As anticipated here
, last Tuesday I stopped in at a bookstore after work and picked up the new Stephen Hawking book
, co-authored with Leonard Mlodinow.
First off, I should point out that I'm not a scientist, though it helps that I'm familiar with the Heisenberg uncertainty principle and some of the basics of quantum physics -- both of these concepts are critical to Hawking's discussion. In any case, this book is clearly aimed at non-scientists. It's only 180 pages and technical language is kept to a bare minimum, considering the nature of the subject. And there's essentially no math, although Hawking is quite emphatic about the importance
of mathematics to the real work of moving science forward; for example, the advance of human knowledge was seriously inhibited until the development (in India) of positional notation about 1,300 years ago, despite the many brilliant figures produced by earlier civilizations such as Greece and Rome.
The main problem the book sets out to address is the origin of the universe -- "Why is there something rather than nothing?" Since that question has traditionally been the province of philosophy, the book spends quite a lot of space on explaining how the world of atomic and sub-atomic particles and events, as revealed by quantum physics, works in a completely different way than the larger-scale world we can directly observe; it renders traditional philosophical approaches pretty much useless for understanding reality. The quantum world is almost unbelievably strange, and yet all of these phenomena have been confirmed by a vast range of experiments performed over nearly a century. Quantum physics is bizarre, but it is true
. And no, it does not legitimize this or that form of ancient mysticism, as quite a few less-than-honest authors have claimed. It's something entirely new.
This is not a book for people whose reaction to quantum physics is to throw up their hands and gabble blankly about how amazingly weird it is. Hawking pays you the compliment of expecting you to actually get
I won't try to summarize the book's whole argument, which is itself a summary of far more complex work, but the gist of it is this: based on what we now know about physics, absolute nothingness would be an unstable and indeed impossible condition. That's why there is something rather than nothing. There can't be nothing. The very nature of reality does not allow it. To understand why, read the book, and be sure to follow the argument carefully. After I finished reading, I had to spend some time re-thinking what I had read before I was sure that I really understood why the conclusion follows from the theories and from the observational evidence which has verified them. As I said, the book is written for the non-scientist, but the concepts it explains have taken generations for some of the most brilliant people in the world to work out and confirm by experiment. There's a limit to how easy it can be made.
Much attention has been given to Hawking's dismissal of God, a point barely mentioned in the book. Hawking is far too cautious to claim that science has proven that God does not exist (religious concepts are usually defined in such a way as to be immune to testing by experiment or observation, thus they are irrelevant to science). What he does say is that science has shown that a deity, or any kind of supernatural intervention, is not necessary
to explain the fact that the universe exists. And this is clearly true.
The book also addresses a related issue: the fact that the natural laws of the universe seem to be oddly well-arranged to allow for environments hospitable to life. If any of the laws of nature were even slightly different, the universe would be a different place -- in most cases, different in ways which would not allow life-bearing environments to exist. This has been known for some time, and theists have argued that the too-convenient laws of nature must have been fine-tuned by a deity to favor life.
The real explanation is that the nature of reality which made the universe inevitable also made it inevitable in every possible way, not just the one way we are familiar with. That is to say, there is a vast number of universes (Hawking estimates their number as a 1 followed by 500 zeroes), with every possible combination of different natural laws. Inevitably, the universe we are living in and observing is one of those where the natural laws do allow life; only such a universe could have allowed us to evolve.
It is awe-inspiring to know that our species is capable of achieving understanding of such profound and difficult matters.