Interesting summary of some aspects of Black Holes.<p>I recently read a centennial volume on history of General Relativity of which Black Holes are extreme cases.  Except for some initial GR solutions and astronomical confirmations in its first decade, GR became a backwater branch of physics for the next 50 years until Thorne and Hawking came along. I was in college in 1973 when the term Black Hole came into public use, though the book mentions some claims of earlier usage. Just giving some exotic phenomenon a snappy name can focus attention. I recently re-saw the 1967 Star Trek episode about time travel back as an UFO incident. They use the black hole concept, except called it a dark star then.  Gravitational singularity was a competing name, but not as snappy.  (To be precise it is possible to have an event horizon without a singularity, so they are not exactly the same thing.)