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The Kardashev scale

The Kardashev scale is a method of measuring a civilization's level of technological advancement, based on the amount of energy a civilization is able to utilize. The scale has three designated categories called Type I, II, and III. A Type I civilization uses all available resources impinging on its home planet, Type II harnesses all the energy of its star, and Type III of its galaxy. The scale is only hypothetical, but it puts energy consumption in a cosmic perspective. It was first proposed in 1964 by the Soviet astronomer Nikolai Kardashev. Various extensions of the scale have been proposed since, from a wider range of power levels (types 0, IV and V) to the use of metrics other than pure power.


In 1964, Kardashev defined three levels of civilizations, based on the order of magnitude of power available to them:

Type I

"Technological level close to the level presently attained on earth, with energy consumption at about 4×1019 erg/sec[1] (4 × 1012 watts.) Guillermo A. Lemarchand stated this as "A level near contemporary terrestrial civilization with an energy capability equivalent to the solar insolation on Earth, between 1016 and 1017 watts."[2]

Type II

"A civilization capable of harnessing the energy radiated by its own star (for example, the stage of successful construction of a Dyson sphere), with energy consumption at about4×1033 erg/sec.[1] Lemarchand stated this as "A civilization capable of utilizing and channeling the entire radiation output of its star. The energy utilization would then be comparable to the luminosity of our Sun, about 4 × 1026 watts."[2]

Type III

"A civilization in possession of energy on the scale of its own galaxy, with energy consumption at ?4×1044 erg/sec."[1] Lemarchand stated this as "A civilization with access to the power comparable to the luminosity of the entire Milky Way galaxy, about 4 × 1037 Watts."[2]

Energy development

Type I civilization methods

  • Large-scale application of fusion power. According to mass-energy equivalence, Type I implies the conversion of about 2 kg of matter to energy per second. An equivalent energy release could theoretically be achieved by fusing approximately 280 kg of hydrogen into helium per second,[6] a rate roughly equivalent to 8.9×109 kg/year. A cubic km of water contains about 1011 kg of hydrogen, and the Earth's oceans contain about 1.3×109 cubic km of water, meaning that this rate of consumption could be sustained over geological time scales.
  • Antimatter in large quantities would have a mechanism to produce power on a scale several magnitudes above our current level of technology. In antimatter-matter collisions, the entire rest mass of the particles is converted to kinetic energy. Their energy density (energy released per mass) is about four orders of magnitude greater than that from using nuclear fission, and about two orders of magnitude greater than the best possible yield from fusion.[7] The reaction of 1 kg of anti-matter with 1 kg of matter would produce 1.8×1017 J (180 petajoules) of energy.[8] Although antimatter is sometimes proposed as a source of energy, this is currently infeasible. Artificially producing antimatter according to current understanding of the laws of physics involves first converting energy into mass, so there is no net gain. Artificially created antimatter is only usable as a medium of energy storage but not as an energy source, unless future technological developments (contrary to the conservation of the baryon number, such as a CP Violation in favour of antimatter) allow the conversion of ordinary matter into anti-matter. There are a number of naturally occurring sources of antimatter [9][10][11] we may theoretically be able to cultivate and harvest in the future.
  • Renewable energy through converting sunlight into electricity by either solar cells and concentrating solar power or indirectly through wind and hydroelectric power. Currently, there is no known way for human civilization to successfully use the equivalent of the Earth's total absorbed solar energy without completely coating the surface with man-made structures, which is presently not feasible. However, if a civilization constructed very large space-based solar power satellites, Type I power levels might be achievable.

  • Figure of a Dyson swarm surrounding a star

    Type II civilization methods

  • A Dyson sphere or Dyson swarm and similar constructs are hypothetical megastructures originally described by Freeman Dyson as a system of orbiting solar power satellites meant to enclose a star completely and capture most or all of its energy output.[12]
  • Perhaps a more exotic means to generate usable energy would be to feed a stellar mass into a black hole, and collect photons emitted by the accretion disc.[13][14] Less exotic would be simply to capture photons already escaping from the accretion disc, reducing a black hole's angular momentum; known as the Penrose process.
  • Star lifting is a process where an advanced civilization could remove a substantial portion of a star's matter in a controlled manner for other uses.
  • Antimatter is likely to be produced as an industrial byproduct of a number of megascale engineering processes (such as the aforementioned star lifting) and therefore could be recycled.
  • In multiple-star systems of a sufficiently large number of stars, absorbing a small but significant fraction of the output of each individual star.
  • White holes, if they exist, theoretically could provide large amounts of energy from collecting the matter propelling outwards.
  • Capturing the energy of gamma-ray bursts is another theoretically possible power source for a highly advanced civilization.
  • Type III civilization methods

  • Type III civilizations might use the same techniques employed by a Type II civilization, but applied to all possible stars of one or more galaxies individually.[15]
  • They may also be able to tap into the energy released from the supermassive black holes which are believed to exist at the center of most galaxies.
  • The emissions from quasars can be readily compared to those of small active galaxies and could provide a massive power source if collectable.
    1. 1. Kardashev, Nikolai (1964). "Transmission of Information by Extraterrestrial Civilizations". Soviet Astronomy (PDF) 8: 217. Bibcode:1964SvA.....8..217K.
    2. 2. Lemarchand, Guillermo A. Detectability of Extraterrestrial Technological Activities. Coseti..
    3. 3. Kaku, Michio (2010). "The Physics of Interstellar Travel: To one day, reach the stars.". Retrieved 2010-08-29.
    4. 4. Sagan, Carl (October 2000) [1973]. Jerome Agel, ed. Cosmic Connection: An Extraterrestrial Perspective. Freeman J. Dyson, David Morrison. Cambridge Press. ISBN 0-521-78303-8. Retrieved 2008-01-01. "I would suggest Type 1.0 as a civilization using 1016 watts for interstellar communication; Type 1.1, 1017 watts; Type 1.2, 1018 watts, and so on. Our present civilization would be classed as something like Type 0.7."
    5. 5. Energy - Consumption'!A1 "Consumption by fuel, 1965-2008" (XLS). Statistical Review of World Energy 2009, BP. 31 July 2006. Retrieved 24 October 2009.
    6. 6. Souers, P. C. (1986). Hydrogen properties for fusion energy. University of California Press. p. 4. ISBN 978-0-520-05500-1.
    7. 7. Borowski, Steve K. (1987-07-29). "Comparison of Fusion/Anti-matter Propulsion Systems for Interplanetary Travel" (PDF). Technical Memorandum 107030. San Diego, California, USA: National Aeronautics and Space Administration. pp. 1-3. Retrieved 2008-01-28.
    8. 8. By the mass-energy equivalence formula E = mc˛. See anti-matter as a fuel source for the energy comparisons.
    9. 9. Than, Ker (August 10, 2011). "Antimatter Found Orbiting Earth-A First". National Geographic News.
    10. 10. Adriani; Barbarino; Bazilevskaya; Bellotti; Boezio; Bogomolov; Bongi; Bonvicini; Borisov (2011). "The discovery of geomagnetically trapped cosmic ray antiprotons". The Astrophysical Journal 736 (29): L1. arXiv:1107.4882. Bibcode:2011ApJ...736L...1H. doi:10.1088/2041-8205/736/1/L1.
    11. 11. "Antimatter caught streaming from thunderstorms on Earth". BBC News. 2011-01-11.
    12. 12. Dyson, Freeman J. (1966). "The Search for Extraterrestrial Technology". In Marshak, R. E. Perspectives in Modern Physics (New York: John Wiley & Sons).
    13. 13. Newman, Phil (2001-10-22). "New Energy Source "Wrings" Power from Black Hole Spin". NASA. Archived from the original on 2008-02-09. Retrieved 2008-02-19.
    14. 14. Schutz, Bernard F. (1985). A First Course in General Relativity. New York: Cambridge University Press. pp. 304, 305. ISBN 0-521-27703-5.
    15. 15. Kardashev, Nikolai. "On the Inevitability and the Possible Structures of Supercivilizations", The search for extraterrestrial life: Recent developments; Proceedings of the Symposium, Boston, MA, June 18/21, 1984 (A86-38126 17-88). Dordrecht, D. Reidel Publishing Co., 1985, p. 497-504.
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