The last line of the Conclusion chapter (which was actually written first) reads: "For, with evident rhyme but illusive reason, the Universe is what it is!", but what does this mean? It means that the world around us clearly exhibits a logical pattern susceptible to mathematical analysis and description, but seeking a rationale — a how, or why — is quite different, and likely a futile subjective aspiration.
The concept of a block universe has been around for a very long time in philosophy. It is not especially popular because serious treatments of it must relegate phenomena such as motion, dynamical change, causality, and free will to our subjective reality only. That is, not ontologically real, and having no reality beyond conscious minds.
The loss of an objective present moment has implications for the nature of consciousness — which is extensively explored in this book as it is the cornerstone of its block universe proposal — and everything that we perceive or experience in relation to science. For instance, without dynamical change then there can be no objective causality.
Causality is an empirical principle by which we rationalise dynamical change, but it defies reductive analysis. It is employed as an explanatory tool in science allowing us to interpret data or mathematics, and yet it is an axiom of experience that is not present in any equations. The methodological reductionism of science allows change to be explained causally in terms of lower levels of change, until it then becomes inappropriate, as with entanglement and quantum contextuality. This contrasts with our real-world view of causation where we look for the bigger picture, effectively upscaling rather than downscaling. For example, we might say that a storm caused damage to a wall rather than the collective pressures of molecules in a turbulent region of the atmosphere moving its centre of gravity to an unsustainable position.
While eternalism posits that all times are equally real, the block universe model posits that all space and time is equally real and unchanging. The more perdurant approach taken in this book essentially posits that we exist in a true block universe, and that this explains the appropriacy of mathematical description, including the core notions of true and false. However, the book does not directly equate the space-time of relativity with this real block universe — this is presented in detail in the second book (The Parallax of Physics).
The book also presents a detailed account of special relativity and quantum mechanics that the casual reader may find very helpful in understanding the issues.