Xref: utzoo talk.politics.misc:8979 sci.misc:1309
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From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: talk.politics.misc,sci.misc
Subject: Re: NOT greenhouse effect / solar power satellites
Message-ID: <11012@mimsy.UUCP>
Date: 11 Apr 88 10:27:58 GMT
References: <22678@bbn.COM> <5564@well.UUCP> <761@spdcc.COM>
Distribution: na
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 54

>In article <5564@well.UUCP> pokey@well.UUCP (Jef Poskanzer) writes:
>>Steve Elias is, as Jerry Pournelle put it, "not merely uninformed but
>>aggressively misinformed."  This thermal pollution bullshit seems to recur

In article <761@spdcc.COM> eli@spdcc.COM (Steve Elias) writes:
>    speak for yourself, Jef.  we don't need bullshit comments like this.
>    it figures that you would quote Pournelle.  you are both assholes.

Sorry Steve, but Jef is right, even if he is offensive about it
(and even if he does sharpen his incisors every morning :-) ).

>     efficiency has nothing to do with the problem of thermal pollution.

Efficiency has *everything* to do with it---total system efficiency
and thermodynamical equilibrium (if you prefer big words).

>>So, if you insist on being utterly paranoid and worrying about the thermal
>>balance of the Earth, you should be out there campaigning hard for SPS,
>>since by your own criteria it's 3.6 times better!  [namecalling deleted]

>   i didn't come up with the theory myself ... [more namecalling deleted]
>   [implication that] Frank Drake [first proposed it] ... all energy
>   produced by solar power satellites would not otherwise enter the
>   earth/atmosphere system.

Not exactly, but close enough.  The reason Jef is right and you are
wrong, however, is that not all enegry that enters the earth/atmosphere
system stays there.

>   so your silly arithmetic is pointless.

Not so.

Replacing a rainforest with a desert raises the albedo (reflectivity)
of the region.  This means that more of the energy that enters the
earth/atmosphere system is reflected back out of earth/atmosphere
system.  In the same manner, replacing a desert with a solar collector
array reduces the albedo of the region, meaning that more of the
energy that enters the earth/atmosphere system stays there.

In other words, we have various choices for producing more energy
(assuming that we intend to produce more energy: this is a different
argument altogether and is worthy of a separate flame war for me to
mediate :-) ).  In one of them (SPS), we throw more energy at the
ecosystem from outside; in other (local solar power), we increase the
energy retained within the ecosystem from that which already touches
it.  If you work out the numbers, one scheme results in approximately
1.1 joules retained for every joule we get to use; the other results in
about 4 joules retained for every joule we get to use.  There are
no schemes that result in less than 1 joule retained per joule used,
although there may be schemes that result in <1.1.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris