**The Grand Design**

By Stephen Hawking and Leonard Mlodinow

I always wonder how could Stephen Hawking write so many good books given his disability. I heard that his assistants spent great effort in the transcription. Now he teamed up with Mlodinow in writing this book. Mlodinow is a good writer. He should be able to convey Hawking’s thought more effectively.

The reputation of this book preceded its publishing. Before it was printed, the publisher played up the theme that the book would prove that god is not needed in the creation of the universe. It could just be a promotion gimmick. But it kicked off heated discussion, before the book was even read.

I first read the book in the library of a cruise ship last year, just the essential chapters owing to limited time. Back in Hong Kong, I borrowed the Chinese version from the library. Then I bought the original version in Eslite. Thus I read the book three times. But don’t worry. It is not a thick book and can be read in a few days.

The actual content of the book is not as inspiring as I expected. It is a good description in layman term the development of physics and the modern theories. Many chapters are devoted to explaining the basis of reality, the history of scientific development and early experiments. On modern physics, there is a good description on general relativity and quantum mechanics. It even touches on modern particle physics of leptons and fermions, and its Standard Model which has been accepted by the science community several decades ago. All these are well known subjects which have been around for a long time. The book introduces the M theory which is a collection of several string theories aiming to represent a unification of all types of forces. But this is still work-in-progress. If one is interested in science news, all these have already been reported in the newspapers.

One subject which is of particular interest is an explanation on Heisenberg’s Uncertainty Principle. Most people understand that observation result is always uncertain because the observation itself, even the light shining on the object, could alter its state. But the definition of the principle is that one could not measure the exact position of an object and also its exact velocity. Position is one fixed point while velocity is speed of travel between two points. Following detailed mathematical deduction from formulas of several theories, Heisenberg proved the Uncertainty Principle as:

or dX . dP >= h/2

where dX is the standard deviation in position, dP is the standard deviation in momentum (mass x velocity), and h is the Planck Constant, which is a very very small constant number. The equation states that both dX and dP cannot be zero, and either could be very large while the other very small for the equation to hold true. Based on this principle, it is derived that that is no absolute emptiness. Vacuum has been found to have a very low level of energy. Furthermore, within a very small duration of time, there could be a burst of very high energy, in the form of matter and anti-matter annihilating each other in a small fraction of a second.

Applying this scenario to a macro scale, within 13 billion years, the age of the universe, which is only a very small fraction of the time of infinity, there could be a burst of very high energy in the form of equal amount of matter and anti-matter annihilating each other. It is still in progress and the remaining energy form the present universe, at least for another short moment of some billions of years.

As regard how the universe could appear from nothing, it is only mentioned in the last page of the book. Here are his exact words, not meant to be understood in an instant:

“Because gravity shapes space and time, it allows space-time to be locally stable but globally unstable. On the scale of the entire universe, the positive energy of the matter could be balanced by the negative gravitational energy, and so there is no restriction on the creation of the whole universe. Because there is a law like gravity, the universe can and will create itself from nothing. Spontaneous creation is the reason there is something rather than nothing.”