Have we not seen some previously thought to be impossible ideas come to life? Concepts such as The Heisenburg Uncertainty Priniciple, General and Special Relativity, Atoms in general, the big bang have all been upheld by scientist the world over, so why not the idea of black holes? Is the concept of infinite density with a finite mass so hard to grasp? Black holes do exist, and I cannot see any reason to say that they do not exist.