r/AndyWeir

I’ve had this lingering question about the Eridians in Project Hail Mary for months, and now I’ve gotten several other people invested in finding an answer.

What was the Eridian equivalent of the printing press?

For humans, the printing press was one of the most consequential inventions in history because it allowed information to be reproduced accurately, efficiently, and on a massive scale. It helped drive the scientific revolution, the religious reformation, the American revolution, etc.

But Eridians communicate through sound and can't see. So how did they solve the same problem?

I’m assuming Eridians probably have perfect or near-perfect recall, since they can’t casually take notes and reread them the way humans can. But even with amazing memory, you still need some way to preserve and distribute information. Erid is also a massive planet, so relying on travel and word-of-mouth to pass information around the globe seems wildly inefficient.

My first thought is some kind of record/record player system.

Maybe they developed a physical medium like a vinyl record that stores sound, and copies could be distributed to libraries and private collections like a written book. You could then "play" a scientific paper, history book, and so on.

But that raises even more questions. A record player would require controlled, prolonged mechnical motion. Did Eridians have to invent electricity, or some equivalent power source, before they could mass-distribute recorded information? Could an earlier version have been mechanically powered, like hand cranks, water wheels, or even animals running on treadmills? (I recently learned dog treadmills were used to churn butter in the 1800s).

You could imagine an even more primitive precursor being something like those sculpturesthat produce music when wind passes through them.

Then there’s another problem: if early record players weren't easy to acquire, did Eridians have to go somewhere at a scheduled time to hear new information? Instead of checking a book out of a library, would you basically attend a "playing" of the newest publication like we go to the movies? If so, that doesn't seem any better than organized storytelling or word-of-mouth. I realize there's a lot of clarification and context needed here, but I can't stop thinking about all the details.

The other, much simpler possibility is braille.

If so, their printing press equivalent might literally be a machine that stamps or molds 3D characters into some material.

Their version of "paper" would probably need to be much more rigid and durable than ours, since the information has to retain its physical texture rather than just hold ink. But technologically, this seems like a much more straightforward and feasible path to mass-producing information.

The record/record-player explanation is way more interesting to me, but the tactile-writing explanation seems much more logical.

Unless there’s some third solution I’m completely overlooking.

TL;DR: What was the Eridian printing press: record + record player, or braille? And if it was recorded sound, how did they mass-produce and play recordings before developing modern machinery/electricity?