wrote in message oups.com...

What's further confused me about the above two answers is the mention
of the magnetic field. Does this mean that as matter approaches the
event horizon, some of it becomes polarized opposite to the black hole?
How could that be possible, if the hole itself is spinning?

Temperatures in the accretion disk are *very* high. The matter
there is ripped apart into a plasma composed of electrons,
protons, and some very highly ionized nuclei. These charged
particles are subject to interaction with the powerful
electromagnetic fields wrapped around the black hole.