HDTenEightyP/NetNews huggingface dataset:
From: griffin@sage.cc.purdue.edu (The Crystal Griffin)
Subject: Re: Title/author?? (please help me remember)
Organization: Purdue University Computing Center
Distribution: usa
Date: Sat, 19 Dec 1992 03:15:53 GMT

In article <1992Dec18.233956.24513@iscnvx.lmsc.lockheed.com> baylor@NEBULA.SSD.LMSC.LOCKHEED.COM writes:
>In article <1gso64INNo1c@mirror.digex.com>, nbull@access.digex.com (Nicholas Bull) writes:
>>Dear sci-fi readers,
>>
>>I'm trying to remeber the title &/or author of a sci-fi novel I
>>read 20 years ago, when I was about 12.  I kind of remember the
>>plot:
>>
>>Location: Earth (maybe) or a planet somewhere.  There are two
>>cities, one which specializes in Science and the other in
>>Art--but the two cities don't know about each other.  I think the
>>action starts in the Art city.
>>
>>[Story description deleted]

>It sounds like a certain Arthur C. Clark story, whose title I
>keep forgetting. The young man is Alvin.  He is of an age to 


Howdy-

ZT here.

It IS definitely by Clarke, but I can't come up with the title either.
  I'm almost positive it has the word 'City' in it.  He came out with
  a sequel not too long ago, and it was pretty good, really, although
  it was done with the 'help' of his !@#$% co-writer.

Just for my Record.

                       The Crystal Griffin

Xref: sparky rec.arts.sf.science:3729 rec.arts.startrek.tech:6900
From: leonardo@mills.seas.ucla.edu (Leonardo E. Blanco De Freitas)
Newsgroups: rec.arts.sf.science,rec.arts.startrek.tech
Subject: Re: Time Travel and Causality Violation
Date: 11 Dec 92 03:25:24 GMT
Followup-To: rec.arts.sf.science
Organization: SEASnet, University of California, Los Angeles


    No, the multi-dimensional time idea does not require an infinite
number of dimensions of time. It requires only two. If you want to add
more, you can, but it is not necessary.
    I think many people didn't understand what I said when I said the
universe must have multi-dimensional time. It is easier to understand
if we use a small analogy...
    In the usual sense, time is a line. One-dimensional, infinite in
both directions. If, on the other hand, time has two dimensions, how
many universes can exist? The answer is not two, but infinity! You see,
there are an infinite number of straight (and otherwise) lines that
can lie on a plane (whereas only one line can lie on a straight line).
Thus, our timeline is only a branch of a tree containing potentially
infinite other universes. The only thing that is required, as someone
mentioned, is that meta-time travel be not allowed. If that is the case,
THEN you would need a third dimension to explain changes in that time
plane. However, we don't have to deal with that.
    As I mentioned in e-mail to somebody in the net, the single-timeline
universe is but a simplification of the planar time universe. In other
words, you have a planar time, but you choose to follow the events of
ONE particular timeline.
    It cannot be denied that time travel produces a serious paradox.
So, you have two choices (it's the second time I say this...)

1) Forget time travel: it is impossible (I would guess that faster-
   -than-light travel goes as well, for reasons I won't care to
   mention...)

or

2) Allow more than one dimension of time. If you don't want all uni-
   verses existing at the same time, that's fine. However, you can't
   resolve certain paradoxes with one single timeline if time travel
   is allowed (see a previous posting by someone else; sorry I don't
   have the reference... :(  ).

    I won't be back to see how this develops until January 11, when
the Spring Quarter begins :(, but if you care to e-mail me I will be
able to read it by then (news postings, on the other hand, will most
likely be discarded by my news server :(  ).


______________________________________________________________________________
                                    __                 |
                      __...------~~~~~~~~------...___  |Leonardo E. Blanco
 ___________________/<_______________________________> |leonardo@seas.ucla.edu
(___________________)   ~~>----____________-----~~     |
  /   /           /      /          ~~                 |"The needs of the one
 /   / ..---===~~~~~~~~~~|                             |outweigh the needs of
 `-----------------------|                             |the many."
          `-------------'                              | -Kirk & Spock, STIII

Newsgroups: rec.arts.sf.science,alt.folklore.science
From: singley@helix.nih.gov (Erick Singley)
Subject: Re: The Marching Morons (was Re: Cindy the Disco Queen)
Organization: (National Institutes of Health, Bethesda, MD)
Date: Wed, 16 Dec 1992 22:36:04 GMT

>>bviously you can never reach 100% by increasing  numbers by a % (though 
>>=you could get a serious amount of .9s *grin* )

>I hope that's not representative of the mathematical ability of the employees
>of NIH.  Since the tax is applied to his property, increasing that tax by 12%
>per year must inevitably raise his taxes to above his income, unless his income
>is increasing at more than 12% per year.

I stand corrected. Having no property, I stupidly had 'personal income' stuck
in my mind. ;-(. That'll teach me to look before I leap...
Erick
--
singley@clinpharm.niaaa.nih.gov
Newsgroups: rec.arts.sf.science
Subject: Teleport Gate Paradox (New?)
From: morgan@arc.ab.ca (Sean Morgan)
Date: 11 Dec 92 13:12:50 MDT
Distribution: world
Organization: Alberta Research Council

Several books have used the idea of a teleport gate:  Heinlein's survival
school disaster (Doorways in the Sky?), Biggle's _All the Colors of Darkness_,
Niven of course, the new Hyperion books, and so on.

What if you had two of these set up in your lab back to back, so that as
you went through the second one, you would pop out of the first, as shown by
smiley:

            Direction of Travel
              <----------

           |                   |
           |-)    :--)       :-|
           |                   |

We can see that one smiley is half in and half out of the gate.  As soon as his
eyeballs have gone through, he should be able to see the back of his own head
(the smile, in this case).

Now let's move the gates close together. Soon he can now tap himself on the
back.  Closer still, and he is crowded up against his own back:

           |    |
           |-):-|
           |    |

A little harder to see, smiley is still in the middle, but his friend has
stepped aside.  Now the paradox:  Assuming that the "membrane" of the gate
cannot transmit a shear stress, what happens when the gates are move even
closer, or even touch?

This really has me wondering.  The only thing that makes sense to me is that
this is proof that such a thing can never exist.
-----------------+-------------------------------
Sean Morgan      |  ALBERTA  6815 - 8 Street N.E.
                 | RESEARCH  Calgary, AB, Canada
morgan@arc.ab.ca |  COUNCIL  T2E 7H7
From: swf@tools3teradata.com (Stan Friesen)
Newsgroups: rec.arts.sf.science
Subject: Re: Time Travel and Causality Violation
Date: 17 Dec 92 19:00:34 GMT
Distribution: world
Organization: NCR Teradata Database Business Unit

Actually the greatest argument against the existance of time travel was brought
to my attention by my brother:

If it is possible why aren't we up to our ears in temporal archaeologists and
time tourists?

Can you imagine what Dallas in 1964(I think) would have been like if time travel
were possible?  At last, the chance to find out for yourself who *really* killed
JFK!!

Or the crowd in Moscow a couple of years ago when the Soviet Union collapsed!
[Imagine, Yeltsin saved by time travellers :-)

-- 
sarima@teradata.com			(formerly tdatirv!sarima)
  or
Stanley.Friesen@ElSegundoCA.ncr.com
From: david@kbssun1.tamu.edu (David Browne)
Newsgroups: rec.arts.sf.science
Subject: Re: Teleport Gate Paradox (New?)
Date: 15 Dec 1992 06:08:30 GMT
Organization: Texas A&M University, College Station, TX
NNTP-Posting-Host: kbssun1.tamu.edu
X-Newsreader: Tin 1.1 PL4

What happens when you put the receiver gate _through_
the transmitter gate?


David Browne
david@kbssun1.tamu.edu

Newsgroups: rec.arts.sf.science
From: markbr%radian@natinst.com (markbr)
Subject: a modest proposal - Toutatis in 2004
Date: Thu, 17 Dec 1992 22:23:18 GMT
Organization: n.o.y.b


Intro:
1)
A couple of weeks ago, the asteroid Toutatis (pronounced, I am told, Two-to-tea)
passed within 2M miles of the Earth. It will return, at least for a while (I
assume it's orbit is changing) every four years. The next two passes will be
further, but in 2004 is will be < 1M. 
2)
The space program is (and has been) floundering. No firm goal has been decided
for it (or ones too big).
3) 
The Incredible Shrinking Space Station is absurd. By the time it gets up,
it will be a tin can drop-kicked out the airlock door.

Therefore:
   I have formed a committee (of one, suckers, er, I mean volunteers welcome),
tenatively named "The Asterix Group" (from the comic, since that's who he
swears by, being a pre-Roman Gaul). Our (editorially speaking) slogan, and
our goal is 
		Toutatis in 2004!

The first project of this committee is to answer these questions:
   1) Is it technologically feasable to add enough controllable delta-v
	to Toutatis so that by 2004 we could move it into Earth orbit
	(somewhere between 1K & 22.3K miles out, *well* above any trace
	of atmosphere, but keeping in mind the Van Allen Belts); and
   2) if it is technologically feasable, what is the most economical
	(cost-effective) way to do this?

If done, this would give us a serious base in space, one easily accessable
by current technology, and big enough to build an industrial park in space.
Staff could cheaply be rotated to the Moon, and, less occasionally, to Earth.

Any takers?

	mark
From: S.A.McIntyre@durham.ac.uk (Scott A. McIntyre)
Newsgroups: rec.arts.sf.science
Subject: Re: Time Travel and Causality Violation
Date: 14 Dec 92 21:19:17 GMT
Reply-To: S.A.McIntyre@durham.ac.uk
Organization: University of Durham


Personally I think that time travel is an attractive concept and perhaps possible, but the
concept of paradoxes makes me consider whether or not it will ever be possible in the
frame of reality we are now experiencing.

What would happen if Our Reality did develop the ability to flit through the various
dimensions of time / space....and came back to the say present, when such an ability is
not known, and introduced it.  Ignoring the paradox of the needed reality to facilitate
the travellers sojourn in the first place, could time travel be accelerated in development
by applying principles and devices we do not currently understand or have?

My wife thinks I read too much science fiction.

Perhaps she's right.

But I'm bored with Earth and the time I'm stuck in...anyone else want out?

Scott
From: colin@callisto.pas.rochester.edu (Colin Roald)
Newsgroups: rec.arts.sf.science
Subject: Re: Do starships collapse when flying near c?
Date: 19 Dec 92 23:32:50 GMT
Organization: U(r) AstroTheory Group

flatline@uni-paderborn.de (Michael Wehking) writes:
>max@west.darkside.com (Erik Max Francis) writes:
>|> flatline@uni-paderborn.de (Michael Wehking) writes:
>|> 
>|> > Starships flying near c accumulate mass from the energy of their 
      'stardrive'.
>|> > Is there a point where the ship has accumulated
>|> > enough mass to collapse (to a black hole :-) or do I make a 
      serious mistake?

Actually, yes, you are making a mistake, but it's a very common one.  
This is hard to explain (partly because I don't really understand it
myself), but I've been taught not to look at these things that way.
In special relativity, energy and momentum and force (which all depend
on mass) transform _as_if_ the mass of an object becomes larger in a 
moving frame, but _rest_mass_ is a fundamental quantity independent of
the velocity of an object.  

Also, energy and momentum and force all depend on an object's _inertial_
mass; gravitational mass is the provice of general relativity, and since
I've never studied that I'm not going to stick my neck out.

Anyway, lots of weird stuff happens near c, but sudden collapse to a 
singularity is not one of them.


>Does this mean that starships flying with the 'right' speed will fall into a 
>black hole anyway (the rest of the universe)?

Well, maybe, but only from the trivial perspective that *everything* is
within the event horizon of the universe, if indeed there is one.  

Does that help any?



colin roald rational |  he opened up his mind and snapped out of the groove
   romantic mystic   |  he saw both sides of everything and found he could
  cynical idealist   |    not move.                    -- james mcmurtry
Newsgroups: rec.arts.sf.science
From: pksuk@rodan.acs.syr.edu (Peter K. Suk)
Subject: Re: WASTE HEAT
Organization: Syracuse University, Syracuse, NY
Date: Thu, 10 Dec 92 21:55:03 EST

In article <Byz54n.Eyn@bunyip.cc.uq.oz.au> 
scooper@kepler.physics.uq.oz.au ( Steven Cooper ) writes:

>rob@hoster.eng.ohio-state.edu (Rob Carriere)
>in article <1992Dec3.053440.13735@ee.eng.ohio-state.edu> writes:
>
>>scooper@kepler.physics.uq.oz.au (Steven Cooper) writes:
>
[stuff about how to sneak up on a system deleted]
>
>>What?! Inter system warfare? What a silly concept. Let's assume our
>>assailants are silly for the purposes of the argument...

Of course, Steve!  Space warfare is pointless!  (It's a fact!  :)

>Since you've come from another system you will be moving relativistically 
>( unless you're unusually patient ). 

Space warfare will probably take generations.

>my two cents worth here.
>
>My original comments about stealth were actually concerned more with 
>interplanetary stealth rather than interstellar. Maybe a scaled down version 
>of the above manouvre might still work ( assuming the sentinels are asleep ).

You and those ice-cream licking sentinels!  Those check-writing, AI,
IR-telescope-looking, waterlogged sons of Baal are going to save
everything, right!?  WRONG!  I'm gonna BLOW THEM UP!  :)

*maniacal laughter!*

But seriously now, wouldn't they be the first target?

	--Peter Kwangjun Suk



Newsgroups: rec.arts.sf.science
From: pksuk@mothra.syr.EDU (Peter K. Suk)
Subject: Re:  WASTE HEAT
Organization: Syracuse University, Syracuse, NY
Date: Sat, 12 Dec 92 01:32:44 EST

In article <1992Dec10.051646.11715@ucselx.sdsu.edu> 
maxc0452@ucselx.sdsu.edu (Legene) writes:

>>>In case you do want to do that, though, you can (mostly) avoid showing your
>>>tailpipe by obliquely overshooting your destination and then braking on the
>>>far side.  
>>>
[deleted]
>     You might also want to use the magnetic field of a gas giant in
>the target system for a bit of added deceleration and/or course
>deflection without emitting a lot of heat.  

My first impulse with this is: NO WAY.  At such extreme angles to the
ecliptic, your delta-V is going to be HORRENDOUS.  Besides, if you
just arrived from another system, you probably have a whole bunch of
delta-v left over from that.  But if you can show me wrong, then 
throw those calculations out there.

>     At first I was going to suggest aerobraking in a gas giant's
>atmosphere, on the far side of the planet from any observers.  But I guess
>after that the ship would be emitting quite a bit of heat.  

You could ditch the aero-shell in the planet's atmosphere.  A thermos-bottle
arraangement would keep you from radiating.  However, an advanced solar
civilization will have settlements around its gas giants.

>Of course, if it did this it would, maybe, be able to get some
>hydrogen for fuel more easily than with an interstellar ramscoop.
>They might have to turn off such a ramscoop before reaching the target
>system anyway -- those things are apt to have quite a bit of strength
>over a large volume, I'd imagine.

If you're going to be either 1) going full tilt into the system or 2)
going at an extreme angle, then any such contact with an atmosphere
will be liable to release phenomenal amounts of energy.  Anything made
of normal matter would rapidly learn about the joyous plasma phase.

Of course, some would say that ramscoops are hoky.  (Like me.)  But
in principle they are as reasonable as hyper-efficient drives.  Just
another case of aesthetics here.

	--Peter Kwangjun Suk
From: nbull@access.digex.com (Nicholas Bull)
Newsgroups: rec.arts.sf.science
Subject: Title/author?? (please help me remember)
Date: 18 Dec 1992 14:45:24 GMT
Organization: Express Access Online Communications, Greenbelt, MD USA
Distribution: usa
NNTP-Posting-Host: access.digex.com

Dear sci-fi readers,

I'm trying to remeber the title &/or author of a sci-fi novel I
read 20 years ago, when I was about 12.  I kind of remember the
plot:

Location: Earth (maybe) or a planet somewhere.  There are two
cities, one which specializes in Science and the other in
Art--but the two cities don't know about each other.  I think the
action starts in the Art city.

Main characters: A young man (or oldish boy--maybe 14-18 yrs old)
and an old man.  The old man is sort of a mayor of the city but
also sort of like the grand wizard of the city.  The young man is
a bright kid who sort of becomes the old man's apprentice.

There is a statue of the founder of the city; the founder is
pointing down towards some sort of mosaic of tiles around the
base of the statue.  Somehow the young man figures out that the
tile the statue is pointing at controls a door which opens onto a
subway-type system.  As it turns out, the subway is connected to
the other city (which may be underground???).  The young man
makes the journey to the other city.  Maybe he falls in love with
a young woman there, I can't remember.  Anyway, the two cities
Need Each Other for some reason which I have forgotten.  Of
course, each is suspicous of the other so it takes the young
man's idealistic naivetee to bring them together.  Presumably all
live happily ever after.

I read this around the same time as I read the Foundation Trilogy
(back when it was one), the Cities in the Sky books, and Earth
Abides.  Guess that doesn't mean it came out at the same time,
though.

I appreciate any help anyone can give me. 

Newsgroups: rec.arts.sf.science
From: bucknerb@bnr.ca (Brent Buckner)
Subject: Re: Time Travel and Causality Violation
Organization: Bell-Northern Research, Ontario, Canada
Date: Fri, 18 Dec 1992 16:58:16 GMT

In article <1992Dec18.154730.15628@porthos.cc.bellcore.com> ccw@prefect.cc.bellcore.com (wood,christopher) writes:
>
>My favorite time paradox is this one:  One builds a time machine, of any
>sort.  It could have a receiver and a transmitter if you like.  One
>gathers together a group of people, and some unique object.  One
>announces that at precisely 8:00, one will put the unique object into
>the time machine, set to go back in time half an hour.  At 7:30, if an
>object emerges from the time machine, one destroys the time machine and
>the unique object.  Now what happens?
>

In the parallel universes scheme, there are two resulting universes.
In Universe 1, at 7:30 you received no object, so you put the
object into the time machine.  In Universe 2, at 7:30 you received
an object, so you destroy the time machine and the object.

In the single-universe no-paradox scheme, you do not receive
the object at 7:30.  When you try to send the object at
8:00 you fail.   

-- 
at Bell-Northern Research
voice:        (613) 765-2739
Canada Post:  P.O. Box 3511, Station C, Ottawa, Canada, K1Y 4H7
I do not claim that BNR holds these views.
From: mt90dac@brunel.ac.uk (Del Cotter)
Newsgroups: rec.arts.sf.science
Subject: Re: Territorial Disputes
Date: 17 Dec 92 18:20:08 GMT
Organization: Brunel University, West London, UK

In article <1992Dec15.141750.2877@cs.rochester.edu> Paul Dietz writes:
>Here on earth, empires collided because they became possible at about
>the same time.  Fundamentally, this is because everyone is of the same
>species, the evolution and spread of which synchronized the clocks, so
>to speak.  In the galaxy, however, different empires will start at
>wildly different times.  Stories that assume everyone is at a low
>level, or is expanding all at once, are just too implausible.  There
>is no longer any good excuse to ignore the Fermi Paradox.
>
>Moreover, on a long time scale, stars move!  The average random
>velocities of stars in our neighborhood is about .01% of the speed of
>light.  In 10 million years, stars will separate by about 1000 light
>years.  In 1 billion years, by 100,000 light years: about the size of
>the galaxy.  Some stars travel an order of magnitude faster than
>this.  So even if empires do collide, their boundaries will get
>progressively fuzzier.

I've got a paper on this.

Author:  Martyn J. Fogg

Title:   Temporal Aspects of the Interaction among the First Galactic 
		 Civilisations: The "Interdict Hypothesis"

Journal: ICARUS _69_, 370-384 (1987)

Martyn describes a simulation he ran in which the rate of birth of 
civilisations is once every thousand years and the proportion of
civilisations which undertake interstellar flight is one in a hundred.
A constant speed of expansion (the 'wavespeed') is assumed for all civs.
For all wavespeeds chosen, the galaxy is filled before the formation
of the Solar System.  For none of the wavespeeds chosen (the highest
being 0.1c) is this done by a single civ.  After saturation of the
galaxy, differential rotation smears the 'empires' out so that the
distribution of intelligence becomes increasingly well-mixed.  The
inhabitants of a saturated galaxy necessarily agree, in the interests
of stability, on certain conventions, one of which is to set aside the
small number of stars formed in the last five billion years (~0.6%) as
'wilderness preserves' (the old 'Zoo Hypothesis').

I don't buy it myself, but it does seem to fit in with Peter's ideas of
inter-species peace and harmony.
-- 
 ',' ' ',','  |                                                  |  ',' ' ',','
   ', ,','    |       Del Cotter       mt90dac@brunel.ac.uk      |    ', ,','  
     ','      |                                                  |      ','    
Newsgroups: rec.arts.sf.science