The concept of a black hole was first contrived in by John Michell 1783. For a long time, many notable scientists, including Albert Einstein, believed black holes were merely theoretical. However, in the last century, astronomers have gathered a good deal of observational evidence for the existence of black holes.
Different types of black holes form through different processes.
Because black holes severely warp the fabric of spacetime, they have a curious effect on the passage of time as seen by an outside observer.
Black holes are singularities: points of infinitely small volume with infinite density. However, the amount of a mass concentrated in a black hole varies, and the mass determines how wide the black hole's sphere of influence is.
A black hole is a region of space where the force of gravity is so strong that the escape velocity exceeds the speed of light.
What would happen if I fed animatter into a black hole? Could this be a treatment to get rid of black holes? No. Antimatter has positive mass just like ordinary matter, so the black hole would merely get larger and heavier. Whatever fireworks happened inside the hole, if the anitmatter met up with ordinary matter…
On page 20 of the March 2004 issue, you say the 3-billion-solar-mass black hole in the center of the galaxy M87 has an average density about that of air. I would love to understand how this makes any sense. The diameter of a black hole scales directly with its mass. That is, if you double…