Roy wrote, "It's not hard to demonstrate that the (time-varying)
magnetic field
doesn't penetrate a non-ferrous shield, if you believe (correctly) that
a time-varying magnetic field will produce a current on a nearby
conductor."

Yes, it's all easy to demonstrate. It's used in practice all the time:
the shielding in a transmitter, the aluminum shield cans around IF and
RF coils, the copper strap around a power transformer (used
specifically to lower the external magnetic field around the
transformer, so it won't couple into low-level audio circuits or affect
colors on a color CRT).

And indeed it all agrees with theory. For this one, you need little
more than Faraday's Law of Magnetic Induction.

It's fine with me if there are people who don't want to be bothered
with theory, but if they profess that something works by means
different from the theory that I understand and which agrees with the
observations I make, they shouldn't expect me to believe them without
putting some very serious effort into explaining why the accepted
theory is wrong. I believe Yuri when he tells me his antenna works.
But I'm not buying into his explanation of HOW it works.

Cheers,
Tom