This book pauses with sufficient frequency during its romp through science from particle physics to astrophysics to take pokes at theistic religion to make it clear that the author's intention is to cast a shot across the bow of "God of the gaps" thinking which seeks refuge in the question, "Why there is something rather than nothing." The author explains that phenomenal progress has been made in the past century that has brought us to the cusp of operationally addressing questions regarding origin, current condition and ultimate fate of our cosmos.
The book describes how in the process of pursuing these questions the very meaning of these questions has evolved along with our understanding of the universe. The recent findings that the dominate part (99%) of the universe is made up of material we can't see (i.e. dark energy and dark matter) has changed our distinction between something and nothing. After sighting examples from quantum physics and astrophysics that show; (1) particles appearing from nothing, and that (2) empty space is not "nothing" (it's a quantum field), the author proceeds to show that "nothing" is an unstable condition thus "something" was inevitable.
As with most recent physics, these explanations are not all that easy to comprehend, and beyond my ability to accurately summarize in a book review such as this. If you're interested to pursuing this subject further I recommend this YouTube Link
that provides a 50 minute lecture by the author that generally covers the first ten chapters of this book. The final four chapters explores a variety of possible concepts of the universe and/or multiverses.
I was fascinated to learn how controversial and uncertain the definition of "nothing" was. For scientists empty space--what formerly could have passed for nothing--now has a new dynamic that dominates the current evolution of the cosmos. Some contentious theologians on the other hand have insisted that their concept of "nothing" is more profound than anything that a scientist might understand to be "nothing." They insist that a "nothing" that contains the potential for "something" can't be truly "nothing." The author counters that a "nothing" which contains the potential of creation is no less worthy than the theist's God who has the potential to create. My own observation is that a "nothing" with no God exudes nothingness more completely than a "nothing" than includes the existence of God.
"We have discovered that all signs suggest a universe that could and plausibly did arise from a deeper nothing--involving that absence of space itself--and which may one day return to nothing via processes that may not only be comprehensible but also processes that do not require any external control or direction. In this sense, science...does not make it impossible to believe in God, but rather makes it possible to not believe in God. Without science, everything is a miracle. With science, there remains the possibility that nothing is. Religious belief in this case becomes less and less necessary, and also less and less relevant. ... I believe that if we are to be intellectually honest, we must make an informed choice, informed by fact, not by revelation."
The following are my own musings, not necessarily from the book:
I think the author is needlessly critical of supersymmetric string theory. He admits that it is a mathematical model that rationalizes the relationships between subatomic particles using 10 dimensions, but he says it has never explained or predicted anything in particle physics. Well, maybe so, but I foresee a possibility that a version of string theory may end up providing the best possible model for dark energy and dark matter. Dark energy is apparently everywhere in our universe including under our noses. Since we can't see it I propose that it may have something to do with those seven unseen dimensions. And perhaps the dark matter may consist of strings with no vibration. (I suspect some readers will laugh at my thoughts. I don't care. Thinking up crazy ideas is fun.)
The following are two concepts that were new to me and that I learned from this book:1. Faster than the speed of light?
If space expands at an ever increasing rate, it is possible for objects to move away from each other faster than the speed of light without violation of the theory of relativity. This is because the speed of light applies to speed through space, not space itself which has no limit on how fast it can expand. (i.e. Space does not obey the law of space-time.) If space itself expands at an increasing rate, eventually the expansion will exceed the speed of light and consequently light from the most distance stars will not be visible. This will lead to a condition in two trillion years when all stars that are not included within our local super cluster of constellations will not be visible to earth-like observers in our constellation. (It won't be earthlings doing the observing because our sun will burn out long before then.) This condition will erase all observable evidence of the big bang.2. Changing ratio of dark energy to dark matter
The ratio of dark energy to dark matter has been changing as the universe expands. Early in the history of the universe the constant quantity of dark matter was more concentrated within the smaller universe and thus it was the dominate constituent. Dark energy is different in that it remains at the same concentration throughout the expanding universe and thus in the distant future will be the dominate constituent as dark matter becomes diluted by the expanded size of the universe. We currently live at a unique time in the history of the universe when both dark energy and dark matter are measurable. The author described this as a special time in history because it is the only time when we would be able to tell how special it is.
Wikipedia.com has articles on dark energy and dark matter for those interested in reading more.