# A small primer on vacuum fluctuations

Discussion in 'Pseudoscience' started by SimonsCat, Jan 21, 2017.

1. ### SimonsCatRegistered Member

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There has been a lot of discussion recently on the topic of fluctuations in spacetime and whether, ''they cause a heat signature.''

A heat can only be generated by a system, if the system contains some kind of motion in its elementary/fundamental structure. As I explained also, there are no two ways around it, if you speak about heat energy you must be referring to motion within the system!!!

Now, if you remove all visible matter and energy from a square measure of space, you will find that zero point energy fields persist: in other words, the heat cannot be ONLY generated by the visible matter in the universe, there must be residual motion of other systems ie. fluctuations.

There are subtle but very important differences between off-shell (virtual) to on-shell (visible) matter. I always found it interesting to note that while virtual particles do exist, they cannot be described by the same operators we use to describe ordinary matter - ordinary matter consists of Hermitian matrices making them observables, while fluctuations, exist for such a short time, we would be forced to find some other description for them.

So this is really a no-brainer - the question is largely rhetorical based on what I just said, but here we go:

''if you removed all visible matter and energy from a system, but you still find a residual heat, what could be causing a heat signature if not caused by vacuum fluctuations.''

Be careful in your replies, remember, heat is motion.

3. ### SimonsCatRegistered Member

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Note also, because virtual particles are not visible, they could be a dark matter candidate.

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7. ### SimonsCatRegistered Member

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Van der Waals forces was mentioned in another thread in which another poster said that zero point energy is just Van der Waals forces. Let me explain why this way of thinking is faulty: instead, what should be said, is that Van der Waals forces most [likely] have origins in zero point fluctuations. Note, that this doesn't actually exclude virtual particles, you still need them to explain Van der Waals forces in the context of field theory which treats fluctuations as the fundamental case of the quantum phenomenon, whereas, Van der Waals is actually applied to molecules or atoms. So it's not that Van der Waals forces is wrong in any way... or the concept of virtual particles, but rather, they should go hand in hand.

''In physical chemistry, the van der Waals forces (or van der Waals interaction), named after Dutch scientist Johannes Diderik van der Waals, are the residual attractive or repulsive forces between molecules or atomic groups that do not arise from covalent bonds, nor ionic bonds.[1] It can be shown that van der Waals forces are of the same origin as the Casimir effect, arising from quantum interactions with the zero-point field.[2]''

8. ### SimonsCatRegistered Member

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The renormalization of the electron self energies, also requires the existence of the virtual particles that screen its infinite spectrum. This has also been known for a while.

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11. ### SimonsCatRegistered Member

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And if you lot are interested in theoretical physics, here is another post of mine, which accounts for the contribution of curved space (using the geometric series) to background zero point fluctuations by using a Sakharov approach to calculating its respective Lagrangian. I discovered it was possible to talk about those fluctuations in the context of the Friedmann equation.

note: for some reason we have the wrong sign in that formulation, I think it could be

$\dot{R}^2 = \frac{8 \pi G R^{2}_{0}}{3c^2} \rho + \int \frac{\hbar c}{mR^{2}_{H}} R^n \frac{dk}{k^{n-2}}$

but it doesn't change very much, not the context of what is being discussed anyway.

12. ### Q-reeusValued Senior Member

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You are obviously referring to me, and as repeatedly done before, attribute to me notions I do not believe. Go check what I actually wrote! Get it right - fool!
Yes - YOUR thinking is faulty. The ZPE's that physically count are those owing to matter particles, not the vacuum.
Gibberish.
We are into quote wars? Bad form not to quote the source, which with a little effort turned out to be a passage from: https://en.wikipedia.org/wiki/Van_der_Waals_force
Mine will trump yours. From first main para and next passage in: https://en.wikipedia.org/wiki/Casimir_effect
The relevant references (first one already given twice in the other thread):
[5]: Jaffe, R. (2005). "Casimir effect and the quantum vacuum". Physical Review D. 72 (2): 021301. arXiv:hep-th/0503158Freely accessible. Bibcode:2005PhRvD..72b1301J. doi:10.1103/PhysRevD.72.021301.

[6]: Nikolic, H. (2016). "Proof that Casimir force does not originate from vacuum energy". Physics Letters B. 761: 197. arXiv:1605.04143Freely accessible. Bibcode:2016PhLB..761..197N. doi:10.1016/j.physletb.2016.08.036.

Last edited: Jan 22, 2017
13. ### exchemistValued Senior Member

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......But not all motion is heat. See my response to the other thread.

Furthermore, radiation of suitable wavelength is also described as "heat", since when matter absorbs this, its temperature is raised. One would not normally describe radiation as "motion", though of course it is emitted due to matter in motion, and puts matter in motion when it is absorbed.

14. ### Q-reeusValued Senior Member

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He continues to ignore the bleeding obvious. If ZPE motion is a form of heat, and all acknowledge it persists at absolute zero (so already a contradiction in terms), it implies any body can act as a perpetuum mobile and endlessly give off EM radiation "because whenever charges accelerate they radiate according to Larmor formula". Bunkum.

15. ### SimonsCatRegistered Member

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Yes, you expect the zero point thermal contribution to ''heat'' up objects in the universe. I have demonstrated why this is false.

The problem is that zero point fields in general, are sitting right on the precipice of absolute cold: It's not reasonable to expect fluctuation thermal contribution to even happen, heat does not spontaneously flow from a colder body into a warmer one.

16. ### SimonsCatRegistered Member

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But you prefer to listen to a mathematician and computer analyst than a real physicist who teaches zero point fields. I already explained, if zero point fields was actually bunk, Susskind would not teach it in stanford.

Only the other day, you believd $t\rightarrow 0$ was physically possible for a gas. I demonstrated why you were wrong, but you are now very angry with me and you have stalked my threads to find issues with my physics. It's amusing, somewhat.

17. ### SimonsCatRegistered Member

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some work:

''Understanding the quantum vacuum To understand the quantum vacuum we need to consider quantum fluctuations not only of matter fields but also of space-time itself. The following should be considered: 6.1 The quantum vacuum is far from empty. It is a seething mass of virtual particles flashing in and out of existence and wild fluctuations of energy and all forms energy can take including gravity and fluctuations in the curvature of space-time; 6.2 The quantum vacuum is not separate from flat space-time. It is space-time at very small scales of distance and time; 6.3 The quantum vacuum borrows energy from flat space-time. Virtual particle pairs are created from the borrowed energy, the virtual particles annihilate and the borrowed energy is repaid within a time determined by the uncertainty principle. This is a never ending process of interaction between the quantum vacuum and flat space-time; 6.4 Quantum fluctuations occur in both the quantum vacuum and flat space-time; 6.5 A member of a virtual particle pair may escape into flat space-time to become a real particle in a process similar to the Hawking radiation; 6.6 The smearing effect of the uncertainty principle causes the boundary between the quantum vacuum and flat space-time to be ill defined; 6.7 Quantum fluctuations obscure the value of the field of an electrically charged particle and “amplify” the strengths of the three non gravitational forces; and 6.8 The effects of space-time fluctuations can only be fully explored when we have a complete theory of quantum gravity. Frikkie de Bruyn''

This work is important because while fluctuations naturally arise from curvature, there doesn't need to be a curvature present for a vacuum fluctuation. They also occur in flat space. Point being, space may not be completely flat as we understand it anyway.

18. ### Q-reeusValued Senior Member

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Susskind is highly talented but not last time I checked an infallible god. He has his own deep-end weirdo ideas like entanglement owing to 'micro-wormholes' linking all particles together.
This has become a trademark signature of yours - making up shit. I keep challenging you to quote me as having said this or that and you keep ducking. Please desist.
Amusement is quite mutual then. But there are better ways to be amused.

19. ### Q-reeusValued Senior Member

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Indeed correct re that last bit. But here's the absurdity of your belief ZPE equates to heat: http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/fermi.html
Check the 'temperatures' that Fermi ZPE nominally equates to. Your notion, 'logically' followed, would have us all incinerated instantly!

20. ### SimonsCatRegistered Member

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I'd be careful about how you ''sum'' up or interpret a science article. We have had problems there before based on your gross understanding of a subject... such as the application of a limit... I will take a look.

21. ### SimonsCatRegistered Member

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and no surprise... there is no mention of a zero point energy in that article.

22. ### Q-reeusValued Senior Member

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Then you are ignorant of what Fermi motion is then. Those 'temperatures' in that table persist at zero degrees Kelvin i.e. absolute zero - believe it or not.

23. ### SimonsCatRegistered Member

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It doesn't say anything about zero kelvin in that article!!! I read those temperatures as being multiplied by a factor of
x 10^4 K!!!