The remains of collapsed stars, black holes possess enormous gravities that pull in and annihilate any matter that strays too close. The latest evidence and theories for these bizarre objects are presented in this intriguing book, including how black holes were first predicted, how they form, their physical properties, and how scientists detect them. Also covered are the giant black holes now known to lurk at the centers of most galaxies and the possibility of using these objects as cosmic gateways.