|MadSci Network: Astronomy|
1/ SETI is of the oldest quests known to Man, in one form or another; to actually have an interest in the wider Universe, and to seek out other intelligences is a definition of Humanity itself. Without a desire to understand the Universe and our possible place in it, Humanity is little more than a rather unpleasant homicidal ape whose existence has little or no value. 2/ The assumption that, without faster than light travel, we cannot get there, is oversimple. The nearer stars are less than 10 light years away. Using antimatter - or even light sail propulsion backed by solar driven lasers - it is quite conceivable to reach speeds of 0.25-0.3 c ; accelerating at 1 g over 1 year, such a speed could be reached; allowing for acceleration and deceleration, travel to 10 light years could be accomplished within 40 years, or 20 years to Alpha Centauri. Remember that Aluminium , discovered in 1826, remained an expensive and uselss laboratoy curio until electrical extraction from bauxite.So it could be with anti-matter.The maximum attainable human life span, using present knowledge, is easily 120 years and could doubtless be quite a bit more by the time interstellar travel becomes a live issue. Thus, a reasonable fraction of a human lifespan could contain an interstellar voyage. 3/ Alternatively, O'Neill type Island space colonies could allow slower transport of larger numbers over generations. These would be fuelled and resupplied from Oort cloud comets in our own and the target systems, reproducing a Polynesian "island hopping" style of migration. Thus the truly awesome scale of interstellar distances can be brought down to more manageable proportions. There is a growing concensus among serious students of interstellar travel that it is now not inconceivable- merely very difficult and expensive! My own guess - and I would not swear to this in a court of law - is that we are nearer in time to the first interstellar voyages than we are to Napoleon Bonaparte's campaigns. 4/ We now know that the lifespan of a technological liberal civilization is dependent on accessible space development, since the threat of asteroid/cometeary impacts puts paid to the chances of surviving with all our eggs in one planetary basket. This factor may in part account for our lack of visitors, since planetary formation elsewhere is also accompanied by comets and asteroids, as far as we can tell- and the newly discovered extrasolar planetary systems are beginning to give us real data. 5/ The discovery that some other species had come to the same crossroads as we now face, and has made it through , would be of enormous reassurance to us that there is a possible longterm future. 6/I agree with you that communication - or at any rate initial discovery by radio - is a long shot; but it is the cheapest way, and so has to be tried. In fact, I suspect that detection of anomalous activity around another star will prove an index of a space-faring civilization, rather as the anomalous existence of free oxygen and methane in co- existence in our atmosphere is a signature for the presence of Life( Lovelock, Gaia hypothesis). 7/ Finally, the non-discovery of ET , if maintained over a long and diligent search, would be an important scientific and philosophical negative; it is difficult to prove an absolute negative- but the odds lengthen with experience and prolonged search by a variety of methods. If it emerges that we are either alone or at any rate very rare, the responsibility on us to ensure the survival, growth, and development of Mind to its full potential is compelling - indeed it would be our raison d'etre. This would mean that space colonization, so far from being an idle luxury, is actually our principal justification for existence as a species, as Man alone of all Earth's creatures can accomplish this. It becomes, like SETI itself, a quasi-religious quest, and a defining charcteristic of Humanity itself, against which opposition is inappropriate, if not futile. Further, if we prove to be alone or rare, we face NO ethical problems in pursuing a galactic destiny . We would face no Indians, Aztecs, or Incas on our path of "conquest". The writer HG Wells once wrote that "For Man, the future is all the Universe, or nothing!" It is surely of the first importance to learn whether, as minds, we face that future alone or not. Michael Martin-Smith
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