Hostname: page-component-8448b6f56d-qsmjn Total loading time: 0 Render date: 2024-04-18T00:36:45.877Z Has data issue: false hasContentIssue false

Three explanations for extraterrestrials: sensible, unlikely, mad

Published online by Cambridge University Press:  05 October 2016

Simon Conway Morris*
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK
*

Abstract

The Fermi Paradox (or Question) has moved back into central focus. This is for a number of reasons, not least the evidence for both the abundance and antiquity of many extra-solar systems, the extrapolation of current technological trends to suggest that even inter-galactic colonization (by self-replicating machines) is plausible (if not desirable), and the recurrence of evolutionary solutions (convergence) in the terrestrial biosphere suggesting that features such as intelligence and tool-making are not fortuitous outcomes, but frequent if not universal. Here I review the three possible solutions to the Fermi Paradox. First, extraterrestrials certainly exist (and may be abundant), but for one reason or another (probably mundane) we have not yet met them, or at least found evidence for their existence. Second, against all expectations, we are alone. Third, we have entirely misunderstood the sort of universe we live in and have become unwitting hostages to a strict materialist explanandum that in refusing to acknowledge the other realities of our Universe has derailed any prospect of explaining the apparent absence of extraterrestrials.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2016 

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

Alié, A. & Manuel, M. (2010). The backbone of the post-synaptic density originated in a unicellular ancestor of choanoflagellates and metazoans. BMC Evol. Biol. 10, e34.Google Scholar
Annis, J. (1999). An astrophysical explanation for the great silence. J. British Interplanetary Soc. 52, 1922.Google Scholar
Armstrong, S. & Sandberg, A. (2013). Eternity in six hours: intergalactic spreading of intelligent life and sharpening the Fermi paradox. Acta Astronaut. 89, 113.Google Scholar
Atri, D., Melott, A.L. & Karam, A. (2014). Biological radiation dose from secondary particles in a Milky Way gamma-ray burst. Int. J. Astrobiol. 13, 224228.Google Scholar
Bains, W. (2004). Many chemistries could be used to build living systems. Astrobiology 4, 137167.Google Scholar
Ball, J.A. (1973). The zoo hypothesis. Icarus 19, 347349.Google Scholar
Barnes, R., Jackson, B., Greenberg, R. & Raymond, S.N. (2009). Tidal limits to planetary habitability. Astrophys. J. 700, L30L33.Google Scholar
Baxter, S. (2001). The planetarium hypothesis. A resolution of the Fermi Paradox. J. British Interplanetary Soc. 54, 210216.Google Scholar
Baxter, S. (2002). Touching Centauri. In Phase Space: Stories from the Manifold and Elsewhere. HarperCollins, London, 380–408.Google Scholar
Beane, S.R., Davoudi, Z.S. & Savage, M. (2014). Constraints on the universe as a numerical simulation. Eur. Phys. J., A 50, e148.Google Scholar
Benner, S.A., Ricardo, A. & Carrigan, M.A. (2004). Is there a common chemical model for life in the universe? Curr. Opinion Chem. Biol. 8, 672689.Google Scholar
Bostrom, N. (2003 a). Astronomical waste: the opportunity cost of delayed technological development. Utilitas 15, 308314.Google Scholar
Bostrom, N. (2003 b). Are you living in a computer simulation? Philosophical Quart. 53, 243255.Google Scholar
Bostrom, N. (2005). The simulation argument: reply to Weatherson. Philosophical Quart. 55, 9097.Google Scholar
Bostrom, N. (2008). Where are they? Why I hope the search for extraterrestrial life finds nothing. MIT's Technol. Rev. 111 (3, May/June), 7277.Google Scholar
Bostrom, N. (2009). The simulation argument: some explanations. Analysis 69, 458461.Google Scholar
Bostrom, N. & Kulczycki, M. (2011). A patch for the simulation argument. Analysis 71, 5461.Google Scholar
Bradbury, R.J. (2001). Life at the limits of physical laws. Proc. SPIE 4273, 6371.Google Scholar
Brin, G.D. (1983). The “Great Silence”: the controversy concerning extraterrestrial intelligent life. Quart. J. Royal Astronomical Soc. 24, 283309.Google Scholar
Carter, B. (2008). Five- or six-step scenario for evolution? Int. J. Astrobiol. 7, 177182.Google Scholar
Chopra, A. & Lineweaver, C.H. (2016). The case for a Gaian bottleneck: the biology of habitability. Astrobiology 16, 722.Google Scholar
Ćirković, M.M. (2009). Fermi's paradox – the last challenge for Copernicanism? Serbian Astronomical J. 178, 120.Google Scholar
Ćirković, M.M. (2015). Kardashev's classification at 50+: a fine vehicle with room for improvement. Serbian Astronomical J. 191, 115.Google Scholar
Ćirković, M.M. & Bradbury, R.J. (2006). Galactic gradients, postbiological evolution and the apparent failure of SETI. New Astron. 11, 628639.Google Scholar
Ćirković, M.M. & Vukotić, B. (2008). Astrobiology phase transition: towards resolution of Fermi's paradox. Orig. Life Evol. Biospheres 38, 535547.Google Scholar
Ćirković, M.M., Dragićević, I. & Berić-Bjedov, T. (2005). Adaptationism fails to resolve Fermi's paradox. Serbian Astronomical J. 170, 89100.Google Scholar
Conway Morris, S. (2003). Life's Solution: Inevitable Humans in a Lonely Universe. Cambridge.Google Scholar
Conway Morris, S. (2005). Aliens like us? Astron. Geophys. 46, 4.244.26.Google Scholar
Conway Morris, S. (2011). Predicting what extraterrestrials will be like: and preparing for the worst. Phil. Trans. Royal Soc. Lond., A 369, 555571.Google Scholar
Conway Morris, S. (2013). Life: the final frontier for complexity? In Complexity and the Arrow of Time, ed. Lineweaver, C.H., Davies, P.C.W. & Ruse, M., pp. 135161. Cambridge University Press, Cambridge.Google Scholar
Conway Morris, S. (2015a). The Runes of Evolution: How the Universe Became Self-Aware. Templeton.Google Scholar
Conway Morris, S. (2015 b). Bioastronomy. In 52 Things you Should Know About Palaeontology, ed. Cullum, A. & Martinus, A.W., pp. 3031. Agile Libre Mahone Bay, Nova Scotia.Google Scholar
Conway Morris, S. & Caron, J-B. (2014). A primitive fish from the Cambrian of North America. Nature 512, 419422.Google Scholar
Dawes, L.J., Sugiyama, Y., Lovicu, F.J., Harris, C.G., Shelley, E.J. & McAvoy, J.W. (2014). Interactions between lens epithelial and fiber cells reveal an intrinsic self-assembly mechanism. Dev. Biol. 385, 291303.Google Scholar
Diamond, J. (1995). Alone in a crowded universe. In Extraterrestrials: Where are they?, ed. Zuckerman, B. & Hart, M.H., pp. 157164. Cambridge University Press, Cambridge.Google Scholar
Duggin, I.G., Aylett, C.H.S., Walsh, J.C., Michie, K.A., Wang, Q., Turnbull, L., Dawson, E.M., Harry, E.J., Whitchurch, C.B., Amos, L.A. et al. (2015). CetZ tubulin-like proteins control archaeal cell shape. Nature 519, 362365.Google Scholar
Dyson, F.J. (1960). Search for artificial sources of infrared radiation. Science 131, 16671668.Google Scholar
Eiraku, M., Takata, N., Ishibashi, H., Kawada, M., Sakakura, E., Okuda, S., Sekiguchi, K., Adachi, T. & Sasai, Y. (2011). Self-organizing optic-cup morphogenesis in three-dimensional culture. Nature 472, 5156.Google Scholar
Flores Martinez, C.L. (2014). SETI in the light of cosmic convergent evolution. Acta Astronaut. 104, 341349.Google Scholar
Fogg, M.J. (1987). Temporal aspects of the interaction among the first galactic civilizations: the “Interdict hypothesis”. Icarus 69, 370384.Google Scholar
Forgan, D.H. (2011). Spatio-temporal constraints on the zoo hypothesis, and the breakdown of total hegemony. Int. J. Astrobiol. 10, 341347.Google Scholar
Freeth, T., Bitsakis, Y., Moussas, X., Seiradakis, J.H., Tselikas, A., Mangou, H., Zafeiropoulou, M., Hadland, R., Bate, D., Ramsey, A. et al. (2006). Decoding the ancient Greek astronomical calculator known as the Antikythera mechanism. Nature 444, 587591.Google Scholar
Fritz, J., Bitsch, B., Kührt, E., Morbidelli, A., Tornow, C., Wünnemann, K., Fernandes, V.A., Grenfell, J.L., Rauer, H., Wagner, R. et al. (2014). Earth-like habitats in planetary systems. Planet. Space Sci. 98, 254267.Google Scholar
Galante, D. & Horvath, J.E. (2007). Biological effects of gamma-ray bursts: distances for severe damage on the biota. Int. J. Astrobiol. 6, 1926.Google Scholar
Garrett, M.A. (2015). Application of the mid-IR radio correlation to the Ĝ sample and the search for advanced extraterrestrial civilizations. Astron. Astrophys. 581, L5.Google Scholar
Gladman, B., Dones, L., Levison, H.F. & Burns, J.A. (2005). Impact seeding and reseeding in the inner Solar System. Astrobiology. 5, 483496.Google Scholar
Gowanlock, M.G., Patton, D.R. & McConnell, S.M. (2011). A model of habitability within the Milky Way galaxy. Astrobiology 11, 855873.Google Scholar
Gray, R.H. (2015). The Fermi paradox is neither Fermi's nor a paradox. Astrobiology 15, 195199.Google Scholar
Gray, P.M., Krause, B., Atema, J., Payne, R., Krumhansl, C. & Baptista, L. (2001). The music of nature and the nature of music. Science 291, 5254.Google Scholar
Griffith, R.L., Wright, J.T., Maldonado, J., Povich, M.S., Sigurđsson, S. & Mullan, B. (2015). The Ĝ infrared search for extraterrestrial civilizations with large energy supplies. III. The reddest extended sources in WISE. Astrophys. J. Suppl. Ser. 217, e25.Google Scholar
Haisch, B. (2014). Is the universe a vast, conscious-created virtual reality simulation? Cosmos History 10, 4860.Google Scholar
Hart, M.H. (1975). An explanation for the absence of extraterrestrials on Earth. Quart. J. Royal Astronomical Soc. 16, 128135.Google Scholar
Haqq-Misra, J. & Kopparapu, R.K. (2012). On the likelihood of non-terrestrial artefacts in the Solar System. Acta Astronaut. 72, 1520.Google Scholar
Herzing, D.L. (2014). Profiling nonhuman intelligence: an exercise in developing unbiased tools for describing other “types” of intelligence on earth. Acta Astronaut. 94, 676680.Google Scholar
Jimenez, R. & Piran, T. (2013). Reconciling the gamma-ray burst rate and star formation histories. Astrophysical J. 773, e126.Google Scholar
Jones, E.M. (1985). Where is everybody? Phys. Today 38, 11, 13.Google Scholar
Kardashev, N.S. (1964). Transmission of information by extraterrestrial civilizations. Sov. Astron. 8, 217221.Google Scholar
Lineweaver, C.H. (2001). An estimate of the age distribution of terrestrial planets in the universe: quantifying metallicity as a selection effect. Icarus 151, 307313.Google Scholar
Lineweaver, C.H., Fenner, Y-S. & Gibson, B.K. (2004). The galactic habitable zone and the age distribution of complex life in the Milky Way. Science 303, 5962.Google Scholar
Livio, M. (1999). How rare are extraterrestrial civilizations, and when did they emerge? Astrophysical J. 511, 429431.Google Scholar
Mayr, E. (2004). Are we alone in this vast universe? In What Makes Biology Unique? Considerations on the Autonomy of a Scientific Discipline, pp. 209217. Cambridge University Press, Cambridge.Google Scholar
McInerney, J.O., Martin, W.F., Koonin, E.V., Allen, J.F., Galperin, M.Y., Lane, N., Archibald, J.M. & Embley, T.M. (2011). Planctomycetes and eukaryotes: a case of analogy not homology. Bioessays 33, 810817.Google Scholar
Morrison, I.S. & Gowanlock, M.G. (2015). Extending galactic habitable zone modeling to include the emergence of intelligent life. Astrobiology 15, 683696.Google Scholar
Piran, T. & Jimenez, R. (2014). Possible role of gamma ray bursts on life extinction in the universe. Physical Rev. Lett. 113, 231102.Google Scholar
Sandberg, A. (1999). The physics of information processing superobjects: daily life among the Jupiter brains. J. Evol. Technol. 5, 134.Google Scholar
Simpson, G.G. (1964). The nonprevalence of humanoids. Science 143, 769775.Google Scholar
Smart, J.M. (2012). The transcension hypothesis: sufficiently advanced civilizations invariably leave our universe, and implications for METI and SETI. Acta Astronaut. 78, 5568.Google Scholar
Tipler, F.J. (1980). Extraterrestrial intelligent beings do not exist. Quart. J. Royal Astronomical Soc. 21, 267281.Google Scholar
Tomarev, S.I. & Piatigorsky, J. (1996). Lens crystallins of invertebrates. Diversity and recruitment from detoxification enzymes and novel proteins. European J. Biochem. 235, 449465.Google Scholar
Wandel, A. (2015). On the abundance of extraterrestrial life after the Kepler missions. Int. J. Astrobiol. 14, 511516.Google Scholar
Webb, S. (2002). If the Universe is Teeming with Life … Where is Everybody? Fifty Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life. Copernicus Books.Google Scholar
Wiley, K.B. (2011). The Fermi paradox, self-replicating probes, and the interstellar transportation bandwidth. arXiv: 1111.6131.Google Scholar
Williams, C. (1931). Many dimensions. Faber & Faber, London.Google Scholar
Williams, C. (1937). Descent into hell. Faber & Faber, London.Google Scholar
Wilson, P., Wolfe, A.D., Armbruster, W.S. & Thomson, J.D. (2007). Constrained lability in floral evolution: counting convergent origins of hummingbird pollination in Penstemon and Keckiella. New Phytol. 176, 883890.Google Scholar
Worth, R.J., Sigurdsson, S. & House, C.H. (2013). Seeding life on the moons of the outer planets via lithospermia. Astrobiology 13, 11551165.Google Scholar
Wright, J.T., Mullan, B., Sigurdsson, S. and Povich, M.S. (2014). The Ĝ infrared search for extraterrestrial civilizations with large energy supplies. I. Background and justification. Astrophysical J. 792, e26.Google Scholar
Zackrisson, E., Calissendorf, P., Asadi, S. & Nyholm, A. (2015). Extragalactic SETI: the Tully-Fisher relation as a probe of astroengineering in disk galaxies. Astrophysical J. 810, e23.Google Scholar