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Kardashev scale

Measure of the evolution of a civilization according to its energy consumption / From Wikipedia, the free encyclopedia

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The Kardashev scale (Russian: Шкала Кардашева, romanized: Shkala Kardasheva) is a method of measuring a civilization's level of technological advancement based on the amount of energy it is able to use. The measure was proposed by Soviet astronomer Nikolai Kardashev in 1964[1] and came to bear his name.

Three schematic representations: Earth, Solar System and Milky Way
Energy consumption in three types of civilization as defined by Sagan's extended Kardashev scale

The scale is hypothetical, and regards energy consumption on a cosmic scale. Various extensions of the scale have since been proposed, including a wider range of power levels (types 0, IV to V) and the use of metrics other than pure power (e.g., computational growth or food consumption).

Kardashev first outlined his scale in a paper presented at the 1964 Byurakan conference, a scientific meeting that reviewed the Soviet radio astronomy space listening program. This paper, entitled "Передача информации внеземными цивилизациями" ("Transmission of Information by Extraterrestrial Civilizations"),[1] proposes a classification of civilizations into three types, based on the postulate of exponential progression:

  • A type I civilization is able to access all the energy available on its planet and store it for consumption.
  • A type II civilization can directly consume the energy of a star.
  • A type III civilization is able to capture all the energy emitted by its galaxy.

In a second article, entitled "Strategies of Searching for Extraterrestrial Intelligence" and published in 1980, Kardashev wonders about the ability of civilization, which he defines by its capacity to access energy, to maintain itself and to integrate information from its environment. Two other articles followed: "On the Inevitability and the Possible Structure of Supercivilizations"[2] and "Cosmology and Civilizations", published respectively in 1985 and 1997; the Soviet astronomer proposes tracks to detect super-civilizations and to direct the SETI (Search for ExtraTerrestrial Intelligence) programs.

The scale defined by Kardashev has been the subject of two main re-evaluations: that of Carl Sagan, who refines the types, and that of Michio Kaku, who discards the energy postulate in favor of the knowledge economy. Other debates on the nature of the different types have allowed many authors to question Kardashev's original classification, either to complete it or to refute it. Two critical perspectives have thus emerged: one that questions Kardashev's postulates, judging them to be incomplete or inconsistent, and the other that establishes alternative scales. The Kardashev scale has given rise to numerous scenarios exploring the possibility of more evolved civilizations. These scenarios question, each one in its own way, the three postulates of Kardashev defining a civilization: energy sources, technology and the transmission of interstellar messages.

The framework for the search for, and detection of, advanced civilizations was constructed and theorized during the conference held in 1964 in Armenia, at the Byurakan astrophysical observatory. Starting from a functional definition of civilization, based on the immutability of physical laws and using human civilization as a model of extrapolation, the initial model of Kardashev was developed. Several scientists have conducted various searches for possible civilizations but without conclusive results. Based on these criteria, unusual objects, now known to be either pulsars or quasars, were identified. Kardashev has described in his various publications a set of listening and observing parameters to be taken into account; however, some authors, notably Samouïl Aronovitch Kaplan and Guillermo A. Lemarchand, consider that these are insufficient and need to be completed.