Cosmic Civilizations  

In General > s.a. anthropic principle; multiverse [statistical cosmology].
* Kardashev scale: Type-III civilizations are those societies that engineer on a galactic scale.
@ General references: Kuiper & Brin AJP(89)jan; Carrigan JBIS-a1001 [interstellar archaeology, Dyson spheres, Kardashev civilizations].
@ The main questions: Hatherly CP(04) [where is everybody?]; Schneider IAU-a0905 ["are we alone?" in different cultures]; Ćirković et al AB(09)-a0912 [undermining Carter's anthropic argument against extraterrestrial life]; Barnes PASA(12)-a1112, Stenger a1202 [fine-tuning of the universe for intelligent life?].
@ Types of civilizations: Kardashev SovAstr(64)www [Kardashev scale]; in Sagan 73, 233-234; Hartle & Srednicki PRD(07)-a0704 [are we typical?]; Ćirković JBIS-a0805 [optimization-driven development]; Olson IJAB(16)-a1507 [estimating the appearance rate of K3 civilizations]; Ćirković SAJ(15)-a1601 [on Kardashev's classification]; Lacki a1604 [Type III].
@ Inflation, black holes, and civilizations: Linde PLB(89); Tipler PLB(92), rebuttal Ellis & Coule GRG(94) [ultimate fate of life]; Garriga et al IJTP(00)ap/99-in; Olum Anal(04)gq/03.
@ And future of the universe: Krauss & Starkman ApJ(00)ap/99; Freese & Kinney PLB(03)ap/02 [acceleration]; Ćirković FP(04)ap/02 [long-term]; Page PLB(08)ht/06 [universe rate of decay]; > s.a. cosmology.
@ In the galaxy: Legassick a1509 [age distribution]; Wandel AAstr(17)-a1612-conf [distance estimate].
@ Communication, observation: Gato-Rivera phy/03 [undetectability]; Loeb & Zaldarriaga JCAP(07)ap/06 [radio eavesdropping]; Learned et al PLB(09)-a0805 [using neutrinos]; Learned et al a0809 [signaling using Cepheids]; Atri et al SP(11)-a1101 [messaging protocol]; Stevens et al IJAB-a1507 [self-destructive civilizations, signatures]; Olson JCAP(16)-a1512 [visible size and geometry of aggressively expanding civilizations].
@ Relativistic spaceflight: Yurtsever & Wilkinson a1504 [limits and signatures]; Hoang & Loeb ApJ(17)-a1706 [electromagnetic forces in the interstellar medium].
@ Interstellar exploration, other: Starling & Forgan IJAB(13)-a1311 [interplanetary and interstellar colonization]; Crawford JBIS-a1501 [as a way to avoid the intellectual stagnation].

Probes and Expansion / The Fermi Paradox > s.a. Conformal Cyclic Cosmology.
* Fermi paradox: If there had ever been a single advanced civilization in the cosmological history of our galaxy, dedicated to expansion, it would have had plenty of time to colonize the entire galaxy via exponential growth; Where are they? No evidence of present or past alien visits to Earth is known to us, leading to the conclusion that no advanced expanding civilization has ever existed in the Milky Way; But even if intelligent life developed on a very small percentage of planets in the galaxy, one would expect many civilisations to exist.
* Von Neumann probes: Self-replicating robotic probes that could spread to all stars of our galaxy in a very small time on cosmological time scales, even if they travel well below the speed of light, and could be the means by which civilizations expand.
* Zoo Hypothesis: A proposed solution of the Fermi Paradox, which states that one or more extraterrestrial civilizations know of our existence and can reach us, but have chosen not to disturb us or even make their existence known to us.
@ References: Gros JBIS(05)ap; Gato-Rivera phy/05-talk; Gato-Rivera phy/06-ch [inflation and brane world]; Bezsudnov & Snarskii a1007; Armstrong & Sandberg AAstr(13) + news PhysOrg(13)aug [extension to intergalactic scales]; Webb 15; de Magalhaes SP(16)-a1509 [testing the Zoo Hypothesis]; Solomonides et al a1604-conf [probabilistic analysis]; Kowald JBIS-a1605 [catastrophic errors and breakdown of von Neumann probes]; Olson IJAB(17)-a1608; Sandberg et al a1806-proc [low probability of intelligent life elsewhere]; Olson a2002 [likelihood of observing extragalactic civilizations].
> Online resources: see Wikipedia page.

Principle of Mediocrity > s.a. cosmology; cosmological principle.
* Idea: The statement that we are a typical civilization in the universe, in the same spirit as the Copernican and Cosmological Principles.
@ References: Azhar PRD(15)-a1506 [quantitative assessment].

Doomsday Argument > s.a. inflation; mind.
* Idea: (Carter, Leslie, Gott, Nielsen) The observation that we are among the first 1011 or so humans reduces the prior probability that we find ourselves in a species whose total lifetime number of individuals is much higher, and the chance of a disaster which would obliterate humanity is much larger than usually thought; In other words, the argument that long-lived civilizations must be rare because if they were not, we should find ourselves living in one.
@ References: Kopf et al gq/94; Olum PhilQ(02)gq/00; Tegmark & Bostrom ap/05 [upper bound 1 event/109 years, 99.9% c.l.]; Pisaturo PhSc(09)jan [re Doomsday and Longevity arguments]; Page a0907 [cosmic doomsday]; Norton PhSc(10)oct [artifact of poor logic]; Gerig a1209 [many-worlds version]; Gerig et al JCAP(13)-a1303 [on our prospects for long-term survival]; Benétreau-Dupin PhSc(15)-a1412 [and probabilistic reasoning]; Simpson IJAB(16)-a1601 [longevity of habitable planets]; Loeb a1606-ch [habitability of the universe]; Garisto a2005.

Related Topics > see Boltzmann Brains.

main pageabbreviationsjournalscommentsother sitesacknowledgements
send feedback and suggestions to bombelli at – modified 26 may 2020