Book Review: The Grand Design by Stephen Hawking and Leonard Mlodinow

Recently I finished reading The Grand Design by Stephen Hawking and Leonard Mlodinow. Allow me to take a shot at summarizing each chapter in only one sentence.

1. "The Mystery of Being"
   Although classical realism is useful for describing everyday observable behavior, and quantum physics does the same for the subatomic level, M-theory, a family of different but overlapping theories, is our best shot at understanding our existence.

2. "The Rule of Law"
   Some view natural laws as the work of God, and for miracles to occur, exceptions have to be made to these laws; however, scientific determinism implies that there are no exceptions to the laws of nature.

3. "What Is Reality?"
   Since reality is based on sets of observations that meet expectations according to a predefined model, there can be more than one valid reality.

4. "Alternative Histories"
   The laws of nature only determine the probabilities of various futures and pasts rather than doing so with certainty, and as such, there can be more than one simultaneous future wherein future events can affect the past.

5. "The Theory of Everything"
   M-theory allows for 10⁵⁰⁰ different possible universes existing in 11 dimensions where ours has: 3 we traditionally experience, time (which like space can be navigated forward or backward), and another 7 that are curled up so small we can't perceive them.

6. "Choosing Our Universe"
   Since it is one of 10⁵⁰⁰ possibilities, rather than start with nothing and try to explain why our universe is what it is today, it is better to start with the universe as it exists today and work backward to validate the non-zero probabilities that it could have ended up this way.

7. "The Apparent Miracle"
   In the same way the remarkable coincidences of our solar system were rationalized by the realization that billions of other solar systems exist, the fine-tuning of our universe (e.g., Exactly 3 physical dimensions are required for planets to maintain stable orbits around suns.) can be explained by ours being one of many possible universes each with their own laws.

8. "The Grand Design"
   Since gravity warps both space and time, M-theory is based on a supersymmetric theory of gravity where scientific determinism describes a no-boundary condition universe that can create itself from random variations as demonstrated by the Heisenberg uncertainty principle.

I found this book to be easier to read than A Brief History of Time, but The Grand Design had fewer of the anecdotes that made me really enjoy its predecessor. Whereas A Brief History of Time laid out all of the scientific evidence with historical detail, The Grand Design alludes to them albeit with some good examples. At first I thought the arguments in this book were more philosophical than scientifically convincing; however, upon reflection philosophy and science go hand in hand.

Unification is alive in the lab.