From the celebrated scientist and bestselling author of Seven Brief Lessons on Physics comes a radical new vision of reality, mapping a watershed moment in both physics and philosophy. We are living in an age of scientific advancement on par with that of Copernicus, Galileo, and Newton: a period of discovery that has so fundamentally revolutionized our understanding of the world that it has shaken our most basic assumptions about who we are, and our relationship to all things. In On the Equality of All Things, Carlo Rovelli turns his attention to this reckoning, bringing expertise and clarity to the most mind-bending theories of modern physics. At the heart of this book are the most fundamental questions imaginable: What does it mean to say something exists? What is time, when we now know that it flows differently for different observers? And what kind of world do we live in, if the very building blocks of nature are defined only by their connections? Drawing from the latest advances in science and the teachings of ancient philosophers, Rovelli invites us into a universe that is not made of things, but of relationships. Time is a string of events, and there is no present time in the universe. Cause and effect is an illusion and reality is an intricate and fragile web. And knowledge itself will always be imperfect, impermanent, and incomplete. This is an awe-inspiring meditation on science, meaning, and being that charts the strange majesty of the world we’ve always lived in—from a thinker unafraid to challenge not only centuries of philosophers but our own intuitions about the nature of reality and what organizes it.