HDTenEightyP/NetNews huggingface dataset:
Newsgroups: rec.arts.sf.science
Subject: Re: Niven's teleportation & 2nd law of thermodynamics (was: Superconductors + the 2
From: ecmtwhk@ccu1.aukuni.ac.nz (Thomas Koenig)
Date: Wed, 2 Sep 1992 10:59:45 GMT
Organization: University of Auckland, New Zealand.
Keywords: Niven, teleport

campo@sunthpi3.difi.unipi.it (Massimo Campostrini) writes:

>   After reading several (very entertaining) short stories by
>Larry Niven discussing teleportation, I've always wondered why the
>author pays attention to conservation of energy and momentum, but
>ignores the 2nd law of thermodynamics. As an example, N. supposes
>that teleporting a space probe upward (in a gravitational field)
>takes no energy, but the probe cools down.

I suppose Niven has heard about the second law (otherwise he would
not have written "Unfinished Story #1") but does not understand its
implications, or else he did not stop to think about them when writing
these stories. I think he definitely lacks an internal "reality
checker"; he should also have been able to work out the Ringworld
instability for example, if the thought had ever crossed his mind.
Good thing Niven is not an engineer :-)

>   Any comment on this? Maybe the 2nd law of thermodynamics is
>supposed to be "less fundamental" or "less established" than the
>1st by non-physicists?

Less understood, certainly. There is such a huge mass of semi - mythical
popular misconceptions about it that that is hardly surprising. Also, it
can be derived from statistical mechanics, and who trusts statisticians?
:-) People generally have an idea what energy is (after all, that's what
they pay their electricity supplier for), but entropy is pretty hard
to visualize.

>   As a related comment, I can state that causality IS considered
>less fundamental then the above laws by many physicists.

When did Maxwell's daemon finally get laid to rest? I remember reading
about it in Scientific American a few years ago; was this the first time
anyone published anything about that outside specialized scientific
journals?

WRT causality, I have to read that IEEE newsletter with the report about
measured information propagation at speeds faster than light in vacuum.
My guess would be that the people who reported this have got their
measurements wrong, but I'm sure people said that about Michelson -
Morley, as well :-)
-- 
Thomas Koenig, ecmtwhk@ccu1.aukuni.ac.nz, ib09@rz.uni-karlsruhe.de
The joy of engineering is to find a straight line on a double logarithmic
diagram.
Newsgroups: rec.arts.sf.science
From: dietz@cs.rochester.edu (Paul Dietz)
Subject: Re: Niven's blunders (was:Superconductors + the 2nd law)
Organization: Computer Science Department University of Rochester
Date: Wed, 2 Sep 1992 00:23:01 GMT


Let's inject some realism about the neutrinos...

Neutrinos are *not* going to kill people.  If a single SN delivers a
lethal dose of neutrinos at 3 AU, then to deliver a lethal dose at
300,000 AU (about 4 light years) would require the explosion of 10
billion supernovae.

However, 10^10 SN are not going to be packed into a sphere only a few
light years across.  The core is some 5000 light years across, so the
neutrinos from the SNs will come spread in pulses over 5000 years or
so.  Radiation delivered over a long period is less damaging that a
single rapid dose.  Moreover, being 30,000 light years away, the
neutrino radiation is reduced in intensity by another factor of 10^8
or so.

Niven had a couple of blunders here no one has mentioned.  First of
all, a "chain reaction" of supernovas in the core makes no sense
physically -- there's no way for a star to blow up another one in the
way he imagined.  Stars are very robust objects, and are very far
apart, even in the core.  Hell, even close companions in binary star
systems survive their partners' supernova explosions.  About the only
way for one star to cause detonation in another is for the first to
dump matter onto the second (which must be a white dwarf in close
orbit with the first).

Second, most of the damaging radiation from supernovas is *charged
particles*.  These don't travel in straight lines.  What you'd get is
a cloud of very hot plasma sweeping out from the galactic center.
Anything in that cloud would be bombarded by energetic cosmic rays
from all directions.

	Paul F. Dietz
	dietz@cs.rochester.edu
Newsgroups: rec.arts.sf.science
Subject: Re: Laser weapons
From: ecmtwhk@ccu1.aukuni.ac.nz (Thomas Koenig)
Date: Fri, 4 Sep 1992 05:18:02 GMT
Organization: University of Auckland, New Zealand.

neufeld@helios.physics.utoronto.ca (Christopher Neufeld) writes:

>If I dump a kilojoule of energy
>onto a half-centimetre diameter spot in a time scale short compared to
>the thermal diffusion times in the body (ie. in about a second or less)
>there will be localized heating there enough to do serious damage. You'll
>have flash vaporisation of the surface, and a shock wave moving through
>the person from the target site. More damage than the bullet from a small
>sidearm. You've seen laser scalpels in television footage, they don't
>work by heating up litres of the person in ten degree steps.

One kilojoule of energy will vaporize around 4.E-4 kg of water. I think
it is a reasonable assumption that the steam will travel away from the
spot at the speed of sound, say 300 m/s. The maximum impulse from this
is 0.12 kg m/s. However, not all of the steam will be going into the
same direction, so we probably need to divide this by something close to
three, so we get around 0.04 kg m/s impulse.

If the spot is half a centrimetre in diameter, it has an area of around
2.E-5 m^2; the hole bored by the laser will be around 2.E-4 m (or 0.2
mm) deep.

I assume a bullet from a small handgun would mass around 0.005 kg
(anyone have better figures there?) and probably hit at around 200 m/s,
the impulse is 1 kg m/s then, and the energy 100 J.

In conclusion, I would say we need to beef up our laser to delivering
around 50 kJ with a single pulse to do serious damage. Armour would be
rather simple, btw; just wear a thick sweater drenched in water.
-- 
Thomas Koenig, ecmtwhk@ccu1.aukuni.ac.nz, ib09@rz.uni-karlsruhe.de
The joy of engineering is to find a straight line on a double logarithmic
diagram.
Newsgroups: rec.arts.sf.science
From: neufeld@helios.physics.utoronto.ca (Christopher Neufeld)
Subject: Re: Niven's blunders (was:Superconductors + the 2nd law)
Organization: University of Toronto Physics/Astronomy/CITA
Date: Mon, 31 Aug 1992 19:11:24 GMT

In article <advy9rk@rpi.edu> kasprj@rpi.edu writes:
> 
> Second, they didn't come anywhere near as close to the neutron star as 
>Shaeffer and his ill-fated predecessors did. Remember the inverse-square
>law - if they were a hundred times further away, the gravitational effects
>were only one ten-thousandth as strong.
>
   Tidal effects are due to the gradient of the graviatational field, so
they scale as the inverse CUBE of the distance (for a simple monopolar
source).

>Jim Kasprzak  e-mail: kasprj@rpi.edu or kasprzak@mts.rpi.edu 


-- 
 Christopher Neufeld....Just a graduate student  | Confidence is the feeling
 neufeld@helios.physics.utoronto.ca    Ad astra  | you have before you
 utzoo.utoronto.ca!generic!cneufeld              | understand the situation.
 "Don't edit reality for the sake of simplicity" |
Newsgroups: rec.arts.sf.science
From: daveh@xtenk.wpd.sgi.com (David Higgen)
Subject: Re: Something Nasty in the Human Genome
Organization: Silicon Graphics, Inc.  Mountain View, CA
Date: Fri, 4 Sep 1992 19:36:15 GMT

In article <a3m-DW+@engin.umich.edu>, ingles@rootbeer.engin.umich.edu (Ray Ingles) writes:
> 
> In article <kelso_j.715422933@kultarr>, kelso_j@cs.uwa.oz.au (J Kyle Kelso) writes:
> 
> [galactic genetic takeover-reproducing parasite idea deleted]
> 
>  I suppose, assuming a few things about the universality of
> DNA and the great prevalence of life-bearing planets in the
> galaxy, it might be technically feasible. I doubt it, but
> we'll assume for the sake of the argument that it is.
>  The main problem I see is explaining the origin of such
> creatures. How could such a thing evolve? What are some
> plausible intermediates between this and planet-bound life?
>  On the other hand, you could posit them as designed beings,
> perhaps a biotech counterpart to Fred Saberhagen's Berserkers.
> This makes it more belieavable, but I'd want to know *why*
> anmy race would build such a thing...
> 
> > J Kyle Kelso 
> 
> Sincerely,
> 
> Ray Ingles                  || The above opinions are probably
>                             || not those of the University of
> ingles@caen.engin.umich.edu || Michigan. Yet.

How about just the mad scientist scenario? One hears the opinion, in the
lunatic fringes of environmentalism, that the sooner the human race dies off 
the better.

For "human race" read "intelligent life" on the galactic scale... somebody 
might just actually believe that, and be technically capable enough.

If sufficiently powerful computing & nanotech facilities were available, it 
might be something that could be done by a single deranged individual...


		Dave Higgen (daveh@xtenk.wpd.sgi.com)
From: hughes@dogwood.botany.uga.edu (Wayne Hughes)
Newsgroups: rec.arts.sf.science
Subject: Re: Niven's blunders (was:Superconductors + the 2nd law)
Date: 31 Aug 92 23:50:32 GMT
Organization: Botany Department - U of Georgia, Athens

In article <78796@ut-emx.uucp> slug@ccwf.cc.utexas.edu (Glen Anthony Graham) writes:
>
>Um... if I recall correctly (and it has been a couple of years since I've read
>all the Niven books...), wasn't the "radiation" from the core explosion in the
>form of nutrinos or something like that?  Nutrinos have a nasty habit of being
>able to pass through planets and rocks without slowing down, so underground
>cities would not help at all.  
>
   Neutrinos are not considered damaging radiation.

   Several answers here have presumed that the wavefront would
   be quite discrete and last only a short period of time.  How
   long was it supposed to take before the radiation passed?  I
   would guess years.  A revolving ringworld isn't going to 
   be of much use.

   Wayne
From: advax@reg.triumf.ca (A.Daviel)
Newsgroups: rec.arts.sf.science
Subject: Re: Something Nasty in the Human Genome
Date: 3 Sep 92 00:09:00 GMT
Organization: TRIUMF: Tri-University Meson Facility
News-Software: VAX/VMS VNEWS 1.41

In article <1992Sep2.212113.4959@pony.Ingres.COM>, bobm@Ingres.COM (Bob McQueer) writes...
>In <gapdrr.715446756@gsusgi1.gsu.edu>,
>	dated Wed, 2 Sep 1992 15:12:36 GMT,
>	gapdrr@gsusgi2.gsu.edu (Daniel R T Rothman) writes:
> 
>> 's been done. try Niven's "Wyrms". Must be a tight idea though, you came
>> up with almost EXACTLY the same thing Niven did.
> 
>"Wyrms" is by Orson Scott Card.

Also see Card's Xenocide (finally in paperback in Canada; been waiting 
months...). The idea is kicked around that the descolada virus is an 
artificially created one, but where it came from is left as a loose end (I
thought there were rather a lot of loose ends; maybe there'll be another
book). This virus was able to adapt itself to counter attempts to eradicate 
it, and was supposed to be dynamically balancing an ecosphere of only 4 (?I 
forget) species against climate change.

Andrew Daviel, Vancouver BC
Newsgroups: rec.arts.sf.science
Newsgroups: rec.arts.sf.science
Date: Thu,  3 Sep 1992 12:17:46 -0400 
From: David O Hunt <dh4j+@andrew.cmu.edu>
Subject: Re: Laser weapons
	<5387@arccs1.fed.FRB.GOV>

>pack-sized fusion power supply that can produce large pulses of power.
Presumab
>ly, the technology could be used to produce a small fusion bomb, which
would be
> much more energy-efficient. A 
> 
> 
>        SOMEONE CENSORING INFORMATION???????????????
> 
> 
>ay not be appropriate for the military mission, however -- that's why
we have s
>niper rifles as well as mortars today. In this case, a laser may be the
way to 



David Hunt - Graduate Slave | My mind is my own.          | Towards both a
Mechanical Engineering      | So are my ideas & opinions. | Palestinian and
Carnegie Mellon University  | <<<Use Golden Rule v2.0>>>  | Jewish homeland!
============================================================================
Email:  dh4j@cmu.edu            Working towards my "Piled Higher and Deeper"

"You must think before you act."  --The Children's Hour (Man-Kzin Wars)

Xref: sparky rec.arts.sf.science:2805 rec.arts.sf.written:11739
From: lnh@soliton.physics.arizona.edu (sometimes a Wombat)
Newsgroups: rec.arts.sf.science,rec.arts.sf.written
Subject: Re: Something Nasty in the Human Genome
Date: 3 Sep 92 16:24:18 GMT
Distribution: na
Organization: Society for the Appreciation of Janni Lee Simner

cash@convex.com (Peter Cash) writes:
>
>Kind of intriguing...makes me think that information is encoded in the DNA
>in ways other than the direct code we know about. Hmmm...how about a
>fractal data compression algorithm? Maybe it's a picture of God?
>Directions for the next step in evolution? The Cosmic Self-Destruct
>Command? Guess I'm in one of those moods...

"Help!  I'm being held prisoner in a DNA factory!"

(With appologies to J.P. Hogan)

	Larry "Direct steal" Hammer 
--

                               | "Absence diminishes small loves and increases
LNH@albert.physics.arizona.edu | great ones, as the wind blows out the candle 
insanity needs no disclaimer   | and blows up the bonfire." --La Rochefoucauld
Newsgroups: rec.arts.sf.science
From: dietz@cs.rochester.edu (Paul Dietz)
Subject: Re: Niven's blunders (was:Superconductors + the 2nd law)
Organization: Computer Science Department University of Rochester
Date: Wed, 2 Sep 1992 01:44:19 GMT

In article <1992Sep1.203954.5760@erg.sri.com> rat@erg.sri.com (Ray Trent) writes:

>Last I heard, current theory is that the gravitational collapse in a
>supernova converts some 30-40% of the star's mass directly into
>neutrinos during the first few milliseconds.
>
>Has this estimate changed?


That number never was correct.  Collapse of the core of a type-II SN
liberates around 10% of the *core's* mass (which around 1.4 solar
masses) as neutrinos.  This comes from the binding energy of the newly
formed neutron star.  The rest of the star gets blown away, out of
the gravity well of the neutron star.

Someone in a previous message quoted the hoary chestnut about "a light
year of lead".  Listen: the range of a neutrino is a function of the
energy of the neutrino; talking about the range without talking about
the energy is like talking about the range of a photon in matter
without mentioning wavelength.  A neutrino in the 10's of TeV-range
will have a cross section high enough that the earth begins to be
opaque.  GeV-range neutrinos have high enough cross sections that
neutrino beam experiments can be done at accelerators (using neutrinos
from pion decay).  The cross section of the neutrinos from an SN
explosion varies greatly, with the higher energy neutrinos more easily
detected.

	Paul F. Dietz
	dietz@cs.rochester.edu
Newsgroups: rec.arts.sf.science
From: mvp@hsv3.lsil.com (Mike Van Pelt)
Subject: Re: Niven's blunders (was:Superconductors + the 2nd law)
Organization: LSI Logic/Headland Technology
Date: Tue, 1 Sep 1992 21:52:05 GMT

In article <Btt370.Ly9@watdragon.uwaterloo.ca> jdnicoll@watyew.uwaterloo.ca (James Davis Nicoll) writes:
>Why stop with cities? The vicinity of a supernova is filled with
>plasma, which should provide the conducting surface a stasis field needs.
>Just  enclose the core in a Very Big  stasis field.

I was going to say put a stasis field around your planets, keyed to
shut off after the radiation passes, but your idea is better.  Elegant,
and it has the appropriate scale for Niven to one-up his Ringworld.
(See his "Bigger Than Worlds" essay in "All the Myriad Ways.")  We
know that stasis fields work over periods of at least a billion years.

Only problem is, you can't extract power from the supernovae to make
a megadysonsphere, as in "Bigger Than Worlds".  Unless... Suppose you
can make the stasis field in the shape of a wide toroid...

             () \  |/ / ()
      *     ()  \ \ / /  ()
Known .    ( )   core    ( )<- Toroid (cross section)
 Space  :  ( )  / /| \   ( )
 `  .       ()  / |  \   ()
             ()         ()
Make the toroid as wide as necessary to shield inhabited space.
Put solar collectors inside the toroid.

Hey, maybe this is why some galaxies shoot out jets... :-)
-- 
Mike Van Pelt          | What happens if a big asteroid hits Earth?
LSI Logic/Headland     | Judging from realistic simulations involving a
mvp@hsv3.lsil.com      | sledge hammer and a common laboratory frog, we
sun!indetech!hsv3!mvp  | can assume it will be pretty bad. -- Dave Barry
From: exukozi@exu.ericsson.se (Tom Koziatek)
Newsgroups: rec.arts.sf.marketplace
Subject: Looking for old title
Date: 25 Aug 92 20:58:22 GMT
Organization: Ericsson Network Systems


I'm looking to acquire an old, out of print book entitled 'Stranger from the
Depths', possibly by a Jerry (Gerry?) Turner. Its an old juvenile sf book
I read about 20 years ago. Book locators and major chains have been no help
whatsoever.

If you have a copy you'd be willing to part with, or can point me to someone
who does, I'm willing to pay a good price for it.

Many thanks in advance....

--------------------------------------------------------------------------------
Death is the Ultimate Victor............            
                                                                      -Tom

Note : I don't care that my location shows .se, I'm in Dallas !!
--------------------------------------------------------------------------------
Newsgroups: rec.arts.sf.marketplace
From: hopkins@agora.rain.com (Scott Hopkins)
Subject: Old SF Koontz Books Wanted
Organization: Open Communications Forum
Date: Mon, 31 Aug 1992 21:41:08 GMT

	I'm looking for some old Dean Koontz sci-fi novels from the early
	seventies!  I'm looking for one or all, any will do!!!  Please if
	anyone knows how to obtain some copies, write me at:
					hopkins@agora.uucp

	Any help would be appreciated!
				-Casey Hopkins

Newsgroups: rec.arts.sf.marketplace
From: prec@ellis.uchicago.edu (bruce lyman precourt)
Subject: WANTED: SpiderWorld, Vol.1
Reply-To: prec@midway.uchicago.edu
Organization: University of Chicago Computing Organizations
Date: Thu, 27 Aug 1992 02:35:20 GMT


Anybody out there willing to sell or know where I can get a copy of

_SpiderWorld, Vol.1: The Desert_, by Colin Wilson (Ace, 1987, I think).

Volumes 2,3 & 4 are in print and easy to find. I need VOLUME ONE.

Thanks in advance!

prec@midway.uchicago.edu
From: jt38+@andrew.cmu.edu (Jackson Tam)
Newsgroups: rec.arts.sf.marketplace
Subject: SW Micro Figures Wanted !
Date: 25 Aug 92 21:43:38 GMT
Organization: Freshman, Architecture, Carnegie Mellon, Pittsburgh, PA



Hi,
Does anybody have  metal SW minatures they want to sell?  
(Please include condition).
 
Thanx !
Jackson
From: blackfyr@clubzen.fidonet.org (Bob Daverin)
Newsgroups: rec.arts.sf.marketplace
Subject: WANTED: Hardbacks
Date: Sun, 30 Aug 92 00:32:06 PST
Organization: Club Zen BBS - Fidonet/UseNet - +1 415 968 8140

I'm looking for hardback copies of all Spider Robinson's Calahan's 
series.  NOT combined editions or book club editions, original hardbacks. 
E-mail me at blackfyr@clubzen.fidonet.org.

------------------------------------------------------------------------------
Bob Daverin -> (blackfyr@clubzen.fidonet.org)
Newsgroups: rec.arts.sf.marketplace
From: markh@wimsey.bc.ca (Mark C. Henderson)
Subject: Re: Old SF Koontz Books Wanted
Organization: Wimsey 
Date: Tue, 01 Sep 1992 23:07:20 GMT

In article <BtvAwn.22D@agora.rain.com> hopkins@agora.rain.com (Scott Hopkins) writes:
>	I'm looking for some old Dean Koontz sci-fi novels from the early
>	seventies!  I'm looking for one or all, any will do!!!  Please if
>	anyone knows how to obtain some copies, write me at:

The latest catalogue from Pandora's Books lists a bunch. You might try
calling them at 204/324-8548.

Mark
Newsgroups: rec.arts.sf.marketplace
From: ve3pak@micor.ocunix.on.ca (Alayne McGregor and Brett Delmage)
Subject: Re: Looking for old title
Organization: M.B. Cormier INC., Orleans (Ont)
Date: Fri, 28 Aug 1992 03:08:54 GMT

In article <1992Aug25.205822.10020@exu.ericsson.se> exukozi@exu.ericsson.se (Tom Koziatek) writes:
>
>I'm looking to acquire an old, out of print book entitled 'Stranger from the
>Depths', possibly by a Jerry (Gerry?) Turner. Its an old juvenile sf book
>I read about 20 years ago. Book locators and major chains have been no help
>whatsoever.

If I'm not mistaken, an edition of this was printed by Scholastic Book
Services (the group that sold books through schools in North America).
Have you tried the children's sections of used bookstores? It shouldn't
be that difficult to find.

Alayne McGregor
alayne@ve3pak.ocunix.on.ca
Newsgroups: rec.arts.sf.marketplace
From: landers@mentor.cc.purdue.edu (Hazard Class Mage)
Newsgroups: rec.arts.sf.marketplace
Subject: WANTED:  Wild Cards I in Hardback
Date: 1 Sep 92 16:02:35 GMT
Organization: Purdue University Computing Center

I'm looking for George R.R. Martin's 
_Wild Cards I_ in hardback to complete
my set, I've got 2-6 from SFBC, by
I is out of print for them.  

I heard that SFBC was the only publisher
of this series in hardback, so I guess
I'm looking for someone's used copy.



-- 
   <===========================><===============================>
   || Christopher Landers      ||  Stamp Out Silly Signatures! ||
   <============== landers@mentor.cc.purdue.edu ================>
Organization: Junior, Art, Carnegie Mellon, Pittsburgh, PA
Newsgroups: rec.arts.sf.marketplace
Date: Sun, 23 Aug 1992 16:31:59 -0400 
From: Faye Levine <fl0m+@andrew.cmu.edu>
Subject: Looking for Heather Broud?

For those of you who were looking for Heather Broud, I got some news
that she is sick and on a medical leave of absence from school.  I have
no more details than that, but that may account for why she's so hard to
find...

Sorry; I don't have any more details.
FLOM.
From: wixer!cactus.org!wixer!pro-smof.cts.com!shiva@cactus.org (System Smof)
Newsgroups: rec.arts.sf.misc
Subject: Re: Agnostics and Athiests
Date: 1 Sep 1992 07:44:18 -0500
Organization: The SMOF-BBS: Science Fiction Online Since 1985 [512-467-7317]
NNTP-Posting-Host: cs.utexas.edu

speers@opus.mcds.com (Daniel E. Speers) writes:

>
>  Second Question:  If God can do anything, can (s)he create
>                    a rock that (s)he cannot lift?
>
>
>Ignorance is bliss...
>

That one's easy. An omnipotent God can change the rules at will, create a rock
he cannot lift, and then change the rules so that he can now lift the rock.
 ____________________________________________________________________
/                                |                            |      \
|SMOF-BBS 512-467-7317 PCP=TXAUS |"The World's First Online   | __|__ |
|    Proline:  shiva@pro-smof    | Science Fiction Convention"| \_|_/ |
|    Internet: wixer!pro-lep!pro-smof!shiva@cs.utexas.edu     |   |   |
\________________________________|____________________________|______/


Newsgroups: rec.arts.sf.misc
From: mji@niksula.hut.fi (Mikko Inkinen)
Subject: Re: H? R? Giger
Organization: Helsinki University of Technology, Finland
Date: 28 Aug 92 08:01:52

In article <MebD2De00gpI0qK1J1@andrew.cmu.edu> ap1i+@andrew.cmu.edu (Andrew C. Plotkin) writes:
>>    I'm interesting in H.R.Giger's art works 
>
>Speaking of which, does anybody know what the "H.R." stands for? We

     Hans Rudi Giger, if I remember correctly.

--
     mji@niksula.hut.fi  /
     Mikko Inkinen      /   I might have been here
     JMT 11 L 234      /                   - Werner Heisenberg
     467 697          /
Newsgroups: rec.arts.sf.misc