I've been trying to understand how dipole antennas work, and I believe I understand the basics when they're fed via a balanced feed line. In fact, every dipole physics YouTube video and web page I can find explains how they work with a balanced feed line as the example.
But how do they work with an unbalanced feed line, such as coax? In that case, the shield of the coax is connected to one half of the dipole. What's driving that half of the dipole?
This is a closely related question: Coax fed dipole: shield goes to one side, yet is grounded via chassis line to Earth
However, it never fully explains what's driving that grounded half of the dipole.
The best I've managed to surmise, is that perhaps the center conductor of the coax somehow affects the inner diameter of the shield of the coax in an equal and opposite manner, and THAT force is what drives the 2nd half of the dipole. But I'm not sure, and no one seems to discuss this directly in any resource I can find.
The other option I've considered is that perhaps the driven half of the dipole is influencing the non-driven half, due to its proximity to the EM field. In that case, the coax wouldn't really play a role other than giving the current somewhere to flow when that half of the antenna is influenced (but that seems wrong since that half should radiate that energy...).
So put simply: in a dipole antenna driven by coax feedline, what's powering the half of the dipole that's connected to ground? Where does that current come from?