You may wonder which quantum physics book is best for you. The answer will strongly depend on how much you know about science and possibly even quantum physics. It may also depend on personal preferences and why you want to learn more about quantum physics. Some people think word is king, others love illustrations with colorful images. Therefore, we decided for our quantum mechanics book reviews to not just give a mark on the book on total. Rather, we give marks for different categories, making the review process much more scientific.

In the following we will lay out our review categories and how we put marks on them for specific books. Marks for each category will range from one to five stars, with five stars being the best mark. We try to have our criteria for marks such that everyone can easily check the marks as one would expect from scientists. That is, we try to avoid marks that come about by subjective feelings.

## Motivation for Quantum Physics

Possibly the most crucial question is if a book provides a good explanation on why quantum physics is needed. This motivation should become evident already on the first few pages of the book. We believe that certain aspects of quantum physics, like the uncertainty principle and the particle-wave duality, or at least superposition of states should be named already during the first few pages.

Therefore, we add two stars (to the minimum of one star), if a book provides at least one region of physics where the classical physics comes to wrong results, and quantum physics is needed, during the first 20 A4 pages of the books. Since books can have different sizes, which would make comparison unfair, we take instead of 20 pages as many pages of the books as are needed to fill 20 pages of the normed size A4. In the following, we simply speak about the number of A4 pages and mean the mentioned renormalized number of pages.

We add another star, if the book explains the uncertainty principle during its first 20 A4 pages.

We add another star, if the book explains particle-wave duality, or at least the principle of superposition of states during the first 20 A4 pages of the book.

## Images

For images it is important that they are well adopted to the text and make explanations clearer. Any good book will abide to this basic rule, and we are unlikely to review a book that does not fulfill this requirement. However, differences can occur in the number of images and whether the images are in color.

If there is on average at least one image per two, four, eight or sixteen A4 pages, we add four, three, two, or one additional stars, respectively. Again, we renormalize page numbers to a book written in normalized size A4.

If at least some images are in color, we add one additional star, unless the book already has five stars.

## Formulas

The correctness of formulas is king, but for physics students, it is also important that there is a formula for each point of knowledge. Otherwise, doing calculations is not trained but needed for exams.

For formulas, we start with five stars. We subtract one star if we find more than one mistake per ten formulas, and we subtract two stars if we discover more than one mistake per five formulas. Unfortunately, quantum physics books are usually thick and there will be a risk that there are formulas with mistakes that we do not discover.

We subtract one star if there are on average less than two formulas per A4 page and we subtract two stars if there is less than one formula per A4 page.

## Quantum Physics Exercises

We award 1 star for exercises if there are no exercises at all in the book. You may say, it should be 0 stars in this case, but we adopt the standard range from 1 to 5 stars. We award 2 stars, if there are very few exercises and 3 stars, if there is on average at least one exercise every 10 A4 pages. We award one additional star if solutions to some exercises are provided, and two additional stars if there are solutions to all exercises.

## Additional Remarks

You may wonder, why we do not provide a mark for the quality of text. We considered this, but decided against it since the quality of text is very subjective. One book might be great for beginners, while another book might be great if you already have some prior knowledge. Instead of a star rating we will provide some additional text to each book where we for example mention who the proper audience is, in our minds. Since text is the most important part for a book, we will actually start with this text section.

## Summary for our quantum mechanics book reviews

We laid out the exact process of how we in our quantum mechanics book reviews provide marks for different qualities of the book. The qualities we mark are the motivation for quantum physics, the images, formulas, and exercises. The reviews are completed by an overview in the beginning of who the book is mostly aimed for.