Only Man on Earth

One of my favorite thought experiments came to mind a few days ago while I was sitting in an Irish pub called the Library, inspired by the immense knowledge around me and by a couple of Guinnesses.

All images are created with DALL·E for brainstorming.

Thought experiment

A single man lives in a prehistoric version of the Earth with no technological resources. He is immortal and arrives with no tools or equipment, just the clothes on his back.

He is a polymath with a general knowledge of craftsmanship, engineering, mathematics, chemistry, physics, manufacturing, geography, history, and philosophy.

His objective is to reconstruct civilization, rediscover technologies and build something similar to today’s world.

He would need to start at the very beginning of the tech tree, first mastering fire, hunting and gathering, shelter building, and crafting stone tools. Over time he would move on to more advanced technology.

The needle

I originally stole the idea from neuroscientist Sam Harris, who posed the question in an audio clip on his Waking Up meditation app. His question was this: How long would it take this man to construct a single metal needle, something commonplace in today’s society?

According to Wikipedia:

The earliest needles were made of bone or wood; modern needles are manufactured from high carbon steel wire and are nickel- or 18K gold-plated for corrosion resistance. High-quality embroidery needles are plated with two-thirds platinum and one-third titanium alloy.

We could all pick up something like this at Home Depot tomorrow, but it would take the only man on Earth years, possibly decades, to craft a metal object with modern precision. It could take months to achieve full food security and a solid shelter. He then might practice building stone tools, and start a search for a good mining location.

The point is, we are all standing on the shoulders of giants. Nearly nobody has the full breadth of knowledge required to build a needle from start to finish, let alone an iPhone. Our lonely hero could take thousands of years to build a rudimentary computer.

Solidarity, simulations, settlements

This thought experiment has captivated my interest and I want to continue writing and thinking about it. It offers insight into how dependent we are on one another, but it also inspires the imagination to think about what a single determined person could be capable of. Time is the only barrier for our adventurer, and he has no shortage of it.

Maybe his job is to achieve intergalactic travel before the Earth’s climate becomes uninhabitable. Maybe he’s in a simulation, trying to unlock branches of the tech tree to beat a high score, like some futuristic video game.

He might build settlements in different areas, traveling for years at a time before returning to one. He would find the inventions he left behind, bringing back memories of determination and frustration. He would feel like a time traveler, coming upon the ruins of a long-fallen civilization, himself being the sole inhabitant. He would remember the last time he looked at his now-collapsed stone house, thinking he would return in a few decades but instead return centuries later.

In other settlements, maybe an underground lair with a mine shaft, he would remember finding copper and iron for the first time, and rediscover his first prototype of a typewriter.

It’s nearly unconscionable what his existence would be like.

Record keeping

As soon as he has a record keeping system, he might start rewriting Nicomachean Ethics, Meditations, The Art of War and religious texts. Then he would move on to later philosophers like Thomas Aquinas and then renaissance writers, enlightenment writers.

He would record all his knowledge of chemistry, physics, mathematics, history, astronomy, engineering, computer science.

He would try to record modern stories from memory: Lord of the Rings, Harry Potter, Star Wars.

He might end up with a great library that he can pull information from. His vast knowledge of the surrounding environments, plants, animals, weather patterns, and philosophical lessons learned from living in solitude would inhabit the bookshelves too.

He might author stories and leave them for decades, forgetting about them, so that he can come back and enjoy them as a reader.

Informational critical mass

Given a form of record keeping, there is a maximum amount of information that can be stored by a single person. This is because of information decay. Information storage methods are imperfect and impermanent so there’s a need to maintain or replicate this information to new storage locations or new mediums altogether. At a certain point, information decay will outpace information creation and replication.

This seems like a non-issue in our society because anything uploaded to the internet is “permanent,” right? Permanent suggests forever, and forever is a long time. Think about how many people are necessary to maintain the information we have on the internet. A single person would not be capable of this without a breakthrough in automation.

The idea of the informational critical mass suggests that a single person developing a tech tree may never achieve AI technologies like large language models.

After recording on parchment, paper, then large disks, our hero may eventually use modern solid-state drives. If the informational critical mass is lower than the data needed to train LLM models, this branch of the tech tree is off limits.

What other branches of the tech tree might be off limits? Or would time prove to be the solution? Maybe his information storage and automation technology will continue to improve until the critical mass is high enough to train these models.

The future

There’s a lot to think about in this thought experiment. What would the planet look like after 10,000 years? 100,000? 1,000,000?

At the moment this has piqued my interest and I’m going to continue to write about it here in my notes.