What kind of civilization have aliens built?



Although space agencies around the world have been studying extraterrestrial life (aliens) for many years, their existence has not been discovered yet.

Kurzgesagt, a YouTube channel that animates scientific topics, is conducting a thought experiment on the question 'What kind of civilization is built when aliens exist?'

What Do Aliens Look Like? The Kardashev Scale-YouTube


The observable universe is about 13 billion years old, is about 2 trillion in galaxy and 200 is believed to have been included (2 × 10 23) number of star.



If we limit

ourselves to the Milky Way galaxy , which is the galaxy that contains the solar system, it is said that there are 40 billion planets located in the habitable zone where life is likely to be born.



Given these numbers, the idea that 'there are absolutely no aliens' seems rather unlikely. If such aliens are discovered, human stereotypes can be overturned.



I don't know if the aliens are human race's allies or enemies. But before that, what kind of civilization did the aliens we were looking for have?



When civilizations other than human beings existed in this vast universe, the civilization level can be considered from the stone age level to the future human level. This movie is about exploring the universal rules that intelligent life forms follow by considering what aliens are like.



The civilization we are discovering at the moment is only human civilization, so we start our study here. In addition to the ability to create spirits and tools, primitive humans possessed characteristics such as curiosity, competitiveness for resources, and expansionist spirits.



When an intelligent lifeform has evolved on a planet other than the earth, it is natural to think that the intelligent lifeform also has characteristics similar to humankind. Furthermore, since the laws of physics do not change on planets other than the Earth, it is thought that intelligent lifeforms outside the earth also use 'energy' in some way. The progress of civilization can be calculated fairly accurately from two points: 'how much energy is extracted from the environment' and 'how the extracted energy is used.'



Primitive human beings could only handle their own bodies, but gradually they became able to use fire, and developed devices such as windmills and waterwheels that handle kinetic energy.



The amount of energy handled by the population and humankind is increasing year by year. Comparing 1800 and 2015, the population is 7 times larger, and the amount of energy handled by humanity is 25 times larger. The increase in the amount of energy handled by the population and humankind is expected to continue in the future.



Regarding such energy, Soviet astronomer

Nikolai Kardashev proposed in 1964 the ' Kardashev Scale ', which is a concept of 'dividing the degree of development of the cosmic civilization according to the usage of energy'. We have come up with a scale that considers the 'degree of civilization development' of an alien civilization that has not yet been discovered.



There are various revisions to the Kardashev Scale, but basically the degree of civilization is divided into four stages.



Type 1 civilization is a civilization that can utilize all the energy of the planet in which it lives.



Type 2 civilization is a civilization that can utilize the energy of not only its own planet but its own

planetary system .



Type 3 civilization is a civilization that can utilize the energy of the galaxy.



Type 4 civilization is a civilization that can utilize the energy of multiple galaxies.



Civilizations of less than type 1 range from primitive hunting life forms to humans hundreds of years later...



It is believed that civilizations of less than type 1 exist in the Milky Way galaxy in addition to humans.



Human beings are transmitting radio waves to explore these extraterrestrial civilizations...



The reach of radio waves is about 30 light years in diameter. Even if the reach of radio waves exceeds 200 light-years in diameter, the radio waves can only be emitted in a very small area, considering the diameter of the Milky Way galaxy at 100,000 light-years.



Even if an alien a few light years away catches a radio wave from humankind, the radio wave is attenuated and covered with noise, and it is possible that it is not known to have originated from an intelligent life form.



It is estimated that the human race of today is about 'type 0.75 civilization' on the Kardashev scale...



It is believed that a Type 1 civilization can be reached within hundreds of years if no accident such as 'Earth becomes a dead planet' occurs.



All Type 1 civilizations are considered to have a keen interest in the universe, as they are believed to possess characteristics such as curiosity, competitiveness for resources, and expansionist spirit. Therefore, it is considered that the civilizations of type 1 to type 2 advance to other planets than themselves, and colonize or

terraform other planets.



As civilization continues to expand, more resources will be needed, more space will be required, and more energy will be consumed. Therefore, it is possible that a civilization belonging to type 2 is creating a huge building such as a

Dyson sphere that covers a star like an egg shell and uses all the energy generated by the star. If such a huge building is completed, the amount of energy obtained will be virtually infinite.



Even if the energy obtained becomes infinite, if the alien has a curiosity, a competitiveness for resources, and an expansionist spirit, another star many light years away is sought for the next frontier. You may start looking for it. For a Type 2 civilization, the distance to another star could even be as much a sense to us as the distance from Earth to Pluto.



The path from Type 2 to Type 3 is hard to imagine for humanity today.



Is there a way to move to a distant place that takes thousands of years to move?



Even if you can move around, there can be the question of whether you can communicate with such a remote place. Perhaps, as a result of the move, the originally one civilization may be split into multiple civilizations. Interplanetary movement is a life-threatening challenge.



The closer a civilization is to Type 3, the more difficult it becomes to consider how it will be.



Type 3 may have discovered physics laws that humankind has not discovered, how to control dark matter, and how to move faster than light. We can even have difficulty understanding the technology and behavior that drives it.



We try to understand highly civilized aliens like Ali tries to understand humanity. Even aliens that are close to Type 3 may think of humanity as 'the civilization level is too low to speak.'



Type 3 aliens may be feeling something about humanity similar to 'the feeling we have in bacteria.' Such aliens may not think that “human beings are conscious”. All we can do is pray that they are good.



If there are aliens with a level of civilization that allows us to manipulate even another universe, we may be the creators of our universe.



If the above thought experiments using the Kardashev scale were correct to some extent, civilizations of type 3 and above would be expected to carry out activities on a scale that cannot be overlooked. It is almost certain that there is no Type 3 or higher civilization to do.



If 'type 3 civilization existed in the past but died out', then there should be some wreckage. However, the remains of huge structures such as the Dyson sphere have not been discovered.



The preferred alien civilizations for humankind are types 1.5 to 2.5. This level of civilization is more advanced than mankind and is not too far apart to understand. They may have completed a huge building and are sending vast amounts of information to the universe.



If there was such a civilization, they would also be looking for a civilization other than their own.



However, it is possible that these thought experiments are fundamentally wrong. It is an illusion of mankind that 'if an advanced civilization should expand into space for expansion,' human imagination may even be immature enough to imagine the true appearance of aliens. In any case, mankind has never encountered civilizations other than mankind, and it is difficult to imagine what aliens really look like, and we are just beginning to look for aliens.



in Science,   Video, Posted by log1k_iy