Why don't we have black holes floating around our oceans?
It's not as if the Schwartzchild radius is a physical boundary though; it's just the event horizon, a mathematical definition. If you were free falling into a black hole you might not even notice when you passed through it. The black hole is still a singularity and speaking about it's density this way is absurd. (I mean absurd in the way it makes no sense, not as an insult to you personally.) These concepts of density at the local physical level and cosmic level are very different.
Why don't we have black holes floating around our oceans?
It's not as if the Schwartzchild radius is a physical boundary though; it's just the event horizon, a mathematical definition. If you were free falling into a black hole you might not even notice when you passed through it. The black hole is still a singularity and speaking about it's density this way is absurd. (I mean absurd in the way it makes no sense, not as an insult to you personally.) These concepts of density at the local physical level and cosmic level are very different.