I have only one question about black holes, why are we studying them and how are they going to benifit mankind in any way. Looking at asteroids, its possible for one to hit earth, so we should be considering them, but why black holes?
I guess it is true that there is unlikely to be any event in the near future endangering human life that involves Black Holes. However, if that were the criteria upon which we based what we should study there would be no computers for me to tell you this! There are many things which benefit humankind, and I believe strongly that one of them is the search for knowledge. I think most people would agree that art for art's sake benefits humankind, so why not science for science's sake!
Black Holes may also be fundamental to properly understanding gravity which is very useful. In fact it is necessary to include corrections from General Relativity (which has been much better understood through the study of Black Holes) to the Global Positioning Satellites in order to make them accurate to more than a few metres. This may ultimately help blind people have a better standard of living and I believe has already been used to rescue lost people.