HDTenEightyP/NetNews huggingface dataset:
From: s5223927@titan.ucc.umass.edu (Daniel Lescohier)
Newsgroups: rec.arts.sf.science
Subject: Re: Cherryh's technology (was: SF about doing science ?)
Keywords: Don't read _Twistor_
Date: 15 Apr 92 02:55:18 GMT
Organization: University of Massachusetts, Amherst

In article <1992Apr14.041927.16381@ccu1.aukuni.ac.nz> ecmtwhk@ccu1.aukuni.ac.nz (Thomas Koenig) writes:
>
>One other thing which peeves me are the speed and acceleration.
>Accelerating at 10 g's will not get you up to light speed in a matter
>of minutes.

	True.  It would take about 35 days to get to light speed at 10g
acceleration (3*10^8 m/s / 100 m/s^2 = 3*10^6 s = approx. 35 days.)
That's extremely fast compared to today's standards, however.
 


-- 
 Daniel Lescohier        | InterNet: s5223927@titan.ucs.umass.edu (until May)
 Univ. of Massachusetts  |---------------------------------------------------
 Amherst, MA (until May) | FidoNet:  1:101/138 (permament address; after May)
  [quote deleted]        |        (Daniel.Lescohier@f138.n101.z1.fidonet.org)
Newsgroups: rec.arts.sf.science
From: john@galois.WPI.EDU (John F Stoffel)
Subject: Re: Ringworld Ending [was Re: Strength of skrith (sp?)]
Organization: Phule's Company
	<1992Apr13.064543.20533@ccu1.aukuni.ac.nz>
	<1992Apr13.110305.16102@cs.rochester.edu>
	<1992Apr13.165408.12926@eng.cam.ac.uk>
Date: Tue, 14 Apr 1992 16:56:49 GMT

>>>>> On 13 Apr 92 16:54:08 GMT, pjh@eng.cam.ac.uk (P.J. Hogben) said:
P.J.> Nntp-Posting-Host: club.eng.cam.ac.uk

P.J.> Louis Wu and Speaker-To-Animals are in pressure suits in the portion
P.J.> of the building with the flycycle "glued" in. There is a long strand
P.J.> of monofilament glued to the building and passing through their ship
P.J.> (What was it called now?) held in place by the airlocks. The woman
P.J.> they picked up (forgot her name too) is in the ship along with Nessus
P.J.> the Puppeteer who is in the autodoc. Now what I want to know is how
P.J.> did Wu and Speaker get BACK to their ship? Or could the woman have
P.J.> been told how to operate the hyperdrive? And if so, would the building
P.J.> have been dragged along aswell and could Wu have coped with the Blind
P.J.> Spot? (I seem to remember that the Kzin weren't bothered by it.) 

P.J.> When I read the book, I got the impression that Niven didn't know how
P.J.> to get Wu and Speaker back to the ship so he just glossed over it

Sure ,they just used the reactionless thruster in the flycycle to fly
themselves back to the "Liar" when they had both passed through the
"Fist of God"

			John

--
Youth of today!  Join me in a mass rally for traditional mental attitudes!
-------------------------------------------------------------------------------
john@wpi.wpi.edu | BELA LUGOSI is my co-pilot..
From: jschell@sdcc13.ucsd.edu (The Master)
Newsgroups: rec.arts.sf.science
Subject: Re: Dyson Sphere
Summary: read Ring of Charon
Date: 9 Apr 92 05:49:48 GMT
Followup-To: rec.arts.sf.science
Organization: University of California, San Diego


	For those of you interested in Dyson Spheres, read _The
Ring of Charon_ by Roger MacBride Allen.  It's about
self-reproducing Dyson Spheres that were created by some extinct
race and they are basically sentient beings in their own right.
It's a good adventure story, too, maybe a bit overdone, but still
pretty enjoyable.  I'm just waiting for the sequel, 'cause it
desperately needs one.

BCNU.

+----------------------+------------------------------------------+
|      The Doctor      |  Andre, you mean to tell me that you     |
|  --> Jon Schell <--  |  have lost _another_ sub?                |
|      The Master      |             -- The Hunt for Red October  |
+----------------------+-------------------------------------+----+
| No one else would be crazy enough to claim these opinions. | 42 |
+------------------------------------------------------------+----+
From: markrose@spss.com (Mark Rosenfelder)
Newsgroups: rec.arts.sf.science
Subject: Re: Psychohistory
Date: 14 Apr 92 20:46:27 GMT
Article-I.D.: spss.1992Apr14.204627.28549
Organization: SPSS Inc.

In article <1992Apr13.171823.27610@murdoch.acc.Virginia.EDU> abb3w@fulton.seas.Virginia.EDU 
(Arthur Bernard Byrne) writes:
>    Hari Seldon: Well, my skills are not unique... there are a total
>      of fifty mathematicians presently employed by my project, some
>      of whom might have been able to develop the field similarly to
>      the way I did, had I not done so first.  [...]
>      In short, had I not been here, someone else would have filled my place.

while in article <1992Apr13.230214.9785@m.cs.uiuc.edu> sane@cs.uiuc.edu
(Aamod Sane) writes:
>   Hari Seldon: My theory is that when you get enough people 
>     *who do not know psychohistory* together
>     history is determinate.  [...]

I think one of you gentlemen is wrong.  

If historical conditions were right for the development of psychohistory, 
then the Galactic Empire is no longer filled with psychohistorically naive 
rabble and history is no longer determinate.  

If on the other hand it *is* possible to keep the Empire ignorant of 
psychohistory, then it can't be maintained that dozens of 
proto-psychohistorians were available to take Seldon's place.

For an interesting argument that the social sciences will never be able
to be as predictive or reductive as the physical sciences, see John
Searle's _Minds, Brains, and Science_, chapter 5.

(Myself, I think psychohistory is impossible, but makes for some very
entertaining stories, at least till R. Daneel turns up.)
From: martinc@hatteras.cs.unc.edu (Charles R. Martin)
Newsgroups: rec.arts.sf.science
Subject: Magnetic sails
Date: 4 Apr 92 05:22:13 GMT
Distribution: rec
Organization: /theta/theta5/unc/martinc/.organization

I want to direct everyone's attention to the article ion this month's
Analog on magnetic sail propulsion.  The general idea is you use a big
(kilometers radius) superconductive loop to make a magnetic field; this
field interacts with the solar wind or the Earth's magnetic field to
generate a force.

The reason I want to direct your attention to it is that there are some
points I don't understand (and the damned thing is full of equations
with bad typography and bad editing).  In particular, I'm curious about
the idea of launch from Earth's surface (apparently) by magnetic
repulsion near the magnetic poles.

If there is anyone around who understands this well enough, would you
kindly hold up your hand so's I can grill you?

Thanks

Charlie
--
Charles R. Martin/(Charlie)/martinc@cs.unc.edu/(ne crm@cs.duke.edu) 
O/Department of Computer Science/Sitterson Hall/UNC/Chapel Hill, NC 27599
H/3611 University Dr #13M/Durham, NC 27707/(919) 419 1754
The universe is full of magical things patiently waiting for our wits to
grow sharper.  -- Eden Phillpot, I'm told.  Anyone have a better reference?
From: abb3w@fulton.seas.Virginia.EDU (Arthur Bernard Byrne)
Newsgroups: rec.arts.sf.science
Subject: Re: Psychohistory
Date: 13 Apr 92 17:18:23 GMT
Organization: University of Virginia

In article <1992Apr10.201851.3739@spss.com> markrose@spss.com (Mark Rosenfelder) writes:
>   Interviewer: Welcome to 'State your claim'!  First, we have with us
>      psychohistorian Hari Seldon!
>
>   Hari Seldon: My theory is that when you get enough people together
>     history is determinate.  I say the Galactic Empire is going to
>     fall apart for 30,000 years.  However, with careful management
>     this can be reduced to 1000 years.
>
>   Interviewer: But that wouldn't happen if you had never existed, 
>     would it?  Isn't that a whacking big difference for one individual
>     to make?
>
>   Hari Seldon: Well, this is where my theory falls to the ground.

Alternate alternate response:

    Hari Seldon: Well, my skills are not unique... there are a total
      of fifty mathematicians presently employed by my project, some
      of whom might have been able to develop the field similarly to
      the way I did, had I not done so first. A rather trivial
      exercize in Psychohistory shows that due to several of the
      forces leading to the collapse of the empire make it so that
      any development such as mine would initially be encouraged,
      providing the necessary environment for one able to do the work.
      Of course, as the work became more sucessful, it would come
      under opposition, but the necessary groundwork to deal with that
      would have been finished by then. Furthermore, the probablity of
      collapse is only about 12% per generation, leaving a considerable
      window in which a later mathematician could have developed the
      science instead, had I not existed. In short, had I not been here,
      someone else would have filled my place.

AB^2
Newsgroups: rec.arts.sf.science
From: tbmg9061@uxa.cso.uiuc.edu (Thomas B MacIukenas)
Subject: Re: Dyson Sphere
Organization: University of Illinois at Urbana
Date: Sat, 11 Apr 1992 04:20:42 GMT


You can add this to the lengthy list of problems with Dyson spheres:

Some kind of system is needed to hold the thing up.  Spinning doesn't
work for spheres, since the top and bottom will cave in.   And you
can't use a system of free flyers, all of which are in stable orbits,
because you could never work out a system of interlocking orbits which
would guarantee no collisions (and that's ignoring gravitational effects
between the flyers!).  You need some kind of thrust system capable of
holding the sphere up against the sun's gravitational pull.  That won't
be cheap, and you'll basically be sending a continuous shower of matter
into the sun (radiation pressure systems won't work, so you need some
kind of reaction mass system).  I don't think it's worth the effort
or the possible environmental effects.

I agree with Larry Niven's Puppeteers:  eventually we'll have such
abundant energy sources that the sun will become unnecessary and we'll
decide to keep it or not based on purely aesthetic reasons, not for
the energy we could get from it.  It just seems to be too much work
getting all the energy out of the sun.
-- 
___-Tom_Maciukenas_(tbmg9061@uxa.cso.uiuc.edu)_________________________________
main(){char c[159],s[159]="main(){char c[159],s[159]=@@@;strcpy(c,s);s[26]=34;s
[27]=0;s[28]=34;printf(s);printf(c);puts(&s[28]);}";strcpy(c,s);s[26]=34;s[27]=
0;s[28]=34;printf(s);printf(c);puts(&s[28]);}
From: nickh@CS.CMU.EDU (Nick Haines)
Newsgroups: rec.arts.sf.science
Subject: Re: Virtual reality, the brain, and high-speed modems.
Date: 7 Apr 92 20:00:03 GMT
Organization: School of Computer Science, Carnegie Mellon University
Originator: nickh@VOILA.VENARI.CS.CMU.EDU

In article <1992Apr7.160153.13146@ux1.cso.uiuc.edu> mjg51721@uxa.cso.uiuc.edu (Michael James Gebis) writes:

> I have recently read a variety of stories concerning COMPLETE virtual
> reality..  where the user has had an implant (or something, sometimes
> this is not very clear) in his brain which totally simulates all
> sensory input, and also receives all commands from the brain.  My
> question is....how much information is this?  How fast an interface
> would be required?  Would a simple parallel port do, or are
> fiber-optics more realistic?  Anyway, thanks.

The `answers' (ie my fairly speculative guesses) are:

1. we have no idea how to do this, or when we will be able to do it.
   My guess is that it will not be possible before 2050.

2. talking of the `I/O bandwidth' of the brain (for instance) is
   mixing ones metaphors: the brain is _not_ a bunch of electrical (or
   electronic) circuits, there are many different sorts of signals,
   and we don't know how much information is carried by each (loosely,
   all the systems are not just analogue circuits, but analogue circuits
   that are parameterized by other sorts of signals (eg.
   blood-chemicals).

3. Given (2), attempting to answer your question in the most useful
   way, the optical interface (optic nerve) carries about 500
   megabytes of information per second, to a first approximation.
   This is the bulk of the information entering the brain.  Probably.
   Say 4Gb/sec, or 30GHz, and you'll be in the ballpark.

4. However, you can fool the brain a lot (ie the unconscious,
   `operating system' level of wetware is prepared to take
   greatly degraded input and interpret it so that the
   `user'---the conscious mind---doesn't notice/care). So maybe
   you could make do with 50Mb/sec.  Given that this will all
   look like insane noise unless there is a lot of structure to
   it, suitable compression (scene descriptions?) could get this
   down to 1Mb/sec, I would guess.

5. Given (1), I don't think talking about doing it with any
   recognizable technology (eg a parallel port hanging off a PC, or a
   SCSI interface, or a fibre-optic from a hand-held
   20-million-processor supercomputer) makes much sense.

6. Who cares about (5) as long as it's a good story?

Oh, and

7. It's a _very_ old idea. It goes back to `how do I know what I see
   is "real"?' (which has been asked for at least 2000 years), and
   Plato's cave.

Nick Haines nickh@cs.cmu.edu
Newsgroups: rec.arts.sf.science
From: csmith@onetouch.COM (Craig Smith)
Subject: Psychohistory
Organization: MCS/OneTouch, Inc.
Date: Thu, 09 Apr 92 16:09:16 GMT

I have a major gripe with Foundation's Psychohistory.

It is based on the gas laws, which say that while the actions of a single
atom are not predictable, a large enough quantity of gas is highly predictable.
Asimov took this and applied it to people to make pychohistory.

The problem is, that every major turning point was predicted by Harry Seldon,
but the actual change was accomplished, not by masses of humanity, but
by a single person!

Now, while following the actions of a mass of people does not make for
a good story, he contradicts the main point the the series by doing
this.

Actually, if we look at history as we know it now, at the center of every
major event in history stood a single person, not a mass of people.

Any refutations? comments?

-- 
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
:: Craig Smith                                         csmith@onetouch.COM ::
:: Columbus, OH                                  ...!uunet!onetouch!csmith ::
::::::::::::::: "Life is a fulltime occupation."--Gene Kalman :::::::::::::::
From: mss2@quads.uchicago.edu (Michael S. Schiffer)
Newsgroups: rec.arts.sf.science
Subject: Re: Psychohistory
Date: 11 Apr 92 01:48:12 GMT
Reply-To: mss2@midway.uchicago.edu
Organization: University of Chicago Computing Organizations

In article <jd0pl64@sgi.sgi.com> daveh@xtenk.wpd.sgi.com (David Higgen) writes:
>In article <1992Apr10.201851.3739@spss.com>, markrose@spss.com (Mark Rosenfelder) writes:

>>    Hari Seldon: My theory is that when you get enough people together
>>      history is determinate.  I say the Galactic Empire is going to
>>      fall apart for 30,000 years.  However, with careful management
>>      this can be reduced to 1000 years.
>> 
>>    Interviewer: But that wouldn't happen if you had never existed, 
>>      would it?  Isn't that a whacking big difference for one individual
>>      to make?

>Alternate last response:

>Hari Seldon: Not at all. If I did not exist, it would be necessary to
>	invent me....

Which, it may be noted, someone did.  (At least according to the
latter-day Foundation books.  I consider the late Foundation
books Asimov's prerogative for contributing so much in so many
areas, but I don't count them with the original trilogy when
coming up with theories, myself.  I prefer the Mule as a unique
mutant and the Seldon Plan as a Good Thing, personally, to the
later reevaluations.)

Mike
-- 
Michael S. Schiffer, LHN, FCS	"Never let your sense of morality prevent
mss2@midway.uchicago.edu	 you from doing what's right!"
mike.schiffer@um.cc.umich.edu	 --Mayor Salvor Hardin of Terminus
mss2@usite-next.uchicago.edu     Isaac Asimov, _Foundation_
Newsgroups: rec.arts.sf.science
From: jmhodapp@aplcomm.jhuapl.edu (Jon Hodapp)
Subject: Re: Dyson Sphere
Organization: JHU/APL
Date: Mon, 13 Apr 92 21:36:33 GMT

In article <s93thINNpoe@agate.berkeley.edu>, goldfarb@ocf.berkeley.edu (David Goldfarb) writes:
> 
> In article <1992Apr12.053740.10984@husc3.harvard.edu> kim3@husc10.harvard.edu (Jason Kim) writes:
> )As far as problems go, the first thing that pops into my mind is:
> )what about comets? Won't they puncture your pretty sphere?
> )
>

Better than the 'destroy the comet' response, it would be great to allow the comet to
hit your hollow, rigid sphere.  As the sphere has to be pretty near perfect, the effect
would be much like ringing a bell.  The inhabitants would occasionally here a low 
pitch, some shaking of dishware, but a beautiful, near perfect tone, that might last
for hours.  It could be a signal for a day of celebration (depending on their
frequency, of course) If hits were daily, it would be too annoying.  But as most
of the material from the solar system went into building the DS in the
first place, there wouldn't be a lot of junk out there anyway.  At last, Pythagorus'
music of the Celestial Crystal Spheres, would be real!

(I hope that it was Pythagorus who postualated that the planets were fixed
to huge crystal spheres, which made beautiful music as they turned.  Humans
could not hear this heavenly music, for we had been hearing it since birth,
and had since tuned it out.)  

Jon               JMHODAPP@aplcomm.jhuapl.edu
-----------------------------------------------------------------------
If some unemployed punk in Trenton, New Jersey, lying on a sofa
with a bong, can get a cassette to make love to Elle McPherson for
$19.95, this virtual reality stuff is going to make crack look like
Sanka.  
-  Dennis Miller
From: stig@Lise.Unit.NO (Stig Hemmer)
Newsgroups: rec.arts.sf.science
Subject: Re: Parallel Universes
Date: 17 Apr 92 15:31:21 GMT
Organization: Anarchy

In article <1992Apr15.215637.8148@ugle.unit.no>, stig@Lise.Unit.NO (Stig Hemmer) writes:
> If this is so, how does they explain the recent experiments where
> measurement one place are affected by whether or not a measurement is
> made elsewhere?
> 
> (What happens is that a wave-like multi-hump interference pattern
> changes into a particle-like single-hump (non)interference pattern)

I have gotten a couple of requests for more info, so I thought I might
as well post it.

The following is a laymans impression, so it is probably wrong in many
details. The main themes should be correct, though. It is based on an
article in Scientific American Nov 1991, pp 36-37.

They _have_ made a QM-action-at-distance experiment which shows
that something definitly happens when you observe things. They have
found that for the purposes of this experiment 'observe' means 'make
QM uncertanity have macroscopic effects'.

Note that this effect _carries_information_, it is not like the EPR
experiment where the experimenters have to compare results to see the
effect.  You can make a telegraph out of this...

As far as I know they have _not_ be able to measure accurately enough
yet to see if this effect is FTL or not. (If anybody has newer
results, please post them!)

As far as I know, again, there are two mayor possibilties: a) The
effect is light speed b) The effect can be made _backwards_
lightspeed, which case a mirror gives us backwards-in-time
communication.

QM and Special Relativity has never really worked together, so theory
can't help us here. 

Personally I favor alternative a, if only because the consequences are
less disturbing. :-)

From a newsarticle I got a reference which I haven't had the time to
follow up, but you can get it unchanged:
In article <CREON.92Jan1145909@wk39.nas.nasa.gov> creon@nas.nasa.gov
(M. Creon Levit) writes:
>Mandel's "pinball" experiment at Rochester (Sci Am, Nov 91 p.p.36-7) cannot
>be used as a superluminal (FTL) telegraph backwards-in-time (BIT) because
>the choice to mismatch the idler photon alternative paths cannot be delayed
>until after the signal photon has been detected.
>
>...
>
>There are experiments that show violation of past-cause /future-effect
>dispersion relations in gamma photon-proton scattering published in Phys.
>Rev.  See Physics Essays review below for details.
>
>For more info see Physics Essays, Vol 4, No 3 Sept 1991 "Design for a
>Superluminal Communication Device" or write Jack Sarfatti, POB 26548, San
>Francisco, CA 94126 or phone (415) 771 2067.

Stig 'Tortoise' Hemmer   aka   stig@lise.unit.no
.no means Norway, a minor kingdom in northern Europe.
Europe is a moon of Jupiters.
This is NOT a .signature virus. Do NOT copy it into your .signature
Organization: Fifth yr. senior, Metallurgy and Materials Science, Carnegie Mellon, Pittsburgh, PA
Newsgroups: rec.arts.sf.science
Date: Tue, 14 Apr 1992 13:33:37 -0400 
From: James William Stepanek <js43+@andrew.cmu.edu>
Subject: Re: Kevlar balloon space stations

>Also: are there radiation problems with Kevlar that aluminum or
>titanium or steel or (grin) rolled iron (whatever we use as materials
>for the walls of our space structures) doesn't have?
Well Kevlar would provide no shielding whatsoever against
electromagnetic ratiation and other forms of radiation above alpha
particles. Also polymers have a tendency to break down under UV
radiation , which happens to be mych more intense in space due to a lack
of ozone shielding.
James Stepanek
esp
From: smith@ctron.com (Larry Smith)
Newsgroups: rec.arts.sf.science
Subject: Re: Help needed for xenobiology project
Date: 7 Apr 92 17:20:06 GMT
Reply-To: smith@ctron.com
Organization: Cabletron Systems, Inc.

In article <1992Apr01.061751.16353@microsoft.com>, iank@microsoft.com (Ian Kennedy) writes:
>In article <pz0h9krdani@netcom.com> dani@netcom.com (Dani Zweig) writes:
>>x90gonyer@gw.wmich.edu:
>>>	I was wondering if anyone out there knows of a really good piece
>>>of SF that has scientifically plausible ailen life.  Items found in Anne
>>>McCaffrey's _Dragonsdawn_ and _The Dragonlover's Guide to Pern_ are my
>>>first choice...

>>McCaffrey's Dragon books are fantasy, not science fiction.  (The only 
>^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>That's funny considering they deal with genetically engineered
>creatures (the dragons, based on a native life form)

McCaffrey's Pern books have an SF background but they are, in fact, pure
fantasy.  The dragons, as specified, have no basis in science.  Their
wings are too short to be able to carry the kind of payload implied by
"firestone" and a genetically unmodified human rider, and their musculature,
even if genetically enhanced far beyond anything now envisioned, would be
incapable of takeoff, unless the skeleton was made of diamond fiber (in which
case the dragons could have it in their skin and be immune to damage from
thread) or metal (in which case dragons would have really interesting dietary
requirements).  If neither of the foregoing, then muscles that strong
would break any bones light enough to permit flight.  The chemical reaction
for firebreathing is mildly scientific but going *between* is not.  Even
if it were, time travel and the paradoxes implied therein would certainly
not be something that could be engineered, even if all the other objections
could be dealt with, nor do I believe any critter could evolve time travel.

Take them for what they are, an SF-based fantasy.  A very nice fantasy (who
wouldn't love to ride such a steed?) but less probable than FTL.

Larry Smith (smith@ctron.com) No, I don't speak for Cabletron.
-------------------------------------------------------------
I have come to the conclusion that one useless man is called a "disgrace",
that two are called a "law firm", and that three or more become a "Congress".
Newsgroups: rec.arts.sf.science
From: mjg51721@uxa.cso.uiuc.edu (Michael James Gebis)
Subject: Virtual reality, the brain, and high-speed modems.
Organization: University of Illinois at Urbana
Date: Tue, 7 Apr 1992 16:01:53 GMT

I have recently read a variety of stories concerning COMPLETE virtual reality..
where the user has had an implant (or something, sometimes this is not very
clear) in his brain which totally simulates all sensory input, and also receives
all commands from the brain.
My question is....how much information is this?  How fast an interface would be
required?  Would a simple parallel port do, or are fiber-optics more realistic?
Anyway, thanks.

Mike Gebis   mjg51721@uxa.cso.uiuc.edu   OR   m-gebis@uiuc.edu