HDTenEightyP/NetNews huggingface dataset:
From: sichase@csa3.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Pure energy (Was:Re: energy, mass, and all that)
Date: 20 Nov 1992 10:08 PST
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
Distribution: world
NNTP-Posting-Host: 128.3.254.198
News-Software: VAX/VMS VNEWS 1.41    


In article <1992Nov20.160419.119506@watson.ibm.com>, platt@watson.ibm.com (Daniel E. Platt) writes...

[... lots of stuff with which I agree deleted ...]

>The argument
>I'm responding to is more like the old Star Trek's episode where
>everyone is staring at a viewer at a glowing blob, and Spock says
>that it is "...pure energy."  In response to that, I want to ask
>"pure energy of what?"  A lot of people come out of their first
>exposure to E=mc^2 thinking that you can completely convert the mass
>in a chunk of desk into 'pure energy.'  Most often, it isn't made
>clear that the 'conversion' occurs in reactions subject to strict
>conservation laws.  Maybe I'm arguing about something pedantic.

This is a good point.  "Pure energy" is meaningless.   Only particles
or collections of particles (virtual or otherwise) can have energy.  
Perhaps you can make some sense of the notion by defining pure energy
to be the total energy of a bosonic field, so that the energy is not
carried by fermions.  A bath of photons, for example, or the energy
stored in a static EM field (virtual photons) comes as close to my
notion of what "pure energy" is as anything I can think of.

I wonder, in fact, if nonlinear light-light interactions might allow one
to create complex photonic objects in the absence of matter, assuming
the photon intensity is large enough that the nonlinearities can be
made arbitrarily important.  

There is an episode of STTNG (which just aired as a repeat last night in
the Bay Area) in which a guy transforms into a being clearly meant to 
be composed of pure energy.  If the entire rest mass of your body were
converted into photons in the same volume, I wonder if the nonlinearities
would be enough to keep your parts interacting enough that you wouldn't
just disassemble.

Never mind.  This is getting silly.

-Scott
--------------------
Scott I. Chase			"It is not a simple life to be a single cell,
SICHASE@CSA2.LBL.GOV		 although I have no right to say so, having
				 been a single cell so long ago myself that I 
				 have no memory at all of that stage of my 
				 life." - Lewis Thomas
Newsgroups: sci.physics
From: snyder@henry.ece.cmu.edu (John Snyder)
Subject: Re: Why is "Physics Today" so expensive?  (Are there student discounts?)
Organization: Physics Department, Carnegie Mellon University
Date: Tue, 17 Nov 1992 04:07:11 GMT

In article <41095@sdcc12.ucsd.edu> ph600fcy@sdcc14.ucsd.edu (Matthew Harrington) writes:
>I looked into subscribing to Physics Today and I was
>shocked that the price was something like $125 for a monthly.  I get
>Science for $47 and it is a weekly!
>
>I know that I should write P.T. with this question, but I'm
>impatient and don't want to wait a month for the reply.  So, is
>there a less expensive way for undergraduates to get Physics Today,
>or am I stuck with trying to find it at the library, where it is
>frequently in use?  Thanks in advance,
>			
>					Regards,
>
>					Matt Harrington
>
>
>PS. Also, are there other general physics periodicals which net.people
>recommend?  Nothing too technical -- just the facts, ma'am.
> 
>-- 
>---------------------------------
>Matthew B. Harrington
>mbharrington@ucsd.edu


There is:  Become a member of SPS (the Society of Physics Students),
or a student member of the American Physical Society.
Physics Today subscription is included in the price of membership.

John
snyder@henry.ece.cmu.edu


Newsgroups: sci.physics
From: srctran@world.std.com (Gregory Aharonian)
Subject: Flying fast enough and becoming a black hole
Organization: The World
Distribution: sci.physics
Date: Thu, 19 Nov 1992 16:18:41 GMT

   I just finished reading a science fiction (actually with an Islamic
setting, a rarity in the field), which had as one of the main points of
the story that if you built a spaceship and continually accelerated,
eventually you relativistic mass, for the size of the spaceship, would
be large enough to cause collapse into a blackhole.  Not being good with
keeping track of boosts, I wonder if in a large enough universe, with
enough energy, if this is possible or meaningful. And if so, what do you
feel in the rest frame of the spaceship when collapse occurs?

It's the first time I ever seen this scenario suggested in a sci or sci-fi
book, and it seems an interesting one to explore.

Greg Aharonian
-- 
**************************************************************************
Greg Aharonian
Source Translation & Optimiztion
P.O. Box 404, Belmont, MA 02178
From: Benjamin.J.Tilly@dartmouth.edu (Benjamin J. Tilly)
Newsgroups: sci.physics
Subject: A "Paradox"
Date: 17 Nov 92 01:46:42 GMT
Organization: Dartmouth College, Hanover, NH
X-Posted-From: InterNews1.0a5@newshost.dartmouth.edu

Here is an interesting problem which I thought of. It is well known
that a charged particle moving through a magnetic field does not gain
or lose kinetic energy. However it is also well-known that a magnet
moving through a magnetic field can gain kinetic energy. But a magnet
is a collection of charged particles each of which does not gain
kinetic energy so how can this be? I believe that I know the answer but
I will just leave this to see if other people come to the same
conclusion that I have.

Ben Tilly
From: mcirvin@husc8.harvard.edu (Mcirvin)
Newsgroups: sci.physics
Subject: Re: energy, mass, and all that
Date: 23 Nov 92 01:19:32 GMT

jtbell@hubcap.clemson.edu (Jon Bell) writes:

>Just out of curiosity, has anyone actually _observed_ the increased mass
>(or weight) of a hot object?  (I'm not disputing Matthew's statement, just
>wondering if there is any direct experimental evidence for it.)

I don't know-- I doubt it's been done in any direct way-- but I do know
that the *time dilation* due to differences in thermal energy has been
observed, by Mossbauer spectroscopy.  Pound and Rebka had to correct for
it in their famous gravitational-redshift experiment, in which they
measured the redshift of photons traveling up a shaft in Jefferson Lab
(and the blueshift of photons traveling down).  They got bad results until
they corrected for the temperature difference between the ends of the
experiment.  Iron-57 nuclei jiggling around at a higher temperature decay
more slowly from their first excited state! 
 
-- 
Matt McIrvin
From: boozer@gallant.apple.com (Chuq Von Rospach)
Newsgroups: sci.physics
Subject: Where can I get basic science equiptment for school age children?
Keywords: catalogs
Date: 24 Nov 92 01:14:34 GMT
Organization: I is a writur


Where can I get the basic science [physics/chemestry] equiptment for teaching
grade school children?

Addresses of places in the San Francisco 
Addresses of mail-order companies

Glenn Boozer
Boozer@apple.com
Newsgroups: sci.physics
From: hougen@focus.csl.uiuc.edu (Darrell Roy Hougen)
Newsgroups: sci.physics,sci.math
Subject: Fresnel coefficients for unpolarized light?
Date: 17 Nov 1992 03:21:27 GMT
Organization: Center for Reliable and High-Performance Computing, University of Illinois at Urbana-Champaign
NNTP-Posting-Host: focus.csl.uiuc.edu
Summary: What are the Fresnel coefficients for unpolarized light?
Keywords: Fresnel,light,polarization

Does anyone know how to compute the power of unpolarized
electromagnetic radiation?  What I really need to know is what the
Fresnel coefficients are for unpolarized light but I think I can
compute them if I can find an answer to the first question.

I suppose one could assume a uniform distribution of polarization
vectors and work from there.  It must be something really simple.

Thanks in advance.

Darrell
From: elliot.weinberg@nitelog.com (Elliot Weinberg)
Newsgroups: sci.physics
Subject: Re: a question on powerfu
Date: 15 Nov 92 08:14:00 GMT
Reply-To: elliot.weinberg@nitelog.com (Elliot Weinberg)
Organization: Nitelog BBS - Monterey, CA - 408-655-1096

SJQ>   >
SJQ>   >      Are there any lasers available which will actually cut things?
SJQ>   > The ones I see for sale in catalogs (like Edmund Scientific) seem only
SJQ>   > to be for demonstration purposes. Is it possible to obtain a laser
SJQ>   > that will cut metal, or are they only industrial ones that weigh tons
SJQ>   > and cost millions? If anyone has any info on this (company names,
SJQ>   > etc.) please reply to mlevin@husc8.harvard.edu.

Since you already have received a relevant response, I hope you will
forgive some reminiscences from earlier days. I wonder how many laser
users know that in the early days(shortly after Maiman's little ruby lit
up the world in 1960) there was much confusion as to how to compare
various lasers with different pulse lengths, powers, energies,
coherence (goes to focusing ability), etc. For quite some time the
standard unit was a Gillette! I. e. the "strength" of a laser was
measured by the number of stacked razor blades that the laser could
punch a hole through in one shot. Those were the days when "MASER"
meant "military applications seem extremely remote" or maybe "more
applied scientists eat regularly". I still have some neat slides showing
sparks flying from one such shot. I guess I don't remember whether a
"hole in one" was par for the course? Regards.
From: kezhao@sdphu1.ucsd.edu (Kezhao Zhang)
Newsgroups: sci.physics
Subject: Maxwell's demon: new results
Date: 17 Nov 1992 06:59:45 GMT
Organization: Physics Department, UCSD
Distribution: world
NNTP-Posting-Host: sdphu1.ucsd.edu


Although there have been some "proofs" of why Maxwell's demon 
cannot work (e.g. Brillouin's arguments), explicit models of Maxwell's 
demon *do* exist even in the realm of classical mechanics.
As shown in a paper in the current issue of the Physical Review A 
(October 15, vol.46, no.8, p.4598), a purely mechanical model of Maxwell's 
demon can be constructed explicitly under the laws of classical mechanics.
(The performance of the demon, of course, violates the second law of 
thermodynamics.)  It is crucial to realize that the effects of Maxwell's
demon on the motion of the gas particles are equivalent to a force which
is velocity-dependent.  To construct the mechanical demon, there is 
no need to consider how information about the movement of the particles 
is collected, processed, and used to control a trap-door of some kind.  
Instead, one can consider what kind of velocity-dependent force fields
(Lorentz force doesn't work) can implement the overall effects of the demon.
The model is simple and straightforward.  Interested readers are referred 
to the above-mentioned article.  If your want PostScript version of text 
(or LaTex version, if you prefer) and the PostScript figures,  please send 
your request to kezhao@sdphu1.ucsd.edu.  We'll send you a copy via e-mail.

Kezhao Zhang 
kezhao@sdphu1.ucsd.edu
Department of Physics
University of California, San Diego
La Jolla, CA 92093

Newsgroups: sci.physics
From: crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass)
Subject: Top 10 Cited References in the 80's
Originator: crb7q@kelvin.seas.Virginia.EDU
Organization: University of Virginia
Date: Wed, 18 Nov 1992 19:33:50 GMT


     Reading the latest Economist (11/14/92), I happened upon the
     ten experimental reports that were most referenced in the 1980's.
     Of the ten, three are physics-related, the other seven are
     biology-related.  The three are:

         2. Bedortz and Muller, "Possible high-Tc superconductivity
            in the Ba-La-Cu-O system", Z. Phys. B, 64:189 (1986).
         3. Wu \etal, "Superconductivity at 93K in a new mixed-phase
            Y-Ba-Cu-O compound system at ambient pressure", PRL, 58:908
            (1987).
         5. Maeda \etal, "A new high-Tc superconductor without a rare earth
            element"  Jap J Appl Phys, 27:3209 (1988).

     It is interesting to speculate that without the discovery of high-Tc
     superconductivity, all of the 'Top 10' would be biology.  Of course,
     judging by the inhuman publication rates of certain people in the 
     medical community, at the level of several hundred publications a year
     some could be wholly self referential (humor inferred).

                                dale bass
-- 
C. R. Bass                                          crb7q@virginia.edu        
Department of Mechanical, 
     Aerospace and Nuclear Engineering
University of Virginia                              (804) 924-7926
Newsgroups: sci.physics
From: pratt@Sunburn.Stanford.EDU (Vaughan R. Pratt)
Subject: Re: Lowneheim-Skolem theorem (was: Continuos vs. discrete models)
Organization: Computer Science Department,  Stanford University.
Date: Sun, 22 Nov 1992 00:27:03 GMT

In article <368@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:
>In article <1992Nov20.182803.14288@CSD-NewsHost.Stanford.EDU>, pratt@Sunburn.Stanford.EDU (Vaughan R. Pratt) writes:
>> >... QM does not predict
>> >the delays to be expected in tests of Bell's inequality. If these arguments
>> >hold, this will provide the incentive to do the experiments to measure these
>> >delays. QM needs to be extended to predict these delays and the only way
>> >to do this is through experiment. My expectation is that these experiments
>> >will provide the first measures of the structure of quantum collapse. I
>> >think it will be impossible to account for this structure with a continuous
>> >model. 
>> 
>> Sounds like an untestable hypothesis.  What experiment could possibly
>> decide whether only countably many reals occur in nature?
>
>The discussion on L-S has apparently misled you. I believe that the
>space-time manifold is discrete, i. e. not continuous. There are many
>ways to discriminate between a continuous and discrete model and this
>has nothing to do with countability.

So why this raging debate about how many reals, then?
-- 
Vaughan Pratt	  		A fallacy is worth a thousand steps.
From: columbus@strident.think.com (Michael Weiss)
Newsgroups: sci.physics
Subject: Re: TIME HAS INERTIA -  LOWENHEIM-SKOLEM PARADOX UNDRESSED
Date: 19 Nov 92 11:09:54
Organization: Thinking Machines Corporation, Cambridge MA, USA
NNTP-Posting-Host: strident.think.com
In-reply-to: abian@iastate.edu's message of 18 Nov 92 19:11:46 GMT

In article <abian.722113906@pv343f.vincent.iastate.edu> abian@iastate.edu
(Alexander Abian) writes: 

   Dear Messrs  PRATT , BUDNIK et al,

	 I will construct two examples of Set-Theories  C and U  such that 
   in C the set {1,2} is countable and in U the set {1,2}  is uncountable!

   [description of C-- a finite collection of sets-- omitted.]

   So, the entire set-theoretical model C has the ABOVE SETS - NOTHING
   MORE.  Of course, it is not a model for ZF set-theory.  However, it is a
   model for some set-theory. [...]  It is a very, very, very weak
   set-theoretical model BUT IT IS A SET-THEORETICAL MODEL !

Are you serious?  Never mind, if this is all just a big put-on, you'd
never admit it.


To quote Humpty Dumpty-- who certainly reacted to provocation-- "there's
glory for you!"


For the record, the Loewenheim-Skolem paradox is considered a paradox
because it says there is a model *of ZFC* which is countable.  And ZFC
contains the theorem "the power set of omega is uncountable".  These two
statements are apparently contradictory, hence the paradox.

And for any readers who haven't seen this before: the contradiction is only
apparent, and is resolved by noting that the bijection between omega and
its power-set-within-the-countable-model is not in the model.
From: columbus@strident.think.com (Michael Weiss)
Newsgroups: sci.physics
Subject: Re: Lowneheim-Skolem theorem (was: Continuos vs. discrete models)
Date: 19 Nov 92 15:54:52
Organization: Thinking Machines Corporation, Cambridge MA, USA
	<1992Nov18.133219.6664@sei.cmu.edu> <362@mtnmath.UUCP>
NNTP-Posting-Host: strident.think.com
In-reply-to: paul@mtnmath.UUCP's message of 19 Nov 92 16:58:18 GMT

In article <362@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:


   I think it will be difficult to build a discrete theory that
   encompasses GR and QM. The issue is not how difficult the theory is, but
   what approach gives the simplest model that accounts for experimental
   results. Arguments about countable sets have little relevance to this
   question. 

Yes! Exactly right!

   They do allow one to avoid making certain errors such as
   thinking that the continuum is a necessary mathematical element in
   any physical theory.

Did anyone ever make this claim, i.e., that it is impossible to build a
consistent physical theory without the continuum?  My impression is that
the Defenders of the Continuum (hmm...  sounds like the title for an SF
novel) in this newsgroup simply prefer continuum math to discrete math--
and also, there are well-worked continuum-based theories, with warts to be
sure, for which detailed discrete replacements have yet to be offered.

"We can dream, but we need not deliberately court nightmares."  For some,
getting rid of R looks like a nightmare.

Personally, I am not fond of the Brouwer-Heyting-Bishop approach to
mathematics.  On the other hand, I think it would be delightful if someone
created a new physical theory out of some strange-smelling brew of math
logic, model theory, and who know what else (braids too, gotta have
braids!), that at one blow "solved" quantum gravity, gave a new resolution
to all the old QM koans, and predicted new, experimentally verified,
physics.  However, I'm not holding my breath.
From: bweiner@ruhets.rutgers.edu (Benjamin Weiner)
Newsgroups: sci.physics
Subject: Re: Top 10 Cited References in the 80's
Date: 19 Nov 92 20:43:09 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass) writes:
>     It is interesting to speculate that without the discovery of high-Tc
>     superconductivity, all of the 'Top 10' would be biology.  Of course,
>     judging by the inhuman publication rates of certain people in the 
>     medical community, at the level of several hundred publications a year
>     some could be wholly self referential (humor inferred).

The top 10 are generally biologists; or medical researchers (who tend
to be worse about spewing out enormous numbers of self-citing papers,
it seems.)  A year or so ago a different survey of highly cited papers,
including theory, had nine biology researchers and Ed Witten as the Top
10 citees.  Witten's appearance was noted as unusual since they are
almost always biologists.

Someone at the Institute for Scientific Information (publishers of SCI)
once told me that the annual appearance of the Top 10 list is awaited
nervously by the people who tend to be on it and that some take falling 
off it very hard (concomitant loss of prestige, money,etc).  Whatever one 
may say about the pressure to publish and reliance on stupid counts of
total papers published in physics, it's worse in medical research.

- Ben
-----[new quote]
"When J. Edgar Hoover gives you a requirement for complete
[telecommunications] surveillance of all Quakers in the United States,
when Richard M. Nixon is a Quaker and he's the President of the United
States, it gets pretty funny."  - Frank Raven, retired NSA official
Newsgroups: sci.physics
From: greg@skatter.usask.ca
Subject: Re: Anyone checking UNITS? (Abian)
Organization: University of Saskatchewan
Date: Mon, 23 Nov 1992 23:48:07 GMT

From article <wcscps.722546141@cunews>, by wcscps@alfred.carleton.ca (Mike Richardson):
>  I was leafing thru the news, and noticed some of what Mr. Abian said
> (IF I may quote): "My little finger has more intelligence than Newton
> and Einstein put together"
>   
>  Very impressive (If true).
> 
>  Mr. Abian also says (In the tag line of each message), 
> "E=mcc (Einstein) must be replaced by E=m(0)exp(-At) (Abian)"
>  
>  Now, I'm a T.A. for 1'st year physics, and if ANYONE handed this in
> they would FAIL.  Not on the basis of theory, but plain UNITS.
> 
> [E]=kg*m*m/s*s
> [mcc]=kg *(m/s)*(m/s)=[E]
>   
>  So far so good...
> However, Mr. Abian says  E=m(0)exp(-At)
> 
> [m(0)]=kg  (of course)
> [exp(-At)]=dimensionless
> 
>  From his equation, I can deduce that [A]=inverse time, but perhaps, 
> Mr. Abian, you missed a proportionality constant somewhere? I may not
> be as intelligent as you claim to be, but I propose a slight
> modification to your theory...
> 
> E=mcc (Einstein) must be replace by E=m(0)C exp(-At) (Abian-DeKok)
> 
> Where the C, of course is a constant with [C]=m*m/s*s
>   Hopefully waiting for future recognition.
> 
> Alan DeKok
> (using Physics Society account)
> 

Touche.... me thinks??  We await the worm....

Newsgroups: sci.physics
From: sarfatti@well.sf.ca.us (Jack Sarfatti)
Subject: Re: One Ramsay error in no-go FTL
Organization: Whole Earth 'Lectronic Link
Date: Wed, 18 Nov 1992 01:44:55 GMT


Ramsay writes:

"If f and g differed only by a phase, then there would be
constructive and/or destructive interference everywhere, uniformly,
according to what that phase difference was."

Let f(x) = e^is(x)g(x)

f(x) + g(x) = g(x)[e^is(x) + 1]

|f(x) + g(x)|^2 = 2|g(x)|^2 {1 + cos[s(x)]}

Conservation of energy requires

Integral{|f(x) + g(x)|^2 dx} = Integral{[|f(x)|^2 + |g(x)|^2]dx}

therefore,

Integral{|g(x)|^2cos[s(x)]dx} = 0

so that Ramsay's remark is not strictly mathematically correct. If the
phase s(x) were constant it would have to be pi/2.

so for example, if i|a,e,+> = |a,o,+>

|a,b> -> |a,e,+>{e^iphi|b,e,+> + i|b,o,->}/sqrt2

= |a,e,+>|b>

Therefore the receiver local probabilities are:

p(e') = |<e'|b>|^2 = [1 + sin(2theta)cos(phi - pi/2)]/2

      = [1 + sin(2theta)sin(phi)]/2

and p(o') = 1 - p(e')

so that the quantum connection signal is

p(e') - p(o') = sin(2theta)sin(phi)
Newsgroups: sci.physics
From: hoyt@isus.UUCP (Hoyt A. Stearns jr.)
Subject: Re: Compelling Mysteries (II)
Followup-To: sci.physics
Keywords: Reciprocal System, Gamma Ray Bursters, Antimatter
Organization: International Society of Unified Science
Date: Mon, 23 Nov 1992 02:51:57 GMT

From the Reciprocal System theory:

In article <1992Nov10.203037.13332@sfu.ca> palmer@sfu.ca (Leigh Palmer) writes:
>
>How 'bout the question of particle-antiparticle asymmetry of the universe? I
>realize that there is a clear majority position in the polls, but is that the
>way we do science?

The universe is symmetric about c. There is an equal amount of anti-mass
in the >c half of the universe, (including galaxies, planets etc).
The light from anti-stars is seen as 2.7K background radiation.
The anti-atoms are seen as cosmic rays, which make their entry to
the <c half at the full speed of light.
>
>What are the gamma ray bursters? 
Anti stars going supernova.

-- 
Hoyt A. Stearns jr.|hoyt@          | International Society of Unified Science|
4131 E. Cannon Dr. |isus.tnet.com -| Advancing Dewey B. Larson's Reciprocal  |
Phoenix, AZ. 85028 |ncar!enuucp!   | System- a unified physical theory.      |
voice_602_996_1717 telesys!isus!hoyt The Universe in two postulates__________|
Newsgroups: sci.physics