The vacuum tag has no wiki summary.
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1answer
144 views
What happens when a piezo crystal is exposed to a vacuum?
Application of mechanical stress to a piezo crystal generates a charge.
Quoting from wikipedia, a 1 cm3 cube of quartz with 2 kN (500 lbf) of correctly applied force can produce a voltage of 12500 ...
2
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1answer
237 views
Why dynamic Casimir effect does not appear in static gravity field?
Dynamic Casimir effect tells us that a constantly-accelerated mirror should emit radiation due to interaction with vacuum. Following principle of equivalence, a similar mirror placed in static ...
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1answer
44 views
How does a pierced vacuum move?
If a can of compressed air is pierced on the right, air pushes out, and the can moves to the left.
If a vacuum container is pierced on the right, which way does it move? Right? Left? Not at all? ...
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1answer
41 views
How does the radius and length of a pipe affect vacuum performance?
Can I use Poiseuille's equation?
Also
If I have a vacuum pump which says that its performance is 30 cubic feet per minutes and I have two pipes (one is radius R1 and L1, the other one is 2*R1 and ...
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155 views
How is it possible the speed of light is not constant?
I was reading this article recently, which summarizes a couple of new studies into the speed of light.
In one paper, Marcel Urban from the University of Paris-Sud, located in Orsay, France and his ...
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60 views
Relating the deformation of Calabi-Yau metrics and the conformal quantum field theories
(v2)
As I read e.g. in this question, the nice holonomy group features of Calabi-Yau manifolds are valuable regarding supersymmetry (I suspect because it's a symmetry involving the target manifold, ...
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125 views
Stability of the vacuum state of interacting quantum fields
"Stability" is generally taken to be the justification for requiring that the spectrum of the Hamiltonian should be bounded below. The spectrum of the Hamiltonian is not bounded below for thermal ...
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de Sitter versus Minkowski QFT and cosmological constant
WMAP/Planck results confirm than we live in a de Sitter-like phase, i.e., a Universe with positive acceleration or positive cosmological constant! Therefore, I believe that a way to solve the ...
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0answers
74 views
Vacuum to vacuum transition amplitude
I have two questions about Vacuum to vacuum transition amplitude.
Can any particle stay in $|0\rangle$?
I was studying this topic from Srednicki's QFT book. He writes in eq.$(6.22)$
$$\langle0|0 ...
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0answers
81 views
How long must two surfaces be in contact for vacuum weld/cementing to occur?
Vacuum cementing apparently is far more likely in space than on a planetary surface in atmosphere. How long must two surfaces be kept in contact with each other in a vacuum for vacuum weld/cementing ...
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226 views
Creating the proper suction
I'm a bit rusty on my fluid dynamics. I'm experimenting with creating my own leaf vacuum.
How would I determine how much suction a fan creates?
Bernoulli's equation would apply correct?
I would ...
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0answers
31 views
How to find the inflow pressure and outflow pressure of blower and vacuum?
To find the outflow pressure of blower and inflow pressure of vacuum is not too difficult. Does any reference information (do not need to be too accurate) of how inflow pressure of blower relate to ...
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86 views
Is this a possible scenario for the teleportation of energy?
Ok, so I've been reading a paper (Here's the paper) published by a physicist named M. Hotta et al. recently and as far as I can tell with my limited understanding, the protocol for the teleportation ...
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254 views
Gravitation and the QFT vacuum
I'm asking this to get yet another lessson in the inability of QFT and GR to cohabit. Many people believe GR must yield to quantization. The question here is as to why the activity of the vacuum ...
