Here is a New Scientist article at:
http://www.newscientist.co.uk/ns/19990626/newsstory5.html
which points out that the Sun is a very special star, and
that SETI seekers may be overestimating the probability of
finding intelligent life elsewhere in the universe.
I will not hide from you that the astronomer making that claim,
Guillermo Gonzalez, has written articles in Hugh Ross' Facts &
Faith journal, eg:
http://www.reasons.org/97q1faf/solarsystem.html
http://www.reasons.org/resources/FAF/98q1faf/98q1seti.html
http://www.reasons.org/resources/FAF/98q4faf/newplanets.html
so it is safe to say that he is an advocate of ID.
I do this to make the point that if he is right, and the
SETI crowd are working under the false assumption that the
Sun is just another star, then it is an example of how ID
is in principle a more fruitful research program than
methological naturalism.
After all, if there really is a Designer, one would expect that
to be the case!
Steve
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What a star!
Marcus Chown DON'T BELIEVE EVERYTHING you read in books--our
Sun is no ordinary star. And its very uniqueness has implications for SETI,
the search for extraterrestrial life, claims Guillermo Gonzalez of the
University of Washington in Seattle: "Unless astronomers narrow down
their search to stars as exceptional as the Sun, they are wasting much of
their time."
The Sun is a single star whereas most stars are in multiple systems. But that
apart, textbooks say the Sun is pretty average. However, after trawling
through the data on the Sun, Gonzalez has found many idiosyncrasies. It is
among the most massive 10 per cent of stars in its neighbourhood. It also
has 50 per cent more heavy elements than other stars of its age and type,
and about a third of the variation in brightness.
The most unusual aspects of the Sun concern its orbit around the centre of
the Galaxy, says Gonzalez. Its orbit is significantly less elliptical than that
of other stars of its age and type, and hardly inclined at all to the Galactic
plane. What's more, the Sun is orbiting very close to the "corotation
radius" for the Galaxy--the place at which the angular speed of the spiral
pattern matches that of the stars.
Gonzalez argues that these exceptional characteristics made it possible for
intelligent life to emerge on Earth. He points out that stable planetary orbits
such as the Earth's are much more likely around single stars like the Sun.
For a massive star with inhabitable planets that are relatively far away,
stellar flare-ups would be little threat to the planets. Heavy elements are
essential to make planets like Earth, and a star with a stable light output is
essential for life.
As for the orbit of the Sun, its circularity prevents it plunging into the inner
Galaxy where life-threatening supernovae are more common. And its small
inclination to the Galactic plane prevents abrupt crossings of the plane that
would stir up the Sun's Oort Cloud and bombard the Earth with comets. By
being near the Galaxy's corotation radius, the Sun avoids crossing the spiral
arms too often, an event that would expose it to supernovae, which are
more common there.
Because life-bearing stars have to be close to the corotation radius, that
rules out more than 95 per cent of stars in the Galaxy in one fell swoop.
"There are fewer stars suitable for intelligent life than people realise," says
Gonzalez, who has submitted his findings to Astronomy & Geophysics.
"I'm amazed at how little thought the SETI people put into selecting their
stars."
Seth Shostak of the SETI Institute in Mountain View, California,
disagrees. "Our targets are all very close to the Sun. They share our
Galactic neighbourhood and motions. If the Sun is the most suitable type of
star to be scrutinised, then we are, indeed, looking in all the best places."
"Most astronomers disagree with Gonzalez," adds SETI researcher Dan
Werthimer of the University of California at Berkeley. "Our Sun is pretty
average. In any case, you don't need a star exactly like our Sun for life."
[...]
(c) Copyright New Scientist, RBI Limited 1999
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"'Social Darwinism' is often taken to be something extraneous, an ugly
concretion added to the pure Darwinian corpus after the event, tarnishing
Darwin's image. But his notebooks make plain that competition, free trade,
imperialism, racial extermination, and sexual inequality were written into
the equation from the start- 'Darwinism' was always intended to explain
human society." (Desmond A. & Moore J., "Darwin," [1991], Penguin:
London UK, 1992, reprint, pp.xix)
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