I always thought that leaving a conversation unfinished was a rude thing. What I was trying to find (as I have previously said) is how much a cat would have to weigh to collapse into a blackhole (assuming the cat when curled up would resemble a sphere with a radius of 15 cm). Last thing, how is “a more common problem” any helpful? I appreciate you trying to help but it feels like telling somebody, who is drowning, that breathing air instead of water would prevent drowning. Again, thank you for trying to be helpful.