I love quantum mechanics. I just don't understand it. It is to me like embracing yes and no at the same time, like believing and not believing in the same instant, like being and not being as one. Yes, Virginia there is something beyond our understanding. And the wonderful thing about the postmodern world is that we know for a certainty (in as much as we can be certain about anything) that we really don't understand this world we have been thrown into. QM proves it. As Al-Khalili points out again and again, even the top physicists turn away when certain questions are asked and let them pass because they have no answer.
But I don't think it really matters what we think. The plain truth of the matter is that from our perspective as macro-creatures in a macro-world, with macro-minds and macro-mind modules molded by the evolutionary mechanism for a macro-world, quantum physics just doesn't make sense--or I should say, it makes good sense if we ignore the fact that the sense it makes is totally different in some very fundamental ways from the world in which we live.
Einstein understandably abhorred the spooky action at a distance--the strange entanglement of particles which has no basis in our conception and no basis in any science prior to QM--and worse yet, no explanation. (We prove things we don't understand.) As Al-Khalili makes clear no one knows how to account for the fact that no matter how far apart two entangled particles get, they seem to be in instantaneous "communication" with one another. Theoretically they could be on opposite sides of the universe. Well, the phrase "opposite sides of the universe" is meaningless, as is so much of our terminology when applied to the very, very large or the very, very small.
And "communication" is the wrong word since instant communication would in effect be information moving in excess of the speed of light, which is still impossible. (I wouldn't bet the ranch on it staying that way, however.) Yet, what other word is there? No one knows! Measure the spin of one entangled particle and you can bet that ranch that the other particle will have the predicted spin. Hocus-pocus, abracadabra--or something like that.
All of which tells me--all of what little I know about quantum mechanics--that the world is not as we think it is, and that down, down the dimensions to a very deep, deep "place," way, way tinier than we can imagine, way, way tinier than the Planck limit, there is--well, by definition, zero, but by imagination possibly a wondrous world so far beyond our ken that it might as well be magic. Indeed, it is surely beyond our notions of magic whatever, however, wherever, whenever it is.
Despite the wonderful color photos and drawings and fanciful artwork, and despite the detailed and even laborious explanations, I am afraid that Al-Khalili's book is not going to unperplex the perplexed. Frankly, QM cannot be understood; it can only be appreciated. And it can only be fully appreciated by those who understand the math. This book, in keeping with a long-standing book-biz tradition contains no math, or at least very little. Well, Schrodinger's equation appears on page 63, and is parsed, as it were, but not solved. It's really there more for decorative effect than anything else, as part of the artwork.
But quantum mechanics can be used. The amazing thing is that applications based on our understanding of it are used everyday all over the world in lasers, computers, CDs, DVDs, rockets to the moon, etc. In other words, it's the same old story. We know enough to employ the ideas for our benefit, but not enough to come to a full understanding or a final theory. My guess is we never will. Scientific knowledge expands like a widening circle in a pond of water as we know more and more about the very large and the very small and the very distant in time and space; but the pond is unimaginably large, large beyond the limits of our senses and our instruments, possibly infinitely large. And so the circle expands and expands but never reaches the shore, possibly because there is no shore.
Incidentally, of course neither the infinitely large nor the infinitely small are allowed in either cosmology or quantum mechanics. There is the Big Bang and no knowledge of what there was before the Big Bang, and of course there is nothing smaller than Planck and the "logic" of QM would allow.
Or is there?
The strength of this book is in the colorful and imaginative artwork and in the mini-essays from physicists such as Paul Davies, Chris Dewdney, Ron Johnson and others along with Al-Khalili's enthusiastic text. But if you think relativity was strange--well, comparing the strangeness of relativity to the strangeness of QM is like comparing the complexities of tick-tack-toe to those of three-dimensional chess.
By the way, Al-Khalili assures us on the copyright page (alluding of course to the "diabolical" Erwin Schrodinger) that "No cats were harmed in the making of this book."