This book, *Quantum Mechanics – The Theoretical Minimum*, is written by Leonard Susskind and Art Friedman. It is the second volume in the Theoretical Minimum series. The first bestselling volume by Leonard Susskind was about classical physics. This second volume intends to make quantum mechanics “as simple as possible, but no simpler”. We find that for anyone not shying away from formulas, they really nailed it.

The roughly A5 size book is comparable easy to read: we managed reading 42 pages per hour in the middle of the book. This makes it possible to read through the roughly 350 pages in a spare weekend, which is a great plus of the book. Simple exercices help you ensure staying on track with your reading. The chapters, called lectures, are

- Systems and Experiments
- Quantum States
- Principles of Quantum Mechanics
- Time and Change
- Uncertainty and Time Dependence
- Combining Systems: Entanglement
- More on Entanglement
- Particles and Waves
- Particle Dynamics
- The Harmonic Oscillator

## Motivation for Quantum Physics

The first lecture starts with a subchapter called “Quantum Mechanics Is Different”. There, you will learn that quantum physics is needed for very small particles, and that quantum measurements are conceptually different from classical measurements. Already the second subchapter is “Spins and Qubits”. The book chooses this modern approach over starting with particle-wave duality. The unusual, but great introduction makes the difference between classical and quantum physics very clear.

It is noteworthy that the uncertainty principle appears already on page 20. However, it mentions not only the inability to measure coordinate and momentum of a particle at the same time. It also mentions the inability to measure the spin at different orientations at the same time. Neat! And later in the book, even the more general uncertainty principle is derived.

The motivation also governs the superposition of states during the first 42 pages (corresponding to 20 A4 pages). Thus there is nothing to complain about the motivation. And 5 stars it shall receive!

## Images

The images in the book do greatly help with the understanding of the topics covered. Since the text is so comparable simple, it does not really matter that the book contains fewer images. We counted 24 images on a corresponding to 165 pages of A4 size. That is roughly one image per 6.9 pages of A4 size. Since all images are black and white only, we can award only three stars for the images. After all, we do have our review principles for a reason. But as said, in practice we did not see any problem with this fairly low number of images.

## Formulas

Calculations in this book are really done step by step. That means, that you rather may see more formulas than other books would have shown for the same content. There are more unnumbered equations than numbered ones, and altogether we counted close to 600. That is clearly enough for such a comparably thin book.

We can also congratulate the authors for achieving a very high degree of correctness of formulas. In a quick read through the book we did not discover a single mistake in the formulas! Even so, we nearly certainly have overseen one or the other, this is very unusual. Thus, all in all, we can gladly award five stars for the formulas in the book.

## Quantum Physics Exercises

The exercices in *quantum mechanics – the theoretical minimum* are fairly simple. They typically only involve one or two steps. Nevertheless, doing them will help any self learner to stay on track. Except for one or two exercises, there are no solutions. Since the exercises are so simple, this is, however no problem in our eyes. Still, to stick to our review principles, we award only four out of five stars for the exercises.

## Summary: Quantum Mechanics – the Theoretical Minimum

*Quantum Mechanics – The Theoretical Minimum* by Leonard Susskind and Art Friedman is a fantastic book. It is very accessible for the amateur scientist who does not shy away when seeing formulas. But with simple formulas and exercises and crisp clear explanations, it is also a great book for physics students. Probably not the only quantum mechanics book. Topics like perturbation theory or addition of angular momenta are not treated at all. But it is a very understandable book, that can be worked through in a spare weekend. After doing so, conquering one of the more advanced books will be so much easier. What’s next? You probably either want to get the book or compare with other great quantum physics books.

Motivation: | (5.0 / 5) |

Images: | (3.0 / 5) |

Formulas: | (5.0 / 5) |

Exercises: | (4.0 / 5) |