Black Holes
Black holes are without question the strangest of all celestial bodies. Until a few decades ago these ‘end-points of space-time’ could be thought to be merely a quirk in the mathematics of Einstein’s general relativity. Today we are reasonably certain that a black hole with a mass equal perhaps to four million times that of the sun occupies the center of our galaxy – and there is speculation that back holes may account for much of the ‘dark matter’ of the universe. In this lecture we go on an imaginary journey into a black hole in order to get a virtual feeling of the abyss that lurks behind our familiar notions of space and time.
For a popular narrative about black holes, see, e.g., Stephen Hawking, A Brief History of Time, Bantam Books, London, 1988
or, if you read Italian, my booklet Buchi Neri, Gribaudo Edizioni, 2003