Pre Big Bang State

[Dubbelosix]

A system to be at absolute zero, requires the system be Newtonian, and absolute zero is the absence of quantum motion. Since a system,. such as an oscillator can never reach absolute zero, because it would imply all motion is lost, this requires a correction term.

 

But because Exchemist doesn't understand this physics, he cannot help himself but troll the world with half-baked understanding of quantum field theory.

[Dubbelosix]

In fact, the last time I had this argument with him, I explained about the vacuum expectation value - how in Newtonian physics, the vacuum does not possess an energy, while in quantum mechanics, fluctuations exist. It is surprising to me, after all the links and information I provided, he still pertains to this lie of his understanding.

[Dubbelosix]

You may be right :) But what or who is wrong and why ? :(

 

 

Qouting from the first thing that google comes across

"

Absolute zero. Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. Absolute zero is the point at which the fundamental particles of nature have minimal vibrational motion, retaining only quantum mechanical, zero-point energy-induced particle motion.

"

Absolute zero is not a forbidden state, it exists theoretically and is very close to being reached. Could this be what exchemist means.

 

 

No, this couldn't possibly be what he means, because we cannot reach absolute zero. We can get very close, but cannot actually reach it. This is an experimental fact.It is true that it is the lowest temperature, but it is not the absence of temperature (zero Kelvin) but shows that vacuum energy contributes a sum so that we can only approach absolute zero, but never reach it. This is well-explained by academics.

[exchemist]

Just for good measure here's another reference confirming that zero point energy remains at absolute zero

https://www.britannica.com/science/absolute-zero

 

I quote:

"The concept of absolute zero as a limiting temperature has many thermodynamic consequences. For example, all molecular motion does not cease at absolute zero (molecules vibrate with what is called zero-point energy), but no energy from molecular motion (that is, heat energy) is available for transfer to other systems, and it is therefore correct to say that the energy at absolute zero is minimal."

 

Which seems to be a virtually a paraphrase of what I said about it. :)

[Dubbelosix]

First of all, zero point energy is different to zero temperature (known as zero Kelvin). Once that sinks in, we can move on and I'll teach you about vacuum states.

Edited January 17, 2019 by Dubbelosix

[Dubbelosix]

See, zero temperature systems are in fact predicted from classical mechanics, and its even predicted in some classes of quantum theory, however true fluctuation theory involves a concept that you cannot actually ever reach zero temperatures, so the notion of a Newtonian vacuum does not exist. This means you can never actually reach absolute zero temperatures in the case of zero Kelvin, because quantum theory forbids it with the presence of vacuum fluctuations.

[Dubbelosix]

Singularities could indicate something becomes a certainty or alternatively is ludicrous.

 

The temperature in your equations is intriguing. This is why I asked what happens when T goes to zero.

 

The HUP does not include temperature, so does not give any insight. Hawking black body radiation does include temperature, but requires heat as far as I can see to be meaningful. 

 

Would you like to discuss the T = 0 K in your equations, which is apparently theoretically possible, even if an equation forbids it.

 

 

I couldn't possibly say what happens for any model that would purport to a situation which cannot retain the laws of quantum mechanics. I have studied black hole particles as possible minimum refrigerators and found some convincing evidence it might be possible, but the main thermodynamics still held so I quickly made it clear in those investigations that I take the third law seriously and that no system, that includes the universe, can ever exist at zero temperatures. The universe could get infinitely large (and infinitely flat) and it still would never reach zero Kelvin.

 

As for the uncertainty principle. it does play a role. Oscillators have a motion that is attributed to the motion.

[OceanBreeze]

See, zero temperature systems are in fact predicted from classical mechanics, and its even predicted in some classes of quantum theory, however true fluctuation theory involves a concept that you cannot actually ever reach zero temperatures, so the notion of a Newtonian vacuum does not exist. This means you can never actually reach absolute zero temperatures in the case of zero Kelvin, because quantum theory forbids it with the presence of vacuum fluctuations.

 

You are very confused.

 

zero point energy is the energy that remains at 0 temperature, or absolute zero.

 

There is nothing in physics that says a Temperature of absolute zero cannot be reached.

 

quantum mechanics does say that a state of zero energy cannot be reached because then the uncertainty principle would be violated.

 

That is, in a zero energy state we could precisely know both the position and velocity of a particle.

 

It is because of zero point energy that the uncertainty principle still holds at absolute zero Temperature.

 

zero Temperature is possible, zero energy is not.

[exchemist]

I should perhaps add something to what I have said so far, which may help understanding.

 

In Statistical Thermodynamics, temperature determines the degree to which excited states above the ground state are populated. The number n(i) of molecules or atoms in the ith excited state, with an energy εi above the ground state,  is given by n(i) = n(0) p(i) exp (-εi/kT).  

 

 The Stat TD meaning of absolute zero is the condition in which all the atoms or molecules are in the ground state. 

 

Note that this says nothing at all about what energy may remain in the ground state.  The energy of the ground state, if any, does NOT contribute to temperature.

Edited January 17, 2019 by exchemist

[Dubbelosix]

This can clearly be shown wrong, since Plancks law is a temperature dependent system and T cannot reach zero, because of the correction term

 

[math]\frac{1}{2}\hbar \omega[/math]

 

Which is the energy of the ground state oscillator, so in other words, it contributes the same towards temperature, so you are totally wrong.

[Dubbelosix]

Do yourself a favor and actually learn something, instead of prancing about with your archaic, and erroneous knowledge:

 

https://www.researchgate.net/publication/237115571_Zero_Point_Energy_Planck_Radiation_Law

[Dubbelosix]

You are very confused.

 

zero point energy is the energy that remains at 0 temperature, or absolute zero.

 

There is nothing in physics that says a Temperature of absolute zero cannot be reached.

 

 

 

This is so stupid, and I don't know how many times you go around giving people this false knowledge. Zero temperature refers to a zero Kelvin state, it is well-known and well-written about that no system actually exists at a zero temperature, instead, a correction is given into the equations because you cannot create a perfect vacuum.

 

There is no state at zero temperatures, all that exists is the ground state, known as the zero point field which contributes a true ground temperature to the vacuum.

[exchemist]

All this stuff about oscillators misses the point that an oscillator in its ground state cannot, by definition, emit any radiation. (If it could it would need to drop to a state below its ground state.)

 

So the zero point energy of an oscillator does not contribute to black body radiation. In other words a black body at absolute zero does not radiate at all.

[Dubbelosix]

They are a contribution of heat, do you know Plancks law?

[Dubbelosix]

Let's try you on something, Plancks law is

 

[math]E = \hbar \omega \frac{1}{e^{\frac{\hbar \omega}{kT}} - 1}[/math]

 

What happens if [math]T \rightarrow 0[/math]?

Edited January 17, 2019 by Dubbelosix

[Dubbelosix]

I'll save you some pain, if [math]T[/math] goes to zero, then there can be no energy present at all. It is a general fact of the work of Planck and others, that the energy of a system is roughly proportional to its thermodynamic properties. In classical mechanics, an expectation of a vacuum state is

 

[math]<0|H|0> = 0[/math]

 

This is a ground state, no energy present and no temperature can be present, system indicating a perfect vacuum. In quantum mechanics however, this is not true and the expectation value is

 

[math]<0|H|0> \ne 0[/math]

 

This is because of vacuum fluctuation motion, and motion is the approximation to a temperature. This is why a system cannot ever reach a zero temperature state, because Plancks law was shown to require a correction term to prevent temperature going to zero

 

[math]E = \hbar \omega \frac{1}{e^{\frac{\hbar \omega}{kT}} - 1} + \frac{1}{2}\hbar \omega[/math]

 

This means the fluctuation is in fact contributing a minimal temperature to the vacuum.

Edited January 17, 2019 by Dubbelosix

[exchemist]

Further misunderstanding. The radiation law predicts the radiation from matter, considered as a set of quantised oscillators. At absolute zero it predicts no radiation, which is what I have been saying.

 

However that does not mean there is no energy in the oscillators themselves (i.e. in the matter responsible for the radiation), because whatever energy they retain in the ground state does not allow them to emit radiation. 

 

Thus an object at 0K can have as much zero point energy as it likes and yet emit zero radiation, as would be expected for an object at absolute zero. 

Edited January 17, 2019 by exchemist