HDTenEightyP/NetNews huggingface dataset:
From: schuette@wl.com (Wade Schuette)
Subject: Re: Nevada Casino - 200 miles up
Organization: Warner Lambert / Parke-Davis
Date: Wed, 26 Aug 1992 10:56:12 GMT

This reminds me of a total time-killer problem we had in grad school.
Imagine a rope constrained to be vertical (ie moving) over some point
on the equator (or relax for variants) and , oh, 40000 miles long.
Forget atmosphere. Then you release the rope.  Describe, even qualitatively,
the subsequent motion of the rope.

Hint - for starters, the bottom goes UP.

-- 
==================================================================
R. Wade Schuette         schuette@wl.com    Ann Arbor, MI, USA
Newsgroups: sci.physics
From: m14494@mwvm.mitre.org (Mike White)
Subject: Re: Uncertainty Principle
Organization: The MITRE Corporation
Distribution: na
Date: Fri, 4 Sep 1992 15:21:15 GMT

Dave Griffiths writes:
> I just read (Stephen Hawking) a nice explanation of the Uncertainty 
Principle...
> Does it make any sense to talk about a particle having an unknowable, but
> precise, position and momentum...

Gee..., I'm not certain.   ;-)


************************
* These are my opinions only.*
************************
Newsgroups: sci.physics,sci.environment,misc.consumers
From: crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass)
Subject: Re: Radioactivity and Superstition; was: Re: Are Your Light Bulbs Radioactive?
Organization: University of Virginia
Date: Wed, 2 Sep 1992 18:12:38 GMT

In article <1992Sep2.172549.29172@ornl.gov> de5@ORNL.GOV (Dave Sill) writes:
>In article <1992Aug29.000626.16080@u.washington.edu>, whit@milton.u.washington.edu (John Whitmore) writes:
>>In article <l9ns6oINNmol@utkcs2.cs.utk.edu> de5@ORNL.GOV (Dave Sill) writes:
>>
>>>Few of which are radioactive, since most folks don't have concentrated sources
>>>laying around their house...unless they have smoke detectors or compact
>>>flourescents.  Which is *exactly* the point the originator of this thread was
>>>trying to make.  Radioactivity *is* a different kind of threat than most
>>>parents are used to dealing with. 
>>
>>	This is not true; ALL organic foods are radioactive (carbon-14,
>>remember?), and potassium contains 0.01% of K-40... so an eight-year-old
>>child (just about hammer-wielding age) has a 'safe and adequate'
>>recommended dietary intake of circa 1 gram of potassium per day...
>>which comes to about two microcuries.
>
>Which of my statements is not true?  Do you consider organic foods
>concentrated sources of radioactivity?  I think they are only in the literal
>sense, i.e., they're more radioactive than air or water.  But if they are as
>concentrated as the sources in smoke detectors and compact fluorescents, why
>don't the manufacturers just use a chunk of cucumber and remove the warning
>label?

     Untrue: "Radioactivity *is* a different kind of threat than most 
              parents are used to dealing with".
     Untrue:  the implication that the sources in smoke detectors and
              flourescent bulbs constitutes a realistic threat to our
              children due to radioactivity.

     I'd love to see your house (if you have kid(s)), if you still consider
     this a discussion of realistic threats. 

                             dale bass
-- 
C. R. Bass                                           crb7q@virginia.edu
Department of Mechanical and Aerospace Engineering
University of Virginia
Charlottesville, Virginia                            (804) 924-7926
From: amnell@klaava.Helsinki.FI (Marko Amnell)
Newsgroups: sci.physics
Subject: Re: Axiom of Physics
Date: 29 Aug 92 19:10:04 GMT
Organization: University of Helsinki

In article <mcirvin.715102339@husc8> mcirvin@husc8.harvard.edu (Mcirvin) writes:
>andrew@rentec.com (Andrew Mullhaupt) writes:
>
>>Quantum mechanics is often phrased in terms of axioms, but even the most
>>ardent proponent of the quantum theory would have to admit that the axiom is
>>part of the theory. 
>
>Not only that: in QM the stated axioms are often only part of one
>interpretation of the theory!  Paul Dirac and Murray Gell-Mann would
>disagree as to what the axioms are, or even how many there are. 
>
>The unusual thing about QM is that unlike, say, different formulations
>of classical mechanics, the various sets of axioms proposed seem so
>fundamentally contradictory to each other.  The surprising thing is that
>they all lead to the same predictions for at least the vast majority of
>experiments.

I don't know too much about this stuff myself, but I remember seeing a
book by Mario Bunge once called _Foundations of Physics_ in which he
discussed 'proto-physics' (non-empirical axioms?) and an explicit axiom
system for QM.
From: johncobb@ut-emx.cc.utexas.edu (John W. Cobb)
Newsgroups: sci.physics
Subject: Re: What's new with chaotic dynamics?
Date: 1 Sep 92 18:54:39 GMT
Reply-To: johncobb@ut-emx.cc.utexas.edu (John W. Cobb)
Distribution: na
Organization: The University of Texas at Austin

In article <25755@dog.ee.lbl.gov>, sichase@csa3.lbl.gov (SCOTT I CHASE) writes:
|>In article <l9l9fdINNrf6@news.bbn.com>,
hagstrop@oberon.mathcs.carleton.edu (Paul Hagstrom) writes...
|>>I realize that this is an incredibly unfair question to ask, but I
will pose it  
|>>anyway, just to see what the response is..
|>> 
|>
|>I suggest "controlling chaos" is a good paper topic.  It is new and trendy,
|>and there are good introductory papers in Science, Nature, etc. that you
|>could dig up.

And if you want to go directly to the article that nature and Science report
on, The Citation is:

Shinbrot et. al. Physical Review Letters Vol 68, no 19 11 May 1992 p.2863

There was another paper later from this group on improved techniques a few
motnhs later in PRL.

Look at nearby dates in Science, etc to see more "laymen's terms" reports.

The basic idea is that if you dynamical system has chaotic trajectories,
then the current trajectory should be very close (in some sense) to a
trajectory that will take to any given specific point in phase space. So
you can institute a control system that will allow you to converge to a
particular state without using much brute force. Your corrections will
only be slight because you will rely on the phase space dynamics to do
most of the work. Of course the tough part is to figure out which trajectory
to hop onto and how to stay there (since you are on a manifold with positive
Lyapunov expoenents). Neat huh?

john w. cobb
jwc@fusion.ph.utexas.edu
From: mcirvin@husc8.harvard.edu (Mcirvin)
Newsgroups: sci.physics
Subject: Units (was Re: E=MC^2)
Date: 31 Aug 92 21:38:26 GMT
Article-I.D.: husc8.mcirvin.715297106

popetz@ux1.cso.uiuc.edu (Clinton C. Popetz) writes:

>I hate units.

>"The '1 over 4 pi e not' is there because the coulomb is a fundamentally
> stupid unit of charge."		
>				-My Special Relativity Prof

Yeah... in the RIGHT units, it's just 1 over 4 pi.  ;-]
-- 
Matt McIrvin, Cambridge, Massachusetts, USA 
Newsgroups: sci.physics
From: sci20035@nusunix3.nus.sg (LIM WOOI BENG)
Subject: de Broglie wavelength.....
Organization: National University of Singapore
Date: Thu, 27 Aug 1992 05:34:07 GMT


I want to pose this question which my tutor asked my tutorial group. He
said that a de Broglie wavelength does not have a corresponding
wavelength because it does not 'understand' time being in nature a
standing wave. Now I would like to ask the people in this group..is that
a fact....? 

					*The-Edge*
*******************************************************************
* If my tutor know I am doin this he will KILL me!!               *
*******************************************************************
From: flower@hpcc01.corp.hp.com (Graham Flower)
Date: Wed, 26 Aug 1992 16:20:08 GMT
Subject: Re: Satellite spying
Organization: the HP Corporate notes server
From: frank@rover.uchicago.edu (Frank - Hardware Hacker - Borger)
Subject: Eating habits; was: Radioactivity and Superstition; 
News-Software: VAX/VMS VNEWS 1.41    
Reply-To: frank@rover.uchicago.edu
Organization: Joint Center for Radiation Therapy
Date: Fri, 4 Sep 1992 14:25:00 GMT

In article <JMC.92Sep3224636@SAIL.Stanford.EDU>, jmc@cs.Stanford.EDU writes...
>I stand corrected by John De Armond.  I believe his figures, but I'll
>undercut his price.  I'll eat as many as Jym Dyer will supply at a mere
>$5k a bulb.  See Jym, we capitalists really do compete.

	How 'bout the poor cannibals? Since people are mildly radioactive
	this may shorten their lives.

	Side note: If you die in our hospital but are a labratory animal
	rather than a human, we can't bury you normally, but have to send
	you to a low-level radioactive waste disposal facility.

   Frank R. Borger - Physicist    __       Internet:  Frank@rover.uchicago.edu
Michael Reese - Univ. of Chicago |___      Phone : 312-791-8075 fax : 567-7455
  Center for Radiation Therapy   | |_) _   The race may not be to the swift nor
    2929 South Ellis Avenue        | \|_)  victory to the strong, but that's
    Chicago, Illinois 60616           |_)  how you bet. - Damon Runyon
From: mcirvin@husc8.harvard.edu (Mcirvin)
Newsgroups: sci.physics
Subject: Misner et al.
Date: 29 Aug 92 02:23:37 GMT
Article-I.D.: husc8.mcirvin.715055017

matmcinn@nuscc.nus.sg (Mcinnes B T (Dr)) writes:

> You will get a deeper
>understanding of eg General Relativity from Friedman's "Foundations of
>Spacetime theories" than from the grotesquely over-praised MTW.

I'll have to look that up.

I still can't decide how I feel about MTW.  It gets referred to a lot
on this group, but that has a lot to do with the fact that it devotes
a lot of time to weird things involving black holes, and explains
that particular subject in fair detail with lots of examples and nice
pictures.  There are, however, a lot of problems with the book.  I
despise the portions in which it lapses into bad free-verse poetry or
clipped stereo-manual language without articles.  The latter seems to
happen, furthermore, when complicated calculations are being described.
Also, the machinery it builds up to explain cotangent spaces and 
differential forms is far too baroque for what is being explained, and
I suspect it mostly confuses people.

Its major virtues are that it is fairly encyclopedic, at least concerning
developments up to 1973, and that it has a lot of very good diagrams 
where most books have none. 

Personally, from what I've read, I like Wald's book.  It was written
a decade after MTW and Weinberg and consequently has some newer stuff
in it.
 
-- 
Matt McIrvin, Cambridge, Massachusetts, USA
From: sichase@csa3.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Re: My son would like to know about photons...
Date: 27 Aug 92 19:31:15 GMT
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
Distribution: na
Reply-To: sichase@csa3.lbl.gov
NNTP-Posting-Host: 128.3.254.198
News-Software: VAX/VMS VNEWS 1.3-4   

In article <12950072@hpspdla.spd.HP.COM>, ric@hpspdla.spd.HP.COM (Ric Peregrino) writes...
> 
>>The simple answer would be "No."
> 
>What about beta decay? This doesn't "split" a quark, but it does transform
>one quark into another with the release of an electron and it's antineutrino
>(I think?). So in some sense the original quark was broken into constituents.

It is important to disabuse yourself of this notion once and for all.
It's just not true.  As several previous posts have tried to explain, you
need to think in terms of quantum fields in order to correctly picture
the situation.  Energy is transfered from one quantum field to another.
In beta decay, an oscillation of a quark field is eliminated in favor ofof
excitations in several other fields.

But at no time did the quark contain any other particles.

In the days before the quark model, people tried to construct some models
which fit your intuition.  Hagedorn (now mostly retired at CERN) invented
the "Thermodynamic Bootstrap" model, which is still fun to study.  
Every particle was considered a thermodynamic distribution of all other
particles, called a fireball.  He was able to "derive" the mass spectum
of the resonances from a self-consistency condition, and people were very
impressed.  Then quarks came along and provided a much nicer picture of 
the contents of protons, neutrons, etc. and the Bootstrap model fell
on very hard times.

-Scott

--------------------
Scott I. Chase			"The question seems to be of such a character
SICHASE@CSA2.LBL.GOV		that if I should come to life after my death
				and some mathematician were to tell me that it
				had been definitely settled, I think I would
				immediately drop dead again."      - Vandiver
From: jac@ds8.scri.fsu.edu (Jim Carr)
Newsgroups: sci.physics
Subject: Re: My son would like to know about photons...
Date: 3 Sep 92 14:14:07 GMT
Reply-To: jac@ds8.scri.fsu.edu (Jim Carr)
Organization: SCRI, Florida State University

In article <1992Sep1.133516.28886@tpl68k0.tplrd.tpl.oz.au> keithh@tplrd.tpl.oz.au (Keith Harwood) writes:
>
>In article <10506@sun13.scri.fsu.edu>, jac@ds8.scri.fsu.edu (Jim Carr) writes:
>> 
>> In this sense, you cannot split a photon since it has no constituent 
>> parts; a photon is an elementary particle.  
>
>Er, not only can you chop photons into pieces, but you can use scissors
>to do so. Well, OK, they have to be hi-tech scissors. Get an aperture 
>and chopper wheel with so many teeth and rotating at such a speed that 
>the aperture is open for a time of half a metre at the speed of light. 
>Get a source of metre long photons (a green line of krypton is handy
>for this) and shine the light through the aperture. The photons coming
>out at the other side are only half a metre long. However, this isn't

 So you think a single photon consists of an infinity of constituent 
 parts, so that it can be cut at any point along its "length"?  This 
 is not the conventional wisdom.  There is plenty of proof that a 
 single photon changes its properties only when it interacts electro-
 magnetically with some other particle, and then it can be argued 
 that you really have created a new photon. 

>as much fun as it seems. One of the rules for playing this game is
>that when we chop a photon in half, all the energy goes into one of
>the halves, leaving nothing for the other. This means that the 

 Then it sounds like you still have one photon, right?

>half length photons coming out have almost the same colour as the
>ones going in, they are just slightly paler. (Translation into 
>physics: the photons coming out have the same centre wavelength,
>but the line is broader.)

 Now it sounds like you are talking about an ensemble of photons, 
 not a single photon, since the "line width" is not a property of 
 a single photon.  A single photon has a well-defined energy/color. 

--
J. A. Carr                                    |  "The New Frontier of which I  
jac@gw.scri.fsu.edu                           |  speak is not a set of promises
Florida State University  B-186               |  -- it is a set of challenges."
Supercomputer Computations Research Institute |   John F. Kennedy (15 July 60)
Newsgroups: sci.physics
From: dietz@cs.rochester.edu (Paul Dietz)
Subject: Re: Inertial drive?
Organization: Computer Science Department University of Rochester
Date: Tue, 1 Sep 1992 01:22:10 GMT

In article <1992Aug31.231110.26645@wdl.loral.com> mab@wdl39.wdl.loral.com (Mark A Biggar) writes:

>In article <0fhS02Go20x701@JUTS.ccc.amdahl.com> drp40@cd.amdahl.com writes:

>>An office mate recently mentioned having heard about something called
>>an "inertial drive" which was an enclosed device with some sort of motor
>>and geared arrangement which would produce a force in a single direction
>>by converting rotational inertia into "linear" (??) inertia.  Sounds 
>>pretty bizarre.  Anyone have any details on this?

>This is the "Dean Drive" made famous in the early to mid 60's in
>Analog Magizine.  General Opinion is that it was a fake.  Dean applied
>for patents but no one has been able to reproduce the effect since. 
>Because Dean would not let anyone else touch his prototype one one was able
>to perform the obvious experment of suspending it from wires and seeing if
>it didn't hang straight (if it hangs displaces sideways and doesn't occilate
>then it is producing a unidirectional force).  For a possible explaination
>of how it could work see references to "Davis" mechanics which proposes
>that there is an additional force law like Newtons involving forces 
>proportional to changes in acceleration (called jerk).


Be aware that if you accept that physical laws are independent of the
reference frame, then if you can violate conservation of momentum, you
can also violate conservation of energy.  "Inertial drives" [sic]
are really perpetual motion machines of the first kind.

	Paul F. Dietz	
	dietz@cs.rochester.edu
From: jac@ds8.scri.fsu.edu (Jim Carr)
Newsgroups: sci.physics
Subject: Re: Units (was Re: E=MC^2)
Date: 3 Sep 92 14:40:50 GMT
Reply-To: jac@ds8.scri.fsu.edu (Jim Carr)
Organization: SCRI, Florida State University

In article <10571@sun13.scri.fsu.edu> jac@ds8.scri.fsu.edu (Jim Carr) writes:
>
>So 9 x 10^{13} Joules from 1 gram would be the equivalent of the energy 
>released by 0.02 megatons (21,500 tons or 4.3 million pounds) of TNT. 
                                           ^^^

correction, 43 million pounds, caught just after :-( I hit RETURN.


--
J. A. Carr                                    |  "The New Frontier of which I  
jac@gw.scri.fsu.edu                           |  speak is not a set of promises
Florida State University  B-186               |  -- it is a set of challenges."
Supercomputer Computations Research Institute |   John F. Kennedy (15 July 60)
Newsgroups: sci.physics
From: firth@sei.cmu.edu (Robert Firth)
Subject: Re: Impure Mathematics
Organization: Software Engineering Institute
Date: Thu, 27 Aug 1992 13:21:41 GMT

In article <suzanne.74@mailhub.scf.lmsc.lockheed.com> suzanne@mailhub.scf.lmsc.lockheed.com (Suzanne Barrett) writes:

>... So-called "cute" postings that denigrate other 
>races, the opposite sex, are NEVER in good taste.

and concludes with:

>Suzanne who has spent far to many years trying to avoid the Neanderthal 
>mentality evident by this poster. 

Priceless, absolutely priceless.  Don't you love it when these
Cro-Magnon prigs fall flat on their neotenous faces?
From: weemba@sagi.wistar.upenn.edu (Matthew P Wiener)
Newsgroups: sci.physics
Subject: Re: Misner et al.
Date: 31 Aug 92 14:04:25 GMT
Reply-To: weemba@sagi.wistar.upenn.edu (Matthew P Wiener)
Organization: The Wistar Institute of Anatomy and Biology
In-reply-to: mcirvin@husc8.harvard.edu (Mcirvin)

In article <mcirvin.715055017@husc8>, mcirvin@husc8 (Mcirvin) writes:
>I despise the portions in which it lapses into bad free-verse poetry or
>clipped stereo-manual language without articles.  The latter seems to
>happen, furthermore, when complicated calculations are being described.

Actually, Wheeler is sometimes at his best when he gets poetic.  He and
his coauthors don't deliver occasionally, but Wheeler is trying to reach
beyond formulae to motivate somebody to make his visions rigorous.

>Also, the machinery it builds up to explain cotangent spaces and 
>differential forms is far too baroque for what is being explained, and
>I suspect it mostly confuses people.

Yet it's worth understanding!  See William L Burke SPACETIME GEOMETRY
COSMOLOGY, an undergraduate introduction that spells out this very
visualization in great clarity.
-- 
-Matthew P Wiener (weemba@sagi.wistar.upenn.edu)
From: tekman@ecn.purdue.edu (Erkan Tekman)
Newsgroups: sci.physics
Subject: Re: LaTeX submission to Phys. Rev. ?
Date: 27 Aug 92 19:30:05 GMT
Distribution: na
Organization: Purdue University Engineering Computer Network

In article <13525.2a9ce733@ohstpy.mps.ohio-state.edu>, balbes@ohstpy.mps.ohio-state.edu writes:
|> In article <1992Aug27.170256.26054@noose.ecn.purdue.edu>, tekman@ecn.purdue.edu (Erkan Tekman) writes:
|> > By the way, you may also send figures via e-mail if you have them in
|> > postscript format (not the encapsulated one, though).
|> 
|> When did this happen?  The insert published a few months ago
|> said they were working on it but couldn't yet accept postscript.

I did submit figures via e-mail in late January this year, and the page-proofs
had everything in place. No problem so far.

Here is the message I got from Phys. Rev. people on figure submissions:

  We can accept figures by electronic mail as long as they are
  formatted using PostScript.  It is necessary to follow these
  simple steps:

  1.  It is essential that line lengths for PostScript files do
  not exceed 80 characters.

  2.  Many gateways will drop completely a line that begins with
  a period.  It is essential, therefore, that a blank space is
  inserted at the beginning of any such lines before being transmitted.

  3.  These files have the potential to be very large, and since many
  systems are unable to transmit files over 100,000 bytes, it may be
  necessary to break the files appropriately for transmission purposes.

  4.  Please do not send us Encapsulated PostScript files; such files
  are designed for graphics import/export and will not print when sent
  to a printer.  Please send us PostScript files that use a regular
  page description.

Erkan Tekman
tekman@ecn.purdue.edu
From: tak@maxwell.physics.purdue.edu (Todd A. Keaffaber)
Newsgroups: sci.physics
Subject: I need help making PAW, TAS, and GEANT
Keywords: PAW, GEANT, TAS
Date: 25 Aug 92 18:04:13 GMT
Organization: Purdue University Physics Department


	I would like to build PAW, TAS, and GEANT on a DEC 5000/240
running Ulitrix 4.1.  I am having trouble getting the make files to
work and want to know if anybody has those three programs working
on the same system.   I can use either cnl200 or cnl201.
	Any help will be apprecited.

				Thanks,
				Todd
				keaffabe@purds0.physics.purdue.edu
			or	tak@maxwell.physics.purdue.edu
From: keithh@tplrd.tpl.oz.au (Keith Harwood)
Newsgroups: sci.physics
Subject: Re: My son would like to know about photons...
Date: 1 Sep 92 03:17:58 GMT
Organization: Telectronics Pacing Systems


In article <10506@sun13.scri.fsu.edu>, jac@ds8.scri.fsu.edu (Jim Carr) writes:
> In article <1992Aug26.142916.533@csc.canterbury.ac.nz> phys169@csc.canterbury.ac.nz writes:
> >I have a question on behalf of my 9-year old son...
> 
> Great!  I hope he has more.  Having followed the thread, I want to 
> reinforce Scott Chase's answer as the best response to the question:
> 
> >If you can split atoms, can you split photons?
> 
> That is, an atom is made up of identifiable constituent parts: protons, 
> neutrons, and electrons.  These constituents can be rearranged in 
> various ways, one of which is the splitting (fission) of an atom that, 
> under appropriate conditions, releases energy because the constituents 
> are more tightly bound in the final configuration. 
> 
> In this sense, you cannot split a photon since it has no constituent 
> parts; a photon is an elementary particle.  
> 

Er, not only can you chop photons into pieces, but you can use scissors
to do so. Well, OK, they have to be hi-tech scissors. Get an aperture 
and chopper wheel with so many teeth and rotating at such a speed that 
the aperture is open for a time of half a metre at the speed of light. 
Get a source of metre long photons (a green line of krypton is handy
for this) and shine the light through the aperture. The photons coming
out at the other side are only half a metre long. However, this isn't
as much fun as it seems. One of the rules for playing this game is
that when we chop a photon in half, all the energy goes into one of
the halves, leaving nothing for the other. This means that the 
half length photons coming out have almost the same colour as the
ones going in, they are just slightly paler. (Translation into 
physics: the photons coming out have the same centre wavelength,
but the line is broader.)

Keith Harwood.
Xref: sparky sci.physics:13925 alt.sex:28126