A core part of the longtermist project is making it very clear to people today that 21st century humanity is far from the peak of complex civilization. Imagine an inhabitant of a 16th-century medieval city looking at their civilization and thinking “This is it; this is civilization close to its epitome. Sure, we may build a few more castles over there, expand our army and conquer those nearby kingdoms, and develop a new way to breed ultra-fast horses, but I think the future will be like this, just bigger”. As citizens of the 21st century we’re in the position to see how wrong this would be, yet I think we’re prone to making a very similar type of error. 

To get past this error, a fun exercise is to try to explain the scale of 21st century civilization in terms of concepts that would be familiar to our 16th century friends. Then we can extrapolate this into the future to better intuit the scale of future civilisations. Here are two ways to do so:   

Military power: The United States military is the strongest armed force in the world today. How do we convey the power of such a force to citizens of the distant past? One way would be to ask them to consider their own military - foot soldiers, bowmen, cavalry, and all - and then ask how many such armies would be needed to rival the power of the modern-day US military. I’d guess that the combined armies of 100 medieval kingdoms would struggle to pose a challenge to the US military. Ditto for the 21st century. I expect the combined strength of 100 US militaries^[1] to struggle to make a scratch in the military power of future civilizations. 

Infrastructure and engineering capability: Men and women of the distant past would view modern-day human civilization as god-like engineers. Today, we build continent-spanning electric grids to power our homes and construct entire cities in a handful of years. How do we communicate this engineering prowess to our 16th century medieval city counterparts? I’m no civil engineer, but I estimate that the largest state governments of today could rebuild the entire infrastructure of a medieval city in a handful of months if they tried. Ditto for the 21st century. I expect that the civilisations of the future will be able to rebuild the entirety of Earth’s infrastructure - cities, power grids, factories, etc. - within a few months. To put that into context, imagine a civilisation that, starting in January, could rebuild London, Shanghai, New York, every highway, airport, bridge, port, and dam, by the time summer rolled around. That would certainly qualify them for the title of a supercivilisation!

1. ^{^}

   Again 100 is a rough guess - it could be more or less, potentially by orders of magnitude.

Some recent thoughts on two parameters that measure how technologically advanced a civilsation (civ) is. Feedback appreciated, especially directions to related work.

Main ideas/questions: A civilisation’s stock of knowledge (A) is related, yet distinct to its capital stock/Kardashev level (K). How can we model a civilization's stock of knowledge? And how intertwined are A and K? Is it possible to unlock all the truths of the universe whilst remaining a Kardashev Type I civilisation?

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How can we measure the level of advancement of a civilisation (civ)? There are two parameters that I want to outline here. 

The first is a measure of the stock of capital resources that the civ has. Let’s call this K. A civ that maximizes K is one that has colonized multiple galaxies/galactic clusters, whilst one on the very low end of the spectrum is a medieval village; the majority of the capital stock of this ‘civ’ consists of a few flimsy wooden huts. The Kardashev scale captures what I’m gesturing at here - it measures how advanced a civ is by considering the civ’s energy consumption. On the Kardashev scale the medieval village might be a Type 0.1 civilisation, whereas the civilisation that ‘maximizes humanity’s potential’ is Kardashev Type III or greater.

The second parameter is a measure of a civ’s knowledge, and I want to pull this out as being somewhat independent of a civ’s capital stock (Kardashev level). Let’s call this second parameter A. Concretely, let’s model the task of figuring out everything there is to know about the universe as a task of collecting 100 books. Book 1, 2, 3 are the simplest and easiest bits of knowledge to find - perhaps Book 1 is discovering fire, and Book 2 is developing writing. Every time a civilization advances its state of knowledge, it adds a book to its shelf. So Einstein and co. developing general relativity last century could be thought of adding, say, Book 24 to humanity’s shelf of knowledge^[1], and Niels Bohr and co. formulating quantum mechanics might be like adding Book 27 to the shelf. A civilisation that has maximized A knows everything there is to possibly know about the universe - it has collected all 100 books^[2]. 

An interesting question results from this: How intertwined is progression along the K and A scales? To what extent does being fixed at a given Kardashev scale (say, Kardashev level 1.1) constrain a civ’s attempt to move up the A scale (which we’re measuring by the number of books the civ has on its ‘bookshelf of knowledge’). 

My intuitions have always been that K and A are tightly intertwined - when I think of a civilization that knows all the truths of the universe, I imagine a huge galaxy-spanning empire that transforms entire planets into particle colliders to probe nature’s deepest secrets. But recently I have become less convinced by this. The advent of advanced AI could lead to an intellectual explosion in which, metaphorically, tens of books are added to humanity’s shelf of knowledge, all whilst we remain less than a Type I Kardashev civilisation. 

Some questions that result from this:

• How can we conceptualise and model a civilization's stock of knowledge? I’ve quickly conceptualised it here as accumulating books to a bookshelf; are there other ways that can be grounded in empirical data?
• Given a suitable model of a civilisation’s stock of knowledge (A), how intertwined is A with a civilisation’s capital stock K?
  • There are some clear constraints. For example, the LHC was required to discover the Higgs Boson. But the LHC was also the result of a huge international collaboration and is a mammoth piece of engineering; saying the LHC is out of reach of a medieval village would be an understatement. 
• Given a suitable conception of a civilization's knowledge, what’s the smallest Kardashev level required in order for a civilization to ‘solve everything’? In the framing here, what’s the smallest Kardashev scale required for a civilization to collect all 100 books? 

(1) -  General relativity might be Book 24, Book 5 or Book 99. It clearly can’t be Book 100 as we don’t have a theory of everything. 

(2) A quick tangent on the contents of Book 100 - Might Book 100 be the elusive Theory of Everything, or something else that biological intelligences like us cannot fathom, similarly to how chimps cannot grasp quantum mechanics? That’s an interesting question for sure, but one for another time.