When Were Black Holes Discovered?

Black holes were first theorized by geologist John Michelle in 1783, as merely an object with so much gravity that not even light could escape it. The idea was expanded upon by other noted minds throughout the centuries. Since black holes, if they do exist, cannot be photographed or observed in any conventional fashion, proving one exists has been a difficult task. There is a lot more evidence these days that point to them being real, but as they haven't actually been proven, they've never really been discovered.