The Library of Babel

Codex ET-2 takes its frame from a short story called The Library of Babel, written by the Argentine writer Jorge Luis Borges in 1941. The story is the reason the app exists. This page is a short tour of the story, what it proposes, and what changes when you build a finite version of it in software.

The Story

The narrator is a librarian. He lives in a library that contains every possible book.

Each book is 410 pages. Each page has 40 lines. Each line has 80 characters. The characters come from an alphabet of 25 symbols (22 letters, the period, the comma, the space). Every possible permutation of those characters, filling a book of that size, exists somewhere in the library. Exactly one copy of each.

The library is arranged in identical hexagonal galleries that repeat in every direction. Each gallery has bookshelves on four walls. Each shelf has thirty-five books. The librarians spend their lives walking from gallery to gallery, looking for a book that means something. Most books, of course, do not.

A typical volume in the library reads:

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A few books contain something. The narrator mentions, briefly, that the library must contain his own biography, the true history of the future, his eulogies, false versions of all of these, and every possible refutation of all of them. He has not seen any of them. Neither has anyone else.

Borges wrote the story in 1941. It is six pages long. It has been studied, indexed, and rewritten more times than it deserves and not nearly enough.

What the Story Is Doing

The Library of Babel is not about books. It is about combinatorial spaces, and what changes when you take “every possible thing of size N” seriously.

The library demonstrates two truths about combinatorial spaces that feel paradoxical until you sit with them:

Total libraries are mostly garbage. A space of every possible book is overwhelmingly full of strings of nonsense. The proportion of meaningful books to garbage books is so small it is effectively zero. The library “contains” your favorite novel only in the way that a piano “contains” Chopin: as a possibility, never realized without an enormous amount of work to find it.

Meaning is a discovery, not a creation. If everything that could be written already sits on a shelf somewhere, then writing a sentence is not bringing it into being. It is locating it. Borges is interested in what that does to the idea of authorship, and what it does to a person whose job is to walk the hexagons hoping to find something coherent.

The narrator is not optimistic. The librarians age and die without finding what they were looking for. The library does not care.

Codex ET-2 As the Small Version

The library Borges describes has on the order of 25^{410 × 40 × 80} books in it — a number so large it has no name. Holding it in any actual library, on any actual planet, in any actual universe, is impossible.

So Codex ET-2 picks a smaller combinatorial space that fits in a phone. An 8×8 monochrome bitmap. Sixty-four pixels, on or off. That gives 2⁶⁴ icons. Eighteen quintillion. The full catalog still vastly outstrips human attention — at one icon per second, a single lifetime sees about 0.0000000003% of it — but the math is finite, and the addressing is exact. See Inside the Warehouse for how the catalog is laid out.

What Changes When the Library Is Finite

A few things shift between Borges’s library and ours:

Every icon has an address. Borges’s librarians have no catalog. They wander. Codex ET-2 has a deterministic map: every icon sits at a specific (X, Y) and the same coordinate resolves to the same icon on every device. You can return to where you have been. You can send a friend an address and they will see what you saw.

You can edit your way to an icon. Tap a pixel to flip it. You have walked one step in the catalog. Borges’s library has no editing — you cannot find a book by tweaking a different book. The icons can, because of the way the warehouse is laid out.

The catalog is the math. There is no warehouse building. There are no shelves. The 2⁶⁴ icons exist exactly when the app draws them, and not before. Mathematics is the storage; nothing has been written to a disk.

You still cannot see most of it. That part does not change. A lifetime of swipes is statistically zero of the catalog. Most icons in Codex ET-2 have never been rendered to a screen, by you or anyone. They wait.

Why We Made It

The app does not have a goal. There is no level to clear, no leaderboard to climb, no daily streak to maintain. You walk the warehouse to walk it. You save what means something to you. You share an address with someone you like. That is the whole loop.

Borges’s story is the most precise expression we know of a particular human feeling: that the supply of possible meanings is larger than any one person could ever sample, and that walking it anyway is still worth doing. Codex ET-2 is a small, hand-built version of that feeling, set in pixels you can flip with your thumb.

Read the Story

The Library of Babel is collected in Ficciones (1944) and in Labyrinths (1962). It is six pages long. We recommend reading it once, then reading it again a year later.