As someone working in #Optics, it will never cease to amaze me how easy it is for people to misunderstand each other when the word "mode" enters the discussion.
(To be fair, the proper definition of "mode" in #electrodynamics is far from obvious and/or trivial.)

Short story time:
When I was doing my PhD, we had in the lab an old Argon laser (which we used to pump a Ti:Sapphire, for those familiar with lasers). If you have never seen one, Argon lasers are massive, can output a ton of power, and eat a crazy amount of current, so much that the laser had its own dedicated industrial pentaphase plug.
I don't remember how many Amperes of current flew in those cables. What I remember is that, when you turned on the switch in the morning, the change in current (from zero to whatever the steady state value was) was enough to make the cable shake.
This happens because the electromagnetic field inside and around the cable stores momentum, and so it kicked the cable when building up.
I am not sure that laser still exists, and I have never been able to find a video of a cable shaking when the current is switched on, but it would be great to have such a video when teaching electrodynamics (and in particular how momentum and angular momentum can be stored in an electromagnetic field).
#ITeachPhysics #Physics #Electrodynamics #Laser

#PhysicsFactlet
If you put a dipole close to a mirror it is easy to see that its emission pattern is modified due to interference. A bit less easy to see (and thus less known) is the fact that also the total emitted power depends on the distance from the mirror, as at certain distances a significant fraction of the reflected wave goes back on the dipole in antiphase with the emission, thus reducing the emitted power.
#Physics #ElectroDynamics #Optics #LDOS #Visualization

You could upload your course material to https://www.perusall.com and have them read sections and discuss it in there. For me it was an eyeopener in #condmat and #electrodynamics.

I'm frequently amazed by how useful trudging through Jackson's electrodynamics is for later study in theoretical physics

#physics #Electrodynamics