Editing Kardashev scale (section)

== Reassessments of the Kardashev scale ==

=== Sagan's finer classification ===
In 1973, [[Carl Sagan]] discovered Kardashev's work on the classification of civilizations.<ref name="Galantai-2006">{{Cite journal |last=Galantai |first=Zoltan |date=2006 |title=After Kardashev: Farewell to Super Civilizations |url=https://www.academia.edu/1018345 |journal=Contact in Contex |volume=2 |issue=2 |archive-date=2024-08-18 |access-date=2023-08-08 |archive-url=https://web.archive.org/web/20240818005401/https://www.academia.edu/1018345 |url-status=live }}</ref> He found that the differences between the types Kardashev identified were so great that they did not allow for the best possible modeling of the evolution of civilizations.<ref name="Galántai-2003" /> Consequently, Sagan proposes a more refined classification, still based on Kardashev's types, but integrating intermediate levels using the following [[Logarithmic scale|logarithmic]] [[interpolation]] formula:<ref name="Carrigan Jr.-20102">{{Cite journal |last=Carrigan Jr. |first=Richard A. |date=2010 |title=Starry Messages: Searching for Signatures of Interstellar Archaeology |journal=Journal of British Interplanetary Society |volume=63 |issue=90 |pages=121–126 |arxiv=1001.5455 |bibcode=2010JBIS...63...90C}}</ref>

<math>K = \frac{\log_{10}{W}-6} {10}</math>,

where ''K'' is the Kardashev type of a civilization and ''W'' is the amount of power it uses, in watts. Thus, a ''Type 1.1'' civilization would be defined by a power of 10<sup>17</sup> watts, while a ''Type 2.3'' civilization would be able to harness 10<sup>29</sup> watts.

Moreover, the above formula could be used to extrapolate beyond Kardashev's original types. For example, a '''''Type&nbsp;0''''' civilization, not defined by Kardashev, would control about 1&nbsp;MW of power (equivalent to having around 100 campfires burning at any given time); on Earth, the emergence of Type 0 civilizations is roughly concurrent with the [[Cradle of civilization#Rise of civilization|rise of civilization]] in a general sense.<ref>{{Cite thesis |title=Environmental Change and Human Impact during the Mesolithic-Neolithic Transition in North-West Europe|url=https://research.manchester.ac.uk/files/84029587/FULL_TEXT.PDF |degree=PhD |publisher=[[University of Manchester]] |first=Sarah Elizabeth |last=Kneen |date=2014}}</ref>

Sagan estimated that, according to this revised scale, 1970s humanity would be Type 0.7 (about 10 [[terawatts]]),<ref name="Sagan-19732">{{Cite journal |last=Sagan |first=Carl |date=1973-07-01 |title=On the detectivity of advanced galactic civilizations |url=https://dx.doi.org/10.1016/0019-1035%2873%2990112-7 |journal=Icarus |language=en |volume=19 |issue=3 |pages=350–352 |bibcode=1973Icar...19..350S |doi=10.1016/0019-1035(73)90112-7 |issn=0019-1035}}</ref> equivalent to 0.16% of the power available on Earth.<ref name="Wilson-20112">{{Cite book |last=Wilson |first=Richard |title=International Seminar on Nuclear War and Planetary Emergencies – 43rd Session |publisher=World Scientific Publishing Company |year=2011 |isbn=978-9814365925 |edition=1st |pages=51–61 |chapter=Energy and the Environment in the Next Millenium |doi=10.1142/8232}}</ref> This level is characterized, according to him, by the ability to self-destruct, which he calls "technological adolescence".<ref name="Lemarchand-20002"/> In 2021, the total [[World energy supply and consumption|world energy consumption]] was 595.15 [[Joule#Exajoule|exajoules]] (165,319&nbsp;[[Kilowatt-hour#Watt-hour multiples|TWh]]),<ref>{{Cite web |title=The Statistical Review of World Energy 2022 |url=https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2022-full-report.pdf |url-status=live |archive-url=https://web.archive.org/web/20230821195021/https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2022-full-report.pdf |archive-date=2023-08-21 |access-date=2023-08-24 |website=bp}}</ref> equivalent to an average power consumption of 18.87 TW or a Kardashev rating of 0.73&nbsp;(to 2 [[Significant figures|s.f.]]).<ref>{{Citation |last1=LePoire |first1=David J. |title=Energy Flow Trends in Big History |date=2020 |url=https://doi.org/10.1007/978-3-030-33730-8_9 |work=The 21st Century Singularity and Global Futures: A Big History Perspective |pages=185–200 |editor-last=Korotayev |editor-first=Andrey V. |access-date=2023-09-09 |series=World-Systems Evolution and Global Futures |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-33730-8_9 |isbn=978-3-030-33730-8 |s2cid=213212248 |last2=Chandrankunnel |first2=Mathew |editor2-last=LePoire |editor2-first=David J.}}</ref>

Sagan also suggests that, for completeness, an alphabetical scale should be added to indicate the level of [[Social change|social development]], expressed in the amount of information available to the civilization. Thus, a Class A civilization would be based on 10<sup>6</sup> [[bit]]s of information (less than any recorded human culture), a Class B on 10<sup>7</sup>, a Class C on 10<sup>8</sup>, and so on. Humanity in 1973 would belong to the "0.7 H" class.<ref name="books.google.com">{{cite book |last=Sagan |first=Carl |url=https://books.google.com/books?id=lL57o9YB0mAC&pg=PA156 |title=Cosmic Connection: An Extraterrestrial Perspective |year= 2000 |publisher=[[Cambridge University Press]] |others=[[Freeman Dyson]], David Morrison |isbn=978-0-521-78303-3 |editor-last=Agel |editor-first=Jerome |edition= |series= |location= |pages= |language= |chapter= |doi= |oclc= |id= |quote=I would suggest Type 1.0 as a civilization using 10<sup>16</sup> watts for interstellar communication; Type 1.1, 10<sup>17</sup> watts; Type 1.2, 10<sup>18</sup> watts, and so on. Our present civilization would be classed as something like Type 0.7. |author-link=Carl Sagan |access-date=2008-01-01 |orig-date=1973 |via=[[Google Books]]}}</ref> According to Sagan, the first civilization with which humanity would come into contact could be between "1.5 J" and "1.8 K"; a galactic supercivilization would be at the "3 Q" stage, while a federation of galaxies could be at the "4 Z" stage.<ref name="Lemarchand-20002"/> The information and energy axes are not strictly interdependent, so even a level Z civilization would not have to be Kardashev Type&nbsp;III.<ref name="books.google.com" /> Sagan believed that no civilization had yet reached level Z, speculating 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 large distances.

In 2017, the total amount of information generated on the [[internet]] was [[Zettabyte Era|26 zettabytes]] (with an estimated 120 zettabytes in 2023),<ref>{{Cite web |title=Data growth worldwide 2010-2025 |url=https://www.statista.com/statistics/871513/worldwide-data-created/ |access-date=2023-11-19 |website=Statista |language=en |archive-date=2024-08-30 |archive-url=https://web.archive.org/web/20240830140921/https://www.statista.com/statistics/871513/worldwide-data-created/ |url-status=live }}</ref> equivalent to 0.73 R/S on Sagan's combined scale.

=== Kaku and the knowledge economy ===
In ''[[Physics of the Future]]'' (2011), American physicist [[Michio Kaku]] examines the conditions for humanity to converge on a Type&nbsp;I planetary civilization. This convergence is based primarily on the [[knowledge economy]]. Kaku uses the Kardashev scale, but develops it by adding an additional stage: a Type&nbsp;IV civilization would be able to draw the energy it needs from [[Extragalactic cosmic ray|extragalactic radiation]]. By studying the evolution of technologies that have changed history ([[paper]], the [[integrated circuit]]), Kaku believes that humanity is moving toward a civilization of planetary dimensions, the "starting point" of which is the [[Internet]].<ref name="Hamish-2012">{{Cite web |last1=Hamish |first1=Clift |last2=Mandeville |first2=Tom |date=2012 |title=Towards a Global Civilisation: An Evolutionary Perspective (14th International Schumpeter Society Conference) |url=http://www.aomevents.com/media/files/ISS%202012/Clift.pdf |url-status=dead |archive-url=https://web.archive.org/web/20220813065004/http://www.aomevents.com/media/files/ISS%202012/Clift.pdf#federation=archive.wikiwix.com&tab=url |archive-date=2022-08-13 |access-date=2023-08-07 |website=aomevents.com }}</ref>

A Type&nbsp;I civilization consumes [[Power (physics)|power]] on the order of thousands to millions of times our current planetary output, about 100 trillion trillion watts. It would have enough energy to manipulate the occurrence of certain natural phenomena, such as [[earthquake]]s or [[volcano]]es, and could build cities on the [[ocean]]s. We can see the beginnings of a Type&nbsp;I civilization in the fact that a global language is developing ([[English language|English]]), a global communication system is emerging (the [[Internet]]), a global economic system is in the making (the establishment of the [[European Union]]), and even a globalized culture is standardizing humanity ([[mass media]], [[television]], [[rock music]], and [[Cinema of the United States|Hollywood movies]]).<ref name="Kaku-2007" /> To achieve Type&nbsp;I, humanity must be able to communicate with the rest of the world and to focus on several areas: building [[infrastructure]] to facilitate communication and cooperation, [[education]], [[research and development]], and [[innovation]], as well as building strong ties between [[diaspora]]s and their countries of origin, and between migrants and non-migrants.<ref name="Hamish-2012" /> If development fails, it is likely that the world will not be able to achieve Type&nbsp;II. If these areas do not develop, Kaku predicts that humanity will sink into the "abyss":<ref name="Hamish-2012" /> an advanced civilization must grow faster than the frequency of occurrence of [[Extinction-level threat|extinction-level]] cosmic catastrophes, such as [[Impact event|comet or asteroid impacts]]. A Type&nbsp;I civilization should also be able to master [[Spaceflight|space travel]] to deflect threatening objects. It would also have to anticipate the onset of [[ice age]]s and modify the climate long before they occur to avoid them.<ref name="Kaku-2007" />

In addition, in his books ''[[Hyperspace (book)|Hyperspace]]'' and ''[[Parallel Worlds (book)|Parallel Worlds]]'', Michio Kaku has discussed a Type&nbsp;IV civilization that could harness "extragalactic" energy sources such as [[dark energy]].<ref name="ParallelWorlds">{{cite book |last=Kaku |first=Michio |title=Parallel Worlds: The Science of Alternative Universes and Our Future in the Cosmos |title-link=Parallel Worlds (book) |date=2005 |publisher=Doubleday |isbn=978-0-7139-9728-6 |location=New York |page=[https://archive.org/details/parallelworldsjo00kaku_753/page/n335 317] |author-link=Michio Kaku}}</ref>

=== Zubrin's planet mastery ===
In ''Entering Space: Creating a Spacefaring Civilization'', [[Robert Zubrin]] suggests another form: his definition of a Type&nbsp;I civilization is described as one that has achieved full mastery of the resources of its planet (global), a Type&nbsp;II of its solar system (interplanetary), and a Type&nbsp;III would have unleashed the full potential of the galaxy (starfaring civilization). Metrics other than pure energy consumption have also been proposed.<ref name="Entering Space">{{Cite book |last=Zubrin |first=Robert |url=https://archive.org/details/enteringspacecre00zubr |title=Entering Space: Creating a Spacefaring Civilization |date=1999 |publisher=Penguin Publishing |isbn=978-1-58542-036-0 |url-access=registration}}</ref>

He ponders the possibility of a Type&nbsp;IV civilization, one that would dominate the universe, noting that there are limits to how minds can connect and interact on a galactic or intergalactic basis. As an example, he mentions that communication from the center of our [[Milky Way|galaxy]] to its edge would take about 50,000 years (since [[Superluminal communication|nothing can travel faster than light]], according to our understanding of physics).<ref>{{Cite journal |last=Krasnikov |first=S. V. |date=1998-04-15 |title=Hyperfast travel in general relativity |url=https://link.aps.org/doi/10.1103/PhysRevD.57.4760 |journal=Physical Review D |volume=57 |issue=8 |pages=4760–4766 |doi=10.1103/PhysRevD.57.4760|arxiv=gr-qc/9511068 |bibcode=1998PhRvD..57.4760K |s2cid=55825213 }}</ref><ref name="Entering Space" /><!-- I will gladly insert more information, but I will have to read the book first. - IrrationalBeing, 2023-08-07. Update 2023-08-22: Almost finished it. -->

=== Barrow's microdimensional mastering ===
The astronomer [[John D. Barrow]] of the [[University of Sussex]] has hypothesized that there are other stages beyond Type&nbsp;III. These Type&nbsp;IV, V, or even VI civilizations would be able to manipulate cosmic structures (galaxies, galactic clusters, superclusters) and even escape the [[Big Crunch]] through holes in space.<ref name="Kaku-2007" />

Barrow also proposes an "anti-Kardashev scale": he observes that humans have found it more cost effective to extend their ability to manipulate their environment to smaller and smaller scales rather than to larger and larger ones. He, therefore, proposes a reverse classification, from Type&nbsp;I-minus to Type Omega-minus:
* '''[[Mechanical engineering|Type I-minus]]''' is capable of manipulating objects on the scale of itself: building structures, mining, joining and breaking solids;
* '''[[Medical engineering|Type II-minus]]''' is capable of manipulating [[gene]]s and altering the development of living things, transplanting or replacing parts of themselves, reading and manipulating their [[genetic code]];
* '''[[Molecular engineering|Type III-minus]]''' is capable of manipulating [[molecule]]s and [[Covalent bond|molecular bonds]], creating new materials;
* '''[[Nanotechnology|Type IV-minus]]''' is capable of manipulating individual [[atom]]s, creating nanotechnology at the atomic level, and creating complex forms of [[artificial life]];
* '''[[Nuclear engineering|Type V-minus]]''' is capable of manipulating the [[atomic nucleus]] and engineering the [[nucleon]]s that compose it;
* '''[[Femtotechnology|Type VI-minus]]''' is capable of manipulating the most elementary particles of matter ([[quark]]s and [[lepton]]s) to create organized complexity among populations of elementary particles; 
* '''Type Omega-minus''' is capable of manipulating the fundamental structure of [[Spacetime|space and time]].<ref name="Impossibility: Limits of Science and the Science of Limits">{{cite book |last=Barrow |first=John |url=https://archive.org/details/impossibility00barr |title=Impossibility: Limits of Science and the Science of Limits |date=1998 |publisher=[[Oxford University Press]] |isbn=978-0-19-851890-7 |location=Oxford |page=[https://archive.org/details/impossibility00barr/page/n140 133] |author-link=John D. Barrow |url-access=limited}}</ref>
''In Impossibility: The Limits of Science and the Science of Limits'' (1998), Barrow proposes a scale ranging from "BI" to "BVI", with an ultimate stage he calls "BΩ", the former characterized by the possibility of manipulating one's environment, while the latter allows for the modification of [[spacetime]].<ref>{{Cite journal |last=Smart |first=John M. |date=2012-09-01 |title=The transcension hypothesis: Sufficiently advanced civilizations invariably leave our universe, and implications for METI and SETI |url=https://www.sciencedirect.com/science/article/pii/S0094576511003304 |journal=Acta Astronautica |series=Searching for Life Signatures |language=en |volume=78 |pages=55–68 |doi=10.1016/j.actaastro.2011.11.006 |bibcode=2012AcAau..78...55S |issn=0094-5765 |archive-date=2022-05-04 |access-date=2023-08-09 |archive-url=https://web.archive.org/web/20220504015655/https://www.sciencedirect.com/science/article/pii/S0094576511003304 |url-status=live }}</ref>

=== Galántai's miniaturization and resilience to catastrophes ===
[[File:Impact_event.jpg|alt=Color illustration. A burning object pierces the surface of a much larger object.|thumb|For Zoltan Galántai, a scale classifying civilizations should be based on their ability to survive catastrophes, particularly those of cosmic origin, such as an [[Impact event|asteroid impact]].]]
Zoltan Galántai recognizes the important role that Kardashev's classification has played in the SETI program, but he believes that another scale is possible, without using energy consumption, by resorting to miniaturization. The hypothesis of Donald Tarter, researcher at SETI, is that a civilization based on [[nanotechnology]] would not need an ever-increasing amount of energy. A Type&nbsp;I civilization that masters local space travel could colonize its planetary system and even the [[Oort cloud]] without needing an amount of energy that would make it Type&nbsp;II.<ref name="Galantai-2006" /> This scale loses its meaning beyond Type&nbsp;II, since it is impossible to predict the evolution of civilizations over long distances in a galactic colonization process. Finally, the Kardashev scale is the product of an era of insufficient scientific knowledge, which considered the possibility of stellar object [[CTA-102]] as an artificial Type&nbsp;III source, whereas today we know that it is a [[Active galactic nucleus|galactic nucleus]].<ref name="Galantai-2006" />

In another article, Zoltan Galántai suggests considering another scale, no longer based on energy consumption, but on a civilization's ability to survive natural and cosmic disasters. Type&nbsp;I would describe a civilization capable of surviving a local natural disaster, like the [[Ancestral Puebloans|Anasazi]]. A Type&nbsp;II civilization would have the means to withstand a regional or continental disaster, and finally Type&nbsp;III could face a global disaster such as an [[Impact event|asteroid's impact]], a [[supervolcano]]'s eruption, or an [[ice age]]. Beyond the first three types are civilizations that have scattered throughout the galaxy. The Type&nbsp;IV civilization would still be vulnerable to some cosmic threats, while the Type&nbsp;V civilization would be technically immortal, as no cosmic catastrophe could reach it.<ref name="Galantai-2006"/> The Kardashev scale can be a relevant tool for preventing catastrophes, whether human or natural, according to Richard Wilson, who relates this scale to the power of destruction, in [[TNT]]. A Type&nbsp;I civilization would use 25 [[TNT equivalent|megatons]] of equivalent TNT per second, a Type&nbsp;II civilization 4 × 10<sup>9</sup> times more (4 billion hydrogen bombs per second), while a Type&nbsp;III civilization would use 10<sup>11</sup> times more.<ref name="Wilson-20112"/>