"What we have learned [about our Universe] is amazing. The Universe is 13.7 billion years old, it has a temperature of just under 3 degrees above absolute zero, and its spatial geometry is flat. The enormous expanse of space that we can see today, filled with hundreds of billions of galaxies, began as an intensely hot, almost infinitely dense soup of energy that has expanded and cooled since the beginning of time and space. Space itself is expanding in a great cosmic stretch that has recently begun to kick up a notch--the Universe is accelerating. And it is dark. The cosmic inventory is dominated by dark energy (72%) and dark matter (23%) [both of which we can't see]; normal matter, which comprises everything we [can see and] have ever been able to hold in our hands or examine with our instruments, comes in a distant third, contributing only about 5% of everything that is."
The above comes from the epilogue of this well-written, very informative book by Dr. Evalyn Gates, Assistant Director of the Kavli Institute for Cosmological Physics and a Senior Research Associate at the University of Chicago.
So what is this book about? As might be deduced from the above quotation, it's about the dark side of the Universe--dark matter, dark energy, even black holes.
Dark matter is the hypothetical matter that holds the galaxies together. WIMPs (Weakly Interacting Massive Particle), mentioned in this review's title, are one of the leading candidates for a type of dark matter. Dark energy is the hypothetical form of energy that permeates all of space and tends to increase the rate of expansion of the Universe. (A black hole in general relativity is a region of space in which the gravitational pull is so powerful that nothing, including light, can escape its pull. Black holes can't be seen directly.)
As mentioned, dark matter and dark energy can't be seen. How are astronomers to look for these things they can't see? That's where "Einstein's telescope" comes in.
Technically, Einstein's telescope is called "gravitational lensing." This book explains how it works. (Note that gravitational lensing is one of the predictions of physicist Albert Einstein's Theory of General Relativity.)
Einstein's telescope or gravitational lensing can be used to solve the biggest mysteries of the Universe by using ordinary luminous matter to discover dark matter and its distribution (as well as other dark objects such as black holes and objects too far away to be seen by our best telescopes such as other Earths). This discovered dark matter itself can be used to probe for the imprint of dark energy (and the very structure of space and time).
The final chapter is a fantastic discussion of "gravity waves" (or gravitational waves). A gravity wave is a fluctuation in the curvature of space-time which propagates as a wave, traveling outward from the source. Predicted again from Einstein's Theory of General Relativity.
This book is quite accessible. No prior knowledge of science of any kind is assumed. Those with a science background will find that the first three chapters cover familiar ground.
Throughout the book are helpful black and white illustrations (pictures, graphs, etc.). As a bonus, there is a section of ten beautiful full-color photographs.
Finally, my only minor problem with this book is that I would have appreciated in having all new terms introduced in the main narrative listed (with definitions) in a glossary.
In conclusion, this is an extraordinary and captivating book!! And don't worry! You don't have to be MACHO to read it. (MACHO stands for Massive Astrophysical Compact Halo Object.)
(first published 2009; preface; acknowledgements; glossary of acronyms; 12 chapters; epilogue; main narrative 270 pages; notes; illustration acknowledgments; index; about the author)
<<Stephen Pletko, London, Ontario, Canada>>