HDTenEightyP/NetNews huggingface dataset:
Newsgroups: rec.arts.sf.science
Subject: Re: Niven's teleportation & 2nd law of thermodyna
From: campo@sunthpi3.difi.unipi.it (Massimo Campostrini)
Date: 10 Sep 92 09:54:08 +0100
Reply-To: campo@sunthpi3.difi.unipi.it
 <FRANCIS.92Sep3094741@galois.dogwood.atl.ga.us> <1992Sep9.145536.5299@wts.com>
Distribution: world
Organization: Istituto Nazionale di Fisica Nucleare, Pisa, Italy

In article <1992Sep9.145536.5299@wts.com>, jbf@wts.com (Jens B. Fiederer) writes:
|> In article <FRANCIS.92Sep3094741@galois.dogwood.atl.ga.us> francis@dogwood.atl.ga.us (John Stracke) writes:
|> >In article <1992Sep2.204731.4669@msc.cornell.edu> hillyard@msc.cornell.edu writes:
|> >
|> >>From article <1992Sep2.114236.428@cine88.cineca.it>, by campo@sunthpi3.difi.unipi.it (Massimo Campostrini):
|> >>[...]
|> >>>    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?
|> >>
|> >>It is less fundemental in the sense that it is a statistical law.  Entropy
|> >>can go down in a system--its just unlikely.
|> >
|> >Make that *extremely* unlikely.  Sufficiently unlikely that it
|> >probably has not occurred more than a handful of times in the history
|> >of the Universe to date.
|> >
|> It has happened innumerable times!!!  The trick is to choose VERY SMALL
   ====================================
|> SYSTEMS.  The larger the system, the more the laws of large numbers
|> predominate.
|> 
|> Jens

   Not for macroscopic systems; a small decrease in entropy 
like 1 Joule/Kelvin has a probability of approx. 
exp(Delta(S)/k) = exp(-7.3*10^22) = 10^(-1.7*10^23).
There are probably less than 10^55 Kg of matter in the universe.
Compare it with 10^(-1.7*10^23)... it's as good as 0.
   Of course thermodynamics is not applicable to *very* small systems 
(e.g. less than 10^4--10^6 atoms).

-- 
        Massimo Campostrini,
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa,
Piazza Torricelli 2, I-56126 Pisa, Italy  ||  Phone: (+39)(50)42093
Internet: campo@sunthpi3.difi.unipi.it    ||  Fax:   (+39)(50)48277
Newsgroups: rec.arts.sf.science
From: rwallace@unix1.tcd.ie (russell wallace)
Subject: Re: Mini-Atomics
Organization: Trinity College, Dublin
Date: Wed, 9 Sep 1992 21:10:11 GMT

In <1992Sep9.130719.6060@sctc.com> beede@sctc.com (Mike Beede) writes:

>rwallace@unix1.tcd.ie (russell wallace) writes:

>>Basically a fission device requires a critical mass, and therefore a
>>certain minimum amount of fissionable material. (Though you *can* reduce
>>the explosive yield almost arbitrarily by making the bomb inefficient so
>>that most of the material remains unfissioned.)

>This critical mass thing is not really true, is it?  As I understand
>it, the problem is fission products escaping without causing further
>fission. If that can be prevented, a chain reaction can take place in
>any reasonable amount of material.  So, for instance, if I could
>create something that reflected all neutrons, I might be able to have
>a 1 gram fission bomb (if I could assemble it fast enough).  Is this
>correct?

Yes, but no such material exists. In a far-future sf scenario, you could
assume one (e.g. "scrith", the Ringworld floor material, would probably
do), but in that case why not just assume micro-fusion bombs which don't
require a fission trigger?

--
"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: wengland@stephsf.com (Bill England)
Subject: Re: Mini-Atomics
    <rwallace.716111131@unix1.tcd.ie>
Date: Fri, 11 Sep 1992 12:43:11 GMT
Organization: Stephen Software Systems Inc., Tacoma/Seattle, +1 800 829 1684
X-Bytes: 1071

In article <rwallace.716111131@unix1.tcd.ie> rwallace@unix1.tcd.ie (russell wallace) writes:
>[...]
>Right. In fact I don't think you could do it with chemical explosives,
>not unless the material was at least reasonably close to the critical
>mass. The requirement for such pressure in a fusion bomb is precisely
>why the device requires a fission trigger (i.e. for a micro-fission
>device you would seem to need a regular fission bomb as the trigger).
>
  Yes!  You have hit the core with the C4 on this one!

  Ted Taylor mentions that bombs are always assembled in the presence
  of a Giger Counter because they are so close to criticality, and
  C4 is a good neutron reflector,  that  new designs could go critical
  as the plastic was put on. 

  
-- 
 +-  Bill England,  wengland@stephsf.COM -----------------------------------+
 |   * *      H -> He +24MeV                                                |
 |  * * * ... Oooo, we're having so much fun making itty bitty suns *       |
 |__ * * ___________________________________________________________________|
From: seawasp+@pitt.edu (Ryk E Spoor)
Newsgroups: rec.arts.sf.science
Subject: Re: Mini-Atomics
Date: 10 Sep 92 16:30:14 GMT
Organization: University of Pittsburgh

In article <rwallace.716111131@unix1.tcd.ie> rwallace@unix1.tcd.ie (russell wallace) writes:
>In <L-r-dD#@engin.umich.edu> ingles@engin.umich.edu (Ray Ingles) writes:
>> So, if you just surround a less-than-critical mass with enough explosives,
>>you can get a nuclear explosion. (Of course, "enough," most likely, would
>>be more than you'd get out of the fission reaction... right?)

>Right. In fact I don't think you could do it with chemical explosives,
>not unless the material was at least reasonably close to the critical

	Perhaps; HOWEVER, there is some body of evidence to indicate
that it IS possible to trigger a FUSION detonation through the use of
much smaller amounts of modern chemical explosives. Ask around on
sci.physics.fusion; they were having quite a discussion on this particular
topic (chemical-detonation triggered nuclear reactions) several months
ago.

                                 Sea Wasp
                                   /^\
                                   ;;;
From: chinja@geloser.CAM.ORG (delta)
Newsgroups: rec.arts.sf.science
Subject: re: Laser/Future Weapons
Date: 6 Sep 92 03:14:28 GMT
Organization: Gentleman Loser System, Montreal/Qc/Cdn

Hi Everyone!
      I was reading your discussion about the possibilities of replacing
the bullet with some new weapon. The discussion revolves around the use
of movie-type weapons, ie lasers, sonic weapons, etc.
      The primary fault of the discussion is the power requirement of su
weapons. Another interesting point that was not discussed is battle-field
survivability of such weapons.
      I can assume that many who have read this owns or owned a "Walkman"       
type radio. Packed full of electronics, if it has a cassette player, draws
from the battery like crazy. If dropped,...... The battlefield weapon of 
choice, using bullets, is the AK-47. It can withstand almost any abuse
from the user. I can not see in the near future the development of weapons
discussed earlier./s

--
chinja@geloser.cam.org
Gentleman Loser System -- Montreal, Qc, Canada
From: stets@stets.novalis.public.sub.org (Thomas Stets)
Newsgroups: rec.arts.sf.science
Subject: Re: Laser weapons
Distribution: world
Date: Thu, 03 Sep 92 21:09:22 GMT
Organization: Just me.

rwallace@unix1.tcd.ie writes in article <rwallace.715424570@unix1.tcd.ie>:
>
> In <1992Sep1.213233.7293@spss.com> markrose@spss.com (Mark Rosenfelder) writes:
>
> >I'd like to throw some laser weapons into an sf story, but I find I don't
> >know enough about lasers.
>
> >Naturally, we're not talking about those wimpy supermarket lasers here--
> >we want some lasers that can fry people.
>

[ some stuff edited out ]

>
> Basically, lasers as we know them today are inherently useless as
> weapons - they don't put out enough power.
>

I don't know. Lasers are already used in the industry as tools to cut metal.
Of course in these applications the laser is only a few millimeters from
the surface to be cut. I have no idea how much stronger the laser must
be to be affectice over a greater distance. But it doesn't seem impossible.
(Our company is just about to finish a software project for a company
builting these laser-cutters. I'm not involved in that project, but
maybe I can get some informations.)


--
-----------------------------------------------------------------------------
Thomas Stets  Tel. +49 (7031) 04957       ! Sweet freedom whispered in my ear
Holzgerlingen, Germany                    ! You're a butterfly
                                          ! And butterflies are free to fly
stets@stets.novalis.public.sub.org        ! Fly away, high away, bye bye.
-----------------------------------------------------------------------------
From: swf@teradata.com (Stanley Friesen)
Newsgroups: rec.arts.sf.science
Subject: Re: Exploding Bullets
Date: 11 Sep 92 22:50:11 GMT
Reply-To: swf@tdat.teradata.com (Stanley Friesen)
Organization: NCR Teradata Database Business Unit

In article <1992Sep11.170043.7347@en.ecn.purdue.edu> terran@en.ecn.purdue.edu (me) writes:
|  The .44 mag has something of an
|exagerated reputation because it is big and loud.  It _is_ effective, but
|if I had my personal choice, I would take a 30.06 deer rifle with an 8x scope,
|200 yards, and a high degree of concealment any day ;-).
|
As for me, I'd go for an M1A1 Abrams with a *computer* sight, 1000 yards,
and a moderate degree of concealment :-)   (Hey dude, try to blow a hole
if *this* baby)
-- 
sarima@teradata.com			(formerly tdatirv!sarima)
  or
Stanley.Friesen@ElSegundoCA.ncr.com
Newsgroups: rec.arts.sf.science
From: ingles@engin.umich.edu (Ray Ingles)
Subject: Re: Mini-Atomics
Date: Thu, 10 Sep 92 20:49:36 EDT
Organization: University of Michigan Engineering, Ann Arbor

In article <1992Sep10.175629.24244@pbhya.PacBell.COM> whheydt@PacBell.COM (Wilson Heydt) writes:

>Ah, the joys of not knowing istory.
>
>The US used to have a back-pack nuclear demolition charge.  It had a
>dial-in yeild down to the equivalent of 250 tons.  (That ).25 KT,
>folks.)  The Army pulled it out of service after someone realized that
>having a nuke in charge of a couple of Serjeants didn't seem like all
>that hot an idea . . .
>
>Why does everyone seem to think that small nukes are a new idea?
>
>Hal Heydt                    |    "Boycott Time-Warner"

 Do you have any references for this? I'm really interested...


Sincerely,

Ray Ingles                  || The above opinions are probably
                            || not those of the University of
ingles@caen.engin.umich.edu || Michigan. Yet.
From: jtb5@po.CWRU.Edu (Justin T. Ballard)
Newsgroups: rec.arts.sf.science
Subject: Re: Laser weapons
Date: 8 Sep 1992 17:44:50 GMT
Organization: Case Western Reserve University, Cleveland, Ohio (USA)
NNTP-Posting-Host: slc12.ins.cwru.edu


Here's a concept for a future weapon. It seems that the old 
concept of propelled bullets will most likely survive into the
future. One of the things that they will change is the way they
are propelled. One person suggested electromagnetic gun. The
big problem with those are similiar to that of sonic and beam
weaponery, power! We just don't have very much in portable high
power devices. One unusual idea for something like a fortress or
such could be weaponary that would get it's power through 
receptacles in the wall, basically extension cords. Somewhat 
unfeasable(hey who shut off the lights!). My idea for a weapon is
a variation on the hypersonic bullet. For propulsion you could 
use the idea of electric arc? weapon. It works by igniting the 
propellant with an electric arc which turns it into plasma? giving
a higher velocity to your projectile?(taken from a faulty memory
so no flames please). Using that idea gives you the hyper velocity.
The only problem with that is it will tend to leave nice clean holes
in your target. Through a little processor in it to calculate an
approriate penetration depth(probably want this adjustable for 
different targets)and then BLAMMO(one of my favorite explosion 
sounds). The explosive part of the bullet behind the penetrator
goes boom behind the nice strong armor of your target. In fact the
armor may even work for you containing the explosion and further 
damaging your target. It will never get by through the Geneva 
Convention but it will damage about everything else. Hell using 
something like this on a tank would probably take it out with 
little damage to the tank. The internal explosion could be just 
enough to kill the tankers and leave the tank intact. Interesting
idea. BTW, the army is currently testing a field gun using the
plasma arc technology. Later.
-- 
					Justin Ballard
					jtb5@po.cwru.edu
From: nickh@CS.CMU.EDU (Nick Haines)
Newsgroups: rec.arts.sf.science
Subject: Re: Laser weapons
Date: 7 Sep 92 19:13:31 GMT
	<FRANCIS.92Sep3154408@galois.dogwood.atl.ga.us>
	<rwallace.715604300@unix1.tcd.ie>
Organization: School of Computer Science, Carnegie Mellon University
Originator: nickh@VOILA.VENARI.CS.CMU.EDU

In article <rwallace.715604300@unix1.tcd.ie> rwallace@unix1.tcd.ie (russell wallace) writes:

   In <FRANCIS.92Sep3154408@galois.dogwood.atl.ga.us> francis@dogwood.atl.ga.us (John Stracke) writes:

   >Possibly sonics (anybody know feasibility here?).

   Not very; it's the same as lasers, you simply can't get enough power
   output. Also there's no way to keep the sound in a tight beam. (Though
   one weapon I did use in an sf scenario was a sonic stunner that was like
   a directional version of the stun grenades used by anti-terrorist teams;
   it produces a very intense blast of sound that will shock anyone within
   a few metres in a 60 degree arc into immobility. Not a general-purpose
   weapon, but a nice touch I thought.)

But there was that court case in Britain a few years ago of a bloke
who'd built a sonic `projector' to rig a horse race by distracting the
lead horse. Definitely directional.

Nick Haines
Newsgroups: rec.arts.sf.science
From: sdr57@cas.org ()
Subject: Re: Laser/Future Weapons
Organization: Chemical Abstracts Service, Columbus, Ohio
Date: Wed, 9 Sep 1992 14:42:11 GMT

In article <lapuu1INNs1u@appserv.Eng.Sun.COM> fiddler@concertina.Eng.Sun.COM (steve hix) writes:
>
>The AK-47 as "weapon of choice" depends on the terrain.  In a treeless
>region with good visibility, something like the old Enfield SMLE or
>a Springfield 1903A3 would be far better, as the AK isn't all that
>good at long range.  A lot of the mujahadeen seemed to still be somewhat
>partial to the old Enfield.
>
The Mujahadeen tended to take what they could get - AK-47's were
preferred because ammunition resupply was simpler (look, there
Ivan is now - bang - more bullets); the Enfields were loaded with
reloads which cost *money* from the gunsmith.

The point is nonetheless valid - the "weapon of choice" depends on
what you are going to do (shoot what? where?) with it. This opens
up another niche for laser weapons (or sonics) - special applications.
A disposable one-shot laser or sonic which was rugged enough to be dropped
more or less at random over an occupied region could be a useful tool
in fostering underground movements - a gun to get a gun. A single-shot
.45 pistol made out of stamped metal was used in WWII for that purpose.
It was accompanied by pictorial instructions.

******************************************************************************
Renegade academician. They're a dangerous breed when they go feral,
academics are...a chemist, too.
		    -(James P. Blaylock in "Lord Kelvin's Machine")

My organization hasn't agreed with any of my opinions so far, and
I doubt they'll start now.

Stanley "Ya nee speon" Roberts
From: swf@teradata.com (Stanley Friesen)
Newsgroups: rec.arts.sf.science
Subject: Re: Mini-Atomics
Date: 9 Sep 92 23:47:40 GMT
Reply-To: swf@tdat.teradata.com (Stanley Friesen)
Organization: NCR Teradata Database Business Unit

In article <1992Sep8.191358.21168@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes:
|In article <1992Sep8.162944.25894@lmpsbbs.comm.mot.com> johnmc@comm.mot.com (John McCash) writes:
|< would be. As I hazily recall, the conversion efficiency of a fission
|< warhead is about either 3% or 30%. This would mean that either 1 gram
|< or .1 gram would be converted to energy. I think critical mass for
|< plutonium is roughly 10kg, 
|
|Californium would be dicey to make into a bomb -- a solid lump of the
|stuff would glow white hot from the decay heat -- but I have read
|about a proposal to make curium-245.

Not to mention giving everyone nearby a lethal dose of radiation in
a rather short time.

| This isotope can be bred from
|the curium in thermal fission reactor waste; the proposal I saw was to
|use 14 MeV neutrons in a fusion reactor blanket.  The critical mass is
|supposed to be about 50 grams.  ...
|
|Yield can be computed as follows.  ...
|  If 10%, then the
|yield is about 2 tonnes TNT/gram.  The 50 gram mass liberates about
|100 tonnes of TNT equivalent.

Yow!  A bullet that packs a punch larger than the largest conventional
bomb used by the armed forces. (The 5000 lb bunker buster).

100 tons of TNT would obliterate a city block (or more)!


-- 
sarima@teradata.com			(formerly tdatirv!sarima)
  or
Stanley.Friesen@ElSegundoCA.ncr.com
Xref: sparky rec.arts.sf.science:2891 rec.arts.sf.written:12096
From: smt1179@ritvax.isc.rit.edu (Tom Thatcher)
Newsgroups: rec.arts.sf.science,rec.arts.sf.written
Subject: Re: Something Nasty in the Human Genome
Date: 13 Sep 92 04:37:51 GMT
Reply-To: smt1179@ritvax.isc.rit.edu
Organization: Rochester Institute of Technology

In article <rwallace.716203570@unix1.tcd.ie>, rwallace@unix1.tcd.ie (russell wallace) writes:
>In <1992Sep10.212615.768@csc.canterbury.ac.nz> chisnall@cosc.canterbury.ac.nz (The Technicolour Throw-up) writes:
>
>>From article <1992Sep8.094119.26816@crc.ac.uk>, by gwilliam@crc.ac.uk (Gary Williams x3294):
>>>>In article <1992Sep3.031844.21399@news.eng.convex.com>, cash@convex.com (Peter Cash) writes:
>>>>Hmmm. I read an article in my local newspaper a few days ago that claimed
>>>>that several research teams have found a "fractal pattern" in the "junk"
>>>>DNA of many diverse lifeforms, including man. (According to one team, the
>>>>fractal complexity was highest for man, according to the other, it wasn't.)
>
>Yes, but wouldn't you naturally expect to find fractal sequences in the
>junk DNA? After all, the junk DNA is formed not by random nucleotides
>getting appended one by one, but by the duplication (and subsequent
>modification) of segments of DNA of various sizes. Hence you would

You are making a questionable assumption with the use of the word "junk"
to describe DNA that we still have after 3 billion years of evolution.
"Selfish Gene" theory holds that life is just DNA's way of making more DNA.
Just because we don't know what some DNA does doesn't mean it does nothing.
At the very least, it has done a very good job of keeping itself around,
which is the whole point, from the DNA point of view.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
^  "What must I do to convince you?"            ^  Tom Thatcher            ^
^  "Die."                                       ^  University of Rochester ^
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
From: m1phm02@fed.frb.gov (Patrick H. McAllister)
Newsgroups: rec.arts.sf.science
Subject: Re: Mini-Atomics
Date: 9 Sep 92 22:08:21 GMT
Reply-To: m1phm02@fed.frb.gov (Patrick H. McAllister)
Organization: Federal Reserve Board, Wash, DC

In article <1992Sep4.214545.25904@bert.eecs.uic.edu>, artn@bert.eecs.uic.edu (Ellyn Sandor) writes:
|> 	But... what is the minimum practical size of a fission or fusion
|> bomb?  The aforementioned projectile bomb is purported to vaporize about
|> one city block.  Is that realistic?  Can an atomic grenade be made, say
|> one to ten pounds, which can destroy a single building?  A few ounces
|> for a room?

NY Times today (9/9) has an op-ed piece by someone who sounds a bit paranoid about a secret program to build small nukes. The article talked about bombs with yields down to about 10 tons (for use as super "bunker busters"). You might be able to get a better answer to your question in sci.military. I believe the critical variables are how much the fissionable material can be compressed and how efficiently neutrons can be injected/kept in the bomb.

Pat
From: be726@cleveland.Freenet.Edu (Joseph A. Ellis Jr.)
Newsgroups: rec.arts.sf.science
Subject: Re: Laser weapons
Date: 5 Sep 1992 20:46:31 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: be726@cleveland.Freenet.Edu (Joseph A. Ellis Jr.)
NNTP-Posting-Host: hela.ins.cwru.edu


In a previous article, jc@crosfield.co.uk (jerry cullingford) says:

>In article <1992Sep1.213233.7293@spss.com> markrose@spss.com (Mark Rosenfelder) writes:
>>I'd like to throw some laser weapons into an sf story, but I find I don't
>>know enough about lasers.  
>In reality, for frying people - probably not. At least not for continuous
>or rechargeable units. Disposable, single/few shot ones may be a little better.
>
Actually, there's a way to get around this and related problems. Go back to the
old internal combustion / gunpowder technology. Ammo consists of a single-use
solid-state laser emmiter and power-cell combination. The weapon's _internal_ 
power source contains only enough juice to power the cooling and sighting
mechanisms. Small, light weapons would have a limited number of shots, and 
larger assault lasers would be belt-fed... but the belts would be MUCH lighter
and machine-gun links. There probably WOULD be a sound associated with firing
these, though it would be more like the crack of a large spark than the usual
"laser whine" we hear in movies. However, the sound would be all at the point
of origin, and not downrange... unless it hit something that exploded with 
steam (like flesh... or concre 

What advantages? Well, the usual. No recoil, very long and accurate range, good sniper weapon. Disadvantages? Hi-tech reloads, fog and metal chaff make good
countermeasures. Fun toys, but expensive. You have to have a good reason to
want/have one... and the cops are going to be VERY interested in the reasons you give!
-- 
 Joe Ellis  o/~ The Synthetic Filker o/~    |     TesserAct Studios
     Internet:   usr6184a@tso.uc.edu        |       P.O. Box 18577
        GEnie:   J.ELLIS22                  |     Fairfield, OH 45018
    All filked up and no place to sing!     |   New Dimensions In Filk!
Newsgroups: rec.arts.sf.science
From: ins894r@aurora.cc.monash.edu.au (Aaron Wigley [Wigs])
Subject: Re: Laser weapons
Organization: Monash University
X-Newsreader: Tin 1.1 PL5
Date: Mon, 7 Sep 1992 11:36:18 GMT

Nick Haines (nickh@CS.CMU.EDU) wrote:
: In article <1992Sep3.184558.4898@spss.com> markrose@spss.com (Mark Rosenfelder) writes:
:    very futuristic, are they?  Can anyone think of anything that's likely
:    to replace them?
: 
: Sure. Smarter guns. Aimed by AIs with fast servos, nanotech gray-goo

Why bother with servos? You can decrease the size needed by using the
'shape memory metals' (or whatever the media calls them :).

Just have a fin made out of the stuff, and to change shape, just pass
a current through the fin. 

A few friends and myself came up with the idea of guidable arrows, when we
were at archery the other week. The fletching would be perfect if replaced
by a steerable fin :-)

The Wigs of Oz,
Aaron Wigley