Regarding recent posts about black holes, here’s another YouTube video by The Science Asylum on the topic (published February 16, 2019): “Black Holes can SPIN?!?”
I’ve previously highlighted The Science Asylum as a science communicator. This latest video is an interesting overview of black holes: non-spinning vs. spinning, the math vs. reality inside and outside event horizon(s), the ergosphere, frame dragging.
And here’s a YouTube video on the ehtelescope channel “Zoom into M87 Explaining Formation of the Supermassive Black Hole Image” (published on Apr 15, 2019) which visualizes a black hole which has been much in the news lately.