[Florin_Andrei]

It's not ionizing radiation. Even if it did that, with a metallic shield on the outside, any amount of static charge on its surface generates zero field inside - this is a perk of metallic shielding.

Two real issues with massive RF energy density:

1. Penetration depth. Even if you have a continuous metallic bubble with no holes, some RF radiation still leaks inside, depending on material nature, thickness, frequency, etc. The amount is small, but it's not zero.

2. If energy density in the RF beam is huge enough, the shield / cage starts heating up. You could conceivably melt it if you take this game far enough, or poke holes in it.

[ggoss]

There is a net zero electric field inside, true, but isn't that because a charge accumulates on the inside surface of the cage that is equal and opposite to that induced on the outside surface?

With regard to #1, I agree, but the degree of RF leakage is not universally small - it depends on the frequencies you encounter and the properties of your cage (material, mesh thickness and "pore" size, etc). As frequency increases (and wavelength decreases), your pore size must decrease to effectively block it, eventually becoming a solid shell (through which propellers will, of course, generate no thrust). I agree with #2.

[Florin_Andrei]

> There is a net zero electric field inside, true, but isn't that because a charge accumulates on the inside surface of the cage that is equal and opposite to that induced on the outside surface?

No. In a conductor, all free charges migrate to the outside surface.