Spacetime 102: Kardashev scale & Dyson swarm
The observable universe is about 90 billion light-years in diameter and has existed for about 13 billion years old with about at least two trillion galaxies, each with 20,000 billion x billion stars. And, it's the assumption that there are probably 40 billion earth-like planets in the habitable zone of their stars.
And we still see nobody out there.
But saying that there is nobody out there seems like we are giving up too soon even without looking. Organizations like SETI (Search for extraterrestrial intelligence) are actively looking for our probable new friends/enemies.
But what are we exactly looking for?
Humans started out with nothing but minds and hands that could build tools. We know that humans are curious, competitive, greedy for resources, and expansionist. And it would be good to assume that aliens would behave exactly in a similar pattern and grow as intelligent beings/creatures. In no time, we multiplied and our population grew while we consuming 20x more of the energy we previously consumed. This process will continue in the future.
Based on these facts, scientist Sir Nikolai Kardashev developed a method of categorizing civilizations, from cave dwellers to gods ruling over galaxies.
The Kardashev Scale is a method of ranking civilizations by their energy use.The scale has been refined and expanded on over the decades, but in general, it puts civilizations into four different categories.
Type I to IV
- Type I civilization is able to use the available energy of their home planet.
- Type II civilization is able to use the available energy of its star and planetary system.
- Type III civilization is able to use the available energy of their galaxy.
- Type IV civilization is able to use the available energy of multiple galaxies. They may also be able to tap into the energy released from the supermassive black holes which are believed to exist at the center of most galaxies.
To compare, you can compare a rat to a human. To rats, we could be seen as gods. Anything type of communication with them will not be comprehended by the rat. For us, they are a just nuisance and nonessential creatures.
Right now, humanity ranks at about 0.75.
If progress continues and we don't burn down our planet, we will become a full Type 1 civilization in the next few hundred years.
But how do we become Type II?
The path to type II is to gather resources from other planets and bodies like asteroids. This might start with outposts in space, then transition to infrastructure near the home planet, move on to colonies, and end with terraforming other planets, by changing their atmosphere, their rotation, or position.
At some point, civilizations may embark on the largest project to become a Type 2 civilization. i.e harnessing the energy of their star by building a Dyson Swarm/Sphere.
A Dyson sphere or Dyson swarm and similar constructs are hypothetical megastructures originally described by Freeman Dyson as a system of orbiting solar power satellites meant to enclose a star completely and capture most or all of its energy output.
Once this megastructure is finished, energy has become practically unlimited for molding the home system to however they see fit.
There are also type V of civilizations who can control collections of universes (aka superclusters) but the concept is so far beyond reach that it is even hard to imagine what a civilization like this might look like.
A Type 2 civilization might already consider humanity too primitive to talk to.
A Type 3 civilization might feel about as we feel about the bacteria living on the anthill.
So is this classification correct? Absolutely no. It is seen as a thought experiment that we use to predict and segregate what a possible civilization may or may not look like.
If a civilization beyond type II did exist, it would be hard not to see or view them. Their technology would be so far beyond our own that it would be clear to us. If they did exist, we should be able to see the remains and artifacts of their existence floating aimlessly somewhere in the universe.
But we haven’t found anything yet. But that doesn’t mean they are or were never out there. Maybe we are just not looking closely or looking in the wrong place or looking at it in the wrong way.