The Search for Extra Terrestrial Intelligence
"Not all scientists accept the notion that other advanced civilizations exist. A few who have speculated on this subject lately are asking: if extraterrestrial intelligence is abundant, why have we not already seen its manifestations? Think of the advances by our own technical civilization in the last 10,000 years, and imagine such advances continued over millions or billions of years. If any civilizations are that much more advanced than we, why have they not produced artifacts, devices and even cases of industrial pollution of such magnitude that we would have detected them? Why have these beings not restructured the entire Galaxy for their convenience?
And why has there been no clear evidence of extraterrestrial visits to the Earth? We have already launched slow and modest interstellar spacecraft called Pioneers 10 and I 1 and Voyagers 1 and 2 -which, incidentally, carry small golden greeting cards from the Earth to any space-faring interstellar civilizations which might intercept them. A society more advanced than we should be able to ply the spaces between the stars conveniently, if not effortlessly. Over millions of years such societies should have established colonies which themselves might launch interstellar expeditions. Why are they not here? The temptation is to deduce that there are at most only a few advanced extraterrestrial civilizations - either because we are one of the first technical civilizations to have emerged, or because it is the fate of all such civilizations to destroy themselves before they are much further along.
It seems to me that such despair is quite premature. All such arguments depend on our correctly surmising the intentions of beings far more advanced than ourselves, and when examined closely I think these arguments reveal a range of interesting human conceits. For example, why do we expect that it will be easy to recognize the manifestations of very advanced civilizations? Is our situation not closer to that of isolated societies in the Amazon basin, say, who lack the tools to detect the powerful international radio and television traffic which is all around them? Also, there is a wide range of incompletely understood phenomena in astronomy. Might the modulation of pulsars or the energy source of quasars have a technological origin? Or perhaps there is a galactic ethic of noninterference with backward or emerging civilizations."
Extracted from Carl Sagan's article on SETI.
And why has there been no clear evidence of extraterrestrial visits to the Earth? We have already launched slow and modest interstellar spacecraft called Pioneers 10 and I 1 and Voyagers 1 and 2 -which, incidentally, carry small golden greeting cards from the Earth to any space-faring interstellar civilizations which might intercept them. A society more advanced than we should be able to ply the spaces between the stars conveniently, if not effortlessly. Over millions of years such societies should have established colonies which themselves might launch interstellar expeditions. Why are they not here? The temptation is to deduce that there are at most only a few advanced extraterrestrial civilizations - either because we are one of the first technical civilizations to have emerged, or because it is the fate of all such civilizations to destroy themselves before they are much further along.
It seems to me that such despair is quite premature. All such arguments depend on our correctly surmising the intentions of beings far more advanced than ourselves, and when examined closely I think these arguments reveal a range of interesting human conceits. For example, why do we expect that it will be easy to recognize the manifestations of very advanced civilizations? Is our situation not closer to that of isolated societies in the Amazon basin, say, who lack the tools to detect the powerful international radio and television traffic which is all around them? Also, there is a wide range of incompletely understood phenomena in astronomy. Might the modulation of pulsars or the energy source of quasars have a technological origin? Or perhaps there is a galactic ethic of noninterference with backward or emerging civilizations."
Extracted from Carl Sagan's article on SETI.
posted by anantha | 1:47 AM
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