Pandora had her box. Adam and Eve had their apple. Physicists have the expanding universe. Whether the universe expands forever into a deep freeze or eventually contracts back into a hellish speck containing all energy, the future looks grim. Michio Kaku in his book Parallel Worlds doesn’t let these portends cause any dismay as he provides plenty of ideas for dealing with and possibly escaping from a failing universe. For after all, opening a box wasn’t the end of the world, nor was eating an apple.
Nearly all cosmologists agree that our universe isn’t static. It’s apparently expanding at an accelerating rate. A long time from now, living beings, even ones adapted to a low density environment, will eventually be unable to process information, or anything else, and thus couldn’t live. This we deduce from many years research with telescopes, antennas and very fast computers. Step by step with the observations are the mathematical reasonings. The uncertainty principle, quantum mechanics, relativity, string theory all try to correlate the forces, fields and particles that constitute our existence. But, once entering into the realm of mathematics, the equations can lead to places that aren’t observable. Here, the fifth dimension is more than a musical group. String theory may need up to 11 dimensions for its resolution, but where are these dimensions located? Not much farther past this issue is the thought of many universes. Maybe the other dimensions are in other universes. In consequence, should our universe be no longer habitable, then perhaps we need just pop into another one and continue on.
This book on parallel worlds by Michio Kaku’s is a serious, science based review of alternate universes and their relevance to us. Using very little scientific jargon, Kaku takes the reader along the standard trail from Greek philosophers up to today’s cosmologists. Along the way, he includes notice of the works of Newton, Halley, Darwin, Einstein, Gamow and other luminaries. These references, however, don’t obscure the main thrust which is to enable understanding of our universe. Kaku explains why the night is black, how the uncertainty principle links to consciousness, and where quantum theory can lead to infinite realities. His main focus though is on the potential of string theory. He effectively argues that we need a theory of everything to deal with the expanding universe and, today, string theory is the best candidate. Kaku expects that one of the treats available with this theory is the ability to explore black holes and determine if they are a potential escape route to other universes.
As can probably be deduced from the previous paragraph, this book covers a lot of high-end physics in a very short time. But, as Kaku wanted, it can be read and grasped without any previous introduction to physics or cosmology. Given that the reader is expected to concur with the idea of future civilisations fabricating their own universe, there still remains a lot that remains a matter of faith. I compare this to the challenge of teaching a blind person about colour. Kaku easily passes this challenge. The book does draw on much at the forefront of today’s research in physics, but the reader isn’t left hanging.
As can be expected in a relatively small book that tackles a large topic, its pace is fast. By assuming no prior knowledge, Kaku needs to and does cover a lot before he gets to the life stages of universes. Universes and a unifying theory aren’t his sole objective as he considers today’s research into gravity waves and some attempts to discover the Higgs boson. He even contemplates research and engineering far into the future. For example, he sees the possibility for warp drive in the sense of a network of paths connecting people on disparate, distant planets. But the book’s focus is on a grand unifying theory and how its discovery could shape humanity’s future.
By using simple descriptions, Kaku shows off the works of today’s physicists so that anyone can understand and appreciate their work. He maintains a nice balance between detail and corollary. This, together with a copious glossary and a large ‘notes’ section, makes this book easily accessible to anyone. As can be expected, sometimes the topics drift especially to the philosophical side of things. However, given that the concept of the book is on alternate universes, this is fair game. Hence, whether to appreciate the complexity of our existence, have an exhilarating companion reader for Star Trek episodes, or simply to get hyped up on physics, this book works.
Our own world has more than enough challenges to keep us busy for eons. There may, however, come a time when we the Earth is a safe abode for us all. Then would be a good time to consider how we might survive the end of our universe. Michio Kaku in his book Parallel Worlds takes a step in this direction. Certainly we have many obstacles to overcome, but we are also showing the ability with which to overcome them.
Review by Mark Mortimer