Quote: "black holes are any matter that has an infinite decity and there for infinite gravity"
Black holes don't have infinite gravity, or else they would have sucked up the universe.
Infinite density != infinite mass. Gravity is based off mass, not density.
F = gravitational force.
D = distance
Quote: "F = G(mass1*mass2)/D squared.
(G is the gravitational constant, which has the same value throughout our universe.) "
http://www.qrg.northwestern.edu/projects/vss/docs/space-environment/3-mass-and-distance-affects-gravity.html
BTW, this formula can be used in a 2d simulation if you're feeling adventurous;)
Quote: "Can you explain that last sentence, please. It`s very interesting."
He's talking sci-fi mumbo jumbo.
As for fitting in a pin prick. It's because the atoms are extremely close together. There's huge amounts of space between atoms in a molecule, kind of like on the scale of how far away planets are from each other (though I don't know the exact ratio of space to atom in normal space
Think of taking a giant sponge and rolling it up into a tiny ball, it's like that, only way more compressed.
Hurray for teh logd!