The Fabric of Reality – Part I: The Good Stuff

Back in June, I wondered how long it would take me to read The Fabric of Reality, by David Deutsch. Well, it took just about a week. This is not a book to tackle at the end of the day. The book is so challenging, it’s physically tiring to read and think about and react to. That’s why I have a lot I want to say, but since I can’t stand long blog posts, I’m going to divide my response into two parts: what I like and what I don’t. First, the good stuff.

The early chapters are exciting. I totally emphasize with his childhood dream of understanding everything. (I wanted to be Leonardi da Vinci.) I like the way he draws unexpected connections between disparate fields. I agree that the role of science is to find better explanations. So I was very intrigued by his desire to synthesize a true Theory of Everything, not just physics, but Life, the Universe, and Everything.

The four strands:

The book’s Theory of Everything is based on these four fields of knowledge, as expanded on by these four thinkers:

  • Quantum Physics – Hugh Everett
  • Evolution – Richard Dawkins
  • Epistemology (study of knowledge) – Karl Popper
  • Computability – Alan Turing

As stated in the dedication, the book takes these ideas seriously, and pursues them to conclusions that make many people uneasy (especially the Many Worlds Interpretation). The book gives you primers on each of these fields and steadily draws them closer to each other.

While the way these are woven together is fascinating, I wondered: Why these four? The closest explanation comes toward the end when he says what they have in common is that each are accepted and rejected by the very people who use them. That’s interesting, but why does that make those the four threads vital to understanding Everything? In the penultimate chapter about the four strands he argues that they need to be brought together, but doesn’t quite succeed in doing so. (This reminds me of how The View At the Center of the Universe also fails to completely achieve its ambition.)

The coolest ideas:

The argument in Chapter Two, that the two-slit experiment can best be explained by the many worlds interpretion is so elegant and beautiful, I’m willing to believe in the multiverse. In essence, the photon that goes through the slit in our universe interferes with all the other photons going through the other universes. There’s no travel between the universes, but they do weakly interact, growing weaker as they diverge.

In Chapter Eleven, he argues there is no such thing as the “flow of time.” Our perception of time is our conscious awareness of the difference between the present and the past. Since the universe is constantly changing, the more distant past is more different, thus contributing to the illusion that the past is flowing away from us, and that we are flowing into an uncertain future.

In Chapter Eight, he emphasizes that organisms aren’t the replicators, genes are. He argues that genes are encoded knowledge about the environments they are adapted to. Because of this information, if you looked at the same strand of DNA across the multiverses, you would find that the encoded genes would have the same sequences across the universes, whereas “junk” DNA would vary randomly. I love the image of this imposing a crystalline structure across the universes.

Also in Chapter Eight, the book suggests that maybe the universe hasn’t existed long enough for lifeforms to evolve with the power to change the universe on a scale we can observe. Remember, we and our descendants have five billion years to figure out what to do when the sun expands. Plenty of time to colonize the universe. It reminds me of the green stars in Learning the World, which are evidence of spheres of life gathering around the stars.


The Terminology and Summary sections at the end of each chapter are very helpful. However they underscore the gross omission of Notes. Without thorough footnoting, it’s impossible to see where he gets some of his arguments. Oops. Now I’m starting to veer into what I didn’t like.

A goldmine of mind-blowing ideas.