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Date: Thu,  1 Mar 90 03:02:06 -0500 (EST)
Subject: SPACE Digest V11 #95

SPACE Digest                                      Volume 11 : Issue 95

Today's Topics:
	   Re: Did SEASAT See More Than It Was Supposed To?
			Dissassembling the Sun
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Date: 27 Feb 90 17:41:07 GMT
From: elroy.jpl.nasa.gov!usc!zaphod.mps.ohio-state.edu!uwm.edu!cs.utexas.edu!ut-emx!walt.cc.utexas.edu!wastoid@decwrl.dec.com  (Matthew Feulner)
Subject: Re: Did SEASAT See More Than It Was Supposed To?

In article <2274@syma.sussex.ac.uk> nickw@syma.susx.ac.uk (Nick Watkins) writes:
>In article <1990Feb23.175643.13944@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>>In article <2235@syma.sussex.ac.uk> nickw@syma.susx.ac.uk (Nick Watkins) writes:
>>as implausible that it could stay secret for over a decade, especially
>>since I don't think DoD has any "prerogative" over civilian research
>>satellites.
>
>Jonathan McDowell has pointed out to me that the DoD sponsored the Geosat ERM
>(exact repeat mission) which repeated some of the measurements, so the
>"murder" theory seems pretty unlikely.

Geosat is a Navy satellite originally used for high resolution ocean
geoid recovery.  After its original mission was completed, it was
"moved" into the ERM (= SEASAT orbit) for scientific studies.  I don't
think it has a SAR on board.  Also, it doesn't have a scatterometer,
which means the altimeter can not compensate for wet tropospheric
effects as well as SEASAT could => less precise altimeter measurements.

Matthew Feulner

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Date: 27 Feb 90 19:23:36 GMT
From: frooz!cfa.HARVARD.EDU@husc6.harvard.edu  (Steve Willner, OIR)
Subject: Dissassembling the Sun

From article <1990Feb18.032915.4123@cs.rochester.edu>, by 
dietz@cs.rochester.edu (Paul Dietz):
> Well, we 
[i.e. future advanced civilizations may]
> disassemble the outer planets and then the sun (the latter is
> the hardest; you need on the order of 10^7 years if you fully utilize
> the sun's power output; presumably more power could be produced to
> speed things up).  

Longer than that, I suspect.  If the Sun were of uniform density, its
potential energy would be just 1.2 G M^2/R (if I've done the integral
right).  The time for the Sun to radiate that amount of energy at its
current luminosity would be 4E7 years.  But in reality, the Sun's mass
is highly  concentrated towards the center, and the potential energy is
much greater.  I suspect also that the process efficiency may be rather
less than one.

I'm cross-posting to sci.astro to see if someone knows a quantitative
value for the "much".  My stellar structure courses were too long ago.
-------------------------------------------------------------------------
Steve Willner            Phone 617-495-7123         Bitnet:   willner@cfa
60 Garden St.            FTS:      830-7123           UUCP:   willner@cfa
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End of SPACE Digest V11 #95
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