HDTenEightyP/NetNews huggingface dataset:
From: cs92dy@cen.ex.ac.uk (D.Young)
Newsgroups: rec.arts.sf.science
Subject: Energy efficient time travel
Date: 23 Nov 92 15:20:14 GMT
Distribution: rec.arts.sf.science
Organization: Computer Unit. - University of Exeter. UK


	Having recently seen a discusion of the use of time travel as a
means of teleportation I can now present you with an energy eficient means of
time travel (sorry, uni-directional only).  This revalation was given to me,
by whichever deity is having a go a ruling the world today, duing a Languages and Programming lecture.

	It was commented that time passes more quickly than expected while
debugging C++.  Further discusion among students reveals that this is a
frequently observed phenomenon and is apparently not an artifact of the 
measuring device (human beings).  It has been observed that during the
debugging of C++ programs the programmer experiences a time dilation of
magnitude determined by the inverse square of the distance of the deadline.
i.e. if a programmer is working in a terminal room for a percived time of one
hour, depending on the deadline by which their program must be completed
a period of three to four hours may pass in the real world.  In extreme cases
when the program is badly misfunctioning within an hours of the hand in date 
programmers experince more severe effects, for example doing one hours worth
of debugging in a 24hour session in front of a terminal.

	Thus it would appear that is the crew of a starship could be set
a mamoth programming task which was ungently required to be finished by a
point in time around 10 minutes hence (the actual time by which they must
finish could be arranged so as to maintain a distance of 10 minutes from
present) they could be transported over many light years without expensive
cryogenic freezing or acceleration the ship to relatavistic velocities.

	Does any one else out there a) notice the phenomona described,
				    b) consider it feasible?

--
    _/_/_/   _/     _/   
   _/    _/ _/     _/    "All the important lessons in life are learned
  _/    _/   _/_/_/      just a few seconds too late to be really useful."
 _/    _/     _/
_/_/_/       _/
-- 
    _/_/_/   _/     _/   
   _/    _/ _/     _/    "All the important lessons in life are learned
  _/    _/   _/_/_/      just a few seconds too late to be really useful."
 _/    _/     _/
Newsgroups: rec.arts.sf.science
Subject: Re: Sci-Fantasy Weapons (Was: Re: Weapons systems?)
From: "Andrew C. Plotkin" <ap1i+@andrew.cmu.edu>
Date: Thu, 19 Nov 1992 11:09:24 -0500 
Organization: School of Computer Science, Carnegie Mellon, Pittsburgh, PA

Excerpts from netnews.rec.arts.sf.science: 18-Nov-92 Re: Sci-Fantasy
Weapons (Wa.. Joel Upchurch @upchrch.U (1246)

> You didn't read the story closely. The ball was orbiting 1200 miles up
> or about 200 times closer than moon is to the earth. If I recall
> correctly tides are an inverse fourth power relationship of distance.

Inverse cube. (Tidal force is produced by the difference in the strength
of gravity at various locations; so it is the derivative of an inverse
square, which is an inverse cube.)

--Z

"And Aholibamah bare Jeush, and Jaalam, and Korah: these were the borogoves..."
Newsgroups: rec.arts.sf.science
From: treitel@gracie.IntelliCorp.COM (Richard Treitel)
Subject: Re: Whimsical 'flat Earth' comments
Date: 18 Nov 92 22:21:57 GMT
Organization: preferably none

In article <1992Nov17.200401.23463@ncsu.edu>, tsjenki@eos.ncsu.edu (TIMOTHY SCOTT JENKINS) writes:
|> I was thinking that while a disk shaped plannet is not likely to 
|> exist in the real world, what about a planet that is only roughly spherical?

Y'guys can check out "Mission of Gravity" by Hal Clement.  Try to find the
edition that includes the article where he explains how he got the idea.
Briefly, it's a superJovian planet with a condensed-matter core and such
a short day that it bulges *far* more at the equator than Jupiter.  He has
gravity varying by two orders of magnitude between equator and poles.

		- Richard

P.S. there's nothing whimsical about Clement's physics {:-|
Newsgroups: rec.arts.sf.science
Subject: Re: FTL
From: morgan@arc.ab.ca (Sean Morgan)
Date: 16 Nov 92 17:11:05 MDT
Distribution: world
Organization: Alberta Research Council

In article <BCR.92Nov13121443@hpl3sn02.cern.ch> bcr@cernapo.cern.ch (Bill
Riemers) writes:
                                       ^^^^
>If negative matter does exist, you are going to have a hard time finding
>a large enough chunk of it to build your ship...

You don't try to find it, you make it.  Just give a few gigabucks to those guys
at CERN (see ^^^^)...

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

Newsgroups: rec.arts.sf.science
From: cfc6418@rigel.tamu.edu (chuck)
Newsgroups: rec.arts.sf.science
Subject: Re: Sci-Fantasy Weapons (Was: Re: Weapons systems?)
Summary: Feasible?  We're not even trying, here.
Keywords: infeasible space weapons kill KILL
Date: 17 Nov 92 15:13:00 GMT
Article-I.D.: rigel.17NOV199209131117
Followup-To: rec.arts.sf.science
Organization: Texas A&M University, Academic Computing Services
News-Software: VAX/VMS VNEWS 1.41

In article <1992Nov14.121743.22969@newstand.syr.edu>, pksuk@mothra.syr.EDU (Peter K. Suk) writes...
>----- wolfone@ccwf.cc.utexas.edu (Patrick Chester) writes:
> 
>> max@west.darkside.com (Erik Max Francis) writes:
>>]I've been thinking about combat in space, and am wondering if anyone has 
>>]come up with any novel weapons/delivery systems.
> 
>[Stuff deleted]
> 
>>Obligatory anime rip-offs:
>>      -Minovski Particle generator? :)
>>      -Beam Sabers :)
>>      -Wave Motion Gun :)
> 
>For those of us not so well versed in anime, what _is_ a Minovski Particle
>generator?  What is it's explaination or basis?  Your smileys make it likely
>that lots of folks reading won't like the idea, but, goddamn it, I'm 
>curious.  (Also, the reactions might be amusing.;) 
>What do you mean by 'Beam Saber?'  (Same stuff applies as above.)
> 
These two apply to the GUNDAM sieries, A Minovski particle is a radar adsorbing 
particle used in the stories to explain why radar and guided weapons don't work
(plot device, no guided weapondry)  The beam saber was a varation on the 
particle gun, it used an emmiter and a powerfull magnet to create a sword
shaped field of highly charged particles.

-------------------------------------------------------------------------------
Thantalos- aka Chuck
breeder of the fluffy rabits from hell, maker of the holy handgrnades of 
antoth, and the AGGIE FROM HELL!
-------------------------------------------------------------------------------
Newsgroups: rec.arts.sf.science
From: pciszek@nyx.cs.du.edu (Paul Ciszek)
Subject: Re: Hopping from place to place
Organization: University of Denver, Dept. of Math & Comp. Sci.
Distribution: rec
Date: Tue, 24 Nov 92 03:11:06 GMT

Well, the nice thing about literally *hopping* from place to place is that
the reaction mass, namely the moon, is provided for free.  This should
figure more heavily in your "cost" than energy, since limitless energy
can be obtained from solar panels, while gasses and liquids will be too
precious to vent into the vacuum.

And if your hopper contains an elastic energy-retention device, you could
get by with even less energy consumption.  Kangaroos are remarkably
effecient this way.


Paul Ciszek pciszek@nyx.cs.du.edu | When planning for posterity, we ought to
                                  | remember that virtue is not hereditary.
                                  |     --Thomas Paine
Newsgroups: rec.arts.sf.science
From: neufeld@helios.physics.utoronto.ca (Christopher Neufeld)
Subject: Re: Weapons systems?
Keywords: high-G space weapons
Organization: University of Toronto Physics/Astronomy/CITA
Date: Mon, 23 Nov 1992 16:14:47 GMT

In article <1992Nov22.120640.13084@newstand.syr.edu> pksuk@mothra.syr.EDU (Peter K. Suk) writes:
>
>What if you built an entire warship around this principle?  You could
>cool the entire thing down to a few degrees K.  If everything is 
>horrendously efficient, then you stay cool for a while.  No radiators
>shouting, 'Hey You!  Missle!  I'm over here!'  
>
>So, is this thermodynamically legal?
>
   Yes, briefly. Not in the steady state. Your ship will be trying to
generate heat, if for no other reason than the 100 watt space heaters
which represent each human being. You'd have to carry your cold sink
around with you. A block of material with a high heat capacity and a low
temperature would be ideal, but heat capacities generally fall rapidly
with temperature, so you probably accept a higher temperature cold sink
rather than designing the system for millikelvin startup temperatures.
Once the cold sink warms up past the average temperature of the ship
around it the efficiency of the system goes down in a hurry and you have
to pump more and more energy into the cold sink for each joule of heat
you steal from the ship. Think of it as mounting the radiators on the
inside of your ship and putting something around them to store the heat.
Oh yes, you'll have to dump that heat load to space some time later.
   If you're trying not to radiate thermally you'll have a hard time
applying thrust. If you want to pretend to be a thirty degree rock
(roughly the mean temperature of the background within the galaxy (the
stars heat things up above the three K we all know and love)), you'll
have little choice of thruster systems. Cold helium or hydrogen thrusters
would work. Rock-tossing reaction jets could probably be designed to
radiate minimally. Ion drives, I expect, are out. Those newly neutralized
atoms shooting out of the nozzle are going to be hot and probably not in
the ground state. You'll have transition lines from cesium (or whatever
you choose as your atomic species) standing out like a banner at the
nozzle.

-- 
 Christopher Neufeld....Just a graduate student  | Don't let your mind
 neufeld@helios.physics.utoronto.ca    Ad astra  | wander -- it's too little
 utzoo.utoronto.ca!generic!cneufeld              | to be let out alone.
 "Don't edit reality for the sake of simplicity" |
From: max@west.darkside.com (Erik Max Francis)
Newsgroups: rec.arts.sf.science
Subject: Re: Sci-Fantasy Weapons (Was: Re: Weapons systems?)
Keywords: tidal forces Niven
Date: 21 Nov 92 04:23:50 GMT
Organization: The Dark Side of the Moon +1 408 245 SPAM

pcm@cs.brown.edu (Peter C. McCluskey) writes:

> The mass determines the tide at any given radius from the center of
> the object, but the density determines how small that radius can get,
> and the tides are inversly proportional to the cube of that radius
> (if we ignore the effects of General Relativity).

Oh, yes, I'm aware of that.  We were actually referring to the tidal 
effects on bodies of water from a neutronium sphere in orbit of largish 
mass.  There the water tides are important (tides on the Earth), but the 
tidal effects on you are not (you're not going to feel stretched in any 
particular axis :-).

Actually, I realized later that I misinterpreted Niven's meaning.  The 
tides happen extraordinarily fast; it did not occur to me that the 
neutronium sphere could have been in a lower (thus faster) orbit.  So I 
just misinterpreted his meaning.  (I _was_ quite young when I read it for 
the first time, so when I got misled, it must have been hard to weed that 
out.)

----------
Erik Max Francis   Omnia quia sunt, lumina sunt.  Coming soon:  UNIVERSE _ | _
USmail:  1070 Oakmont Dr. #1 San Jose CA 95117  ICBM:  37 20 N  121 53 W _>|<_
UUCP:  ..!apple!uuwest!max   Usenet:  max@west.darkside.com   464E4F5244   |
Newsgroups: rec.arts.sf.science
From: griffin@sage.cc.purdue.edu (Zack Thompson)
Subject: Re: Hopping from place to place
Organization: Purdue University Computing Center
Distribution: rec
Date: Mon, 23 Nov 1992 21:37:09 GMT

In article <MARTINC.92Nov23120127@hatteras.cs.unc.edu> martinc@hatteras.cs.unc.edu (Charles R. Martin) writes:
>One of those little points that somebody like Ctein would certainly
>catch if I get it wrong....
>
>Say you're travelling point to point on a vaccum planet like the Moon.
>Is it more or less energy efficient -- make that "delta-vee efficient"
>-- if you
>
>(a) do a helecopter-like hover on your jets (seems unlikely) and move
>    across the surface at a constant altitude
>
>(b) do many short hops ballistically
>
>(c) make one big ballistic jump: burn, wait, do a jet landing.
>
>... and in the interest of building up the physics education I should
>have had but avoided because I was a philosophy major, why?
>
>My *intuition* is that c is cheaper than b which is cheaper than a.
>--
>		Charles R. Martin/(Charlie)/martinc@cs.unc.edu
>     Dept. of Computer Science/CB #3175 UNC-CH/Chapel Hill, NC 27599-3175
>	    3611 University Dr #13M/Durham, NC 27707/(919) 419 1754
>     "Oh God, please help me be civil in tongue, pure in thought, and able
>      to resist the temptation to laugh uncontrollably.  Amen." -- Rob T


Howdy-

ZT here.

Choice (B) might be cheapest if you can do it this way--
  Do a short hop, and have a hard point to land on (ie rock not dust),
  Then when you come down, DON'T slow yourself down with jets, instead,
  let your tremendously efficient shock absorbers (shock storers,
  actually) store up most of the energy left over, and then, with a 
  small jet assist BOING!  Sort of like what your leg tendons do.  And
  with the moon's 1/6G then this ought to get REAL efficient and 
  reasonably smooth.  The only problem would be landing in dust... but
  I guess you still have the jets.  Problems, anybody?
Newsgroups: rec.arts.sf.science
From: dietz@cs.rochester.edu (Paul Dietz)
Subject: Re: "Reactionless" Drive (Was: Re: Weapons systems?)
Keywords: high efficiency drives
Organization: University of Rochester
Date: Sat, 21 Nov 1992 13:52:10 GMT

In article <1992Nov19.141338.10252@newstand.syr.edu> pksuk@rodan.acs.syr.edu (Peter K. Suk) writes:
>In article <1992Nov19.025917.23404@newstand.syr.edu> I wrote:

>>In the March 1988 _Analog's_ "Science Fact" column, Thomas Donaldson put
>>together information on schemes for converting energy from fusion
>>reactions.  One of these devices he calls a "Taussig Generator" after
>>its inventor...
>
>>The claimed efficiency of this device is 75%.  It could also extract energy
>>from a matter/antimatter reaction.  We could use this device to power a 
>>free electron laser.  These have a theoretical efficiency of 65%.
>>(Scientific American, forget when.)  This gives us 48.75% of the energy
>>in our fuel expressed as photons all moving in the same direction.
>
>Let me correct myself.  This is wrong since much of the energy can be
>expressed as neutrinos.  (One-half?)  The following is also wrong.



Antimatter annihilation does not produce (many) neutrinos directly.
Instead, it produces annihilation products like charged pions whose
decay produces neutrinos (muon and kaon decay can also produces
neutrinos).

*If* those charged pions interact with nucleons before decaying,
their energy can be extracted in useful form without production
of neutrinos.

BTW, the use of a fancy generator isn't really necessary.  Just dump
the annihilation products into a heavy shield and extract the energy
as heat.  Then radiate the heat backwards, using a big mirror to
collimate it.  Thermal radiation has momentum just like gammas.

The thrust is miniscule, of course, but the Isp is high.
Thrust can be made higher by using a large radiator composed
of very small refractory particles.  The limit there would be
set by the need to keep the temperature low enough to prevent
the particles from evaporating.

One complication would be that the heavy shield degrades as its nuclei
are shattered by annihilation products (charged pions, being strongly
interacting, are quickly absorbed in dense matter).  This will make
neutrons that get absorbed into other nuclei, which decay, and are
themselves broken up, and so on.  Ideally things can be arranged so
that nucleons get cycled through many such reactions before they are
lost.  Some of the fragments could be recycled for reaction with the
antimatter.

	Paul F. Dietz
	dietz@cs.rochester.edu



Newsgroups: rec.arts.sf.science
From: pksuk@mothra.syr.EDU (Peter K. Suk)
Subject: Re: "Reactionless" Drive (Was: Re: Weapons systems?)
Keywords: high efficiency drives
Organization: Syracuse University, Syracuse, NY
Date: Sun, 22 Nov 92 11:17:51 EST

In article <1992Nov21.135210.26111@cs.rochester.edu> 
dietz@cs.rochester.edu (Paul Dietz) writes:

>In article <1992Nov19.141338.10252@newstand.syr.edu> 
>pksuk@rodan.acs.syr.edu (Peter K. Suk) writes:
>>In article <1992Nov19.025917.23404@newstand.syr.edu> I wrote:
>
>>>In the March 1988 _Analog's_ "Science Fact" column, Thomas Donaldson put
>>>together information on schemes for converting energy from fusion
>>>reactions.  One of these devices he calls a "Taussig Generator" after
>>>its inventor...
>>
>>>The claimed efficiency of this device is 75%.  It could also extract energy
>>>from a matter/antimatter reaction.  We could use this device to power a 
>>>free electron laser.  These have a theoretical efficiency of 65%.
>>>(Scientific American, forget when.)  This gives us 48.75% of the energy
>>>in our fuel expressed as photons all moving in the same direction.
>>
>>Let me correct myself.  This is wrong since much of the energy can be
>>expressed as neutrinos.  (One-half?)  The following is also wrong.
>
>Antimatter annihilation does not produce (many) neutrinos directly.
[deleted]

Thanks for the info.  This is why I read this group.

>BTW, the use of a fancy generator isn't really necessary.  Just dump
>the annihilation products into a heavy shield and extract the energy
>as heat.  Then radiate the heat backwards, using a big mirror to
>collimate it.  Thermal radiation has momentum just like gammas.  

No kidding :}   Is your newsreader cutting off my posts?  
(I admit they're a little on the long side.  But that's MY idea!)
(No ill will.)

>The thrust is miniscule, of course, but the Isp is high.
>Thrust can be made higher by using a large radiator composed
>of very small refractory particles...[deleted]

Why would this increase your thrust?  Is this a scheme for utilizing
more reactions / unit time?  Explain.  (I'm very curious.)
And, what are the units for Isp?  I know it's a measure of efficiency.
Exactly what is it?

>One complication would be that the heavy shield degrades as its nuclei
>are shattered by annihilation products (charged pions, being strongly
>interacting, are quickly absorbed in dense matter)...[deleted]

The same Donaldson article I referred to mentioned the use of 'active'
materials in reactor construction.  He used wood and bone as examples
of materials which would constantly renew themselves.  The material for
reactors would utilize nanotech or be heavily genetically engineered.  
(This is not as far out as it sounds.  Read the article.  _Analog_  
Mar 1988.)

Of course, it seems to me that the penalty incurred by needing to carry
around shielding material reduces the efficiency.  (Though this thing is
_still_ phenomenal.  But would it be able to overcome friction with
interstellar hydrogen?)

	--Peter Kwangjun Suk
From: dl91@ecs.soton.ac.uk (D Lewis)
Newsgroups: rec.arts.sf.science
Subject: Philadelphia Experiment (Project Rainbow)
Date: 18 Nov 92 13:09:38 GMT

Re: stcak@cc.newcastle.edu.au

This information comes from the book "The Philadelphia Experiment -
Project Invisibility" by Charles Berlitz and William Moore.

In October 1943 at the Philadelphia Naval Dockyards an experiment
utilising the Unified Field Theory of Dr Albert Einstein was carried
out on a destroyer escort. The ship was the DE 173, sold at a later
date to the Greek navy. Using naval degaussers, a magnetic field was
projected around the ship, which disappeared in a green mist until
only the impression of the ships hull could be seen in the water.
The DE 173 was reported to have appeared at the Norfolk Naval
Dockyards and to have subsequently disappeared. 
 The experiment was a success, except for the effects on the crew, who
seemed to have kept the ability to disappear. One crewman walked
through the wall of his house and vanished, a few others disappeared
in a Philadelphia bar, much to the waitress' consternation.
 The experiment was first heard about in correspondance to one Morris
K. Jessup, who had written a book entitled "The Case for the UFO". The
letters (four in total) were from a Carlos Allende (sometimes Carl
Allen) who claimed to have witnessed the experiment from the deck of
the S.S. Andrew Furuseth (the boat on which Allende was serving). The
letters contained detailed information on the Philadelphia Experiment,
much of which was corroborated by other witnesses in the book. 

- Well, that's the most important information. Even if it is all
bunkum as some think, it still makes for an excellent piece of sci-fi.

P.S. The reason the eexperiment hasn't been repeated (though some say
the Government was still carrying out experiments at least until 1976)
is that noone really understood what was going on.
From: klaus@diku.dk (Klaus Ole Kristiansen)
Newsgroups: rec.arts.sf.science
Subject: Re: Whimsical 'flat Earth' comments
Date: 19 Nov 92 13:24:42 GMT
Organization: Department of Computer Science, U of Copenhagen

djb6@ellis.uchicago.edu (Dennis Brennan) writes:

>Some bizarre things that occured to me:

>From time to time in speculative/escapist fiction of dubious
>hard-science merit authors create "flat" planets.  

>- How is day/night supposed to work?  Have any internally
>  consistent explanations been created?

Yes. Just have the sun circle the earth.

>-How about seasonal variation?

>-What about climate?  If, geometrically, the scheme consists of a plane
>and a point not on the plane, then some area of the plane is a heck
>of a lot closer to the sun than other parts.  Wouldn't it be hotter there?

That's easy. You see, the sun circles around an axes running parallel
to the line from the tail to the head of A'tuin. The earth rotates
around a vertical axes. The sun of course makes a circle a day, the
earth makes a rotation a year. A point near the edge will have summer
twice a year, when it is close to where the sun raises, and where it sets.
A point near the hub will have less seasonal variation.

Klaus O K
From: max@west.darkside.com (Erik Max Francis)
Newsgroups: rec.arts.sf.science
Subject: Re: Sci-Fantasy Weapons (Was: Re: Weapons systems?)
Date: 21 Nov 92 04:33:16 GMT
Organization: The Dark Side of the Moon +1 408 245 SPAM

"Andrew C. Plotkin" <ap1i+@andrew.cmu.edu> writes:

> Inverse cube. (Tidal force is produced by the difference in the strength
> of gravity at various locations; so it is the derivative of an inverse
> square, which is an inverse cube.)

Ah, that answers my question to him.  So typically is the "tidal force" 
measured as a force, a stess, a strain, or what?

----------
Erik Max Francis   Omnia quia sunt, lumina sunt.  Coming soon:  UNIVERSE _ | _
USmail:  1070 Oakmont Dr. #1 San Jose CA 95117  ICBM:  37 20 N  121 53 W _>|<_
UUCP:  ..!apple!uuwest!max   Usenet:  max@west.darkside.com   464E4F5244   |