[mac_was]

Wasn't the black hole a truth you can't prove for a pretty long time? Scientists 'believed' that they are true and tried to prove their existence. See: https://www.sciencefocus.com/space/who-really-discovered-bla...

[qsort]

There's a difference between making a definite claim and pointing out that Newton's model allows the existence of such an object. I'm not going into "quid est veritas?" type of discussions because it's a bottomless pit that leads nowhere, but it seems to me like "black holes could exist" is a statement much like "an artificial general intelligence could exist". It's not ruled out by the model, but a-priori we have no idea.