Scientists have determined that aliens differ in their level of development, so each humanoid must belong to some category - there are three of them. The Russian astronomer revealed the essence of each category: one of them includes humanoids, which feed on either the energy of the locality or the energy of the whole galaxy.
According to the expert, the amount of energy consumed by the planet's population determines the level of technology development, so that all civilizations can be divided into three types: those belonging to the first type consume all the energy located on the way from the parent star to the planet, individuals from the second category prefer to extract energy on their own, and third-class personalities are devouring the power of the entire galaxy.
Experts from the University of Rochester do not quite agree with this distribution of their Russian colleague: its scale seems to have a connection with the energy received, but it does not provide for waste, that is, the final consumer product that worsens the situation on the planet. For civilization to develop, society needs to think not only about the extraction and proper use of energy, but also about the search for methods that would help to nullify the negative consequences of the activities of extraterrestrial civilizations.