#### Who Should Read This Book

This book is for the curious-minded, tech-savvy, popular science reader willing to examine a fresh perspective of the universe and the physical laws that govern, a perspective centred on a quantum mechanical computational model radically different from the Newtonian mechanical approach. It’s an enjoyable read, full of new insights.

## Synopsis

Most physical theories adopt a mechanistic view when examining natural phenomena where any system can be modelled as a machine whose initial conditions and dynamics govern its future behaviour.

In this book, *Programming the Universe — A Computer Scientist Takes on the Cosmos*, Professor Seth Lloyd proposes a radically different approach centred around a computational universe that programs and computes itself.

Although this statement and the book’s title sound like a nice piece of science fiction, it is not.

The author argues that the quantum computational model he (and other researchers) are proposing is equally valid as a natural and physical phenomena model. The theories of quantum mechanics, relativity, and the Standard Model of Particle Physics are not changed; they are, however, examined under a different lens.

The lens that Professor Lloyd employs is as follows: every quantum mechanical particle in the universe (photon, electrons, atoms…) can be represented as quantum bits or qubits. These qubits can be either information or instructions. The random collisions and interactions between them are operations that the universe has performed since its beginning and will continue to perform until eternity.

And what exactly is the universe computing? Itself!

The idea that complexity is coded into an organism from its inception and the organism’s evolution is just an unfolding of what has been encoded in it is an old philosophical concept that attempts to explain the emergence of new and complex features from simple forms.

Seth Lloyd took this idea further and applied it to the universe in a rigorous framework governed by quantum mechanics.

Below is a list of some of the fascinating topics covered in the book:

**Entropy**: aside from Professor Roger Penrose’s captivating dissection of entropy and the second law of thermodynamics in his book*Cycles of Time*, I have not come across a text that dedicates as many pages to this topic as this one. This book, however, treats the subject in the context of information theory, a substantial deviation from the classical discussion of ideal gases, thermal equilibrium, and entropy.**Quantum Computing:**This book is not about quantum computing, contrary to what the title might lead the reader to believe. However, it does go into some detail in explaining specific aspects of quantum mechanics and quantum computing that are relevant to the book’s central theme.**Computation**as a model for explaining natural phenomena is one of the most original thoughts in the book and its primary focus. The author examines fascinating issues such as the “universal computer” and our ability to predict the length of time a program needs to finish.**Complexity:**this is one of Dr Seth LLoyd’s main areas of expertise. It was a welcome and exhilarating, if not a slight deviation from the book’s main topic. His explanation of system complexity and*logical depth*, one of its measures, was pure joy.**Emergence**of complex features: We are all familiar with the story of the billion monkeys randomly typing on typewriters and how one of them will eventually come up with Hamlet, just by pure chance. Seth Lloyd takes this trivial (and inaccurate) analogy and modifies it to provide a compelling explanation of the emergence of complex features in the universe (such as life) with the help of quantum randomness. I think this section of the book was the richest and most insightful.

In summary, this small and fascinating book is well worth your time—there aren’t many books with a similar approach to physics.

#### Has the Book Achieved Its Aim?

The book aims to present a view of the universe based on computation, where every atom, molecule, and photon is a qubit undergoing constant quantum computations. The journey from the conventional mechanistic Newtonian view was not easy, but the author made it smooth, enjoyable, and accessible.

## Key Metrics

## Quick Review

**Recommended Read**

## Format

### Form Factor

**Hardback**

**ISBN-10:** 0-224-06438-X**ISBN-13:** 978-0224-064385

24 x 3.8 x 16.2 cm**223 **pages

## Themes

- Quantum Computational Universe
- Complexity
- Entropy
- Cosmology
- information Theory
- Universal Computers

- Quantum Mechanics
- Relativity Theory
- Second Law of Thermodynamics
- Quantum Computing
- Quantum Randomness
- Logic Circuits
- Quantum Gravity

## Content

**Well Structured, Smooth Flowing**

Although the book is divided into three parts, there is not much variation in the themes discussed. In effect, the author slowly introduces all the prerequisites required to assimilate his proposition on the quantum computational model of the universe. The story flows easily, and the logic is consistent and easy to follow.

**Original Content**

I have not come across a book investigating an alternative approach to the classical Newtonian mechanistic view for studying the universe. In this regard, the author’s theory is profoundly original. Modelling the entire physical universe as a complex system in which extraordinarily complex structures and beings can emerge is a rare theme in popular science books. This originality makes the book unique in its genre.

**General Tone**

The author’s tone is humble, unassuming, and welcoming. Professor Lloyd’s humour is light and in adequate amounts. The book presents itself as a serious but also fun and enjoyable text.

**Practical Usage**

The book is not very relevant to software engineers from a practical standpoint. It does, however, provide food for thought and makes for many interesting informal discussions for like-minded colleagues.

**Depth**

There is a bit of variation in the treatment depth of some of the discussions in the book. For example, entropy was dissected on many levels, which gave the reader a full 360 view of the topic, while the subject of complexity could have benefited from a broader exploration. I thought the paragraphs on quantum gravity and how this could be incorporated into the quantum computational model were lacking. Overall, the book’s central theme, the quantum computational model of the universe, was very well covered.

**Authority**

The author has spent decades researching and studying the concepts he presented in the book, and in that regard, he is the definitive authority. His ideas and theory are a testament to his deep knowledge and understanding of the subject.

## Style

**Writing Style**

The lucidity and intuitiveness with which Seth Lloyd approaches the multitude of subjects are characteristic of the author’s writing style. The depth of his knowledge, long years of research, and explanation skills make this work a delightful story to read. No paragraphs are dry despite the rarity of anecdotal and historical accounts. The author’s light touches of humour were always welcome.

**Accessibility**

Accessibility is a complex topic to assess for this book in particular. There are no equations, mathematical formulae, or intractable chains of ideas. Still, the whole discussion requires a good knowledge of computer science and quantum mechanics to appreciate the profoundness of the insights of the author’s theory. The author took great pains in describing entropy, bits, logic gates, and computation in their abstract form. The discussion appears to be trivial for someone with a background in software engineering and a solid understanding of physics. The other issues on quantum gravity, complexity, and the emergence of life were quick summaries that are hard to grasp.

## Author

## Bio

**Seth Lloyd** is a mechanical engineering and physics professor at MIT (Massachusetts Institute of Technology). His research has focused primarily on information and complex systems, especially quantum systems.

His work on quantum computation, quantum communication, and quantum biology has been instrumental, especially since it included the first feasible design for a Quantum Computer demonstrating the viability of quantum computing.