“There is … no such thing as the flow of time,” Garner writes in a preface to this searching contemplation of our relationship to time in the wake of Einstein’s theory of relativity, which demonstrated that the linear experience of time—which Garner describes as “beating heart of existence”— that humanity perceives is far from the reality. Time is instead a matter of perspective, as Garner demonstrates through clear and inviting summations of the science, from time dilation to space-time to the brain-bending discoveries of quantum mechanics and, at last, to the question of how it all came to be.

“Somewhere in Spacetime, I am ‘right now’ living out the moment of my first kiss,” he notes. That playful spirit freshens Garner’s tour of science’s current understanding of existence. A lively guide suitable for an engaged lay reader but more resonant and philosophical than most science texts, The Infinite Tree & The Rivers of Time is duty bound, of course, to bring readers up to speed on conundrums like, as Garner wryly puts it, “things that had been thought of as fundamentally ‘wavey’ behaving like particles, and things that had been considered fundamentally solid behaving like waves.” The material can be heady, but helpful illustrations abound, easing readers through the explanations of superposition and the holographic principle.

But it’s in his consideration of the possibilities, though, that Garner’s work stands apart. His discussion of parallel worlds and timelines, for example, bloom into explorations of free will and ethics. Likewise, an exploration of the complexities of entanglement builds to a rousing proclamation of our humanity, even in an existence where multiple versions of each of us might co-exist: What links these “sequential states” of an individual named Bob together, Garner argues, is “the experience of being Bob.” Put another way, each of us is “the product of the differentials between the states of those things. We are the product of change. We are change.”

Takeaway: A head-spinning dive into relativity, quantum entanglement, the illusion of time, and how our humanity connects to it all.

Great for fans of:Carlo Rovelli’s The Order of Time, Rainer Dick’s Special and General Relativity.

Production grades
Cover: B+
Design and typography: A
Illustrations: A
Editing: A-
Marketing copy: A