Fermi's paradox: The last challenge for copernicanism?

Abstract

We review Fermi's paradox (or the 'Great Silence' problem), not only arguably the oldest and crucial problem for the Search for ExtraTerrestrial Intelligence (SETI), but also a conundrum of profound scientific, philosophical and cultural importance. By a simple analysis of observation selection effects, the correct resolution of Fermi's paradox is certain to tell us something about the future of humanity. Already more than three quarters of century old puzzle and a quarter of century since the last major review paper in the field by G. David Brin has generated many ingenious discussions and hypotheses. We analyze the often tacit methodological assumptions built in various answers to this puzzle and attempt a new classification of the numerous solutions proposed in an already huge literature on the subject. Finally, we consider the ramifications of various classes of hypotheses for the practical SETI projects. Somewhat paradoxically, it seems that the class of (neo)catastrophic hypotheses gives, on the balance, the strongest justification to optimism regarding our current and near-future SETI efforts.U ovom clanku pravimo pregled Fermijevog paradoksa (ili paradoksa 'Velike tisine'), ne samo najstarijeg i po mnogo cemu kljucnog problema potrage za vanzemaljskom inteligencijom (SETI), ve i zagonetke sa dubokim opste naucnim, filozofskim i kulturnim znacajem. Jednostavnom primenom analize posmatrackih selekcionih efekata, korektno resenje Fermijevog paradoksa nam gotovo izvesno govori nesto o buducnosti covecanstva. Ovaj problem, star ve vise od tri cetvrti veka a proslo je vise od cetvrt veka od poslednjeg kljucnog preglednog clanka u literaturi koji je napisao G. Dejvid Brin generisao je mnoge domisljate rasprave i ingeniozne hipoteze. Ovde analiziramo precutne pretpostavke ugradjene u razlicite odgovore na ovu zagonetku i predlazemo novu klasifikaciju brojnih resenja koja se pojavljuju u ve ogromnoj literaturi na ovu temu. Konacno razmatramo posledice razlicitih klasa hipoteza na prakticne SETI projekte. Donekle paradoksalno, izgleda da (neo)katastroficke hipoteze daju, kad se sve uzme u obzir, najvise razloga za optimizam u pogledu nasih sadasnjih SETI poduhvata i onih u bliskoj buducnosti.