HDTenEightyP/NetNews huggingface dataset:
From: wiml@milton.u.washington.edu (William Lewis)
Newsgroups: rec.arts.sf.science
Subject: Re: Niven's blunders (was:Superconductors + the 2nd law)
Date: 20 Aug 92 02:55:20 GMT
Article-I.D.: u.1992Aug20.025520.23337
Organization: University of Washington, Seattle

In article <1992Aug11.101042.16489@ccu1.aukuni.ac.nz> ecmtwhk@ccu1.aukuni.ac.nz (Thomas Koenig) writes:
>Has anyone compiled a list of Niven's non-deliberate blunders and
>other misconceptions?
>
>My list, off the top of my head, is:
>
>Rinworld stability (well, that's a classic; has anyone figured wether he
>got it right the second time round?)

  What is there to get wrong? He had an active control system (the
ramjets). Unless one could calculate that the ramjets wouldn't have enough
thrust, or something, but I think ramjets are too theoretical
to do that.

>Rotation in Neutron Star will kill Schaeffer (he owned up to that one
>himself).

  I've only ever heard vague hints about this one, never anything actually
explainingthe problem. What's the catch?

>Holograms: They cannot obscure any object which is before them in line
>of sight (Patchwork Girl comes to mind, when Gil walks through the
>projected moonscape, as does Dream Park and sequels).

  I've come to the conclusion that, in the Future(tm), someone will
invent a device which makes the air fluoresce or something, and
people will call the projected images "holograms" the same way we
call a microwave an oven, or semiconductor RAM "core". There
are just too many impossibilities attributed to holography, otherwise. =8)


-- 
email: wiml@u.washington.edu             |  Home:  Seattle, Washington   |
     (William Lewis)                     |  47 41' 15" N   122 42' 58" W | 
NeXTmail: wiml@ingalls.cs.washington.edu `-------------------------------'
        --*-- Member, Coalition to Preserve Semantic Vacuity --*--
Newsgroups: rec.arts.sf.science
Subject: Re: Human flight.
From: alanb@sdl.mdcbbs.com (Alan Braggins)
Date: 12 Aug 92 14:55:00 GMT
 udel.edu><1992Aug4.013239.3430@u.washington.edu><1992Aug4.121552.20143@genie.s
 lhs.udel.edu> <batwell.712959720@cunews><ins450m.713508003@aurora.cc.monash.edu.au>
Organization: Shape Data (Division of EDS), Cambridge UK
In-reply-to: ins450m@aurora.cc.monash.edu.au's message of Tue, 11 Aug 1992 04:40:03 GMT

>>>>> On Tue, 11 Aug 1992 04:40:03 GMT, ins450m@aurora.cc.monash.edu.au (T.F. Eccles) said:

> Um. There was also a book called "Windhaven" I think, I can't
> remember the author, where humans flew b/w settlements, by dropping
> off cliffs and gliding. The only supporting reason that they could
> do it there and not here, was a lower gravity.....but wouldn't that
> cause a thinner atmosphere?

They also had superior materials - they were using hang-gliders made from
the remnants of the crashed spaceship (including solar sail cloth for 
covering).

Why anyone built a solar sail strong enough to use in atmosphere is another
question...
--
Alan Braggins, Shape Data (A Division of EDS Ltd), Cambridge, UK +44-223-316673
   "Any technology distinguishable from magic is insufficiently advanced."
 "My employer does not necessarily share my views - but I'm working on it."
From: daynem@byron.u.washington.edu (Dayne Miller)
Newsgroups: rec.arts.sf.science
Subject: Re: Evolution under High Gravity
Date: 14 Aug 92 18:38:19 GMT
Article-I.D.: u.1992Aug14.183819.26517
Organization: University of Washington, Seattle

>}   Hello, I am interested in getting the net.consensus (as if there ever
>}is one) on the effects of living in a high gravity environment. I have noted
>}that in *most* SF (at least the I have read), humanoids who live on high
>}gravity worlds (relative to earth gravity anyway) are typically shorter,
>}stockier, and stronger.
>
>Add effects on living in LOW gravity, and cross-post to talk.origins.
>Velikovsites and Talbottians think that EARTH was once a low-g planet!

     It seems to me that there was a story in some anthology dealing with
representatives from a bunch of different planets being brought together
by some "superior" alien race to test their mettle in a competitive environ-
ment, or to fight a battle for them, or some such plotline. Anyway, the 
rep from the humans found that his chief rival was some dude from a high-
gravity world. His race was slightly shorter than the average human, but fairly thin, though quite strong. The single most notable effect of evolving in high
gravity, though, was shit-hot reflexes. The alien could move in a blur when
he wanted to. This makes sense, because in a high-gravity situation, acceler-
ation is much higher, and any evolved beings that deal with ballistics (such
as throwing rocks, swinging from trees, avoiding falling obstacles, etc.) 
would have to have the reflexes to deal with it.

     Anybody know what story this was?

     Dayne Miller
       daynem@u.washington.edu
From: swf@teradata.com (Stanley Friesen)
Newsgroups: rec.arts.sf.science
Subject: Re: Merpeople
Date: 19 Aug 92 19:37:40 GMT
Reply-To: swf@tdat.teradata.com (Stanley Friesen)
Organization: NCR Teradata Database Business Unit

In article <1992Aug18.102138.4220@aston.ac.uk> evansmp@uhura.aston.ac.uk (Mark Evans) writes:
|gapdrr@gsusgi2.gsu.edu (Daniel R T Rothman) writes:
|: bjgaed@bb1t.monsanto.com writes:
|: 
|: I don't believe this is the case. there are well documented instances
|: of smaller, mammal-like dinosaurs that appear to have come relatively
|: far along the intelligence ladder before getting squashed.
|
|How mammal like?
|The last I have heard the metabolic heat generating capacities of 
|dinosaurs are open to conjecture.

Not anymore.  or at least not if the latest results are confirmed by an
independent laboratory.

Just a few *weeks* ago a researcher announced what is essentially *conclusive*
evidence that *most* dinosaurs were endothermic (the more technical term
for 'warm-blooded').  [The only exception he found amoung the species he
checked was Camarasaurus - one of the big sauropod (brontosaur) type
dinosaurs].

Now, I would still quible with 'mammal-like', the dinosaurs with the highest
encephalization quotient were rather more *bird*-like than mammal-like.
(Actually that goes for all dinosaurs, but that that is irrelevant here).

Of course birds are endothermic also.
-- 
sarima@teradata.com			(formerly tdatirv!sarima)
  or
Stanley.Friesen@ElSegundoCA.ncr.com
Newsgroups: rec.arts.sf.science
From: ccw@prefect.uucp (26554-wood)
Subject: Re: Simultaneous events and frames of reference?
Reply-To: ccw@prefect.UUCP ()
Organization: Bellcore, Livingston, NJ
Date: Wed, 12 Aug 92 16:46:44 GMT

In article <drenze.713555927@icaen.uiowa.edu> drenze@icaen.uiowa.edu (Douglass J. Renze) writes:
>I guess I'm foggy on the whole thing about simultaneous events...so here's
>a question...
[description of synchronized clocks on Earth and Alpha Centauri exactly
right, and trimmed]

>Now, come X day, we both perform
>the same action...now, relative to our personal frames of reference, if
>we could somehow "see" each other, would we be performing the action at
>the same time?  I realize that, in my frame of reference, I'd be performing
>the action first (after all, the light cone of his action being performed
>won't reach me for what?  4+ years?) and vice-versa (and, of course, at
>some frame of reference exactly at the midpoint between the two of us) 
>we would be performing the actions simultaneously.

Yup you've got it.

>I guess what I'm also asking (in this case), is whether there is justification
>to choose a particular frame of reference over another.  

Pick the frame of reference that makes the math the easiest.  All
inertial frames of reference are equally valid.

>Peace,

>Doug


Chris



Chris Wood     Bellcore     ...!bellcore!prefect!ccw
                         or ccw@prefect.cc.bellcore.com
From: swf@teradata.com (Stanley Friesen)
Newsgroups: rec.arts.sf.science
Subject: Re: dragons were dinosaurs?
Date: 19 Aug 92 19:44:29 GMT
Reply-To: swf@tdat.teradata.com (Stanley Friesen)
Organization: NCR Teradata Database Business Unit

In article <auwen.714089675@starman> auwen@convex.com (John David Auwen) writes:
|I've always been curious about the origin of various dragon myths.
|I've always read that the dinosaurs were all dead by the time man
|walked the Earth.  But could some of them have survived longer?

Not that much longer.  60 million years is a *long* time, and the fossil
record for the last 5 MY or so is pretty good.  Dinosaurs are not something
we could have missed.

|Is this where the concept of dragons and sea monsters came from?
|
So, no, at least not in the way you mean.

Now there *is* a theory that these legends come from people finding *fossil*
*skeletons*, and mistaking them for recent skeletons, and thus supposing the
animal in question was to be found somewhere around.
(This is certainly a popular explanation for the Amerindian myth of the
Thunderbird).
-- 
sarima@teradata.com			(formerly tdatirv!sarima)
  or
Stanley.Friesen@ElSegundoCA.ncr.com
From: nickh@CS.CMU.EDU (Nick Haines)
Newsgroups: rec.arts.sf.science
Subject: Re: dragons were dinosaurs?
Date: 20 Aug 92 14:01:55 GMT
Organization: School of Computer Science, Carnegie Mellon University
Originator: nickh@VOILA.VENARI.CS.CMU.EDU

In article <Bt92J2.1Gp@teleride.on.ca> stevew@teleride.on.ca (Stephen M. Webb) writes:

   There is no concrete evidence that any dinosaurs have been alive for the
   past several hundered million years.  This isn't to say there haven't been
 	^^^^^^^^^^^^^^^^^^^^^^^^

about 65 million actually (if you define `dinosaur' as `one of the
large reptile species that didn't survive the mass extinction 65
million years ago')


   any, but a few hundred million years is a long time.  Humans have been 
   around in approximately recognizeable form for about 1 million years.
   The oldest known "civilization" is about 7,000 years old.
					    ^^^^^
Depends what you count as civilization. We have cave paintings going
back some 40,000 years, and tool-use somewhat further.

But yes, it's still completely implausible.

Nick
Newsgroups: rec.arts.sf.science
From: evansmp@uhura.aston.ac.uk (Mark Evans)
Subject: Re: Merpeople
Organization: Aston University
Date: Fri, 21 Aug 1992 10:20:52 GMT

swf@teradata.com (Stanley Friesen) writes:
: In article <1992Aug18.102138.4220@aston.ac.uk> evansmp@uhura.aston.ac.uk (Mark Evans) writes:
: |gapdrr@gsusgi2.gsu.edu (Daniel R T Rothman) writes:
: |: bjgaed@bb1t.monsanto.com writes:
: |: 
: |: I don't believe this is the case. there are well documented instances
: |: of smaller, mammal-like dinosaurs that appear to have come relatively
: |: far along the intelligence ladder before getting squashed.
: |
: |How mammal like?
: |The last I have heard the metabolic heat generating capacities of 
: |dinosaurs are open to conjecture.
: 
: Not anymore.  or at least not if the latest results are confirmed by an
: independent laboratory.
: 
: Just a few *weeks* ago a researcher announced what is essentially *conclusive*
: evidence that *most* dinosaurs were endothermic (the more technical term
: for 'warm-blooded').  [The only exception he found amoung the species he
: checked was Camarasaurus - one of the big sauropod (brontosaur) type
: dinosaurs].
: 
: Now, I would still quible with 'mammal-like', the dinosaurs with the highest
: encephalization quotient were rather more *bird*-like than mammal-like.
: (Actually that goes for all dinosaurs, but that that is irrelevant here).
: 
: Of course birds are endothermic also.

That would keep the bio-physists happy,
I think the mammal-like originaly refered to the marine types, which resembled
cetatarns in form.
-- 
-------------------------------------------------------------------------
Mark Evans                                   |evansmp@uhura.aston.ac.uk
+(44) 21 565 1979 (Home)                     |evansmp@cs.aston.ac.uk
+(44) 21 359 6531 x4039 (Office)             |
Newsgroups: rec.arts.sf.science
From: kuijt@umiacs.umd.edu (David Kuijt)
Newsgroups: rec.arts.sf.science
Subject: Re: merpeople
Date: 17 Aug 92 20:57:54 GMT
Organization: UMIACS, University of Maryland, College Park, MD 20742

Kathryn Roth Whitworth writes:

>Sharks have to move all the time, else their gills don't work and they die.

Old information.  That theory has been disproven by one of Jacques Cousteau's
groups within the last ten years or so.  In one of their recent (meaning
within the last ten years; not very recent) documentaries they show some
footage of sharks sitting stationary for hours in one place _without_
currents running new water past them to refresh their oxygen.  This
was in some sort of underwater caves.

David Kuijt



Newsgroups: rec.arts.sf.science
From: rob@watney.eng.ohio-state.edu (Rob Carriere)
Subject: Re: Superconductors
Organization: The Ohio State University Dept of Electrical Engineering
Date: Thu, 13 Aug 1992 07:08:03 GMT

In article <1992Aug12.155104.10111@odin.diku.dk> nomann@diku.dk (Ole Nomann Thomsen) writes:
>How about storing electricity in closed loops of superconducting wire?
>You could have a transformer where one coil is such a loop, and then 
>store/fetch the energy via the other coil.
>This might be a very effective battery, with short rechargeing(sp?) time,

(It's recharging.  This is English, the spelling is never what it should
 logically be.  :)

>big(?) capacity, and virtually no wear.
>
>Questions:
>  Could this work? (I know oh so little about electric engineering).
>  How much power is there "room for" in a closed loop of s.c.w.?

A superconductor is only a superconductor under some conditions.  That the
temperature has to be right is the most well-known one, but not the only one.
One of the other limits is current density, which would limit the amount of
power you can store in a given superconductor loop (of course, you can always
make the loop bigger and thicker and put it in Texas... :).  What the limit is
varies from material to material; I don't think it is high enough in any one of
them to make an effective battery, but I'm hardly a materials expert (ie,
anyone who knows better, please jump in.)  In addition to power limitations,
you also have the problem that your battery `leaks' in that you need power to
keep it cooled.  This pretty much kills the idea for any kind of long term
storage, unless they find a material that is superconductive at room
temperature.

In principle, though, you can do it.  In fact, in the late thirties there was
an experiment (in London if memory serves) where they observed a current going
around in a superconducting loop for several _years_ without noticable loss
(Loss in current, that is.  They did have to cool the aparatus to 4K for all
that time, taking considerably more energy than the loop contained).

SR
---


Newsgroups: rec.arts.sf.science
From: egl1@cunixf.cc.columbia.edu (Elizabeth G. Levy)
Subject: Re: Evolution under High Gravity
Reply-To: egl1@cunixf.cc.columbia.edu (Elizabeth G. Levy)
Organization: Columbia University
Date: Fri, 14 Aug 1992 02:38:29 GMT

Short.  Very short.

Actually, take a look at Forward's _Dragon's Egg_, about creatures
living on the surface of a neutron star (the ultimate in high gravity).

--
This is not a .signature
Newsgroups: rec.arts.sf.science
From: neufeld@helios.physics.utoronto.ca (Christopher Neufeld)
Subject: Re: Superconductors
Organization: University of Toronto Physics/Astronomy/CITA
Date: Wed, 19 Aug 1992 06:21:07 GMT

In article <NICKH.92Aug18193610@VOILA.VENARI.CS.CMU.EDU> nickh@CS.CMU.EDU (Nick Haines) writes:
>In article <Bt6yD6.AGn@helios.physics.utoronto.ca> neufeld@helios.physics.utoronto.ca (Christopher Neufeld) writes:
>
>
>	[hydro energy storage systems]
>
>>      Yes. I knew some had been approved for construction, but are there any
>>   which are actually being used for that purpose by utilities at the
>>   moment, as opposed to prototype or proof of concept plants?
>
>Yes, there are. There's at least one in Wales, and I think at least
>one other somewhere else in Britain. Actively used to store overnight
>excess from the National Grid.
>
   OK, I goofed. I figured I would have heard about them coming on line,
since I did hear about them being planned and approved, but I missed out
on the activation of these systems. I hear in email that there's even one
just a couple of hours from here near Niagara Falls. By any definition
they are in widespread use. Well, I don't get out much...


-- 
 Christopher Neufeld....Just a graduate student  | Confidence is the feeling
 neufeld@helios.physics.utoronto.ca    Ad astra  | you have before you
 utzoo.utoronto.ca!generic!cneufeld              | understand the situation.
 "Don't edit reality for the sake of simplicity" |
From: advax@reg.triumf.ca (A.Daviel)
Subject: Holograms (was Re: Niven's blunders)
News-Software: VAX/VMS VNEWS 1.41    
Organization: TRIUMF: Tri-University Meson Facility
Date: Fri, 21 Aug 1992 01:02:00 GMT

In article <1992Aug20.025520.23337@u.washington.edu>, wiml@milton.u.washington.edu (William Lewis) writes...
> 
>  I've come to the conclusion that, in the Future(tm), someone will
>invent a device which makes the air fluoresce or something, and
>people will call the projected images "holograms" the same way we
>call a microwave an oven, or semiconductor RAM "core". There
>are just too many impossibilities attributed to holography, otherwise. =8)

I recall a neat device from school, used to measure the mass of the electron 
or some such, which consisted of a glass sphere with an electron gun between 
two coils. There was a gas at low pressure, which fluoresced where the beam 
struck it. You could see the electron beam going in a circle, and measure its 
radius as a function of magnetic field. If you turned the tube slightly the 
beam would trace a helix. Of course, it was monochrome and you couldn't put a 
picture on it.

Is it possible to make a display on the following lines ?
You have some gas with 3 energy levels, say 0, 1 & 2. You scan in X with a 
infrared laser beam that pumps it from 0 to 1, and scan in Y with a beam that 
pumps from 1 to 2. Then if the molecule decays from 2 to 0 in one step it 
emits a visible light quantum.

Not sure if I'd want to step into the display though, being scanned by all 
those high-powered lasers... 8)[

Been a while since I did quantum theory..
Andrew
Newsgroups: rec.arts.sf.science
From: m23364@mwunix (James Meritt)
Subject: Re: Niven's blunders (was:Superconductors + the 2nd law)
Organization: MITRE Corporation, McLean VA
Date: Wed, 12 Aug 1992 12:41:19 GMT

In article <MARTINC.92Aug11214645@grover.cs.unc.edu> martinc@grover.cs.unc.edu (Charles R. Martin) writes:
}In article <1992Aug11.101042.16489@ccu1.aukuni.ac.nz> ecmtwhk@ccu1.aukuni.ac.nz (Thomas Koenig) writes:
}
}   neufeld@helios.physics.utoronto.ca (Christopher Neufeld) writes:
}
}   >   Niven strikes again. Superconductors, at least the ones we know about,
}   >are *poor* conductors of heat relative to the normal metals around.
}
}Not to be petty or anything, but in Mote in Gods Eye (at least -- does
}it show up anywhere else?), the heat-superconductor is quite
}specifically described as a HEAT superconductor, and is a wonderous
}thing for just that reason.  The 2nd Empire is quite aware of electrical
}superconductivity. 

There was a superconductor grid embedded in the Ringworld to distribute heat.
From: rob@volga.eng.ohio-state.edu (Rob Carriere)
Newsgroups: rec.arts.sf.science
Subject: Re: Superconductors
Date: 20 Aug 92 03:12:54 GMT
Article-I.D.: ee.1992Aug20.031254.7581
Organization: The Ohio State University Dept of Electrical Engineering

In article <Bt8KAo.IsE@helios.physics.utoronto.ca>
neufeld@helios.physics.utoronto.ca (Christopher Neufeld) writes: 
>   We're arguing semantics at this point. What is 'electrical energy'? It
>isn't the kinetic energy of the electrons in the wire, it isn't really
>even something you can specifically Poynt at [I know, groan].

Yes, we are.  By the way, I was in an overly snappish mood last night
(something to do with a day-long run which someone had seen fit to abort for
me.) and I apologize to you and the other person I followed up to (I lost the
ref, we expire fast around here) for the un-called for tone of voice.

As for the semantics, by your definition (assuming I understand it correctly),
we would have to say that the gastank of your car contains mechanical energy.
This sounds weird.

>   "It is impossible to store mechanical energy in water above a dam
>because mechanical energy is 1/2 m * v^2 and the velocity is zero once
>you've let it sit. The energy is therefore stored in the gravitational
>field." I maintain that this is a somewhat artificial separation, since
>you couldn't store the energy in the gravitational field without a mass,
>and as such it is a misleading distinction.

Well, one man's misleading is another's guiding light... :-)  When you speak
of storing mechanical energy in the water of a reservoir, the first that comes
to _my_ mind is a mental image of a vast, roiling whirlpool in the middle of
the reservoir, whipping up foam in all directions...  So to me, not making the
distinction is misleading.

SR
---
Newsgroups: rec.arts.sf.science
From: myboy@casbah.acns.nwu.edu (Lewis Murtaugh)
Subject: Re: DNA garrotte
Organization: Northwestern University, Evanston Illinois.
Date: Tue, 18 Aug 1992 21:09:51 GMT

In article <1992Aug18.111420.5720@crc.ac.uk> mlush@crc.ac.uk (Mr. M.J. Lush) writes:
>
>      
>  	Can anyone give an estermate of the breaking strain of DNA,
>in say N/cm^2?
>
>        The reason I ask is that I'm working on a race of occult
>assassins who kill useing a garrotte made from the victims own DNA,
>and I want to know if there's enough in the human body (assuming it
>can be non-destructivly removed useing foul means that Mankind-was-
>not-ment-to-know),  or will they have to steal some cells and do
>a bulk culture.
>
>
>-- 
>Michael
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>NPC rights activist           |      Nameless Abominations are people too.


DNA will break if you look at it funny.  I work in a cell bio lab where we do
DNA preps routinely, and one of the things we have to make sure of during our
protocols is that we don't shake or stir the DNA too vigorously.  In fact,
this is bacterial DNA, which comes in strands much smaller than human, and
thus theoretically  subject to less shear force than an enormous human
chromosome.

Also there is the subject of histones.  Human (and I think all eukaryotic) DNA
does not exist naturally in those long strands you see in books.  It is
wrapped around these proteins called histones, which compress it down to the
appropriate size (an unwound human chromosome is supposedly several meters in
length).  It would be next to impossible to destroy the histones and fully
unwind a strand without breaking it.  

Keep in mind that the bonds holding a DNA molecule together along its length
are not carbon-carbon bonds, like in diamond, but much weaker phosphate
bonds.  This allows enzymes to break and rejoin strands at the relatively
low-energy conditions of a cell.

These are just the problems I can think of off the top of my head.  If you
really worked at it, you might be able to get enough seperate strands of DNA
that you could wind together a fiber that would be strong enough to withstand
breaks in the individual strands.  However, there is not this much DNA in the
human body.

Sorry!

--
Charles Murtaugh
Newsgroups: rec.arts.sf.science