When I was 15 or 16, I worked out (just for my own satisfaction) how much plutonium or uranium would be needed to make a gun-type fission weapon. Years later, when the (approximate) amount was unclassified, I found that what I'd done working from data in books from local public library was less than a half a kilogram off from the "actual" amount. Scary.

But this big ol' hole, I have some questions about it. If it's producing a B-flat note as it sucks things into it, what note is it making on the other side, where the stuff is spit out? Could we vary its sound by controlling the spacetime oscillations and thereby make it into a rather large accordion or banjo? And the sound it makes -- is this what is meant when astroguys talk about the "blues event horizon"?