Deleted == 

 I've deleted the black hole "problem".  Black holes have been identified as real for some time now. 

 The black hole line was put in there by , who on his own page claims that he strongly dislikes black holes, and who is working on a new theory that changes Einstein's theory of relativity while protesting that he is not doing soin short, he's a crackpot whose crackpot theories motivate him to over-emphasize scientific uncertainty about black holes.  Which itself doesn't mean the line is wrong, but it certainly does explain it. 

 Scientists may disagree somewhat about unobserved properties of the objects that have been identified as black holes, but those disagreements aren't about qualities so fundamental that they are disagreements about whether the objects are black holes at all. 

 It's true that nobody has seen a singularity, but the fact that nobody has actually seen something doesn't make its existence an unsolved problem, since there's little dispute that it in fact exists.  It's like saying that whether the Earth has a metal core is an "unsolved problem" because we haven't actually seen the core, just deduced its existence.   

 ==