Kardashev scale
The Kardashev scale is a method of measuring a civilization's level of technological advancement based on the amount of energy they are able to use. The measure was proposed by Soviet astronomer Nikolai Kardashev in 1964. The scale has three designated categories:
- A, also called a planetary civilization—can use and store all of the energy available on its planet.
- A, also called a stellar civilization—can use and control energy at the scale of its planetary system.
- A, also called a galactic civilization—can control energy at the scale of its entire host galaxy.
Definition
; Type I
; Type II
; Type III
Kardashev believed that a Type 4 civilization was impossible, so he did not go past Type 3. However, new types have been proposed.
Current status of human civilization
At the current time, humanity has not yet reached Type 1 civilization status.Physicist and futurist Michio Kaku suggested that, if humans increase their energy consumption at an average rate of 3 percent each year, they may attain Type I status in 100–200 years, Type II status in a few thousand years, and Type III status in 100,000 to a million years.
Carl Sagan suggested defining intermediate values by interpolating and extrapolating the values given above for types I, II and III, which would produce the formula
where value K is a civilization's Kardashev rating and P is the power it uses, in watts. Using this extrapolation, a "Type 0" civilization, not defined by Kardashev, would control about 1 MW of power, and humanity's civilization type as of 1973 was about 0.7.
In 2018, the total world energy consumption was 13864.9 Mtoe, equivalent to an average power consumption of 18.40 TW or 0.73 on Sagan's interpolated Kardashev scale.
Observational evidence
In 2015, a study of galactic mid-infrared emissions came to the conclusion that "Kardashev Type-III civilizations are either very rare or do not exist in the local Universe".On October 14, 2015, the detection of an unusual light curve for star KIC 8462852 raised speculation that a Dyson swarm may have been discovered. The SETI Institute's initial radio reconnaissance of KIC 8462852, however, found no evidence of technology-related radio signals from the star.
In 2016, Paul Glister, author of the Centauri Dreams website, described a signal apparently from the star HD 164595 as requiring the power of a Type I or Type II civilization, if produced by extraterrestrial lifeforms. However, in August 2016 it was discovered that the signal's origin was most likely a military satellite orbiting the Earth.
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, 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 humans on Earth could sustain this rate of consumption over geological time-scales, in terms of available hydrogen.
- Antimatter in large quantities would have a mechanism to produce power on a scale several magnitudes above the current level of technology. In antimatter-matter collisions, the entire rest mass of the particles is converted to radiant energy. Their energy density 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. The reaction of 1 kg of anti-matter with 1 kg of matter would produce 1.8×1017 J of energy. Although antimatter is sometimes proposed as a source of energy, this does not appear feasible. Artificially producing antimatter—according to current understanding of the laws of physics—involves first converting energy into mass, which yields no net energy. Artificially created antimatter is only usable as a medium of energy storage, not as an energy source, unless future technological developments allow the conversion of ordinary matter into anti-matter. Theoretically, humans may in the future have the capability to cultivate and harvest a number of naturally occurring sources of antimatter.
- Renewable energy through converting sunlight into electricity—either by using solar cells and concentrating solar power or indirectly through biofuel, wind and hydroelectric power. There is no known way for human civilization to use the equivalent of the Earth's total absorbed solar energy without completely coating the surface with human-made structures, which is not feasible with current technology. However, if a civilization constructed very large space-based solar power satellites, Type I power levels might become achievable—these could convert sunlight to microwave power and beam that to collectors on Earth.
Type II civilization methods
- Type II civilizations might use the same techniques employed by a Type I civilization, but applied to a large number of planets in a large number of planetary systems.
- 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.
- 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. Less exotic would be simply to capture photons already escaping from the accretion disc, reducing a black hole's angular momentum; this is 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 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.
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.
- 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.
- 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.
- The emissions from quasars can be readily compared to those of small active galaxies and could provide a massive power source if collectable.
Civilization implications
The limitation of biological life-form and the evolution of computing technology may lead to the transformation of the civilization through Mind uploading during the transition from Type I to Type II, leading to a digitalized civilization.
Extensions to the original scale
Many extensions and modifications to the Kardashev scale have been proposed.- Types 0, IV, and V Kardashev rating: The most straightforward extension of the scale to even more hypothetical Type IV beings who can control or use the entire universe or Type V who control collections of universes. This would also include Type 0 civilizations, who do not rank on the Kardashev scale. The power output of the visible universe 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.
- * Zoltán Galántai has argued that such a civilization could not be detected, as its activities would be indistinguishable from the workings of nature.
- * In his book Parallel Worlds, Michio Kaku has discussed a Type IV civilization that could harness "extragalactic" energy sources such as dark energy.
- Kardashev alternative rating characteristics: Other proposed changes to the scale use different metrics such as 'mastery' of systems, amount of information used, or progress in control of the very small as opposed to the very large.
- Planet mastery : Metrics other than pure power usage have also been proposed. One is 'mastery' of a planet, system or galaxy rather than considering energy alone.
- Information mastery : Alternatively, Carl Sagan suggested adding another dimension in addition to pure energy usage: the information available to the civilization.
- * He assigned the letter A to represent 106 unique bits of information 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 exchange information effectively 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.
- Microdimensional mastery : John D. Barrow, going by the fact that humans have found it more cost-effective to extend any abilities to manipulate their environment over increasingly smaller dimensions rather than increasingly larger ones, reverses the classification downward from Type I-minus to Type Omega-minus:
- * Type I-minus is capable of manipulating objects over the scale of themselves: building structures, mining, joining and breaking solids;
- * Type II-minus is capable of manipulating genes and altering the development of living things, transplanting or replacing parts of themselves, reading and engineering their genetic code;
- * Type III-minus is capable of manipulating molecules and molecular bonds, creating new materials;
- * Type IV-minus is capable of manipulating individual atoms, creating nanotechnologies on the atomic scale and creating complex forms of artificial life;
- * Type V-minus is capable of manipulating the atomic nucleus and engineering the nucleons that compose it;
- * Type VI-minus is capable of manipulating the most elementary particles of matter to create organized complexity among populations of elementary particles; culminating in:
- * Type Omega-minus is capable of manipulating the basic structure of space and time.
- *According to this scale, humans, having wide expertise in various branches of chemistry and biology, have passed the stage of Type III-minus. Type IV-minus technologies have been seen in areas like nanotechnology, semiconductors, materials science and genetic engineering, whereas Type V-minus has seen large scale application in the field and subfields of nuclear physics. Type VI-minus has had tentative research in the field of particle physics with particle colliders such as the Large Hadron Collider.
- Civilizational range : Robert Zubrin adapts the Kardashev scale to refer to how widespread a civilization is in space, rather than to its energy use.
- * In his definition, a Type I civilization has spread across its planet.
- * A Type II has extensive colonies in its respective stellar system, and
- * A Type III has colonized its galaxy.
Criticism