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pewpewbrrrrrrt t1_je1zbl7 wrote

Reply to comment by mfb- in How does an ideal vacuum have a dielectric breakdown voltage of 10^12 MV/m? If there is nothing there, then how can electricity pass through it? by skovalen

I'm sorry if this is stupid, my understanding of what space/time is would mean there's no way to not have an electric field. Even if you made a vacuum with no charge you would have to use an electric field to make the vacuum inside have no charge therefore there would always be an electric field.

Is that a flawed understanding?

Is an ideal vacuum a theoretical or mathematical concept that is technically impossible in our understanding of physics?

Thank you for any clarification, I think I have a good idea of high school level math + a high level of modern physics concepts so ELI16?

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LeN3rd t1_je2b1yf wrote

Ideal vacuum means there are no atoms/particles. Fields by definition are always there in all of space.

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QuentaAman t1_je6pbn0 wrote

But we're not talking about quantum fields here, right? I also think that's a wee bit too complicated for what he's asking about.

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mfb- t1_je40csp wrote

You can have an electric field strength of zero, that is commonly called "no electric field". You could argue that zero is the strength of the existing field, but that's just semantics. In practice you won't achieve a field strength of exactly zero, of course, but that's just an experimental limit.

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QuentaAman t1_je6oy0t wrote

You can shield against electric fields by using a faraday Cage. This is above highschool level but the wuick answer is that, using maxwells equations, you find the the electric potential inside such a cage is exactly 0 no matter what charges there may be outside the cage. And since the electric field is the gradient of the potential (again, sorry if that's too advanced for you) it is also 0.

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