Can electric charge be enclosed ?

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Discussion Overview

The discussion revolves around the feasibility of enclosing a relatively high electric charge within a non-conducting container, specifically focusing on the technical aspects of maintaining a net charge and the implications for external electric fields. Participants explore theoretical and practical considerations related to electrostatics, insulator properties, and charge stability.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether it is technically possible to enclose a charge greater than 10e-5 coulombs in a non-conducting material like glass or plastic.
  • Another participant clarifies that they are referring to a charge in the center of a sphere, emphasizing that the overall charge of the object would not be zero.
  • A participant raises concerns about the stability of such a charge configuration, mentioning the breakdown field of the insulator and potential neutralization effects from external factors like cosmic rays.
  • There is a discussion about the mechanical strength of the insulator against Coulomb repulsion, with a warning about the possibility of a Coulomb explosion if the charge becomes too concentrated.
  • Further inquiries are made regarding the ability of a glass sphere to withstand a high electric field and whether other insulators with higher breakdown fields exist.
  • Participants discuss the implications of creating a spherical capacitor with charges on its inner and outer surfaces, questioning whether it can maintain its charge over an extended period and generate a net electric field outside.
  • One participant expresses interest in achieving significant attractive or repulsive forces between objects, comparing the complexity of magnetic and electric force calculations.

Areas of Agreement / Disagreement

Participants express various viewpoints on the feasibility and implications of enclosing electric charge, with no consensus reached on the technical limits or configurations that would allow for stable charge retention and external interactions.

Contextual Notes

Participants note limitations related to the breakdown fields of materials, the effects of environmental factors on charge stability, and the mechanical constraints of the insulator material. The discussion does not resolve these complexities.

tabchouri
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Hi everybody

I'm wondering if it is possible to enclose a relatively high electric charge in a non-conducting recipent (say plastic or glass -- macroscopic : centimeters) ?
Is it possible technically ?
if so, what is the limit amount of charge we can enclose ?
if so, would the recipient stay uncharged externally : ie will the recipient attract opposite charges on its external surface OR will the global charge of the recipient stay different from 0 ?

thanks,
tabchouri

PS:
when I said "relatively high charges" I mean |q| > 10e-5
 
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To be much clearer:
I meant an electrostatic charge (+ or -) that is in the center of a glass or plastic sphere: so that the overall charge of the object is not 0. I do not mean a capacitor as the overall electrostatic charge of capacitors is allways 0. Simply : an object that has (and won't lose) an overall electrostatic different from 0 (and in particular |q| > 1e-5),
Can this be done (given current state of technology) ?
 
You do not give units - do you mean 1e-5 coulomb? On a sphere 10 cm in radius the field at the surface would be 9e+6 V/m. Whether your charge configuration will be stable in the short run depends on the breakdown field of the insulator.

Of course, things do get neutralized: corona, cosmic rays. After some time you will have a kind of Leyden jar with a compensating charge on the outside. In other words: a capacitor.

A different limit is the mechanical strength of the material holding the charges together against their Coulomb repulsion. If a cluster or molecule gets too highly charged (by an Auger cascade for example), it will fly apart in fragments - a Coulomb explosion.

PS: This seems off topic - what is the connection with quantum physics?
 
Indeed, my question is pretty off topic, I'm sorry for that; but amongst the others, this sub-forum is the most suitable for it (I think)

yes I meant a charge of 1e-5 coulomb,
Assuming a sphere of 10 cm in radius made of glass, would it stand the field of 9e+6 V/m at its surface ? If not, is there any other insulator with high breakdown field that would stand it ?

About the Leyden Jar effect, assuming that the sphere is in pseudo-vacuum (1e-6 torr inside a much bigger glass recipient), will we still have a capacitor after some time (concerning the little sphere, the external big recipient does not matter) ?

Another silly question:
In fact, I need some objects that will interact by great attraction or repulsion (1 to 10 Newton at a distance of 1 meter). That would be electrstatic charges or permanent magnets (neodymuim or other powerful ones). I think that force calculation and prediction for magnet is pretty complex (compared to electric charges). Besides, forces varies at 1/(r^3) for magnets.
This explains my question.

So here goes the silly new part:
assuming a spherical capacitor (radius 10 cm) having in its center a charge +Q, and on the external surface another charge -Q, the global charge will be 0, just like a neutral atom.

With all the shielding an insolation required, is there any configuration that will make the capacitor hold its charge for a very long time (1 year or longer), and more importantly, will this capacitor generate a net electric field outside the sphere (to have interactions between two capacitors).

thank you very much for any help or remarks
 
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