I've been looking at displacement current and some things I've been reading
seem contradictory. I say "seem" as I'm very sure it's a misunderstanding
on my part.

One apparent contradiction is that displacement currents can propagate
through a vacuum. How can that be so if in fact "displacement current" is
an electric current which I have always believed involves a flow of
electrons. Yes, I know that electrons can flow through a vacuum, but what
I've read seems to have more likeness to field effects than electron flow.

On Thu, 3 Jan 2008, Vince Morgan wrote:
electrons. Yes, I know that electrons can flow through a vacuum, but
what
I've read seems to have more likeness to field effects than electron
flow.

That's because it isn't a current. "Displacement current" is an archaic
term, resulting from Maxwell believing that it was an equivalent current
due to changing dielectric polarisation of the ether. It's no more a
current than dB/dt is a magnetic current.

Note that in a dielectric, you have D = e0 E + P, and dP/dt gives you an
effective current (even if individual electrons don't "flow", but only
move within their own atom or molecule. Given Maxwell's view of vacuum as
a dielectric ether, it was a sensible enough choice of terminology at the
time. Given the modern view of vacuum as vacuum, it's confusing to
students.

Just think of "displacement current" being a way to write dD/dt in words.
And just write "dD/dt" yourself, and you'll never need displacement
current again!

Thank you very much Timo. Now it makes sence.