The microblog: 2018.03.21 05:04:33

2018.03.21 05:04:33 (976308556621205504) from Daniel J. Bernstein, replying to "Aram Harrow (@quantum_aram)" (976297577371942914):

The moment after impact, electrons are moving from the point of impact along the boundary of the cage. Do you claim that the electric and magnetic fields inside the cage are zero? If not, what do you claim the mathematical meaning of @postquantum's "cancel EM waves" claim is?


2018.03.16 00:15:50 (974423960858316800) from "Jonathan Oppenheim (@postquantum)":

By cancelling, I just mean that the field outside the cage is only determined by the value of the field on the cage, not on what is going on inside the cage. A simpler example is to put your lab inside a potential well. There is no limitation to how deep or "thick" the well 1/

2018.03.17 18:29:20 (975061537558687745) from Daniel J. Bernstein, replying to "Jonathan Oppenheim (@postquantum)" (974423960858316800):

So you think that EM variations at the boundary of a Faraday cage are tied to EM variations inside but independent of EM variations outside? Can you please maintain the intellectual discipline to focus on resolving this dispute instead of burying it under a flood of red herrings?

2018.03.17 19:50:37 (975081992885645312) from Daniel J. Bernstein:

Concretely, suppose a lightning bolt hits a Faraday cage from the outside. Q1: Do you agree that this induces motion of electrons along the boundary of the Faraday cage? Q2: Do you agree that this motion of electrons is visible to an EM sensor on the inside of the Faraday cage?

2018.03.21 04:20:55 (976297577371942914) from "Aram Harrow (@quantum_aram)":

1. yes. 2. no, fields cancel out deep inside. To penetrate a Faraday cage you'd want something lower frequency.