The microblog: 2018.03.21 22:33:07

2018.03.21 22:33:07 (976572435578449920) from Daniel J. Bernstein, replying to "Jonathan Oppenheim (@postquantum)" (976541296193081344):

So you're claiming that a Faraday cage blocks magnetic fields? What precisely is the physical mechanism by which you imagine that this happens?


2018.03.21 17:53:38 (976502102896840705) from Daniel J. Bernstein, replying to "Jonathan Oppenheim (@postquantum)" (976381770445869056):

You claimed that Faraday cages "cancel EM waves". I keep asking what this is supposed to mean mathematically, and you keep dodging. Do you claim that an EM sensor inside a cage can't detect a lightning bolt hitting the cage from the outside? How about sensor outside, bolt inside?

2018.03.21 18:18:24 (976508334948962304) from "Jonathan Oppenheim (@postquantum)":

I answered. The EM field outside (inside) the cage doesn't depend on the charges inside (outside) but only on the boundary conditions set by the cage and the charges outside (inside). If you change the potential set by the cage (eg via lightning bolt), of course the field changes

2018.03.21 18:25:52 (976510213489651714) from Daniel J. Bernstein, replying to "Jonathan Oppenheim (@postquantum)" (976508334948962304):

I guess we have to start even more basic. My buddy walks up to a Faraday cage with a magnet and waves it around the outside, not touching the cage. Do you claim that I can't see this on my recordings from EM sensors inside the cage?

2018.03.21 20:29:22 (976541296193081344) from "Jonathan Oppenheim (@postquantum)":

If she does it too quickly, then the electrons won't be able to move fast enough to cancel a rapidly changing field, but from inside the cage, you still can't determine what is going on outside. The fields on the cage are not sufficient to determine the field everywhere outside.