White Holes

[Jackalope]

X-rays are physical evidence, aren't they?

X-rays are evidence of super heated gas. The reason it is superheated is because its believed to be circulating around a black hole. X-rays are indirect evidence.

You know, I was all set to agree with you until I realized that you shifted the goalposts from physical evidence to direct evidence.

X-ray emissions are indirect *physical* evidence, as are the gravitational effects on nearby objects and gravitational lensing on distant objects.

That indirect physical evidence tells us that there's an unseen mass. Theoretical physics tells us that mass is a black hole, to our best understanding.