Astronomy is often thought of as a very visual field, with lots of focus on what we can see. In The Invisible Universe, Matthew Bothwell explores those bits that we can’t see – although that’s a little bit of a disservice as those ‘bits’ amount to the vast majority of the cosmos. Most of the chapters focus on a particular part of the spectrum or a particular discovery. In every case there’s a narrative taking the reader through a potted history, including some very recent discoveries. It doesn’t try to walk linearly along the spectrum or through a history of discoveries, as the journey of humanity’s discovery hasn’t worked like that. No book like this could avoid jumping around in history, but overall there’s a logical flow. Throughout the book, concepts are well explained, using metaphors and analogies to create an accessible writing style. The author’s day job as an observational astronomer comes through, and there are nice anecdotes about trips to telescopes in Hawaii and Chile, and a few from his base at the University of Cambridge, an institution steeped in astronomical history.