Cosmological Koans: A Journey to the Heart of Physical Reality


Through more than fifty Koans—pleasingly paradoxical vignettes following the ancient Zen tradition—leading physicist Anthony Aguirre takes the reader across the world from West to East, and through ideas spanning the age, breadth, and depth of the Universe.

Using these beguiling Koans (Could there be a civilization on a mote of dust? How much of your fate have you made? Who cleans the universe?) and a flair for explaining complex science, Aguirre covers cosmic questions that scientific giants from Aristotle to Galileo to Heisenberg have grappled with, from the meaning of quantum theory and the nature of time to the origin of multiple universes.

A playful and enlightening book, Cosmological Koans explores the strange hinterland between the deep structure of the physical world and our personal experience of it, giving readers what Einstein himself called “the most beautiful and deepest experience” anyone can have: a sense of the mysterious.



This unique and beautifully written masterpiece transforms the deepest mysteries of our universe into a captivating and accessible quest for personal enlightenment.
Max Tegmark, author of Life 3.0

A gem of a book.
Carlo Rovelli, author of Seven Brief Lessons on Physics

A delight for readers raised on Gödel, Escher, Bach and The Dancing Wu Li Masters.
— Kirkus

This is calisthenics for the mind — it will stretch your imagination almost to the breaking point, and your understanding of reality will come away more healthy and flexible than before.
Sean Carroll, author of The Big Picture

A truly creative exploration of physics and its profound insights into the Universe.
Adam Frank, author of Light of the Stars


Kirkus →

Publishers Weekly →

The Wall Street Journal →

Max Tegmark, Facebook →

Nature →

Discover →

Additional Materials

Here are a couple of Koans that ended up on the cutting-room floor due to space constraints, but are still pretty fun. These are both PDFs.

A Lake of Many Reflections

Distant Causes

And here is a brand new Koan written after the book, regarding simulations of human experience:

A Simulacrum of Revenge