Back to Departmental Colloquium: Spring 2017
Departmental Colloquium
Date: Wednesday, Mar 22, 2017
Time: 4:00PM
Location: JWB 335
Nick Trefethen
University of Oxford
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 present results on electrostatic Faraday shielding by Jon Chapman, Dave Hewett and myself (SIAM Review, 2015). Mathematically, this is a problem of harmonic measure. Physically, Faraday shielding cage can be regarded as electrostatic induction by a surface of limited capacitance. |
Computational Mathematics
Applied Mathematics