Parallel worlds

Science fiction presents us with many wacky ideas, and you may wonder whether they have any connection to reality. Well in this book Michio Kaku describes plenty of ideas which seem like fiction but have been given serious consideration by physicists, for instance wormholes, warp drives and time travel. The book is in three parts, starting with a look at the current state of cosmology which is followed by a look at various ideas in physics related to parallel universes. The final part considers how we might reach such a universe. The book is easy to read, and is recommended to anyone wanting to find out more about the strange ideas from science fiction.

However it is a long book and I do think that the readers are presented with too many different ideas to get them clear in their minds. For instance 'Parallel Worlds' may refer to (i) Universes budding off our current one, (ii) Higher dimensions in physics (branes and the like) or (iii) Many worlds quantum theory. Many books fail to distinguish between these, and I hoped that this would do better, but I don't feel that it did. So the book is fine as an inspirational overview of the area, and a must for prospective sci-fi authors, but I would advise a reader wanting a starting point to study the physics to look elsewhere.