https://www.space.com/into-a-black-hole-whats-inside.html
https://www.space.com/mysteries-of-light-and-time.html
https://www.livescience.com/19683-happen-fall-black-hole.html
https://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-a-black-hole-k4.html
https://www.nationalgeographic.com/science/2019/04/first-picture-black-hole-revealed-m87-event-horizon-telescope-astrophysics/#:~:text=First%2Dever%20picture%20of%20a%20black%20hole%20unveiled&text=The%20Event%20Horizon%20Telescope%E2%80%94a,galaxy%20in%20the%20Virgo%20cluster.
https://en.wikipedia.org/wiki/Black_hole#History
https://www.space.com/first-black-hole-photo-science-breakthrough-2019.html
https://www.space.com/dwarf-galaxy-small-black-hole-measured.html#:~:text=In%20order%20to%20measure%20the,black%20holes%2C%20the%20statement%20said.
https://www.physicsoftheuniverse.com/topics_blackholes_singularities.html#:~:text=In%20the%20center%20of%20a,know%20them%20cease%20to%20operate.
https://www.sciencefocus.com/space/quick-qa-what-happens-to-the-light-thats-been-sucked-into-a-black-hole/