Re: Why do we continue to support SETI?

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