Title: Mathematics of the Faraday Cage

 

Abstract: Everybody has heard of the Faraday cage effect, in which a wire mesh does a good job of blocking electric fields and electromagnetic waves. Surely the mathematics of such a famous and useful phenomenon has been long ago worked out and written up in the textbooks? It seems to be not so, and indeed, one of the few treatments to be found in the textbooks, by Feynman, is incorrect. The shielding effect turns out to be not as simple as one might expect: it depends on the wires having finite radius. Nor is it as strong as one might imagine: it improves only linearly as the wire spacing decreases. This talk will explain how the Faraday cage works and tell the story of the surprises Jon Chapman, Dave Hewett and I encountered along the way.