Kardashev Scale

The Kardashev Scale is a scale that determines how much energy one civilisation can harness and utilise. The idea was first theorized in 1964 by human astronomer Nicolai Kardashev, who proposed that there was three types: a Type I, II and III.

However, it is possible that some civilisations, such as Humans, could progress further than a Type III and explore other galaxies and use the energy that the entire observable Universe emits.

Type I
These civilisations can only harness the energy from their entire home planet. This would mean resulting to cleaner and renewable energy sources, such as wind, tidal, solar and geothermal.

Type II
These civilisations can harness all of the energy from their home star, or in case of multiple stars in one system, the energy of those stars. One way to collect the energy of a star is to build a Dyson sphere or Dyson swarm, where large mirrors orbit the star and collect the energy.

Type III
These civilisations are known as galactic civilisations because they can harness the energy of an entire galaxy. They might have colonised or discovered every, single star system in the galaxy. They could even use the energy of the supermassive black hole at the center of the galaxy.

An example of this type of civilisation is Humans.