Black holes aren’t black! If there is one thing everybody knows about black holes it is that they are so dense that even light can’t escape. And yet, as Marcus Chown explains, black holes are some of the most prodigiously luminous objects in space.   So they’re not holes. And they’re not black. But they are among the most fascinating and counter-intuitive objects in the universe. Not to mention that they are, in Marcus’s phrase, “the stuff of physicists’ nightmares.” Why? Because the maths tells us that any star a little bigger than the sun will eventually collapse into a singularity – a point of infinite density and infinite temperature. And physicists don’t like infinities. What are they like? How were they investigated? Who figured it all out? And what do we still not know about them? We talked to Marcus Chown at his publisher’s offices in London. Marcus Chown – Head Of Zeus – £20