First black hole picture: The big mysteries we still need to solve

Leah Crane writes:

‘The first ever image of a black hole, released on Wednesday, raises several important questions. For a start, we don’t know where exactly the light in the image comes from. Next, can we get a similarly good image of Sagittarius A*, the black hole at the centre of our galaxy? It is changing more quickly than the newly pictured black hole, so getting a clean image is more challenging. Finally, can these images help us understand how general relativity and quantum mechanics fit together? …’

Source: New Scientist

Related: An Astrophysicist on on What the Black Hole Image Reveals:

15943 607093fb70318b813d0e9b8531916fbePankaj Joshi:

’Strictly speaking, the system did not see an event horizon, which cannot be seen by definition. Furthermore, although an event horizon necessarily implies a shadow and silhouette, the converse is not true. Nonetheless the observations are still so precise that whatever is casting the shadow must be exotic. No ordinary body could be so small and yet so dark and so massive. A black hole is now the most conservative conclusion. If it is not a black hole, it might be a naked singularity, a type of immensely dense object that I have studied, and that would make a black hole look rather mundane.…’

Via Nautilus