Hostname: page-component-5d59c44645-dknvm Total loading time: 0 Render date: 2024-02-24T03:51:20.202Z Has data issue: false hasContentIssue false

Spatio-temporal constraints on the zoo hypothesis, and the breakdown of total hegemony

Published online by Cambridge University Press:  08 June 2011

Duncan H. Forgan*
Affiliation:
Scottish Universities Physics Alliance (SUPA), Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
*

Abstract

The Zoo Hypothesis posits that we have not detected extraterrestrial intelligences (ETIs) because they deliberately prevent us from detecting them. While a valid solution to Fermi's Paradox, it is not particularly amenable to rigorous scientific analysis, as it implicitly assumes a great deal about the sociological structure of a plurality of civilizations. Any attempt to assess its worth must begin with its most basic assumption – that ETIs share a uniformity of motive in shielding Earth from extraterrestrial contact. This motive is often presumed to be generated by the influence of the first civilization to arrive in the Galaxy. I show that recent work on inter-arrival time analysis, while necessary, is insufficient to assess the validity of the Zoo Hypothesis (and its related variants). The finite speed of light prevents an early civilization from exerting immediate cultural influence over a later civilization if they are sufficiently distant. I show that if civilization arrival times and spatial locations are completely uncorrelated, this strictly prevents the establishment of total hegemony throughout the Galaxy. I finish by presenting similar results derived from more realistic Monte Carlo Realization (MCR) simulations (where arrival time and spatial locations are partially correlated). These also show that total hegemony is typically broken, even when the total population of civilizations remains low. The Zoo Hypothesis is therefore only justifiable on weak anthropic grounds, as it demands total hegemony established by a long-lived early civilization, which is a low probability event. In the terminology of previous studies of solutions to Fermi's Paradox, this confirms the Zoo Hypothesis as a ‘soft’ solution. However, an important question to be resolved by future work is the extent to which many separate hegemonies are established, and to what extent this affects the Zoo Hypothesis.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2011

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

Ball, J. (1973). Icarus 19, 347.Google Scholar
Brin, G.D. (1983). Q. J. R. Astron. Soc. 24, 283.Google Scholar
Cirkovic, M. (2009). Serbian Astrono. J. 178, 1.Google Scholar
Cirkovic, M.M. (2008). J. Br. Interplanet. Soc. 61, 246.Google Scholar
Davies, P. (2010). The Eerie Silence: Are We Alone in the Universe? Allen Lane.Google Scholar
Forgan, D. & Nichol, R. (2010). Int. J. Astrobiol. 10, 77.Google Scholar
Forgan, D.H. (2009). Int. J. Astrobiol. 8, 121.Google Scholar
Forgan, D.H. & Rice, K. (2010). Int. J. Astrobiol. 9, 73.Google Scholar
Freitas, R.A. (1977). Mercury 6, 15.Google Scholar
Freitas, R.A. (1980). J. Br. Interplanet. Soc. 33, 251.Google Scholar
Hair, T.W. (2011). Int. J. Astrobiol. 10, 131.Google Scholar
Haqq-Misra, J.D. & Baum, S.D. (2009). J. Br. Interplanet. Soc. 62, 47.Google Scholar
Lineweaver, C.H., Fenner, Y. & Gibson, B.K. (2004). Science 303, 59.Google Scholar
Miller, G.E. & Scalo, J.M. (1979). Astrophys. J. Suppl. 41, 513.Google Scholar
Ostlie, D.A. & Carroll, B.W. (ed.) (1996). An Introduction to Modern Stellar Astrophysics. Pearson Education.Google Scholar
Rocha-Pinto, H.J., Maciel, W.J., Scalo, J. & Flynn, C. (2000a). Astro. Astrophys. 358, 850.Google Scholar
Rocha-Pinto, H.J., Maciel, W.J., Scalo, J. & Flynn, C. (2000b). Astro. Astrophys. 358, 869.Google Scholar
Rolleston, W.R.J., Smartt, S.J., Dufton, P.L. & Ryans, R.S.I. (2000). Astro. Astrophys. 363, 537.Google Scholar
Snyder, D.L. & Miller, M.I. (1991). Random Point Processes in Time and Space. p. 481, Springer-Verlag: Berlin.Google Scholar
Ward, P. & Brownlee, D. (2000). Rare Earth: Why Complex Life is Uncommon in the Universe. Springer, Berlin.Google Scholar
Wyatt, M.C., Clarke, C.J. & Greaves, J.S. (2007). Mon. Not. R. Astron. Soc. 380, 1737.Google Scholar