Classifying alien civilizations with the Kardashev scale
There is a great deal of energy available to humans — I mean, unthinkable amounts of energy. But, we’ve barely tapped into it. Saying we have scratched the surface of energy harvesting is a gross overstatement. The sun, for example, produces well over a quadrillion (thousand trillion) joules of energy every second. To put that number into perspective, that’s more energy than our species has consumed in our entire existence.
At a time in modern history when our energy production and how it affects our climate are controversial, an interesting thought experiment comes to mind: the Kardashev scale. In 1964, Soviet astronomer Nikolai Kardashev imagined intelligent civilizations strewn across the Universe with capabilities far beyond our own. The result of his musings, the Kardashev scale is, at its simplest, an attempt to classify those civilizations in terms of intellectual and technological advancements.
There are three categories of this scale. The first category, and most primitive one, is a Type I civilization, also know as a planetary civilization: A civilization that stores and uses only a percentage of the energy delivered by its host star. That's the category our civilization falls into. We use some of the energy the Sun delivers to the Earth, be it directly in the form of solar light, or indirectly by burning fossil fuels or harvesting wind energy.
The next type is the Type II civilization. A Type II civilization uses all the energy of its host star. For earth to be considered Type II, we would have consume all quadrillion joules the sun provides. The most likely way this can be achieved is with a Dyson sphere, a hollow sphere that encompasses the host star’s surface and transmits all emitted energy to the civilization. It will be hard to find such a civilization since its star’s light will be blocked by the sphere, limited the survival of life on the planet.
The last and most advanced civilization is a Type III civilization, which harvests the energy of its entire galaxy. To understand how astonishing this is, realize that there are about a hundred billion stars in our own Milky Way, all producing as much or way more energy than our sun.
Type II and III civilizations would be far more advanced than us, in ways we could only imagine. It took only 200 years for us to ascend from horse-drawn carriages to supersonic jets and autonomous vehicles. Imagine if a civilization had more time to exist and grow, say on the order of thousands or millions of years. It would outstrip our technology many times over, achieving things we have only dreamed of. Of course, given that some solar systems and exoplanets are billions of years older than our own, there is no limit.
Energy on Earth is a political pivot, solely because it is extremely scarce. Its geopolitical importance starts international wars, crashes economies, and advances our technology. However, energy is like any other product that follows supply-demand laws. With more of it, its price will diminish tremendously. Energy will begin to play less of a role in conflict, because it simply won't be as valuable anymore.
With more energy, development in underprivileged communities will accelerate. More powerful transportation methods will be engineered, and humans will become a space-faring species. Powerful computers that can support artificial intelligence will be made. The possibilities are endless.
Perhaps, being a Type II or III civilization is in our future — that is, if the innovation never ceases. Until then, we will have to get by with our limited fossil fuels, hydroelectric dams, and solar panels.