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The Billiard Ball Universe
A World With No Bottom
This book argues for a picture of the universe that is mechanical all the way down — and that has no down: layers beneath layers, without a bottom, each one made of ordinary pushing and colliding, like billiard balls.
The claim is deliberately modest. The book does not claim to explain why anything exists; no picture does. It claims something smaller and, I think, defensible: that of all the pictures on offer, this one is less arbitrary — it leaves one mystery where the alternatives leave many. Every serious objection to it is stated in the book at full strength, and the concessions stay on the page.
The book
First edition published August 2026 — a short illustrated volume, including a real dialogue in which an AI argues back; the concessions, in both directions, actually happened.
Paperback, 206 pages, ISBN 978-87-977519-1-6: Amazon.com ($14.99) · Amazon.de (€12.99, ships to Denmark) · other Amazon marketplaces carry it under the same ISBN.
Sources, corrections, errata
This address is printed in the book as the home of its manuscript
sources and its full correction record — every correction made
during writing, kept verbatim. Both live in the book's public repository:
github.com/nielsbj/billiard-ball-universe.
The tag first-edition-1.0 is the book you are holding, down
to the byte — the release is anchored in the Bitcoin blockchain via
OpenTimestamps, and the proofs are in the repository. Errata for the
printed edition live in its ERRATA file, dated against that
tag; there are none yet.
The letterbox is open: contact@billiardballuniverse.com — corrections, objections, questions.