Black Holes are so dense, and produce such intense gravity, that even light can not escape. Theoretical physicists predict that there are situations under which light can escape (which is called Hawking radiation).
Looking through the physics book I came across the black hole. If you went through a black hole your body would be stretched, flattened, and eventually pulled apart. This is on page This has to deal with Chapter 7 Gravitation.
[The black hole] teaches us that space can be crumpled like a piece of paper into an infinitesimal dot, that time can be extinguished like a blown-out flame, and that the laws of physics that we regard as 'sacred,' as immutable, are anything but.
When One Black Hole Eats Another. -- When two black holes are near each other, they will slowly orbit in a death circle. The larger black hole will eventually devour the other resulting in an enormous discharge of energy akin to the Big Bang
Researchers are attempting to create an Earth-size virtual instrument called the Event Horizon Telescope; a worldwide network of radio telescopes powerful enough to snap a picture of the supermassive black hole at the heart of our Milky Way galaxy.