For the first time ever, scientists have captured an image of a black hole. The black hole chosen is a supermassive black hole at the center of the Messier 87 galaxy, 55 million light-years away from Earth. This is huge news, since before this we only had theoretical proofs of black holes with no direct evidence.
A black hole technically doesn’t look like anything since it emits no light, so I understand this to be a capture of light that came very close to the black hole. It appears in a very distinct way that confirms the presence of a black hole.
This is a photograph of a tiny amount of light that has spilled away from a black hole, 55 million light-years away. The fact that we have telescopes that can accurately capture that light is mind-boggling.
Black holes have so much gravity that any light that comes close enough will bend in a very noticeable way. Light that came from our direction can even curve around the black hole and come back at us. The ring that we see around the black hole is actually light that has come from all different directions, which have curved to end up reaching us. One side appears brighter because the black hole is spinning very fast, and the light that was pushed towards us with the spin experiences something like the Doppler Effect for sound.
This video by Veritasium does a great job describing what exactly is happening. Although it was released in anticipation of the actual image, the results were exactly as predicted.