HDTenEightyP/NetNews huggingface dataset:
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: Expansion
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Thu, 1 Oct 92 20:58:37 GMT

In article <30SEP199220042116@zeus.tamu.edu> dwr2560@zeus.tamu.edu (RING, DAVID WAYNE) writes:
>baez@ucrmath.ucr.edu (john baez) writes...
>>>                                           The region of space which is
>>>inside a galaxy satisfies the same local einstein equation as the above
>>>recollapsing example, so why do galaxies live so long?
>> 
>>'Cause they're smaller.  I'm sure one can work out the math, but
>>it's bound to amount to just that.  For example, one can have
>>a fist-sized ball of iron, which will essentially never collapse
>>(quantum fluctuations aside), but a galaxy-sized ball of iron
>>would collapse mighty fast.
>
>I'm surprised at you John, you forgot the atomic repusion! :)
>
>I get that a fist-sized ball of superdust weighing in around a kilogram
>collapses in about an hour. I think that will be about the same for an
>observer in the center of your iron galaxy. But I'm depending on my
>already disproven intuition. :)

You're right, my example was fairly irrelevant, even though what I said
about the ball of iron versus BIG ball of iron is true.  For iron the point
is that gravity beats atomic repulsion for large objects.  Galaxies
aren't held up by atomic repulsion.  So - is, or is not, Dave Ring's
theory right?  Namely, say one takes a ball of "dust" (in the sense of
relativity, i.e., no repulsive forces) of a given density and radius R.
How long will it take to collapse as a function of R?

Extra credit if you solve it for rotating dustballs, so that it's more
like honest galaxies.
From: burton@cfm.brown.edu (Joshua W. Burton)
Newsgroups: sci.physics
Subject: Re: Possible?: 2 integers specifying a point in 3D space.
Date: 26 Sep 1992 05:02:16 GMT
Organization: Brown University Center for Fluid Mechanics
NNTP-Posting-Host: qcd2.het.brown.edu

I'm not quite sure where this one is leading, so I'm worried about tricks
and traps, but I think everyone will agree with the following:

The set of integers is countable; so is the set of n-tuples of integers, for
all finite n.  The set of real numbers is not countable; therefore we cannot
label the real axis, much less any higher-dimensional Euclidean space, with
two (or any finite number of) integers.  If you think you have an integer-
valued list of all the real 3-tuples, or even of all the real numbers on
some open interval, please show it to me, and I will point out a real number
that you forgot to list.

It _is_, of course, possible to label all the points in 3-dimensional space
with only two _real_ coordinates...but not in a way that preserves the notion
of proximity.  Hope this answers the question.

-- 
Stadium sedipilae opt- |======================================================
imum Saeptum Paludosum | Joshua W. Burton  burton@het.brown.edu  (401)351-5908
etiamnunc est. Ain tu? |======================================================

Newsgroups: sci.physics
From: clarke@acme.ucf.edu (Thomas Clarke)
Subject: Can Barbie figure this joke out?
Organization: University of Central Florida
Date: Mon, 5 Oct 1992 20:39:57 GMT

In article <1992Oct05.164436.37819@watson.ibm.com> platt@watson.ibm.com (Daniel  
E. Platt) writes:
> In article <1992Oct5.144625.22281@bcrka451.bnr.ca>, isupstud@bnr.ca (Wayne  
Hutton) writes:
> Should read:
> 
> 	The integral of 'e' to the 'x' is a function 'F' of both 'u' and 'n'.
>
> |> ps. all credit goes to my linear algebra prof (first year college)
> |> 
> |> -todd.
> 
> Dan

Maybe if we had Mattel have Barbie say this, it
would help alleviate math anxiety.

--
Thomas Clarke
Institute for Simulation and Training, University of Central FL
12424 Research Parkway, Suite 300, Orlando, FL 32826
(407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu
Newsgroups: sci.physics
From: pciszek@nyx.cs.du.edu (Paul Ciszek)
Subject:  black holes & baryon number
Organization: University of Denver, Dept. of Math & Comp. Sci.
Date: Mon, 5 Oct 92 03:45:22 GMT

Could someone please clear up the following for me?

Suppose we start with a cloud of hydrogen, with a total baryon number
equal to the number of hydrogen atoms present.  As this cloud goes from
protosun -> star -> supernovae -> neutron star, baryon number is conserved.
Fine and dandy.  Now the neutron star collapses into a black hole.  I guess
I ought to assume the black hole still "remembers" the baryon number somehow.
Now, according to Hawking, the black hole evaporates into "radiation".
Does it "evaporate" into light?  Or did he mean "particle radiation"?
Is baryon number conserved in this last stage?

--
Paul Ciszek, pciszek@nyx.cs.du.edu | No nation was ever drunk when wine was
                                   | cheap.   -- Thomas Jefferson
Newsgroups: sci.physics
From: magdi@uxh.cso.uiuc.edu (Magdi N Azer)
Subject: Sticking coefficients for Ti on Silicon
Organization: University of Illinois at Urbana
Date: Thu, 1 Oct 1992 21:08:58 GMT

I  am looking for the data for sticking coeffients for Ti on Silicon.  Any
help is appreciated.

Magdi N. Azer
magdi@uxh.cso.uiuc.edu
From: paul@mtnmath.UUCP (Paul Budnik)
Newsgroups: sci.physics
Subject: Re: Simple observation about Quantum Kitty Cats
Summary: Its not a hint, its more like being hit on the head with a sledgehammer
Date: 29 Sep 92 15:55:54 GMT
Organization: Mountain Math Software, P. O. Box 2124, Saratoga. CA 95070

In article <1992Sep28.134825.29472@oracorp.com>, daryl@oracorp.com (Daryl McCullough) writes:
> 
> 1. QM, with its quaint axioms
> about measurement processes is an enormously successful theory; there
> are absolutely no hints to the limitations to its applicability.

That depends on what you consider a hint. Quantum mechanics predicts that
by changing the setting on an instrument we can influence what happens
arbitrarily large distances away. There has never been a shred of
experimental evidence supporting such action at a distance. This is more
than a hint at limitations. It is a powerful argument suggesting that
quantum mechanics is false.

The fact that general relativity and quantum mechanics are not mutually
consistent is another hint that all is not well.

I have repeatedly challenged this group to come up with objective reasons
for preferring existing formulations of quantum mechanics to the assumption
that quantum collapse is local physical process. If you are convinced
there are no hints to the limitations of quantum mechanics, you must
have excellent arguments against quantum collapse as a physical local
process. I would love to see them.

Paul Budnik
~
From: tekman@dynamo.ecn.purdue.edu (Erkan Tekman)
Newsgroups: sci.physics
Subject: Re: Can Information Have Physical Units?
Date: 6 Oct 92 04:25:39 GMT
Organization: Purdue University Engineering Computer Network

In article <12950089@hpspdla.spd.HP.COM> ric@hpspdla.spd.HP.COM (Ric
Peregrino) writes:
>Shooting from the hip I'd say information has the same units as entropy,
>which I thought was unitless. But what about Gibbs free energy:
>
>dG = dH + TdS
>
>S then has units of energy/temperture? Maybe I'm just being dense?

information is indeed unitless, one has for the hamiltonian

     H = H_o + h I

including the effects of change in information I, with h being variation of
energy w.r.t. information, that is has unit of energy.  for the energy, on
the other hand

     E = E_o + h/(k ln 2) S

with S being entropy (energy/temp.), and k ln 2 is the elementary entropy
change per bit. so

    S = k ln 2 I

everything fits together...

i just copied these from J. D. Brasher, Int. J. Theor. Phys. vol 30, 979
(1991), by the way ;-)

erkan

tekman@ecn.purdue.edu
Newsgroups: sci.physics
From: dwr2560@zeus.tamu.edu (RING, DAVID WAYNE)
Subject: Re: Spin
News-Software: VAX/VMS VNEWS 1.41    
Organization: Texas A&M University, Academic Computing Services
Date: Sat, 3 Oct 1992 22:34:00 GMT

b5249-23@mathcs.sjsu.edu (Kurt Stocklmeir) writes...
>On sci.physics, it only takes 1 simple statement to create complete
>confusion.  Even if somebody wanted to fine excuses for the complete
>confusion, there are not any excuses for the insults from the fools.

Your comments are most unbusinesslike.

Dave Ring
dwr2560@zeus.tamu.edu
Newsgroups: sci.physics
From: jarleb@athena.uio.no (Jarle Brinchmann)
Subject: Re: Spin
Reply-To: jarleb@athena.uio.no (Jarle Brinchmann)
Organization: Institute for Theoretical Astrophysics.
Date: Thu, 1 Oct 1992 19:27:26 GMT


b5249-23@mathcs.sjsu.edu (Kurt Stocklmeir) writes :

< Blah. Blah deleted >

Well, thanks at least I've found someone which I can take
author kill on. Now you have posted the same nonsense quite
a few times, so now it isn't funny anymore. 




      ---------------------------------------
       Internet: jarleb@medusa.uio.no         
       or        Jarle.Brinchmann@astro.uio.no
      ---------------------------------------
From: gr1c+@andrew.cmu.edu (Greg Howard Rhodes)
Newsgroups: sci.physics
Subject: Re: Mattel protest
Date: 5 Oct 92 12:33:43 GMT
Article-I.D.: andrew.4eo_Oby00WB9N4dnYR
Organization: Senior, Physics, Carnegie Mellon, Pittsburgh, PA


C. R. Bass writes:
>
>     If y'all feel it necessary to 'do something' about the paucity of
>     women in the physical sciences, then go to the middle schools
>     and *teach* math to them in an interesting and wonderful way.  
>
>     However, don't be mislead into thinking that overall numbers
>     of mathematicians will change unless the profession pays as 
>     well as medicine or law.  There seem to be plenty of women in
>     those demanding fields. 
>
>     Also, for most, law school and medical school are tough.
>
>                               dale bass
>-- 
>C. R. Bass                                           crb7q@virginia.edu
>Department of Mechanical and Aerospace Engineering
>University of Virginia
>Charlottesville, Virginia                            (804) 924-7926

Just wanted to say that I think that really missed the point here. The
problem is NOT just that there aren't more women in the field of
mathematics, the problem is that there aren't more women in
math or science related fields, such as: physics, chemistry, computer
science, computer engineering, electrical engineering, mechanical,
aerospace, materials, etc, etc, etc... 

So what you are saying is that women are more money-grubbing than men?
Only when "the profession pays as well as medicine or law" will there
be more women in math and science??!? Clue hammer for you, Dale.

Greg Rhodes
gr1c@andrew.cmu.edu
Newsgroups: sci.physics
From: crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass)
Subject: Re: Aye, I Agree... (actually perturbation theory)
Keywords: Quite so, quite so..
Organization: University of Virginia
Date: Mon, 5 Oct 1992 17:15:05 GMT

In article <stone.718298401@cwis> stone@cwis.unomaha.edu (Travis Stone) writes:
>
>Can any of you suggest a good beginner's-level text in
>Perturbation Theory?  I seek a book that has the following
>requirements:
>
>  (i) Introductory Level--not too much on the theoretical side
> (ii) Lots of worked examples
>(iii) Lots of problems to work at the end of the chapter, and
>      MOST IMPORTANTLY: ANSWERS IN THE BACK OF THE BOOK!
>
>The reason that I pose this conundrum to you, the friendly
>folk of sci.physics, is that as Physics-oriented people,
>you are much more likely to know some good applied-math
>texts; asking the sci.math folks would most likely net me
>a list of theoretical texts explaining the "why it works"
>aspect, and not the "how to do it"---which is what I'm after.

    Though the answers are not worked out in the book, I enjoyed
    Simmonds and Mann's 'A First Look at Perturbation Theory' (Kreiger).  
    It seems to be the way I would have liked to learn perturbation
    theory had I the luxury of actually taking a class 
    before being forced to learn it.   I wish the book had
    been available when I was forced to learn it.

                              dale bass
-- 
C. R. Bass                                           crb7q@virginia.edu
Department of Mechanical and Aerospace Engineering
University of Virginia
Charlottesville, Virginia                            (804) 924-7926
Newsgroups: sci.physics
From: braham@physics.ubc.ca (Stephen Braham)
Subject: Re: black holes & baryon number
Organization: University of British Columbia, Vancouver, B.C., Canada
Date: Mon, 5 Oct 1992 21:07:29 GMT

Paul.Ciszek@mailbox.bison.mb.ca (Paul Ciszek) writes:

>Could someone please clear up the following for me?

>Suppose we start with a cloud of hydrogen, with a total baryon number
>equal to the number of hydrogen atoms present.  As this cloud goes from
>protosun -> star -> supernovae -> neutron star, baryon number is conserved.
>Fine and dandy.  Now the neutron star collapses into a black hole.  I guess
>I ought to assume the black hole still "remembers" the baryon number somehow.
>Now, according to Hawking, the black hole evaporates into "radiation".
>Does it "evaporate" into light?  Or did he mean "particle radiation"?
>Is baryon number conserved in this last stage?

Our present understanding of black hole physics suggests quite the 
reverse- that quantum processes involving black hole states do INDEED
violate pretty much every local conserved number except for spin,
mass/energy and charge. This forms the basis of the no-hair conjecture
for black holes. Future understanding may vary, however :). At present,
black holes can violate baryon number.

			Steve

--
| Name: Stephen P. Braham | Perversion: Quantum Cosmologist|
| Hangout: UBC physics    | Signature:  Euclidean          |
|          Vancouver, BC  |--------------------------------+
|          Canada         | E-mail: braham@physics.ubc.ca  |
From: bweiner@ruhets.rutgers.edu (Benjamin Weiner)
Newsgroups: sci.physics
Subject: Re: LARSONIAN Physics and Astronomy
Date: 28 Sep 92 23:54:12 GMT
Distribution: na
Organization: Rutgers Univ., New Brunswick, N.J.

Scott Chase asks:
> (How does an orthodox physicist behave?  Does he quote Jackson
>chapter and verse?  Does he bow towards Batavia?  Chant from the
>Particle Data book?)

He only believes in Unified Theories that have that little K in a
circle on them.  (If she's very strict she'll only accept the little
U in a circle.)  That's Dewey B. Larson's problem, he never put the
little K in a circle symbol on.  Fortunately it's not an ASCII 
character ...

(guide for the perplexed: this is an obscure religious joke.)
From: doi@tartarus.uwa.edu.au (Daniel Kuan Li Oi)
Newsgroups: sci.physics
Subject: Re: Quantum Zeno Effect, Part 1.
Date: 5 Oct 1992 08:22:26 GMT
Organization: The University of Westrn Australia
NNTP-Posting-Host: tartarus.uwa.edu.au

burt@aupair.cs.athabascau.ca (Burt Voorhees) writes:


>  Back in the late 70's I was quite interested in this effect after
>reading the Misra & Sudarshan paper.  I happened to encounter
>Sudarshan and asked him whether this meant that if I watched myself
>continuously I would not age.  He immediatly began a discussion of the
>relative merits of various forms of meditation.
>  At this late date, having failed to keep a careful enough eye on
>my self, I am not in a position to answer this question from experience.
>But, depressing thought, it would seem that this self-observation would
>have to be at the molecular level.  Too bad.

	Hey, maybe this is a refutation at the existence of God.  Since
the universe has obviously evolved, the assosciated quantum wave
function of the universe is not being continuously collapsed by an
outside observer (ie GOD).  :) ;) :)



Newsgroups: sci.physics,sci.astro,sci.math,sci.philosophy.tech
From: baez@ucrmath.ucr.edu (john baez)
Newsgroups: sci.physics
Subject: Re: Simple observation about Quantum Kitty Cats
Date: 30 Sep 92 16:16:09 GMT
Organization: University of California, Riverside

In article <297@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:
>I have repeatedly challenged this group to come up with objective reasons
>for preferring existing formulations of quantum mechanics to the assumption
>that quantum collapse is local physical process. If you are convinced
>there are no hints to the limitations of quantum mechanics, you must
>have excellent arguments against quantum collapse as a physical local
>process. I would love to see them.

That may be how philosophy works - pitting argument against argument -
but it's not how physics works; there one pits model against model.
Just saying "quantum collapse as a physical local process" won't stack
up against a well-developed formalism that people have successfully
used for decades.  You need to lay out a precise model of quantum
collapse as a physical local process and show how one can calculate
all sorts of things with it.  I.e., you have to match the competition.
OR you have to get ahold of an experiment that shows the existing formalism
makes wrong predictions.  

That's how the game goes: revolutions in physics do not come easily.
From: Bronis.Vidugiris@mailbox.bison.mb.ca (Bronis Vidugiris)
Newsgroups: sci.physics
Subject: Re: FTL Experiment
Date: 24 Sep 92 17:13:32 CST

Organization: Motorola, CCR&D, CORP, Schaumburg, IL

In article <4339@cruzio.santa-cruz.ca.us> snarfy@cruzio.santa-cruz.ca.us writes:
)
)   In   message-ID:   <1992Sep22.025552.17549@lmpsbbs.comm.mot.com>  (Bronis
)   Vidugiris) writes:
)
)    (...stuff deleted...)
)
)   |If you keep the wire _straight_ you'll never observe anything like a FTL
)   |effect  -  feel  free  to  try,  though  :-)

)    I  was wondering when someone was going to bring up this objection. This
)    faulty reasoning even contradicts itself. Assume for the moment one sets
)    up a resonant condition between a straight wire inductance and the  self
)    capacitance  present  due to the air dielectric between the wire and the
)    ground plane. We then modulate the Q factor by shunting a resistance  in
)    and  out  of  the  circuit.

So far so good.

)  By  the  standards  you've imposed , even a
)    straight wire wouldn't give us a valid  result  because  the  signal  is
)    taking a `shortcut' through the air dielectric and the ground plane!

I'm not sure what this is supposed to mean.

By the standards I've imposed, you would expect to find induced voltages and
currents in your groundplane due to the electric and magnetic fields in
the wire.  (If you look, you'll find them.)  By the standards I've imposed,
fields actually permeate space, and you have to consider the fields *both* in
the surrounding space/environment and in the wire to get an accurate answer
in either theory or practice.  By the standards I've imposed, you can observe
the effects of the fields on your measurments by noting the sensitivity of
the resonant frequency of your circuit to ambient conditions by waving your
arms around near the circuit (a simple experiment) - which changes the
behavior of the external fields, and hence changes the behavior of the
circuit.  If you don't believe in fields, you can't explain this easily
observable behavior.  It's all  pretty obvious and easily testable.

)     The  rejoinder  to this is : That's the "secret" to FTL communications.
)    Tesla figured this out long ago . The problem  was  ,this  was  so  easy
)    anybody  could  do  it. If anybody could do it , nobody could make money
)    from it.

The secret to FTL communications is ignoring fields and assuming that signals
must always take the 'long route'?  Doesn't sound very useful to me.  I
want 'FTL' communication over a straight line - 'zig-zag' FTL communication
that allegedly traverses a crooked path in the same time a STL signal could
go from the source to the ultimate destination doesn't either impress me or
strike me as being at all useful.

 * Origin: The Electronic Mailbox (1:348/7.0)

Newsgroups: sci.physics
From: mader@wonk.del.dec.com (Bob Mader)
Newsgroups: sci.physics,misc.forsale.wanted,misc.wanted,pa.forsale,phl.forsale
Subject: Need to buy vacuum equipment
Date: 5 Oct 92 21:17:03 GMT
Reply-To: nicholsonjd%phvax.dnet@smithkline.com
Distribution: na
Organization: Digital Equipment Corporation


IMPORTANT:  I'm posting this on behalf of a friend who can read news but
can't post.  Please reply to nicholsonjd%phvax.dnet@smithkline.com , not
to the poster!  Thanks.


Title: 
I am a private researcher looking at doing some materials work.  If you have
any of the following and wish to sell it, please reply via e-mail.

1) Diffusion pump ~150-200 l/s pumping speed.  I would prefer a conflat flange
on the pump.  I would also hope to purchase the frame which your pump is
currently using.

2) Vacuum chamber (at least 8" dia. and at least 8" long).  I would prefer
conflat flanges, but will accept any flange that will bolt up to the
diffusion pump I will be buying (item #1).

3) Varian Ion Pump Controller 921-0062 (or its equivalent).  It belongs
to the 400 l/s Varian Ion Pump 921-7022

4) Light microscope or binocular dissection scope

5) Sorbtion pump (2 3/4" conflat flange preferred)

6) Short lengths of Nickel wire, Tungsten Wire (5 mil and 10 mil),
   Molybdenum Wire, Indium wire, Tantalum wire.  (I'm too cheap to buy a
   whole roll when I'll probably use only a few inches.)

--
Jim N.
I disclaim it all.  So does my company.
Newsgroups: sci.physics,sci.math
From: gawne@stsci.edu
Subject: Re: How do you draw a straight line?
Organization: Space Telescope Science Institute
Distribution: na
Date: Tue, 6 Oct 1992 23:28:21 GMT

>In article 24242@access.usask.ca, 
choy@skorpio.usask.ca (I am a terminator.) wrote:
>How do you know that the line you draw is really straight? What
>defines straightness?

and somebody else (sorry, I clipped off the name) replied:
>>
>>This is something I've been wondering about since a long time. Although we can
>>make a circle as precise as we want, I think we cannot make a really
>>precise straight line.               [text deleted for brevity]

And John Baez replied to that:

> The compass is nice because it works straight from the definition of a
> circle, while a ruler, as you note, is not so nice since it does not
> work from the definition of a straight line as the shortest path between
> two points. 

Well, how about drawing a circle using the compass on paper, cutting it
out carefully, and folding it in half?  That will give you a line as 
straight as the circle was round to begin with.  In both cases the limiting
process is your hand/eye coordination and the sharpness of your pencil.

-Bill Gawne  (obviously an experimentalist)
Newsgroups: sci.physics