.

The particle would remain a constant temperature of 0k .

0k in respect to (-e) + (+1e) = 0k

The proton being a negative energy with a positive call sign, that cancels out the electron heat. So in my sense of logic a single electron must be naturally T = 0.5k at ground state .

A proton T = -0.5k at ground state

(0.5k) + (-0.5k) = 0k

Your thoughts Sensei ?

added- Whoops ! Did I actually try this time.

 

[Truly Enlightened]

I have to say this does not sound quite right to me.

In matter at absolute zero, all degrees of freedom are in their ground state. Once in the ground state there is no way to extract more thermal energy from the matter, as no state below the ground state exists, by definition. Zero point motion remains in the ground states of many degrees of freedom of QM systems. But this does not represent extractable energy, so it does not contribute to temperature.

In short, my understanding is that the presence of zero point motion does not prevent matter from reaching absolute zero. The reason why it can't seems to me to be the more prosaic one of the impossibility of removing all the extractable (i.e. above-ground-state) energy, unless one were to have a heat sink below absolute zero to receive the heat!

My response to another poster, was to give two reasons why absolute zero was unachievable? I also addressed his notion that space was empty. Because the majority of people on religious forums are not accredited scientists, my comments are meant to be general. I try not to give many non- technical examples whenever possible. Was there something in the Heisenberg principle, or the heat sink examples that didn't seem quite right to you? What about the limitation on acceleration of mass? It is certainly true that as the entropy of the system decreases, electrons will reach their lowest energy state(eigenstate/ground state). It is also true that "thermal motion" describes the movement of atoms relative to each other, and not relative to any reference frame(ground state). Even at the ground energy state of electrons, interaction with the nucleus can still occur(electron capture). But what is the relevance, since absolute zero is not achievable?

If you were to actually reach absolute zero, atoms would no longer vibrate or have any motion, however the atom will still continue to function. Absolute Zero is also impossible to reach, because we can never reach "zero-point energy" in matter. If all energy were extracted from a particle it would no longer exist, since all particles are made of energy.

 

[Truly Enlightened]

I'm ok with exposing my remedial level of scientific understanding lol, that's how I learn.

I've reread your post and you stated absolute zero is not achievable, so I assumed you knew what you were talking about.

So... can something chill to absolute zero or not?

Not.

 

[Truly Enlightened]

Ohhhh... You asked me why mass can never be accerated to the speed of light. Ok... for grins and giggles... because at the speed of light time stops and stuff can't move. Does that win an honorable mention?

No, a dishonorable mention.

 

[exchemist]

My response to another poster, was to give two reasons why absolute zero was unachievable? I also addressed his notion that space was empty. Because the majority of people on religious forums are not accredited scientists, my comments are meant to be general. I try not to give many non- technical examples whenever possible. Was there something in the Heisenberg principle, or the heat sink examples that didn't seem quite right to you? What about the limitation on acceleration of mass? It is certainly true that as the entropy of the system decreases, electrons will reach their lowest energy state(eigenstate/ground state). It is also true that "thermal motion" describes the movement of atoms relative to each other, and not relative to any reference frame(ground state). Even at the ground energy state of electrons, interaction with the nucleus can still occur(electron capture). But what is the relevance, since absolute zero is not achievable?

If you were to actually reach absolute zero, atoms would no longer vibrate or have any motion, however the atom will still continue to function. Absolute Zero is also impossible to reach, because we can never reach "zero-point energy" in matter. If all energy were extracted from a particle it would no longer exist, since all particles are made of energy.

No that is wrong, I believe. You are confusing the possession of energy with temperature.

According to Stat. TD, matter is at absolute zero when all the entities of which is comprised are in the ground state, of all their degrees of freedom.

Take the hydrogen atom. When the electron is in its ground state, the electron still has potential and kinetic energy. But that does not mean that a hydrogen atom has a certain minimum temperature, belew which it cannot go. The same goes for the ground state of a system of vibrational energy levels, in a chemical bond (e.g. harmonic oscillator). Again there is still potential and kinetic energy in the ground state, but that does not define a minimum temperature for the molecule. There is nothing in physics that says to get to absolute zero the electron has to stop moving, or the zero point ground state vibration has to stop, i.e. you have to get (somehow!) below the ground state.

I quote the 2nd para of the Wiki article on Temperature: "The coldest theoretical temperature is absolute zero, at which the thermal motion of all fundamental particles in matter reaches a minimum. Although classically described as motionless, particles still possess a finite zero-point energy in the quantum mechanical description."

 

[james blunt]

No that is wrong, I believe. You are confusing the possession of energy with temperature.

According to Stat. TD, matter is at absolute zero when all the entities of which is comprised are in the ground state, of all their degrees of freedom.

Take the hydrogen atom. When the electron is in its ground state, the electron still has potential and kinetic energy. But that does not mean that a hydrogen atom has a certain minimum temperature, belew which it cannot go. The same goes for the ground state of a system of vibrational energy levels, in a chemical bond (e.g. harmonic oscillator). Again there is still potential and kinetic energy in the ground state, but that does not define a minimum temperature for the molecule. There is nothing in physics that says to get to absolute zero the electron has to stop moving, or the zero point ground state vibration has to stop, i.e. you have to get (somehow!) below the ground state.

I quote the 2nd para of the Wiki article on Temperature: "The coldest theoretical temperature is absolute zero, at which the thermal motion of all fundamental particles in matter reaches a minimum. Although classically described as motionless, particles still possess a finite zero-point energy in the quantum mechanical description."

Consider an atom in motion can still be at rest. What I mean by this is , if an electron is at relative rest to the proton , it is not moving relative to the proton. But the electron and proton are moving relative to everything else.

 

[Truly Enlightened]

No that is wrong, I believe. You are confusing the possession of energy with temperature.

According to Stat. TD, matter is at absolute zero when all the entities of which is comprised are in the ground state, of all their degrees of freedom.

Take the hydrogen atom. When the electron is in its ground state, the electron still has potential and kinetic energy. But that does not mean that a hydrogen atom has a certain minimum temperature, belew which it cannot go. The same goes for the ground state of a system of vibrational energy levels, in a chemical bond (e.g. harmonic oscillator). Again there is still potential and kinetic energy in the ground state, but that does not define a minimum temperature for the molecule. There is nothing in physics that says to get to absolute zero the electron has to stop moving, or the zero point ground state vibration has to stop, i.e. you have to get (somehow!) below the ground state.

I quote the 2nd para of the Wiki article on Temperature: "The coldest theoretical temperature is absolute zero, at which the thermal motion of all fundamental particles in matter reaches a minimum. Although classically described as motionless, particles still possess a finite zero-point energy in the quantum mechanical description."

Temperature is the measurement of the average Kinetic Energy, that is, just how fast atoms and molecules are moving. The higher the measured temperature, the faster molecules and atoms are moving, and the higher the average energy of motion(KE). The lower the temperature, the slower molecules and atoms are moving, and the lower the average KE. Energy is essentially everything and everywhere. It is the abstract notion that all matter possess the ability to do work. Energy is not a thing, it is a property. So I am not sure exactly what you think I am finding confusing.

What I am confused about is what you are disagreeing with? Is violating the Heisenberg Principle not the reason we can't reach absolute zero, from a Quantum perspective? What about the dual nature of matter, from a probability perspective? Or, was it the heat sink example, from a classical perspective? I have already stated that particles would only reach their lowest energy state(not zero), even if achieving absolute zero were possible. I have also stated that that it is impossible for atoms(particles) to be absolutely motionless, because that would also violate Heisenberg's Uncertainty principle. But since absolute zero is unachievable, this is all moot. Do you feel that somewhere in empty space, absolute zero exists?

 

[exchemist]

Temperature is the measurement of the average Kinetic Energy, that is, just how fast atoms and molecules are moving. The higher the measured temperature, the faster molecules and atoms are moving, and the higher the average energy of motion(KE). The lower the temperature, the slower molecules and atoms are moving, and the lower the average KE. Energy is essentially everything and everywhere. It is the abstract notion that all matter possess the ability to do work. Energy is not a thing, it is a property. So I am not sure exactly what you think I am finding confusing.

What I am confused about is what you are disagreeing with? Is violating the Heisenberg Principle not the reason we can't reach absolute zero, from a Quantum perspective? What about the dual nature of matter, from a probability perspective? Or, was it the heat sink example, from a classical perspective? I have already stated that particles would only reach their lowest energy state(not zero), even if achieving absolute zero were possible. I have also stated that that it is impossible for atoms(particles) to be absolutely motionless, because that would also violate Heisenberg's Uncertainty principle. But since absolute zero is unachievable, this is all moot. Do you feel that somewhere in empty space, absolute zero exists?

I am saying that violating the HUP is not the reason we can't get to absolute zero. Zero point motion and energy would still be present in matter at absolute zero, so the HUP would not be violated.

As I understand it, the reason we can't get to absolute zero is simply the "classical" one, that to remove all the extractable (i.e. non zero-point) energy from an object, one would need a heat sink below absolute zero to reject it into, which is impossible.

Another way to put it is that zero-point or ground state energy does not contribute to the temperature of an object and so its presence is not an argument for why we can't get to absolute zero.

 

[james blunt]

As I understand it, the reason we can't get to absolute zero is simply the "classical" one, that to remove all the extractable (i.e. non zero-point) energy from an object, one would need a heat sink below absolute zero to reject it into, which is impossible.

A negative energy heat sink?

 

[Truly Enlightened]

I am saying that violating the HUP is not the reason we can't get to absolute zero. Zero point motion and energy would still be present in matter at absolute zero, so the HUP would not be violated.

As I understand it, the reason we can't get to absolute zero is simply the "classical" one, that to remove all the extractable (i.e. non zero-point) energy from an object, one would need a heat sink below absolute zero to reject it into, which is impossible.

Another way to put it is that zero-point or ground state energy does not contribute to the temperature of an object and so its presence is not an argument for why we can't get to absolute zero.

What happens at absolute zero?

"Practically, the work needed to remove heat from a gas increases the colder you get, and an infinite amount of work would be needed to cool something to absolute zero. In quantum terms, you can blame Heisenberg’s uncertainty principle, which says the more precisely we know a particle’s speed, the less we know about its position, and vice versa. If you know your atoms are inside your experiment, there must be some uncertainty in their momentum keeping them above absolute zero – unless your experiment is the size of the whole universe".

You are correct for Gases, atoms and molecules, and other bounded particles. Zero point energy and harmonic oscillating energies can't be reduced. There will always be a minimum. But for free unbound particles, the situation may be different. At absolute zero, their momentum is zero. Therefore momentum(velocity) becomes known. This is a violation of HUP. To find the position of the particle you need to put energy back into the system, thus never achieving absolute zero. But this is all nonsense since absolute zero can't be achieved, and no bound or unbound particles can have zero momentum. If a particle did, infinity would be required in the standard deviation of position in the HUP. This would be nonsense.

 

[james blunt]

What happens at absolute zero?

"Practically, the work needed to remove heat from a gas increases the colder you get, and an infinite amount of work would be needed to cool something to absolute zero. In quantum terms, you can blame Heisenberg’s uncertainty principle, which says the more precisely we know a particle’s speed, the less we know about its position, and vice versa. If you know your atoms are inside your experiment, there must be some uncertainty in their momentum keeping them above absolute zero – unless your experiment is the size of the whole universe".

You are correct for Gases, atoms and molecules, and other bounded particles. Zero point energy and harmonic oscillating energies can't be reduced. There will always be a minimum. But for free unbound particles, the situation may be different. At absolute zero, their momentum is zero. Therefore momentum(velocity) becomes known. This is a violation of HUP. To find the position of the particle you need to put energy back into the system, thus never achieving absolute zero. But this is all nonsense since absolute zero can't be achieved, and no bound or unbound particles can have zero momentum. If a particle did, infinity would be required in the standard deviation of position in the HUP. This would be nonsense.

Are you sure an electron is not just a point contact of the valence?

That would explain the random position.

 

[exchemist]

What happens at absolute zero?

"Practically, the work needed to remove heat from a gas increases the colder you get, and an infinite amount of work would be needed to cool something to absolute zero. In quantum terms, you can blame Heisenberg’s uncertainty principle, which says the more precisely we know a particle’s speed, the less we know about its position, and vice versa. If you know your atoms are inside your experiment, there must be some uncertainty in their momentum keeping them above absolute zero – unless your experiment is the size of the whole universe".

You are correct for Gases, atoms and molecules, and other bounded particles. Zero point energy and harmonic oscillating energies can't be reduced. There will always be a minimum. But for free unbound particles, the situation may be different. At absolute zero, their momentum is zero. Therefore momentum(velocity) becomes known. This is a violation of HUP. To find the position of the particle you need to put energy back into the system, thus never achieving absolute zero. But this is all nonsense since absolute zero can't be achieved, and no bound or unbound particles can have zero momentum. If a particle did, infinity would be required in the standard deviation of position in the HUP. This would be nonsense.

Thanks for the reply. I read that. But I think your New Scientist reporter has got it wrong, actually. It wouldn't be the first time a science reporter has goofed.

But it's an interesting issue, re unbounded particles. My recollection of the Particle in a Box problem is that an unbounded particle has no zero point energy. The lack of a boundary means the system is not quantised and that the energy of the ground state is zero. But since it is unbounded, its wavefunction extends throughout space anyway, so you have no idea where it is! So Δp.Δx >/= h/4π remains true.