The visible effects we see for black holes are things from well outside the event horizon, where black holes behave as just another gravitational object. Things

The visible effects we see for black holes are things from well outside the event horizon, where black holes behave as just another gravitational object. Things, i.e. gas, can rotate and swirl around them. Since the black hole can be rotating and the gas being slung around violently, it can emit radiation. If I understand correctly, the jets for supermassive black holes can extend out to sizes comparative to the containing galaxy’s diameter. Here’s a nice simulation showing this in action (article in description): https://youtu.be/g1aW8TDOm4A https://youtu.be/g1aW8TDOm4A The YouTube channel Kurzgesagt also has some pretty good illustrations and animations.