Chuck Vandergraaf wrote:
<< It could be argued that Carl Sagan's insistence of abundant life in the
universe is his statement of faith and that a government-funded search for
extraterrestrial life is mixing politics and religion. ;-)
>>
One point that I am reminded of here is that it seems that Sagan's
optimism contrasts with Hugh Ross' pessimism. They both focus
on the probability of life in the universe. So we at least we know
the extremes. For Sagan, it was "right next door", and Ross its "not
even a prayer". That sets that the odds at somewhere at a "ghost of a
prayer".
In any case, the July issue of Scientific American had a fairly
clear discussion on the topic:
In regards to colonization of an extraterrestrial:
"Assuming a typical colony spacing of 10 light-years, a ship
speed of 10 percent that of the speed of light, and a period of
400 years between the foundation of a colony and its sending out colonies
of its own, the colonization wave front will expand at an average
speed of 0.02 light-years a year. As the galaxy is 100,000 light
years across, it takes no more than about five million years to
colonize it completely. Though a long time in human terms, this
is only 0.05 percent of the age of the galaxy. Compared with the other
relevant astronomical and biological time scales, it is essentially
instantaneous."[Where are they: Maybe we are alone in the galaxy after
all. Ian Crawford, Scientific American, 283(1), p. 29.]
"For more than three billion years, Earth was inhabited solely by
single-celled microorganisms. This time lag seems to imply that
the evolution of anything more complicated than a single cell is
unlikely." [Ibidem, p 33.]
There is also a chart of what has been search, the radiative power involved,
and the anticipated class of civilization that could elude all of our
search efforts. To a certain extent, a civilization in the state such
as our own earth might still elude detection because the transmission
is not so powerful. Any civilization that has achieved interstellar
space travel would probably have already been detected as far as I
can tell from the graph. Either that, or there are very very few
such civilizations that survive to the point that they can achieve
interstellar space travel. or..... we are all alone in the universe.
In any case, the notion of space aliens eluding our detection is
probably out of touch with reality. *If* other civilization exist
and exist nearby our own star, they are _at most_, at a similar
level of development as our own human civilization.
I would also be rather skeptical of the notion that other
intelligent life in the universe (_IF_ it exists) is not in
any need of salvation. It's true, only "the world" is fallen,
but what exactly is "the world"?. Clearly at the time of
the writing that would have meant "our world", but it would
seem to me that it could expand to fit whatever world we actually
live in. I am inclined to think that ignorance is bliss,
and the honeymoon is soon over. What is probably important
to think about is how not to screw up like most of the human
race has screwed up before when it comes to issues over land,
economics, power, distribution of goods, considering the foreigner,
etc. We have a bible, but who listens to the word of God?
by Grace alone do we proceed,
Wayne
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