The First Hyperlinked Book

In 2007, a Lutheran pastor and a computer scientist made one of the most reproduced data visualisations ever printed. Eighteen years on, I rebuilt it so you can ask it questions.

In October 2007, a Lutheran pastor named Christoph Römhild emailed a PhD student at Carnegie Mellon called Chris Harrison. He had been assembling a dataset of biblical cross-references — the small marginal notes in a study Bible that point you from one verse to another — and he had already done a lot of the work of trying to see it. He wanted help rendering it.

The pair spent months looking for a form that would hold 63,779 connections without collapsing into noise. What they settled on was disarmingly simple. Lay all 1,189 chapters of the Bible along a horizontal axis, left to right, Genesis to Revelation. Draw every cross-reference as a single arc joining its two chapters. Colour each arc by how far it reaches.

The result is a luminous semicircular dome, and it is now on more walls than most album covers. It picked up an honourable mention in the 2008 International Science and Engineering Visualization Challenge. It gets reproduced in lecture slides, sermon decks, textbooks and Reddit threads, frequently without attribution, which is a shame, because the thing that makes it work is a genuine design decision and not an accident of the data.

Harrison has been explicit that they were chasing beauty ahead of function. That choice is why it endures. A more informative chart would have been forgotten.

What you can’t do with a poster

Here is the problem with a masterpiece printed at 12,240 pixels wide: you can look at it, and that is all.

You cannot ask it which chapter is the most connected. You cannot strip out the local chatter — the thousands of short arcs between neighbouring chapters — to see only the links that leap the entire length of the book. You cannot hover over Isaiah and watch its filaments light up across the New Testament. And you certainly cannot click an arc and read the two verses it joins.

So I rebuilt it as something you can interrogate. It lives here:

→ The Hyperlinked Book

It is Harrison and Römhild’s diagram. I want to be unambiguous about that. The arc form, the chapter axis, the colour-by-distance encoding — all of it is theirs, and every choice I made downstream was made inside a frame they built. What I added is motion, filtering, and the ability to read what the arcs actually say.

What’s underneath

The connections aren’t mine either, and they aren’t generated. They come from the Treasury of Scripture Knowledge, a cross-reference index compiled by hand in the nineteenth century and associated with the preacher R. A. Torrey, digitised and released under a Creative Commons licence by OpenBible.info.

It contains around 340,000 verse-to-verse references. Harrison and Römhild worked from roughly 63,000; the modern set is about five times larger. Collapsing it to chapter level gives 141,763 distinct chapter-to-chapter links, drawn from 328,531 individual references. Every arc on the screen is one of those.

Scripture text is fetched live from a nonprofit’s free API, using the Berean Standard Bible and the King James Version, both public domain. Nothing about the Bible is reproduced or stored in the page beyond the handful of verses quoted in the guided threads. Full passages open on Bible.com in whatever translation you prefer.

Three things you only see when it moves

The crown is the whole argument. Drag the minimum reach slider up and the dense magenta body of the dome evaporates, leaving a thin gold arch. Those are the links that jump a thousand chapters or more — Genesis to Revelation, Exodus to Hebrews, Psalms to the Gospels. They are rare, which is precisely why the exposure curve in my version lifts them: on the original poster they are there, but the sheer density of short-range links tends to drown them.

Hebrews 1 is a fan. Open that chapter and you get a tight spray of arcs reaching back into the Old Testament. Its author strings together seven separate quotations in thirteen verses to make a single argument. You can see the shape of the rhetoric before you read a word of it.

Genesis 2 and Revelation 22 are the same scene. The tree, the river, the presence, the curse, the access — everything lost on the third page is handed back on the last. On the diagram it’s the single widest arc in the entire field. It is also the first thing the intro sequence draws, before the other 141,762 arrive.

Why this is on an AI blog

Because the Bible is a citation graph, and it was built by hand.

We spend a great deal of effort now on retrieval — chunking documents, embedding them, building indices so a model can find the passage that bears on the passage in front of it. The Treasury of Scripture Knowledge is that, done by people, over centuries, on paper. Nobody had the finished corpus in front of them. The books were written by roughly forty authors across something like fifteen hundred years, in three languages, on two continents, and the ones at the end were quoting the ones at the beginning with no way to search them.

You can hold whatever view you like about how that density got there. It is worth looking at either way. Forty-three thousand of those chapter links cross between the Old Testament and the New — connections between documents separated by centuries, made by writers who could not have coordinated.

Look at the dome and you are looking at the structure of a document that was hyperlinked long before anyone had the word.

→ Explore it here

Credit where it is due: the arc-diagram concept is Chris Harrison and Christoph Römhild’s, 2008 — prints of the original are available from Harrison’s site and are worth owning. Cross-reference data from OpenBible.info, CC BY. Scripture from the Free Use Bible API. Built in a browser, one file, no tracking.