“We show that it is natural to introduce the concept of black-hole entropy as the measure of information about a black-hole interior which is inaccessible to an exterior observer. Considerations of simplicity and consistency, and dimensional arguments indicate that the black-hole entropy is equal to the ratio of the black-hole area to the square of the Planck length times a dimensionless constant of order unity. A different approach making use of the specific properties of Kerr black holes and of concepts from information theory leads to the same conclusion, and suggests a definite value for the constant.”

“Jacob Bekenstein found… in 1971 that every black hole must have an entropy proportional to the area of its horizon… Stephen Hawking then refined this by showing that the constant of proportionality must be… exactly one quarter. …entropy is supposed to correspond to a measure of information …Loop quantum gravity… [gives] a detailed description of the microscopic structure of a black hole. …a horizon can have, for each quantized unit of area, a finite number of states. Counting them, we get exactly Bekenstein's result…”

“In a previous paper we showed that a static (nonrotating) black hole cannot be endowed with exterior scalar-meson or massive vector-meson fields. Here we show that the same is true for massive spin-2 meson fields. We also extend the above results to the case of a rotating stationary black hole. We conclude from our results that a black hole in its final (static or stationary) state cannot interact with the exterior world via the strong interactions which are mediated by meson fields such as the π (scalar), ρ (vector), and ƒ (spin-2). A direct consequence of this is the impossibility of determining the baryon number of the black hole by means of exterior measurements alone. This results in the transcendence of the law of baryon-number conservation as originally predicted by Wheeler.”

“A black hole is the ultimate manifestation of a region of strong gravity. The pull of gravity in a black hole is so strong that even light cannot escape from it and time stands still.”

“anymore time in that black hole and ill go insane.”

“Black holes are where God divided by zero.”

“I'm sorry to disappoint science fiction fans, but if information is preserved, there is no possibility of using black holes to travel to other universes. If you jump into a black hole, your mass energy will be returned to our universe but in a mangled form which contains the information about what you were like but in a state where it can not be easily recognized. It is like burning an encyclopedia. Information is not lost, if one keeps the smoke and the ashes. But it is difficult to read. In practice, it would be too difficult to re-build a macroscopic object like an encyclopedia that fell inside a black hole from information in the radiation, but the information preserving result is important for microscopic processes involving virtual black holes.”

“Black holes set a limitation on the number of species of elementary particles—quarks, leptons, neutrinos—which may exist. And black holes lead to a fundamental limitation on the rate at which information can be transferred for given message energy by any communication system.”

“So whereabouts in my body might there be a black hole?”

“This year I'm a star, but what will I be next year? A black hole?”