I admired the premise of this book in terms of using symmetry as a starting point to see how the various pillars of physics like quantum mechanics, classical mechanics and electromagnetism are manifested and the connections between the subjects. In short, it is a masterpiece and actually demonstrates the line of thinking that most of my graduate physics professors only hinted at or suggested might be there (and I don't blame them, it's a deep and difficult topic that few have ventured into let alone mastered). Jakob walks a very fine line in trying to keep the math as simple as possible but also sufficiently powerful to connect and explain the ideas. The math is deep, there is no avoiding it at this level of exploration, but it's also very clearly annotated and described with the same clarity that other textbooks use to describe a simple pendulum. Keep in mind, this is not meant to be a quantum mechanics textbook or a reference for all of electromagnetism. The emphasis is on the origins of those areas, and the author does an amazing job. Bravo!