How Do We Know That Black Hole Comes From Decomposing Stars?

Wad: I really enjoy hearing people out there supporting the next generation of curious scientists. How do we know that black holes come from decaying stars? Wad: It's especially tricky to understand how things in the universe turn into other things, because it usually takes a long time. And everything woud have been a lot slower. But slugs don't send too many emales. O thank you all your parents and teachers for encouraging thinkers of the next generation.