# Cutting fields with shields

So a conductive shield will constrict the electric portion of the EM wave between the conductor and the shield. A high permeability shield would do the same for the magnetic portion.
If we only have one (usually the electric screen), won’t this offset the geometric proportion of the signal’s electric and magnetic components? Electric field is constricted at a radius but the magnetic field goes on freely.
The electric field drops by square of distance, and magnetic drops by cube of distance, so if both types of shielding were utilized, would it matter to have them distanced accordingly from the conductor to preserve coherence? Maybe this would not matter for an interconnect considering how very little of a magnetic field the minimal current produces, but what about a power cable?

People do often describe well-designed unshielded cables as more open sounding and this is attributed to capacitance, but is it necessarily the capacitance that is the culprit, or the spatial constriction of the electric field, capacitance being a necessary effect that follows from the distancing?

I would guess that if the mag field decreases with cube it becomes “insignificant” very quickly in “most circumstances” and thus has been mostly ignored except in special circumstances (transformers maybe, or RF).
I’d also guess that in 99.99% of cases that is fine.
I know you are charting the 0.01% of cases in your research but this may explain why finding the info relevant to audio is so difficult.
Theoretical physics is hard and so very mathsy - this is why I like poking electronics with a (insulated) stick to see what happens at a macro level instead

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Yeah… It is such a winding road to get to understand theoretical physics rigorously that personally, I’ve decided for now to remain a “dilettante” across many fields of research… Good gift of imagination especially in geometry gives a good foundation for intuitive understanding of many theories’ core principles without getting involved in hebrew-esque equations.
Though, on my death bed I would most suffer and regret for not having become a real scientist and engineer. So will have to leave this “dilettante” aspect aside and apply myself! Through time… I’m young yet, luckily.

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