A proton has not changed since the universe was a second old. A knot tied in a loop of string cannot be undone without cutting. A star burns steadily for ten billion years, and then, in its final hour, snaps into one of exactly three possible afterlives. Across the whole night sky, galaxies hang in a single vast web that looks the same in every direction. We are used to explaining each of these marvels with its own private science, in its own private dialect. This book proposes something quieter and far stranger: that beneath all those unrelated vocabularies, one and the same act of self-consistency keeps appearing, wearing a different costume on every floor of the cosmic building.

A Guide to Persistence introduces a way of recognizing that recurring act, a method built on a few plain ideas about what it means for anything to stay. Then it sets off climbing. From the nucleon at the bottom of the world to the global shape of the universe at the top, it stops at ten landings, the atom, the molecule, the living cell, the tissues of the body, the star, the collapsed remnant, the planet, the cosmic web, and asks at each the same three questions. The answers rhyme. The book is candid about what the rhyme proves and what it does not, and it is unusually honest about the places where the method has nothing to say.

There is no mathematics in this book. Every idea is carried by image, story, and ordinary language, so that a curious listener with no special training can follow the argument from the first bound quark to the last fixed point of the cosmos, and come away seeing the familiar world as a single, repeating sentence spoken in many scales.