Let me first point out that I would be the first person to be very happy
if the sorts of things that Gonzales advocates really give support to the
idea that our sun is unique.
However, it seems to me that the sorts of evidence that he provides are
not very convincing:
(1) All the evidence are provided ad hoc, and not through a
hypothetical-deductive method. Probably he could find features that make
Andromeda look like a very unique star too. All he has to do is to
disregard all the features that Andromeda has in common with other stars
and consider them unimportant. (this is a procedure similar to the one
used by some people to find "hidden codes" in the bible)
(2) It is not clear to me how those features that he presented as evidence
of the uniqueness of the sun actually affect the probability of the
evolution of life. On the contrary, it seems to me that all of them occur
in a much larger time scale.
(3) My last point has to do with the anthropic principle. Isn't it curious
that the anthropic principle is used as one of the most strong arguments
for the existence of God by christian cosmologists BUT not by christian
evolutionists? It looks like, once we get to biological evolution,
contingency takes over, and a mechanism that appeared to be deterministic
now is driven by chance? Does God now change the probability of events in
our favor?
Marcio
On Wed, 30 Jun 1999, Stephen Jones wrote:
> Reflectorites
>
> 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
>
> -------------------------------------------------------------------------
> 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."
>
> >From New Scientist, 26 June 1999
>
> [...]
>
> (c) Copyright New Scientist, RBI Limited 1999
> -------------------------------------------------------------------------
>
> --------------------------------------------------------------------
> "'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)
> --------------------------------------------------------------------
>
>
>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Marcio R. Pie
Department of Biology
Boston University
Boston, MA 02215
Office: 617 3536974
Home: 617 7690856