Most likely in the University classroom as an undergraduate student, that's where most people of his generation learned about black holes. But of course what he learned about was ordinary stellar black holes.
It was much later when he made his own "what if" hypothesis on microscopic black holes. After solving the equations of general relativity for this case and including the effects of quantum mechanics, he made his theory including Hawking Radiation, evaporation of black holes, and their eventual explosion. This remains theoretical, as his black holes have still not been observed.
Stephen Hawking began studying black holes while writing his doctoral thesis in the early 1960s. It wasn't until 1974 that he made groundbreaking contributions to the field with his discovery of Hawking radiation, which revolutionized our understanding of black holes.
Albert Einstein is smarter than stephen as albert didn' have much theories then but stephen got use of the present info to find BLACK HOLE.
Actually he didn't.
in space
In the space.
Anywhere.
Black holes and subatomic particles are a subject of interest in the fields of astronomy, astrophysics, and particle physics. Perhaps the most famous to bring to light the notion that black holes could emit particle/antiparticle pairs and thus lose mass through loss of energy would be Professor Stephen Hawking, who proposed that black holes interact with the universe thermodynamically in this way and could potentially evaporate entirely.
Science at this time can find no end to black holes. They seem to last forever.
There several that come to mind since this is a very large subject: Galileo, who said that the sun was the center of the solar system. Another is Steven Hawking who is still trying to find a Theory of Everything but he did predict the existences of Black Holes and Warm Holes.
If you want to learn about black holes, I suggest you either read the Wikipedia article with the title "black hole", or you search for YouTube videos on "black holes".
Black holes can nevr be seen in space. Space is black and so are black holes. People can only see black holes because of the light around the black hole. When a black hole is consuming a giant star, you can see the light around the entire black hole. That's when you know that there is a black hole in the middkle of all that light.
He did not collect evidence. He simply proposed a "what if" then solved the equations of general relativity and quantum mechanics to find out what would happen in such a situation. The results of that analysis are his theories of microscopic black holes that evaporate and eventually explode.His theories have no effect at all on black holes that formed from stars, they don't evaporate.Note: this is exactly what Einstein did when he developed the theories of relativity. He had no evidence, he just proposed a "what if" then determined what would happen in that situation. It took others years to collect the evidence to show those predictions (strange as they were) to be correct.