Mary and John Gribbin's The Science of Philip Pullman's His Dark Materials is a nice starting companion for young readers interested in discovering more about how Pullman's universe uses our own science as a base for much of the storytelling. If you've ever wondered how experimental theology becomes science, this will be a good place to begin.
One of the most comforting aspects of the Gribbins' writing I realized right away is that they are two science-oriented minds unafraid of the word "stuff." Science of isn't something I'd recommend for readers looking to find the most precise schematics of how Lyra's six planets revolve around the sun without toppling over, but it is something I'd say is a very nice hand to younger readers. The Gribbins dive from topic to topic wielding metaphors like inner tubes for crossing the depths of scientific theories and workings. From this, they make comparisons and waves take on properties similar to a slinky, or use a postage stamp to calculate the minuscule width of an atom. Greek oracles and Sherlock Holmes also play helpful roles for analogies. All these come with a sense of humor, something my non-science mind was happy for, adding at one point explicitly that the universe is, thankfully, not full of fizzy soda. Therefore, if you had planned to, please don't shake us.
One of the weakest points in the book came when its authors began explaining a particular sort of science surrounding Lyra's alethiometer reading: the science of deduction. Deduction can't answer a question on an attacking group of Tartars in another country when its reader is a twelve year old child, deduction won't tell a person that Iofur Raknison killed his father, or that Iorek Byrnison should fix the subtle knife, or that sending away a particular pair of spies will mean death. Deduction certainly isn't cheeky enough to tell Lyra she dreamed about a head, and deduction doesn't answer Mary Malone in full proper sentences echoing back her thoughts. True, a storyteller like Lyra could easily lie her way through those questions, but unlike Sherlock Holmes her life centers around herself, her Jordan, and her Oxford.
Still, the authors of Science of are foremost scientists. Their book is an assist into the depths of that world. It's a comforting place to start if you're thinking to discuss His Dark Materials and don't wish for things like Schroedinger's Cat to leap out of the shadows at you. In Lyra's Oxford you could be swallowed alive by string theory or be roughed up by the butterfly effect if you're unprepared. Along with these subjects, readers are also treated to brief and often metaphorical explanations of the Northern Lights, the Quantum world, Jung's Collective Unconsciousness, and a new side to Asriel's coin-flipping analogy for the many worlds theory.
Overall, Science of is something I'd recommend to a younger audience. Appropriately, I picked the book up from the "young adults" section. I say a younger audience not because this is a pandering sort of novel, but more an introduction. Using Science of as a stepping stone has the potential to lead readers further into an interest in the workings of dark matter, or atomic structures. The goal for the Gribbins', I believe, was to create for readers a comfortable area in which to transition from reading and imagination to science and understanding, and their book is a nice start.