The writing in the book is phenomenal, as Krauss always has a very accessible approach to discussing complex scientific topics, such as the creation of the universe. Obviously, Krauss spends a great deal of time in the book explaining the reason physicists have adopted the Big Bang model for the creation of the universe, but this isn't sufficient for his purposes. He has to explain the theory behind how the Big Bang would have been triggered.
This means discussing the very meaning of nothingness itself. As Director of the Origin Project, Krauss has frequently run into debates about the nature of nothingness, so he's extremely deft at handling this discussion. He addresses both the philosophical and religious notions of nothingness, but quickly moves on to explaining what physicists mean by nothingness. The key takeaway is that physics points clearly toward an unavoidable conclusion:
Nothingness is inherently unstable
Out of this instability, a universe of "nothing" would be expected to spontaneously generate an expanding "something" in the form of space, time, and the matter that fills it. The argument is well articulated, thorough, and is presented in a way that's accessible to pretty much all readers. Even those without a science background should find themselves able to fully understand the scientific concepts discussed in this book.
It is difficult to review this book without some measure of comparison with The Grand Design by Stephen Hawking & Leonard Mlodinow, which made a big splash when it came out because it said the universe could be created without the intervention of God. These books are perfectly in accord with each other, but I lean toward Krauss' book as the superior effort. The Grand Design is very unfocused in its approach, specifically in the sense that it's not really clear what the target audience is. I think Krauss is much more focused in his approach, as described in his sub-title. This book is clearly about "why there is something rather than nothing" ... and if you're interested in that subject, then this book will give you the basic scientific understanding that you need.
Publisher: Free Press
202 pages (11 chapters + Epilogue + Afterward by Richard Dawkins + Index)
Release Date: Jan. 10, 2012
Science has been effective at furthering our understanding of nature because the scientific ethos is based on three key principles: (1) follow the evidence wherever it leads; (2) if one has a theory, one needs to be willing to try to prove it wrong as much as one tries to prove that it is right; (3) the ultimate arbiter of truth is experiment, not the comfort one derives from one's a priori beliefs, nor the beauty or elegance one ascribes to one's theoretical models.
As a theorist, I feel that speculation is fine, especially if it promotes new avenues for experiment. But I believe in being as conservative as possible when examining real data, perhaps because I reached scientific maturity during a period when so many new and exciting but tentative claims in my own field of particle physics turned out to be spurious. Discoveries ranging from a claimed new fifth force in nature to the discovery of new elementary particles to the supposed observation that our universe is rotating as a whole have come and gone with much hoopla.
There are three main observational pillars that have led to the empirical validation of the Big Bang ... the observed Hubble expansion; the observation of the cosmic microwave background; and the observed agreement between the abundance of light elements--hydrogen, helium, and lithium--we have measured in the universe with the amounts predicted to have been produced during the first few minutes in the history of the universe.
Physics is, after all, an empirical science, driven by experiment and observation.
... among any sufficiently large number of events, something unusual is bound to happen just by accident.
If we wish to draw philosophical conclusions about our own existence, our significance, and the significance of the universe itself, our conclusions should be based on empirical knowledge. A truly open mind means forcing our imaginations to conform to the evidence of reality, and not vice versa, whether or not we like the implications.
Empty space is complicated. It is a boiling brew of virtual particles that pop in and out of existence in a time so short we cannot see them directly.
At the heart of quantum mechanics is a rule that sometimes governs politicians or CEOs--as long as no one is watching, anything goes.
... quantum mechanical systems explore all possible trajectories, even those which are classically forbidden, as they evolve in time.