John Barrow describes the development of Cosmology over the last hundred years and the array of possible Universes (and their pasts and futures). As usual with Barrow, the text is clear and lucid, although there are so many universes that it is impossible to keep track of them all. However, it appears that the generally accepted model of a Big Bang followed by inflation, with a multiverse of continuous inflation, is not so certainly established. Cosmology has a long way to go before it finds a wholly satisfying and observationally verifiable theory.
However, there are (it seems to me) some annoying errors in the book.
For example; in Figure 2.7a, illustrating positive, negative and zero curvature, the arrow indicating zero curvature seems to me to be pointing to an area of negative curvature. The arrow should be pointing to the next line of triangles up. What is disappointing about this is that it is a copy of Figure 2.1 in Barrow’s earlier book “Impossibility” where the same mistake is made.
Then Figure 8.7 shows the Weak force to be stronger than the electromagnetic, rather than the other way round. It also shows the weak, electromagnetic and strong forces coming together at one “triple cross-over” (p 192). But in fact, the weak and electromagnetic forces combine first and then the electroweak force equals the strong force at a higher temperature. Figure 5.3 in “Impossibility” has the same triple point, even though the text makes clear that the combinations occur at different temperatures.
It seems to me to be reprehensible, on the part of the author and the publisher, that the errors in the earlier book should have been repeated in a second book. I wonder what Barrow would say if one of his students made such errors.