HDTenEightyP/NetNews huggingface dataset:
From: treitel@gracie.IntelliCorp.COM (Richard Treitel)
Subject: Re: Malthusians are mistaken
Date: 7 Jan 93 18:15:53 GMT
Organization: preferably none

In article <1993Jan6.231059.21088@netcom.com>, dani@netcom.com (Dani Zweig) writes:
|> Well, we know this to be true:  Most obviously, birthrates are lowest and
|> empowerment highest in the wealthier countries.  This may or may not
|> imply cause and effect.  Does the correlation hold when you control for the 
|> availability of contraceptives?

It certainly holds in some heavily Roman Catholic countries (Italy, Spain).
The Republic of Ireland has pretty strict laws about contraceptives (though
married couples can get them) and I don't know the birthrate there.

My favourite example is Singapore.  Lee Kuan Yew believed in having an
educated workforce, including females.  He has recently been begging (and
bribing) Singapore's highly educated women to have more babies, which they
just aren't doing.

Look also at the P.R.China.  Contraceptives available, but many babies,
especially in rural areas.  Surprise!


N.B. contraceptives are not *necessary* for family planning.

		- Richard
Newsgroups: rec.arts.sf.science
Subject: Re: Wrecking an O'Neill (Was: Re: Wrecking a Planet)
From: morgan@arc.ab.ca (Sean Morgan)
Date: 11 Jan 93 09:18:44 MDT
Distribution: world
Organization: Alberta Research Council

Is it fair to sum up this thread with:
	"It would take billions of tonnes of shielding to protect an O'Neill colony,
so they will either have to be built inside an asteroid or have a
super-duper star wars defence system"?

Why not make friends with your neighbours instead?  The same reasoning would
say that all of our cities should be built inside mountains, or else you might
as well not bother building the house, since an aggressor would be able to
annihilate it anyway.

Non sequitur.
-----------------+-------------------------------
Sean Morgan      |  ALBERTA  6815 - 8 Street N.E.
                 | RESEARCH  Calgary, AB, Canada
morgan@arc.ab.ca |  COUNCIL  T2E 7H7

Newsgroups: rec.arts.sf.science
From: treitel@gracie.IntelliCorp.COM (Richard Treitel)
Subject: Re: Malthusians are mistaken
Date: 8 Jan 93 21:58:18 GMT
Organization: preferably none

In article <1993Jan8.070715.25019@netcom.com>, dani@netcom.com (Dani Zweig) writes:
|> >>Does the correlation hold when you control for the 
|> >>availability of contraceptives?
|> >
|> >It certainly holds in some heavily Roman Catholic countries (Italy, Spain).
|> 
|> Are we using the same language?  Oh, I see.  No, 'control for', not 'control'.

Yes ... you can't 'control for' unless you have examples of countries with
low availability of contraceptives.  I wasn't answering the whole question,
just trying to provide a few examples.

		- Richard
Newsgroups: rec.arts.sf.science
From: rwallace@unix1.tcd.ie (russell wallace)
Subject: Re: Wrecking a Planet (Was: Re: Sci-Fantasy Weapons)
Organization: Trinity College, Dublin
Date: Fri, 8 Jan 1993 00:15:24 GMT

In <1993Jan7.154159.19572@mail.cornell.edu> phydeaux@guru.med.cornell.edu (Dave Weingart) writes:

>In article <rwallace.726413572@unix1.tcd.ie>, rwallace@unix1.tcd.ie (russell wallace) writes:
>|> Um, no, I'm not talking about a Skylab-type job here, I'm talking about
>|> an O'Neill habitat with mass maybe 1 billion tons. You're going to need
>|> a high-megaton range bomb to wipe it out.

>Poke enough holes in the thing and everyone dies.  No mess, no fuss, and
>your aim doesn't need to be particularly accurate.

A rotating O'Neill habitat will have to have a thick shell of the
strongest available materials, plus enough thickness to stop cosmic rays
and meteors. gGravel isn't going to poke *any* holes in it. Even it it
did (or more realistically if a kiloton-range bomb did) the people are
going to have sealed compartments to get into during red alert (just
like bomb shelters in WW2).


> 
>|> Sure, I'm not proposing something with a max accel. maybe 0.05g could
>|> *dodge* an attack, just that if it makes frequent small random changes
>|> to its orbit, you can't predict where it will be in a month's time and
>|> thus throw unguided bombs from long distances away like you can with a
>|> planet.

>Okay, but then you get into certain practicalities.  How stable will the
>habitat be if you're continually changing the orbit?

Orbits are inherently stable. You slow down a little bit, you get a
little bit closer to the sun, speed up a little bit, a little bit
further away, etc. Who cares if you're 0.01% away from your previous
orbit, if that means your attackers miss by 100 km?


>For that matter, combining with the above, small cheap "smart missles" that
>look for some unique signature (say IR for argument's sake) that just whale
>into the habitat will poke enough holes in it to wipe out everyone inside.

>Of course, then you _can_ get into decoys and smaller, cheaper IR sources
>that just hang out and attract these buggers away from the habitat...

>-- 
>73 de David Weingart  KB2CWF    In the event I am captured or killed, the
>phydeaux@cumc.cornell.edu       Cornell University Medical College and the
>phydeaux@guru.med.cornell.edu   Department of Academic Computing will disavow
>phydeaux@src4src.linet.org      any knowledge of my opinions.
--
"To summarize the summary of the summary: people are a problem"
Russell Wallace, Trinity College, Dublin
rwallace@unix1.tcd.ie
Newsgroups: rec.arts.sf.science
From: jdnicoll@prism.ccs.uwo.ca (James Davis Nicoll)
Subject: Re: Wrecking a Planet (Was: Re: Sci-Fantasy Weapons)
Organization: University of Western Ontario, London
Date: Sat, 9 Jan 1993 01:50:32 GMT
Keywords: n

In article <1993Jan8.171024.22702@lmpsbbs.comm.mot.com> johns@ssd.comm.mot.com (Mike Johns) writes:
>
>Some of the ideas for defending these things seem to assume that they 
>are weapons of a sort rather than a space habitat.  You can't waste infinite
>resources on a commercial venture on the off chance that godless evil red
>martians (TM) are going to take pot shots at it?

	Especially since the g.e.r.m.s will have pacified by the
de-orbiting of Phobos or Deimos.

							James Nicoll
From: dietz@cs.rochester.edu (Paul Dietz)
Newsgroups: rec.arts.sf.science
Subject: Re: Davis Mechanics (was Re: John Woods Campbell)
Date: 11 Jan 93 19:20:13 GMT
Organization: University of Rochester

In article <GERRY.93Jan11101807@onion.cmu.edu> gerry@cmu.edu (Gerry Roston) writes:

> We have all (well almost all) agreed that the original question was
> silly because there is no such thing as an incompressible substance.
> But is that true?  When a star colapses and becomes a black hole, what
> is the density of the material?  Isn't this theorectically a mass of
> nuclei smushed up against ecah other?  If so, how would one compress
> this any further?

One could apply the same argument to atoms!  The same answer
applies: atoms, like nuclei, are not incompressible.  Indeed, no
real material is incompressible; sound must always travel at < c.

Additionally, you can make a black hole out of material of
any density.  The more dense the material, the smaller the black
hole you can make.  Remember, the "radius" of a black hole
is proportional to its mass, so its "density" is proportional
to mass^{-2}.  A black hole of stellar mass has a "density"
of something like 10^16 g/cc, but a black hole of galactic mass
would be less "dense" than air.

	Paul F. Dietz
	dietz@cs.rochester.edu
Newsgroups: rec.arts.sf.science
From: baylor@NEBULA.SSD.LMSC.LOCKHEED.COM
Subject: Re: (oddball question off the topic of...) Wrecking space colonies
Reply-To: baylor@NEBULA.SSD.LMSC.LOCKHEED.COM
Organization: LMSC, Sunnyvale, California
Date: Mon, 11 Jan 93 19:35:03 GMT

In article <MARTINC.93Jan11094439@hatteras.cs.unc.edu>, 
martinc@hatteras.cs.unc.edu (Charles R. Martin) writes:
>
>I've wondered for some time -- what exactly *is* "depleted uranium"?
>238U alone (no 235)?  Iron-poor U?  Old tired stuff?
>--
Depleted uranium is the stuff that's left after they separate the
"enriched" uranium (with which they can make the bombs & reactors).
It probably is not pure U238, but has less of the fissionable isotopes
than before it was processed. Because 238 is the main isotope of Uranium
there is a lot of depleted uranium around. There has been research on
using it in conventional weapons, since it is rather heavy and 
essentially free of cost. (Recycling moves on! ;-)
Newsgroups: rec.arts.sf.science
From: m23364@mwunix (James Meritt)
Subject: Re: Wrecking a Planet (Was: Re: Sci-Fantasy Weapons)
Organization: MITRE Corporation, McLean VA
Date: Fri, 8 Jan 1993 14:50:57 GMT

In article <1993Jan7.221319.22437@nsisrv.gsfc.nasa.gov> xrcjd@assist.gsfc.nasa.gov (Charles J. Divine) writes:
}In article <1993Jan7.160924.20124@mail.cornell.edu> phydeaux@guru.med.cornell.edu (Dave Weingart) writes:
}>In article <1993Jan7.142535.6129@nsisrv.gsfc.nasa.gov>, xrcjd@mudpuppy.gsfc.nasa.gov (Charles J. Divine) writes:
}>|> Depends upon the size of the habitat.  Something the size of Mir or Freedom could be
}>|> taken out as you describe.  Something large -- on the order of an O'Neill colony --
}>|> the problem would be finding the leak(s).  Those scenes of explosive decompression we
}>|> see in SF films are for fairly small structures.
}>
}>They always struck me as silly.  Any structure which is so poorly designed as to
}>blow up if you sneeze at it is _not_ where I'd want to live.
}>
}>However, finding a lot of holes is something else.  To quote some otherwise
}>forgettable movie ad (I think for Deepstar Six), "How long can you hold
}>your breath?"
}
}Once again, I suggest you review the relevant literature.

Would you be greatly offended if it were suggested that others besides yourself
HAVE, and that you may not be omniscient on the topic?


Xref: sparky rec.arts.sf.science:3951 alt.folklore.science:4577
Newsgroups: rec.arts.sf.science,alt.folklore.science
Subject: Re: Malthusians are mistaken
From: leb@violet.ccit.arizona.edu (BASEL, LESLIE)
Date: 6 Jan 1993 13:53 MST  
Distribution: world,local
Organization: University of Arizona
Keywords: I
News-Software: VAX/VMS VNEWS 1.41    

>In Africa, at least, arable land is *not*, in general, in short supply
>(although parts are more heavily populated).  The continent as a whole
>is actually rather sparsely populated.  There are 676 million hectares
>of potentially arable land in Africa; as of 1975 only 30% was in
>cultivation; a projection for 2000 is 39%.  (Source: UN FAO,
>"Agriculture: Toward 2000", 1981.)
> 
>	Paul F. Dietz
>	dietz@cs.rochester.edu

There is a reason that most of the 70% of arable land is not being used:
actually a couple - malaria, diptheria, sleeping sickness, river 
blindness, to name the most common causes of death.  The central portions
of Africa are uninhabitable; in some inhabited areas where Malaria is 
common, the people live just long enough to have and raise kids - they
die at age 30 to 35.  Not an inviting or pretty picture.

Rodger Coghlan




Newsgroups: rec.arts.sf.science
From: rwallace@unix1.tcd.ie (russell wallace)
Subject: Re: Wrecking a Planet (Was: Re: Sci-Fantasy Weapons)
Organization: Trinity College, Dublin
Date: Thu, 7 Jan 1993 13:28:54 GMT

In <1993Jan06.193935.163389@zeus.calpoly.edu> mhorning@zeus.calpoly.edu (Mark E. Horning (Captain Neutrino)) writes:

>rwallace@unix1.tcd.ie (russell wallace) states
>>Surely the easiest and simplest method of wrecking a planet is to just
>>throw enough hydrogen bombs

>	I still think the easist way is to take a bussard ramjet out a
>couple of light years, turn it arround and ram the star. Anyone feel
>like doing the Lorenz transformation on a bussard ramjet accelerating at
>10m/s^2 over a distance of say 10 light years? i don't have the back of
>an envelope handy.

Correct me if I'm wrong, but it seems to me that a Bussard ramjet can
accelerate to no greater a speed than its exhaust velocity, since at
that point each ton of hydrogen will slow it down in collection by the
same amount it will accelerate it. Now, the theoretical maximum exhaust
velocity for a fusion drive is around 20,000-30,000 km/sec; a ship at
this speed will do plenty of damage, but not enough to make it an
economical solution compared to using bombs. (Hydrogen bombs are going
to be a *lot* cheaper weight for weight than a Bussard ramjet.)

--
"To summarize the summary of the summary: people are a problem"
Russell Wallace, Trinity College, Dublin
rwallace@unix1.tcd.ie
Newsgroups: rec.arts.sf.science
From: rwallace@unix1.tcd.ie (russell wallace)
Newsgroups: rec.arts.sf.science
Subject: Re: Wreaking a habitat (was Re: Wrecking a Planet
Date: 10 Jan 93 14:54:56 GMT
Organization: Trinity College, Dublin

In <1993Jan9.200929.11673@julian.uwo.ca> jdnicoll@prism.ccs.uwo.ca (James Davis Nicoll) writes:


>>Sure, but it doesn't matter if you make a few small holes in the
>>radiator, which are easily repaired, and again you have to use missiles
>>rather than bombs or rocks, which makes the operation unreasonably
>>expensive.

>	I can  think  of at least  one way to  couple  the energy
>from an  atomic weapon to a target  in space,   inspired by how
>Orion worked.

OK, go ahead - what way? (BTW: it is a very debatable question whether
the Orion concept was workable.)

>What I  have  in mind wasn't 'a few holes' but enough
>damage to destroy the radiators. I fail to see why people in space
>will find themselves limited to WW II technology (Uncontrolled
>missiles without terminal guidance systems). If smart weapons are
>purchased by 1990 nations, why should that  technology be too
>expensive for a culture  that can build 10**9 t habitats? Making
>a missile with tracking and propulsive ability  is already an
>exploited technology, and  I  expect that if technology that enables
>a 10**9 t hab to accelerate itself should be applicable to missiles
>as well.

I've been saying all along that smart missiles would be needed to attack
a habitat. That's the whole problem: you need smart missiles, which are
much more expensive than the bombs and decoys that suffice to attack a
planet; therefore you can have fewer of them; therefore the defensive
armament will destroy the relatively few missiles before they impact,
given that long-range armament is relatively cheap for a habitat to
build.

And the radiators are not an especially tempting target. Even their
total destruction would probably not kill the habitat, since they could
shut down all nonessential power while repairing at least part of the
capacity. And their total destruction would require hits with nuclear
missiles (unless you can show how a non-nuclear missile, however smart,
is going to destroy a structure that size), and if you can score hits
with nuclear missiles of sufficient power you can destroy the habitat
itself. However, this is unlikely to happen unless the attacking force
is extremely large, for the reasons outlined above.

>>>	.01 m/s**2 lets the hab change its position by ~65 km given
>>>an hour's warning. Of course, actively tracking dirigible torpedos might
>>>well out-do the hab  wrt both acceleration and delta-vee...
>>
>>Sure. See my above comment.

>	And see mine. Habitats  are indeed hard to destroy, as long
>as the builders  use  21st Century technology  and  the attackers  
>refrain from using post-1945 technology. I doubt  those constraints
>will  be met.

When did I state or imply that the attackers would refrain from using
post-1945 technology?

--
"To summarize the summary of the summary: people are a problem"
Russell Wallace, Trinity College, Dublin
rwallace@unix1.tcd.ie
From: martinc@grover.cs.unc.edu (Charles R. Martin)
Newsgroups: rec.arts.sf.science
Subject: Re: ansibles
Date: 8 Jan 93 12:09:59
Organization: UNC Department of Computer Science
NNTP-Posting-Host: grover.cs.unc.edu
In-reply-to: bt756@cleveland.Freenet.Edu's message of 8 Jan 1993 16:36:05 GMT

In article <1ikahlINNck0@usenet.INS.CWRU.Edu> bt756@cleveland.Freenet.Edu (Ken Baxter) writes:


   I just finished Orson Scott Cards Ender trilogy and was fascinating by
   the ansible that figures heavily in the plots. It seems to borrow from 
   string theory but I'm wondering if anyone out there dcan tell me if it
   has any more basis in real physics than that. I also am surprised that I
   don't see more discussion of the Ender books on the sci fi boards.

I think Scott stole it pretty much directly from Ursula LeGuin, name and
all, and the simultaneous transmission idea is so contrary to Acccepted
Physics that I'd be surprised if it has *any* plausible explanation.
--
		Charles R. Martin/(Charlie)/martinc@cs.unc.edu
     Dept. of Computer Science/CB #3175 UNC-CH/Chapel Hill, NC 27599-3175
	    3611 University Dr #13M/Durham, NC 27707/(919) 419 1754
     "Oh God, please help me be civil in tongue, pure in thought, and able
      to resist the temptation to laugh uncontrollably.  Amen." -- Rob T
From: ap1i+@andrew.cmu.edu (Andrew C. Plotkin)
Newsgroups: rec.arts.sf.science
Subject: Re: Wrecking an O'Neill (Was: Re: Wrecking a Planet)
Date: 10 Jan 93 07:06:06 GMT
Article-I.D.: andrew.8fI5Ry200gpI89QF4N
	<rwallace.726676932@unix1.tcd.ie>
Organization: School of Computer Science, Carnegie Mellon, Pittsburgh, PA

Excerpts from netnews.rec.arts.sf.science: 10-Jan-93 Re: Wrecking an
O'Neill (Wa.. russell wallace@unix1.tc (2416)

>  Remember, the
> windows would have to be made shatterproof in case of a meteor impact,
even if they hadn't been designed with missile attack in mind.

But in space, there is no maximum impact velocity that you can design
around. You can always throw rocks faster, at the cost of some more
energy. (Steel-jacketed rocks.) Fast enough rocks make "shatterproof
plastic" a joke.

> Also, a habitat need not necessarily have windows; it could be totally
> enclosed and use fusion power instead. 

For any habitat that expects to be attacked, this would be a necessity.
It will still be vulnerable to fast enough rocks, but the required
kinetic energy would be higher. Not necessarily high enough to
discourage your enemy, of course.

> But even if the windows did shatter, it would be an expensive mess, but
> not fatal. Remember, to kill the population of a habitat, it is not
> sufficient to just put the habitat in vacuum. You must totally
> disintegrate it. 

Ok, I can't kill off the population; all I can do is kill off all the
crops, waste a habitat-worth of air, and force the population to do
nothing but repair work for a while. And it costs me (forgive the
repetition) rocks and energy, both of which are cheap; so I can do it
again whenever I want. I think the habitat rapidly becomes not worth
living in.

>  That's the whole problem: you need smart missiles, which are
> much more expensive than the bombs and decoys that suffice to attack a
> planet; therefore you can have fewer of them; therefore the defensive
> armament will destroy the relatively few missiles before they impact,
> given that long-range armament is relatively cheap for a habitat to
> build.

Long-range armament is cheap for their enemies to build, too. I still
don't see how any defense system can cope with an *unbounded* number of
cheap stupid projectiles.

--Z

"And Aholibamah bare Jeush, and Jaalam, and Korah: these were the borogoves..."
Newsgroups: rec.arts.sf.science
From: ingles@engin.umich.edu (Ray Ingles)
Subject: Pulsars as time machines?
Date: Fri, 08 Jan 93 00:11:53 EST
Organization: University of Michigan Engineering, Ann Arbor

 Okay, Gavin Miller (shocker@miamiu.acs.muohio.edu) recently mentioned
that someone named John Gribbin had proposed that a neutron star might
work as a Tipler-style time machine. (That is, the Closed Timelike Curves
might occur in the neighborhood of a rapidly rotating neutron star.)
 The Tipler-style 'machine' requires a massive cylinder rotating so that
its surface is moving at more than .5c. A pulsar, not being cylindrical,
might need more speed (or might not work at all). But it must at least
have this minimum speed.
 Now, from what I gather, there are pulsars with radii close to that
of Earth's, and some revolve at millisecond rates. If so, this would give
them more than enough speed.
 My question is, *is* this so? What is an "average" radius and speed of
a pulsar? Can we measure the speeds and sizes of pulsars that aren't
aimed at us, and do any of those fall in the following neighborhood?
Anyone have any buddies on sci.space? (I'm loath to post this there-
they get enough traffic as it is, and most wouldn't care...)

       radius                       rate of revolution

       10 km                        ~40 microseconds
       100 km                       ~400 microseconds
       1000 km                      ~4 milliseconds
       10000 km                     ~40 milliseconds


 Now, assume for the moment that at least some pulsars would act as
natural time machines. Something in the right orbit around one could
move back in time. (Light could be bent to go slightly back in time,
perhaps.)
 What might we see if we looked at one? What sort of astronomical
observations would lead us to beleive that this might be going on?


Sincerely,

Ray Ingles                  || The above opinions are probably
                            || not those of the University of
ingles@engin.umich.edu      || Michigan. Yet.
Newsgroups: rec.arts.sf.science
From: m23364@mwunix (James Meritt)
Subject: Re: Wrecking space colonies
Keywords: n
Organization: MITRE Corporation, McLean VA
Date: Mon, 11 Jan 1993 21:57:51 GMT

In article <1isib2INNd23@nz12.rz.uni-karlsruhe.de> ig25@rz.uni-karlsruhe.de writes:
}A planet and its biosphere are so big and fragile that 1), 2) and 6)
}are not really an option, and the chances of a single hit coming
}through are rather large, with unacceptable consequences.

Why are you assuming that you are using the native biosphere?  The
moon, for example, does not have such a thing...
From: m23364@mwunix (James Meritt)
Newsgroups: rec.arts.sf.science
Subject: Re: Wrecking a Planet (Was: Re: Sci-Fantasy Weapons)
Date: 11 Jan 93 15:30:49 GMT
Organization: MITRE Corporation, McLean VA

In article <rwallace.726538409@unix1.tcd.ie> rwallace@unix1.tcd.ie (russell wallace) writes:
}In <1993Jan08.183846.101582@zeus.calpoly.edu> mhorning@zeus.calpoly.edu (Mark E. Horning (Captain Neutrino)) writes:
}
}>rwallace@unix1.tcd.ie (russell wallace) states
}>>In <1993Jan7.173125.20305@linus.mitre.org> m23364@mwunix (James Meritt) writes:
}>>
}>>>In article <rwallace.726348286@unix1.tcd.ie> rwallace@unix1.tcd.ie (russell wallace) writes:
}>>
}>>>heat sink, yes.  But terribly vulnerable radiators.  So to zap it, dump silver
}>>>paint so that it coats the radiator.  And as for the "full power
}>>>generating capacity", if it is environmental, you couldn't accelerate
}>>>(read "move") and it could be closed down with black paint.  And if it
}>>>is internal, so could the planetary base.  
}>>
}>>Who mentioned radiators? The heat sink for a fusion gun or whatever
}>>could simply be the habitat's water reservoir. I think a 10,000-ton
}>>water storage takn could soak up quite a lot of heat (with bleeder
}>>valves in case the water got too hot).
}>>
}>The carnot cycle gives us the maximum possivle efficiancy for any
}>reactor. Get the watter hot enough and all of a sudden your big
}>expensive (or small expensive) nuclear reactor gives you Zero power
}>output. You have to radiate the heat.
}
}Sure, but the water tank is only a temporary buffer while the radiators
}are damaged or overloaded; a total reserve of maybe 1,000,000 tons of
}water is not going to overheat in that time. If it does, you could buy
}time by venting steam into space.
}

A cubic mile of rock would do better.  Ibid an ocean.  You are presenting
options by which, through their specific utilization, planets are better.

A poor argument position.
Newsgroups: rec.arts.sf.science