'The collection of authors is uniformly impressive ... well-written and pedagogical ... this volume provides a rewarding experience for researchers interested in gravity, cosmology, and fundamental physics.' Sean M. Carroll, American Journal of Physics 'As the contributions show, the 21st century promises to become again an exciting time for gravitational physics ... will find its prominent place on my shelf.' Claus Kiefer, General Relativity and Gravitation '... even those with only a 'popular science' interest in recent developments in particle physics, astrophysics, and cosmology will find much to interest them.' David Park, SIAM News '... a fascinating book, aimed at those physicists and mathematicians who have an interest in cosmology.' Mathematics Today "The pictorial presentation ... instantly captures the reader's attention. ... an eminently readable record of a well-timed chorus of friends for someone like Hawking sitting on a perch aloft who hit his 60th birthday and travelled against time and tide.' Contemporary Physics