From: jgacker@neptune.gsfc.nasa.gov (James G. Acker)
Subject: Followup to Schinder Re: Creative speculation
Content-Type: text
Organization: Computer Science, Indiana University
Date: Mon, 24 Aug 92 23:01:33 EDT
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	Once again I apologize for the difficulty of replying directly.
I'm trying to fix it.

	But, regarding points raised:

	1:  ...it is possible to envision highly-intelligent trilobites...
	
	Just to clarify, I didn't say there would be HITs.  Just that
there _might_ have been.

	2:  ...favoring stargazing.   Not that primitive peoples 
wouldn't look at the sky, but they put a lot of effort into sophisticated
"observatories" which acted as eclipse predictors as well as solstice
indicators.  Seasons were obviously harvest- or hurricane-relevant, but
the eclipses (and presumably planetary motions) forced a more strategic 
analysis.
	Now I remember that the Mayan observatories were capable eclipse
predictors, but this could be a faulty memory.  How far back do 
eclipse prediction or eclipse records go?

	3:  I said "...abiogenesis...an event which is so common that it can 
only be shown to have possibly occurred on 1 celestial body... (out of 
billions)."
	Since we're working from a limited data set, I was ironically
mocking our lack of knowledge or ability to know how common or uncommon
such an event is.  The odds, given first-hand evidence, are laughably 
small (as others have noted).  With a greater sample size, the odds might 
obviously improve.  Finding life anywhere else effectively doubles the
occurrence rate and cuts the odds in half (finding life anywhere else would
actually make it likely that it's EVERYWHERE in the Universe -- and it
would be enormous fun if we found even a microbe in Jupiter's fertile
atmosphere.

	5:  Re: Collision frequency:  Sure they happen, fortunately for us
or we might be sophisticated trilobites.  The key is, they are _random_
events.  Size of impacting body, site (limestone vaporization may have
aided the K-T event), and resulting climatic effects are all variable.
Why didn't the Earth get hit so hard it split up?  It appears fortuitous
for the eventual emergence of humanity that they did happen.


	4:  Relevance of moon formation and apparent radius = apparent
solar radius:  _Any other size_ would not have allowed the spectacular 
nature of the solar eclipse.  Why didn't Venus get the perfect-sized 
Moon?  Or Mars?  No, the lucky planet which came equipped with 
observers to appreciate it was this one.  The serendipitous improbability
of life + eclipse has to be noted.  We were lucky!
	Pluto and Charon are another "double planet".  But if the size
ratio was the same between Earth and Moon, we'd get an eclipse every 
orbit.  I just like the high odds against it.

	6:  The bold lipid globule -- I am sorry, you're right.
What I should have said:  This all happened to (or nearby) the one
planet in the entire Universe where it is possible to surmise that a 
bold lipid globule... (started making copies).  We can't be certain 
that the proper environment conducive to emboldening other lipid 
globules exists anywhere else -- though we can speculate that it does,
and I'd like to think it does.  Maybe they need help?  (2010)

	7:  What are the odds?

	Regarding dice rolls and the weak anthropic principle:  If the 
odds against a sequence resulting in US are small, then _RANDOM CHANCE_
had a lot of influence on the evolutionary sequence progressing to US.
Though evolution is NOT, repeat, NOT random chance, it would seem that
the sequence of events leading to the emergence of mankind (and the
development of the current species mix as well) was somewhat random
chance, i.e. if the big rocks had hit during the Carboniferous and not 
the Permian, the mix might have been completely different.
	And random chance gave US the moon as a bonus!
	Cool.


	Hmmm... neat idea:  a sci-fi "discussion" with another intelligence
where their planetary history didn't include all this catastrophism.

	Jim Acker
	jgacker@neptune.gsfc.nasa.gov

Newsgroups: talk.origins