Those who read "A brief history of time" by Hawkings will find this treatise a natural extension to coverage, inter alia, of the ideas on gravity, the discreteness of spacetime, string theory, black holes, the holographic principle, loop quantum gravity, and gravitons. The relationship between modern thinking and Einstein's general relativity, developed with help from Boltzmann, is covered in much detail. Altogether an outstanding account of modern physics applied to cosmology. The mathematics is kept to a minimum, but that does not subtract from the clarity of the work. The book is not for the faint-hearted but is thrilling for those willing to think through the ideas expressed here.