The Grand Design is a short affair, 200 small pages, or just four and a half hours for the audiobook, which is how I ingested it. It also doesn't present any new original work by Stephen Hawking or his co-author, Leonard Mlodinow. Nonetheless, I got a lot out of it, and would recommend it to other physics buffs. I think people who are not already familiar with the field will have a tough time making much sense of the book. So much material is crammed into this small package that you won't really get the full message unless you already know something about things like Classical vs. Quantum theories, The Standard Model of Particle Physics, and String Theory. However, I would recommend that people who might not be ready for the whole book could gain a lot from the first two or three chapters.
The book is basically a condensed history of physics. They cover everything, from the earliest recorded philosophers, through Newton's founding of something we would recognize as science, to today's active string theorists and LHC jockeys. For me, this breakneck-paced survey of thousands of years of human thought was very helpful in pointing out patterns of scientific activity, and how these patterns have changed over time. Again, I think I got a lot out of it because I already have a fairly deep appreciation of the significance of things like Maxwell's Equations and the history of astronomy. The Grand Design helped me understand more deeply how paradigm shifts occur, and what it looks like before the paradigm shifts. For instance, they spend some time talking about how when experiments failed to detect the ether, it took decades before most people stopped trying to "fix" the ether theory and began to look at the implications of the fact that electromagnetic waves can apparently travel through a vacuum (whatever that is).
The first three chapters can probably be understood by anyone, since they cover ancient history and mostly classical theories. The authors talk about many individual philosophers and scientists, the context in which they worked, the experiments or theories which made them famous. These people are not as well known as famous politicians, entertainers, and sports figures, but they should be. Reading this book and learning the names of the greats seems like the least we can do to thank them for making the discoveries which make it possible for you to be reading this now.
Quantum Theory is presented by spending a long time discussing the double slit experiment. This unsettling and versatile experiment involves a particle source, a wall which may have one or two slits in it, and a screen behind the wall which can detect where the particles hit. When both slits are open, and the particles are electrons, photons, and the like, a pattern of interference is found on the detector which "proves" that the particles are behaving as a wave. If you want to understand what this means, and what it is to "know" something, The Grand Design will do a good job of helping you get there. The thing that really blew my mind was hearing that the double-slit experiment has been done with buckyballs, which are 60-atom molecules of carbon. Even these relatively "large" objects showed interference patterns, even when shot one at a time with several seconds between shots. The particles interfere with themselves, because all of the possible paths the particle could take are visited simultaneously by the wave-like nature of the "particle". Trust me, this makes more sense when they explain it.
The double slit experiment is so strange, yet so compelling, that Hawking and Mlodninow's focus on it greatly increased my acceptance of the reality of quantum physics. It doesn't make it comprehensible, but it made it more acceptable for me. I think this acceptance will help a lot in the future of my study of physics.
I was a little disappointed that The Grand Design presented string theory and M-theory as the best candidates we have for a Theory of Everything, without even acknowledging, let alone addressing, the criticisms Lee Smolin levels at string theory in his book, The Trouble with Physics. If you haven't read this, you must immediately do so, if you care about phsyics, science, and education. The Grand Design doesn't even do much in the way of explaining string theory at all. So the first two-thirds of the book is really the part I'm recommending.
Overall, The Grand Design is much less technical than other general audience physics books I've read by authors such as Smolin, Roger Penrose, and Brian Greene. There is no math at all in The Grand Design, and very few diagrams. It's a good candidate for an audiobook.
Just as The Trouble with Physics got me interested in Variable Speed of Light Theories and Quantum Gravity, The Grand Design has spurred further interest in my mind, this time on the implicatioins of the Alternate Histories interpretation of quantum physics. The experiments described leave no room for doubt that spooky actions at a distance are not only possible, but are the law of the universe. And travel across space is not the only thing quantum effects can do. It's unescapable that we actually create the past by observing the present. What could that mean if we could understand and manipulate these forces? What implications does this have for ideas like the notion that we can cause good things to manifest in our lives by thinking about them? What do you think will happen when they try the double slit experiment with a virus? The Grand Design has inspired all sorts of remarkable thoughts in my mind, and I hope it will in yours too.
