Have you ever consider that there is out there, in the vastness of the universe, some other civilization that could be much more advanced than our own? Even if you are not a fan of science fiction you probably had that thought cross your mind at least once in your life right? How could we be alone in this huge universe of ours? Well, let me tell you about this extremely interesting idea of scaling the level of technological advancement of a civilization base on the amount of energy it is able to control. This idea was introduced by the Soviet astronomer Nicolai Kardashev in 1964. He identifies three types of civilizations on his scale, named the Kardashev Scale after him.
Type I is what we call a planetary civilization. Its energy output is about 10^16 W. This civilization would need to harvest most of the energy it’s host start radiate on the planet. In addition, it would have to master nuclear fusion of hydrogen into helium. The absolute control of all renewable energies like wind, water, and geothermal energies, would be acquired. Basically, all forms of energies that could be collected on the planet would be under the control of that civilization.
Type II is a stellar civilization. It has exceeded the energy capability of its home planet and therefor needs to turn to other sources of energy. The energy output of such a civilization is about 10^26 W. That civilization would turn to its star to acquire most of its energy, by building a huge structure around it ( Dyson swarm, ring or sphere). Likewise, that civilization would control and harvest all the other planets, moons and asteroids for energy or building materials. A type II civilization as achieved total control over the stellar system that it originates from.
Type III is called a galactic civilization. This immensely advance civilization collects energy on the scale of an entire galaxy. The energy output for that type is around 10^36 W. At this point, collecting energy from planets and from Dyson Spheres would not meet the energy required by that civilization. They would need to become more innovative like harvesting energy from gamma-ray bursts or find a way to collect energy that is discharged by supermassive black holes. The type III civilization is so technologically advanced that their way of collecting energy most likely exceeds our comprehension.
The human civilization:
We humans have not even reached the type I status. But we are not that far behind. The American theoretical physicist Michio Kaku claims that if we increase our energy output by 3% every year, we would become a type I civilization in about 100 to 200 years, a type II in 1000-2000 years and type III in about 100 000 years. Let just say that we have a long way to go to become the owners of our own galaxy.