Yesterday Tim Wilson asked a good question about capacitors. We know the
answer by now; the fields should be identical in two capacitors. But was
this actually verified? I know that in a gedanken experiment this can be
done by "measuring" the force per unit charge in a small cavity. For example,
by "drilling" a very narrow channal in the dielectric and using it as a tiny
accelerator of ions or electrons. If E are identical in the dielectric and
in the vacuum then the final energy in the channel accelerator, and in the
corresponding vacuum accelerator, should be identical.
a) But was this, or something similar, actually done?
b) Do we need real experiments to verify statements which are logically
obvious?
Ludwik Kowalski