Bioastronomy [was Bloated Stars and excess IR]

From: Robert J. Bradbury (bradbury@www.aeiveos.com)
Date: Fri Aug 13 1999 - 07:03:22 MDT


> Damien Broderick <d.broderick@english.unimelb.edu.au> wrote:

> >But Livio did find significant telltale evidence that some giant
> >stars once possessed giant planets that were then swallowed up.
> >The devouring stars release excessive amounts of infrared light,
> >spin rapidly, and are polluted with the element lithium.
> [...]
> >First, according to Livio's calculations, such a star is bigger
> >and brighter because it absorbs gravitational energy from the
> >orbiting companion. This heats the star so that it puffs off
> >expanding shells of dust, which radiate excessive amounts of
> >infrared light.
>
> Does this impact on one of Robert Bradbury's presumed anomalies?
>

Hmmmmph. I'm not "presuming" anything. Data is data.
It is generally the astronomers themselves who consider it to be
"anomalous" because it is inconsistent with common "expectations".
All I do is try to bring consistency to the picture by expanding
the frame of reference... :-)

It probably dosn't impact my perspective. At the Bioastronomy
conference there was some discussion about the 18+ planets and
a lot of work on ongoing projects to find more planets using various
methods. I think there is pretty general agreement that there is a
strong selection effect at work in the current results -- i.e. we
see big planets with small orbits because that is what we can
best detect currently. Livio's work may do a good job resolving
the problem of why the stars with the massive planets have high
metal concentrations -- they may have already consumed one or
more of these planets.

My interpretation of some of the observations does postulate
that excess infrared radiation is unaccounted for and could
be coming from M-Brains. However, the Livio data is still
focused on un-enclosed stars. These stars are still going to
have atmospheres with a temperature of several thousand degrees K.
They may generate excess infrared, but most of the radiation will
still be in the visible range. My hypothesis suggests that for
enclosed stars all of the visible radiation would be down-shifted
into the infrared and that there would be many orders of magnitude
less radiation in the visible (according to the black body emission
curve). Presumably Livio is working with stars that he can "see",
while my emphasis is on the stars that we cannot "see".

While I've devoted some thought to whether the observed "planets"
could be supercomputers (like the old Jupiter Brians idea), I
can't come up with a good reason why a civilization would waste
most of the energy the star generates. At the Extro4 conference,
Anders indicated that he has an updated version of his J-Brain
paper that adds some additional classifications & structures for
the supercomputers/SIs, but I don't think these help much. The
only explanation I can imagine is that the system is *very*
element poor. This could occur if you had a system that started
out with several large planets. The smaller planets may have
been cast out into space and most of the larger planets crashed
into the star. The material remaining is only enough to build
a J-Brain. This argument is stretched thin however in my opinion.
For this ultimately to hold water, stellar mining would have to
be impossible and I think Robert Freitas would disagree with that.
[And I'm not foolish enough to want to directly disagree with
Robert's educated opinions.]

It is good though, that people are "starting" to give some consideration
to what happens to the planets in the long run. It means that the
winds are blowing in the direction of not only how things begin, but
how they end as well. The Bioastronomy conference was striking in
the very strong emphasis on how life gets started. There was little
or no discussion on what happens to atmospheres, continents, life, etc.
on planets (such as ours) with billions of years of evolutionary potential.
I.e. there was much discussion of our planet (or others like it at
the 2-3 billion year stage), but none at the 6-7 billion year stage.
It is interesting to note that planets around K & M stars should still
be around with many much older than the Earth is (our sun is a G star
and so burns hotter & faster than K & M stars).

For the record, less than 10 people out of 200+ at the conference
stopped by to look at my poster. None to my knowledge were from
either NASA Ames (the location of the Bioastronomy initiative)
or the SETI Inst. One fellow from JPL was fairly interested and
requested a copy of the paper. After Stuart Bowyer (president elect
of IAU Commission 51) reported on the negative results from the Serendip
III search, I pointed out that you could "use Nanotechnology to dismantle
Mercury in 14 days to produce a solar collector enshrouding the star" and
as a result, searches of nearby stars that could be "seen" were unlikely to
yield signs of intelligent life. I also pointed out that the only way to
proceed was to cross the HIPPARCOS data (showing nearby stars with high
parallax motion) with the IRAS data (showing high IR regions) [current
searches tend to use the HIPPARCOS data alone].

Stuart's response could be best summarized as "less than open minded".

During a coffee break, I overheard two young scientists from NASA Ames &
The SETI Inst. discussing "I don't understand the comment about dismantling
Mercury...". So I stopped and did a brief explanation about molecular
disassembly, exponetial growth, etc. When I got through, they had no
"scientific" objections as far as I could determine. At least one however
seemed very concerned that the astrologers would never allow me to
dismantle Mercury since it would cause a signficant amount of disruption
to their frame of reference.

It is going to take a very big hammer and some very long nails....

Robert



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