There's an excellent documentary on photographing black holes, using every major telescope on Earth at the same instant, synchronized, then data-processed to create a single image. Fascinating. Stephen Hawking even made an appearance. We have no clue what goes on (or doesn't) inside one. It's embarrassing for physists to admit something like that, but kinda fun to have free rein to speculate! (but not spectate... nothing to see here!)