TIL the existence of black holes was first proposed in 1783 by John Michell. We weren’t able to capture an image of a black hole until 2019.

https://adsabs.harvard.edu//full/1979JHA....10...42S/0000042.000.html
#til #todayilearned
https://www.reddit.com/r/todayilearned/comments/1gcwk2v/til_the_existence_of_black_holes_was_first/