Kardashev scale

Kardashev scale projections for human civilization ranging from years 1900 to 2030, based on data from the International Energy Agency World Energy Outlook

The Kardashev scale is a method of measuring an advanced civilization's level of technological advancement. The scale is only theoretical and in terms of an actual civilization highly speculative; however, it puts energy consumption of an entire civilization in a cosmic perspective. It was first proposed in 1964 by the Soviet Russian astronomer Nikolai Kardashev. The scale has three designated categories called Type I, II, and III. These are based on the amount of usable energy a civilization has at its disposal, and the degree of space colonization. In general terms, a Type I civilization has achieved mastery of the resources of its home planet, Type II of its solar system, and Type III of its galaxy.^[1] Science fiction also may expand the scale to Type IV, where a civilization has mastery of the resources of its universe, and sometimes Type V, all the universes.

The original and the final draft for this particular scale had energy consumptions ranging so widely from each other, that Kardashev himself revised the scale as to include values between, in hundredths. The human civilization as of 2010 is currently somewhere around 0.72, with calculations showing we will reach Type I status around 2100, Type II status around 3100 and Type III status from 100 000 thousand to one million years time. ^[2]

Energy use

Energy is a static quantity and is denoted in joules. Power is a measure of energy transfer over time, and is denoted in watts (joules per second). The three levels of the Kardashev Scale can be quantified in units of power (watts) and plotted on an increasing logarithmic scale.

• Type I — a civilization that is able to harness all of the power available on a single planet — has approximately 10¹⁶ or 10¹⁷ W available.^[3] Earth specifically has an available power of 1.74  × 10¹⁷ W (174 peta watts, see Earth's energy budget). Kardashev's original definition was 4  × 10¹² W — a "technological level close to the level presently attained on earth" ("presently" meaning 1964).^[4]
• Type II — a civilization that is able to harness all of the power available from a single star, approximately 4  × 10²⁶ W.^[3] Again, this figure is variable; the Sun outputs approximately 3.86  × 10²⁶ W. Kardashev's original definition was also 4  × 10²⁶ W.^[4]
• Type III — a civilization that is able to harness all of the power available from a single galaxy, approximately 4  × 10³⁷ W.^[3] This figure is extremely variable, since galaxies vary widely in size; the stated figure is the approximate power output of the Milky Way. Kardashev's original definition was also 4  × 10³⁷ W.^[4]

Using nuclear explosion tests as a perspective, Tsar Bomba, the largest nuclear weapon ever detonated, released an estimated 57 megaton yield; even a Type I civilization makes use of roughly 25 megatons of TNT equivalent a second, the equivalent of one Tsar Bomba every 2.28 seconds. A Type II civilization controls 4 × 10⁹ times more energy (4 billion hydrogen bombs per second), and a type III 10¹¹ times more yet.

Current status of human civilization

Human civilization is currently somewhere below Type I, as it is able to harness only a portion of the energy that is available on Earth. The current state of human civilization has thus been named Type 0. Although intermediate values were not discussed in Kardashev's original proposal, Carl Sagan argued that they could easily be defined by interpolating and extrapolating the values given above. In 1973, he calculated humanity's civilization type to be 0.7, in relationship to Kardashev's model for Types 0 and I.^[5]

Sagan used the arbitrary formula:

Value K is a civilization's Kardashev rating and W is its power output in watts. Sagan used 10 terawatt (TW) as value W, which was considerably higher than present data suggests.^[6] Sagan's overestimation makes little difference in regards to human civilization's K rating, effecting only a change of 1% in its value (See Table Below). International Energy Agency World Energy Outlook (2005)^[6] and section 7 of Key World Energy Statistics^[7] project values for planetary power utilization yielding these corresponding Kardashev scale estimates:

As of 2007^[update], the Kardashev rating is approximately 0.72, calculated using British Petroleum's primary energy consumption chart for 2007.^[10] It is important to note that as Sagan's Kardashev rating is base-10 logarithmic, a value of 0.72 means we are using approximately 0.16% of the total available planetary energy budget.

Energy development

Methods by which a civilization could feasibly advance to Type I:

• Large scale application of fusion power. Type I implies the conversion of about 5 kg of matter to energy per second. This can be achieved by fusing approximately 1,000 kg of hydrogen into helium each second, a rate roughly equivalent to 3 × 10¹⁰ 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 can be sustained over geological time scales.
• Antimatter production is still beyond our civilization's ability to utilize as a power source,^[11] but any civilization with the technological ability to collect antimatter^[12] in large quantities cheaply, would have a mechanism to produce power on a scale several factors above our current level of technology. In antimatter-matter collisions, the entire rest mass of the particles is converted to kinetic energy. The energy per unit mass is about 10 orders of magnitude greater than chemical energy (compared to TNT), about 4 orders of magnitude greater than the energy that humans liberated today using nuclear fission, and about 2 orders of magnitude greater than the best possible from fusion.^[13] The reaction of 1 kg of anti-matter with 1 kg of matter would produce 1.8 × 10¹⁷ J (180 petajoules) of energy (by the mass-energy equivalence formula E = mc²), or roughly the equivalent of 47 megatons of TNT. For energy comparisons see anti-matter as a fuel source.
• Solar energy — 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 utilize 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 civilizations might employ:

• 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 completely enclose a star and capture most or all of its energy output.^[14]
• 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.^[15][16] 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.
• In sufficiently large number of stellar systems, absorbing a small but significant fraction of the output of each individual star.

Type III civilizations might use the same techniques employed by a Type II civilization, but applied to all of the stars of one or more galaxies individually.^[17] 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.

Civilization implications

There are many historical examples of human civilization undergoing large-scale transitions, such as the Industrial Revolution. The transition between Kardashev scale levels could potentially represent similarly dramatic periods of social upheaval, since they entail surpassing the hard limits of the resources available in a civilization's existing territory. A common speculation^[18] suggests that the transition from Type 0 to Type I might carry a strong risk of self-destruction since, in some scenario, there would no longer be room for further expansion on the civilization's home planet, similar to a Malthusian catastrophe. Excessive use of energy without adequate disposal of heat, for example, could plausibly make the planet of a civilization approaching Type I unsuitable to the biology of the dominant life-forms and their food sources. If Earth is an example, then sea temperatures in excess of 35 °C would jeopardize marine life and make the cooling of mammals to temperatures suitable for their metabolism difficult if not impossible. Of course, these theoretical speculations may not become problems in reality thanks to the application of future engineering and technology. Also, by the time a civilization reaches Type I it may have colonized other planets or created O'Neill-type colonies, so the amount of waste heat could be distributed throughout the solar system.

Extensions to the original scale

The sub-Type I state that human civilization currently occupies was not originally included in the Kardashev scale but is now referred to as "Type 0" or by its K value using Sagan's logarithmic formula (described above).

Zoltan Galantai has defined a further extrapolation of the scale, a Type IV level which controls the energy output of the visible universe; this is within a few orders of magnitude of 10⁴⁵ W. Such a civilization approaches or surpasses the limits of speculation based on current scientific understanding, and may not be possible. Frank J. Tipler's Omega point would presumably occupy this level, as would the Biocosm hypothesis. Galantai has argued that such a civilization could not be detected, as its activities would be indistinguishable from the workings of nature (there being nothing to compare them to).^[19]

However, Milan M. Ćirković has argued that "Type IV" should instead be used to refer to a civilization that has harnessed the power of its supercluster, or "the largest gravitationally bound structure it originated in."^[20] For the Local Supercluster, this would be approximately 10⁴² W.

Dr. Michio Kaku has discussed a type IV civilization, which could harness "extragalactic" energy sources such as dark energy, in his book Parallel Worlds.^[21]

In contrast to simply increasing the maximum power level covered by the scale, Carl Sagan suggested adding another dimension: the information available to the civilization. He assigned the letter A to represent 10⁶ unique bits of information (less than any recorded human culture) and each successive letter to represent an order of magnitude increase, so that a level Z civilization would have 10³¹ bits. In this classification, 1973 Earth is a 0.7 H civilization, with access to 10¹³ bits of information. Sagan believed that no civilization has yet reached level Z, conjecturing that so much unique information would exceed that of all the intelligent species in a galactic supercluster and observing that the universe is not old enough to effectively exchange information over larger distances. The information and energy axes are not strictly interdependent, so that even a level Z civilization would not need to be Kardashev Type III.^[5]

Examples in science fiction

Type I

• All of the civilizations in BioWare's Mass Effect (series) (except for the Reapers) are somewhere in between Type 1 and Type 2.
• The humans from Stargate Universe where they use the power of the planet Icarus to power the stargate and encode of the 9th chevron. This allowed them to gate to the ship Destiny.

Type II

• The territory of Eelong in the Pendragon Series by D. J. MacHale utilizes all power from a belt of suns known as the Skaa.^[22]
• In the Star Trek: The Next Generation episode "Relics", the Enterprise discovers an abandoned Dyson shell a special case of a Dyson sphere.
• The Imperium Of Man from Warhammer 40000, the great galactic empire with more than a million worlds at its control.
• The UNSC and Covenant as seen in the Halo series.

Type III

• Galaxia of The Foundation Series is a galaxy-spanning super-organism which combines all matter and energy in the galaxy into one being which is inherently capable of harnessing its own energy.
• In Star Maker by Olaf Stapledon. The stellar energy output of the whole galaxy is utilized by the Galactic Community of Worlds.^[23]
• Manifold: Time, by Stephen Baxter - in the distant future, descendants of humanity maintain vast Dyson nets around the supermassive black hole remnants of galaxies until they evaporate via Hawking radiation, accessing the energy equivalent of multiple galaxies.
• The civilization shown at the very beginning of the video game Xenogears, and its spiritual successors, the Xenosaga series, depict a civilization that would be a low or mid Type III civilization that has occupied about four galaxies in the local cluster. However, all of this is due to a deus ex machina, for lack of a better term, known as the Zohar Engine, that basically allowed the collective human consciousness to "make" the world they currently have possible, but this was over a 4000 year period. Xenogears however, takes place roughly about 17,000 years after the current period in which the entire civilization that grows on its unnamed planet has based all of its technology from the remains of the 120 kilometer ship "Eldridge". The Zohar Engine took a backseat to the first several thousand years on the world, but eventually was found to be the remote lender of a near infinite power towards the end of the game.
• The Forerunners as seen in the Halo series.
• Iain Banks "The Culture" in and of themselves would constitute a mid or high Type III, but they too have civilizations the exceed them.

Type IV and above

• The backstory of The Dancers at the End of Time series by Michael Moorcock describes a civilization which consumed all the energy in all the stars in the universe, save Earth's own sun, in order to fuel an existence in which the inheritors of Earth lived as nigh-omnipotent gods.^[24]
• In a rare mention of the scale within a work of fiction, the Doctor Who novel The Gallifrey Chronicles, a Time Lord named Manual asserts that "the Time Lords were the Type-4 civilization. We had no equals. We controlled the fundamental forces of the entire universe. Nothing could communicate with us on our level."^[25]
• The Xeelee and Photino Birds from the Xeelee Sequence had power over multiple galaxies, and constructed a ring of superstrings to enter a higher dimension.

Connections with sociology and anthropology

Kardashev's theory can be viewed as the expansion of some social theories, especially from social evolutionism. It is close to the theory of Leslie White, author of The Evolution of Culture: The Development of Civilization to the Fall of Rome (1959). White attempted to create a theory explaining the entire history of humanity. The most important factor in his theory is technology: Social systems are determined by technological systems, wrote White in his book, echoing the earlier theory of Lewis Henry Morgan. As measure of society advancement he proposed the measure energy consumption of a given society (thus his theory is known as the energy theory of cultural evolution). He differentiates between five stages of human development. In the first stage, people use energy of their own muscles. In the second stage, they use energy of domesticated animals. In the third stage, they use the energy of plants (which White refers to as agricultural revolution). In the fourth stage, they learn to use the energy of natural resources - such as coal, oil and gas. Finally, in the fifth stage, they harness nuclear energy. White introduced a formula P=E×T, where P measures the advancement of the culture, E is a measure of energy consumed, and T is the measure of efficiency of technical factors utilizing the energy.

Criticism

It has been argued that, because we cannot understand advanced civilizations, we cannot predict their behavior; thus, Kardashev's visualization may not reflect what will actually occur for an advanced civilization. This central argument is found in the book Evolving the Alien: The Science of Extraterrestrial Life.^[26]

On a more direct level, since the Kardashev scale rates a civilization according to how much energy it is capable of harnessing, it "penalizes" a civilization that invents ways of making more efficient use of the energy already available to it, instead of simply harnessing yet more energy. An extremely advanced civilization might also choose to forgo either the projects or the materialistic growth (expansion) humanity associates with high energy demand.

Robert Zubrin uses the terms to refer to how dominant a species is, rather than energy use. In other words, a Type I civilization has spread across its planet (making present human civilization Type I), a Type II has extensive colonies in its respective stellar system, and a Type III has colonized the galaxy.

See also

• Astroengineering
• Clarke's three laws
• Drake equation
• World energy resources and consumption
• Orders of magnitude (power)
• Orders of magnitude (energy)
• Sustainability
• Technological singularity

Further reading

References

External links

• Kardashev civilizations
• Detectability of Extraterrestrial Technological Activities
• Flash Animation on Civilizations
• After Kardashev: Farewell to Super Civilizations
• Exotic Civilizations: Beyond Kardashev
• Useful Comparisons of Fictional Works Using the Kardashev Scale