Spacewarps

John Gribben explains what Einstein's theories of relativity tell us about the nature of the universe under extreme conditions and discusses some of the many mysteries that have yet to be solved. Do black holes and white holes really exist? Will spacetime expand forever or eventually shrink back down into a singularity? Is time travel possible? What is behind some of the anomalous observations concerning the red shifts of certain celestial objects? As an interested layman, I enjoy reading books like this for the mental stretching it requires of me. John Gribben does a very good job of making a difficult subject understandable, including the best analogy for spacetime that I have ever encountered.