From: hyde@ac.dal.ca
Newsgroups: talk.origins
Subject: Re: Pictures of a sea of lava, and where they may be found
Date: 13 Apr 92 19:43:21 GMT
Organization: Dalhousie University, Halifax, Nova Scotia, Canada

In article <2716@fedfil.UUCP>, news@fedfil.UUCP (news) writes:
> 

> From: Benjamin T Dehner, Iowa State University, Ames IA
> 
> 
> 
>>1) Ted lies about the surface features of Venus.  He claims that Venus is a
>>smooth, lava-covered surface.  The Magellan radar maps of Venus are available
>>via anonymous FTP at ames.arc.nasa.gov (I forget where; ask/look for FAQ on
>>sci.astro or sci.space.news for more info) which CLEARLY show mountainous
>>and rugged terrain.
> 
> Dehner lies in claiming that I ever claimed Venus to be smooth or without
> features;  as lying goes, putting words in other peoples mouthes is a 
> particularly pernicious variety.
> 
> That Venus is mostly covered by lava and much of that recent is well known


	Really?  I have here before me two pictures of
	the venus surface taken by Venera 13 and 14.  The surface
	shown is clearly not lava, nor has it been lava for a
	long time.  It consists of

	"flat light stones, dark soil between them, and
	a quantity of small grains."

	Note that without life, soil takes a considerable time
	to create.  The author also comments that

	"... the process (sedimentation) of the formation of the
	surface details may be nearly the same as in our oceans.
	The simultaneous presence of flat stones and granulated
	material supports the idea of sedimentation."

	So, Ted, the evidence supports a rather old, *sedimentary*
	surface at these sites, not a young pool of hot lava.
	Not, you understand, that I'm claiming the venusian
	surface to be lava-free, after all the earth itself
	has large areas of active lava production, though
	mostly covered by oceans.  It certainly would not violate
	current ideas about terrestrial planets if venus were
	considerably more volcanic than the earth.  With the surface
	as warm as it is, quite a few mantle/lithosphere properties
	should be different from those on earth.

	You can find the forgoing quotes in "Venus", edited by Hunten, Colin,
	Donahue and Moroz, university of arizona press.  The article
	cited was "Summary of preliminary results of the venera
	13 and venera 14 missions" by V.I. Moroz, who I believe was
	a Venera project scientist.


> by now from the probes and may be seen in the Jan. 92 issue of Discover 
> magazine which is readily available.

	Still citing secondary sources, I see.  At least you could
	give the author and his credentials.

  Quotes include "... one of the most
> striking characteristics of the Venusian topography is its distinct shortage
> of craters..."
> 
> That's because the lava flows cover them up.

	No doubt lava has covered some up.  Most large craters were
	formed billions of years ago - plenty of time for this to
	happen.  However, given the evidence of erosion cited above,
	it is at least as likely that most of them were eroded
	away.  Whichever way this issue is decided, it is not evidence
	for a young venus.  If venus were as young as you and Velikovsky
	maintain, and if it were cratered soon after formation,
	neither erosion nor the currently observed lava flow could
	have covered the craters by now.


>>2) Ted shows total ignorance of radiative transfer and atmospheric modeling.
> 
> Again, this is a case in which I can take justifiable pride in my ignorance.
> 
> Dehner obviously refers to the sort of radiative transfer which would allow
> the surface of Venus, which receives less than 2% of any solar energy which
> gets past the cloud tops,

	Wrong.  The surface absorbs 2% (or more - this is wavelength
	dependent) of the energy incident at the *top* of the atmosphere
	(same source, paper is "solar scattered radiation measurements
	by venus probes", by Ekonomov, Golovin, Moroz, and Moshkin).
	You are out by a factor of five.

 which is less than gets past our cloud tops, to
> reach temperatures far in excess of those of the middle cloud layer which
> absorbs 90% of this energy or more,


	The earth's thermosphere absorbs *far* less energy than
	the surface of the earth, yet it is far hotter.  If Sagan's
	theory is in violation of the second law, then so is the
	earth itself.  Care to explain to the atmosphere that it
	doesn't understand the second law as well as you do?

	Or, if that's too tough, you might care to respond to
	my post of last week, in which I explained all this to you.
	

 i.e. to a radiative transfer model which
> is in gross violation of the second law of thermodynamics.


	Bad news, Ted.  Entropy is a predicted variable of
	climate models, and any violation of the second law would
	be evident on examining the potential temperature or
	the entropy fields.  Surprise!  The violation you cite
	is not there.



> 
> I'm PROUD to be ignorant 

	You said that already.

> 
> I do not ever start these name-calling contests.  


	Really?  You've called me a liar (at least twice) and have
	never responded to challenges to back it up.  Seems like your
	above statement is incorrect.  Colour me surprised.


						Bill Hyde
Department of Oceanography
Dalhousie University,
Halifax, Nova Scotia
hyde@ac.dal.ca or hyde@dalac