Ecumenopolis is a theoretical type of planet often depicted in sci-fi stories and films. It has an encompassing, single planet-wide city. For such a world to exist, we would need to have technologies that, for now, are way beyond our reach and are even difficult to imagine.
From today, the 15th of November 2022, there will be more than 8 billion of us. It is estimated that standing one next to another; we could all fit into 1400 sq km/500 sq miles. We could house everybody in tall skyscrapers and accommodate trillions into a planet the size of Earth. With current technologies, we would need the resources of many Earth-size hospitable-to-life planets to support such a large population. Transporting these resources from other star systems would not be energy efficient.
The only way it would work is to have a technology that could assemble material things, especially food and oxygen to breathe, from atoms or even protons and neutrons. All waste and rubbish would need just to be recycled this way. Even if it were possible, it would require enormous amounts of energy. We would need to dismantle other planets and build Dyson Swarm around the Sun that would capture all its energy or find another way to obtain it.
What could be even bigger than an ecumenopolis?
- A planet and its moon could be both ecumenopolises.
- More than one planet in a system could be an ecumenopolis.
- Many planetary systems could be made into ecumenopolis planets.
- The whole galaxy could be made into connected ecumenopolis planets.
- We could build ecumenopolis planets and arrange them in any way we like.
- In the distant future, planets and stars may become obsolete, and we will live differently somehow.
It is currently assumed that our world’s population will peak around 2080 at 10.4 billion; from then on, it will slowly decline. Such projections so far into the future are usually inaccurate, and they don’t consider impossible-to-foresee changes. This decline could be reversed because, at some point in the future, we will evolve to have children in technologically advanced societies. New children will have parents willing to have them and increase the prevalence of traits that will make people want children over time.
The question was: What would be bigger than an ecumenopolis?