Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-19T18:35:15.217Z Has data issue: false hasContentIssue false
  • English
  • Français

Evolution of the number of communicative civilizations in the Galaxy: implications on Fermi paradox

Published online by Cambridge University Press:  23 April 2020

Giorgio Spada Open the ORCID record for Giorgio Spada [Opens in a new window]  and
Daniele Melini
Giorgio Spada*
Affiliation:
Dipartimento di Scienze Pure e Applicate (DiSPeA), Università di Urbino ‘Carlo Bo’, Urbino, Italy
Daniele Melini
Affiliation:
Istituto Nazionale di Geofisica e Vulcanologia (INGV), Roma, Italy
*
Author for correspondence: Giorgio Spada, E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

It has been recently proposed DeVito [(2019) On the meaning of Fermi's paradox. Futures, 389–414] that a minimal number of contacts with alien radio-communicative civilizations could be justified by their logarithmically slow rate of growth in the Galaxy. Here we further develop this approach to the Fermi paradox, with the purpose of expanding the ensemble of the possible styles of growth that are consistent with the hypothesis of a minimal number of contacts. Generalizing the approach in DeVito (2019), we show that a logarithmic style of growth is still found. We also find that a style of growth following a power law would be admissible, however characterized by an exponent less than one, hence describing a sublinear increase in the number of communicative civilizations, still qualitatively in agreement with DeVito (2019). No solutions are found indicating a superlinear increase in the number of communicative civilizations, following for example an exponentially diverging law, which would cause, in the long run, an unsustainable proliferation. Although largely speculative, our findings corroborate the idea that a sublinear rate of increase in the number of communicative civilizations in the Galaxy could constitute a further resolution of Fermi paradox, implying a constant and minimal – but not zero – number of contacts.

Keywords

alien civilizationsFermi paradoxpopulation dynamics
Type
Research Article
Information
International Journal of Astrobiology , Volume 19 , Issue 4 , August 2020 , pp. 314 - 319
Check for updates
Copyright
Copyright © The Author(s) 2020. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Berryman, AA (2003) On principles, laws and theory in population ecology. Oikos (Copenhagen, Denmark) 103, 695–701.Google Scholar
Beverton, RJ and Holt, SJ (2012) On the dynamics of exploited fish populations. Vol. 11. Netherlands: Springer Science & Business Media.Google Scholar
Brey, T (2001) Population dynamics in benthic invertebrates. A virtual handbook. Version 01.2. http://www.thomas-brey.de/science/virtualhandbook (accessed 2 October 2019).Google Scholar
Buis, R (2017) Biomathématiques de la croissance: Le cas des végétaux. Les Ulis, France: EDP Sciences.Google Scholar
Burchell, MJ (2006) W(h)ither the Drake equation? International Journal of Astrobiology 5, 243–250.CrossRefGoogle Scholar
Davies, PC (2012) Footprints of alien technology. Acta Astronautica 73, 250–257.CrossRefGoogle Scholar
DeVito, CL (2013) Science, SETI, and mathematics. New York: Berghahn Books.Google Scholar
DeVito, CL (2019) On the meaning of Fermi's paradox. Futures 106, 389–414.CrossRefGoogle Scholar
Drake, N (2014) How my dad's equation sparked the search for extraterrestrial intelligence. National Geographic, June 30, 2014.Google Scholar
Ebert, TA, Dixon, JD, Schroeter, SC, Kalvass, PE, Richmond, NT, Bradbury, WA and Woodby, DA (1999) Growth and mortality of red sea urchins Strongylocentrotus franciscanus across a latitudinal gradient. Marine Ecology Progress Series 190, 189–209.CrossRefGoogle Scholar
Fabens, AJ (1965) Properties and fitting of the von Bertalanffy growth curve. Growth 29, 265–289.Google ScholarPubMed
Forgan, DH (2009) A numerical testbed for hypotheses of extraterrestrial life and intelligence. International Journal of Astrobiology 8, 121–131.CrossRefGoogle Scholar
Gatto, M, Muratori, S and Rinaldi, S (1988) A functional interpretation of the logistic equation. Ecological Modelling 42, 155–159.CrossRefGoogle Scholar
Gelfand, I and Fomin, S (1963) Calculus of variations. 1963. Revised English edition translated and edited by Richard A. Silverman.Google Scholar
Haqq-Misra, JD and Baum, SD (2009) The sustainability solution to the Fermi paradox. arXiv preprint arXiv:0906.0568.Google Scholar
Hart, MH (1975) Explanation for the absence of extraterrestrials on Earth. Quarterly Journal of the Royal Astronomical Society 16, 128.Google Scholar
Kot, M (2014) A first course in the calculus of variations. Vol. 72. Providence, Rhode Island: American Mathematical Society.Google Scholar
Leitmann, G (1972) A minimum principle for a population equation. Journal of Optimization Theory and Applications 9, 155–156.CrossRefGoogle Scholar
Liquori, A and Tripiciano, A (1980) Cell growth as an autocatalytic relaxation process. In: Barigozzi, C (ed.), Vito Volterra Symposium on Mathematical Models in Biology. Berlin, Heidleberg: Springer, pp. 400–409.CrossRefGoogle Scholar
Malthus, TR (2018) An Essay on the Principle of Population: The 1803 Edition. Yale University Press.Google Scholar
Sandberg, A, Drexler, E and Ord, T (2018) Dissolving the Fermi Paradox. arXiv preprint arXiv:1806.02404.Google Scholar
Tanaka, M (1982) A new growth curve which expresses infinitive increase. Publications of Amakusa Maine Biological Laboratory 6, 167–177.Google Scholar
Volterra, V (1939) Calculus of variations and the logistic curve. Human Biology 11, 173–178.Google Scholar
Webb, S (2002) If the universe is teeming with aliens . . . where is everybody?: fifty solutions to the Fermi paradox and the problem of extraterrestrial life. Cham, Heidelberg, New York, Dordrecht, London: Springer Science and Business Media.Google Scholar
Wolfram Research, Inc. (2010) Mathematica, Version 12.1. Champaign, IL. https://www.wolfram.com/mathematica.Google Scholar
Zwietering, M, Jongenburger, I, Rombouts, F and Van't Riet, K (1990) Modeling of the bacterial growth curve. Applied and Environmental Microbiology 56, 1875–1881.CrossRefGoogle ScholarPubMed