Newsgroup sci.physics 204929

Directory

Subject: Re: What is the Cause of Time Dilation? -- From: throopw@sheol.org (Wayne Throop)
Subject: Re: Magnetic symmetry supports new ocean ridge model -- From: jnhead@anaxamander.lpl.arizona.edu (James Head)
Subject: Some simple questions -- From: "James W. Kincaid III"
Subject: off-topic-notice spncm1996301073708: 8 off-topic articles in discussion newsgroup @@sci.physics -- From:
Subject: Re: "Essential" reality (was: When did Nietzsche wimp out?) -- From: cri@tiac.net (Richard Harter)
Subject: Re: THE INDUSTRIAL RELIGION -- From: yqg023@mrbig.rockwell.com (Jim F. Glass x60375)
Subject: Re: Using C for number-crunching (was: Numerical solution to Schrodinger's Eq) -- From: pausch@electra.saaf.se (Paul Schlyter)
Subject: Re: Fullerene -- From: mseewald@lakeforest.franken.de (Michael Seewald)
Subject: Re: What is the Cause of Time Dilation? -- From: Cees Roos
Subject: Re: Can Science Say If God Exists? -- From: mrjones@yoss.canweb.net (Jones)
Subject: Re: Increasing RADAR cross section or visibility -- From: "Paul Kisatsky"
Subject: Re: [Fwd: Re: The Conscious Mind -- David Chalmers] -- From: andersw+@pitt.edu (Anders N Weinstein)
Subject: Re: Increasing RADAR cross section or visibility -- From: "Paul Kisatsky"
Subject: Re: A photon - what is it really ? -- From: lrmead@ocean.st.usm.edu (Lawrence R. Mead)
Subject: Re: A photon - what is it really ? -- From: lrmead@ocean.st.usm.edu (Lawrence R. Mead)
Subject: Re: Does X = Biblical God Exist (was DOES X ESIST?) -- From: Les Cargill
Subject: Re: Looking for a book on x-ray -- From: meron@cars3.uchicago.edu
Subject: Re: can value of pi change? -- From: meron@cars3.uchicago.edu
Subject: Re: "Essential" reality (was: When did Nietzsche wimp out?) -- From: meron@cars3.uchicago.edu
Subject: Re: A photon - what is it really ? (Question for Mr. Potts) -- From: lrmead@ocean.st.usm.edu (Lawrence R. Mead)
Subject: Re: Mars life: First a few things need explaining... -- From: bcohen@lpl.arizona.edu (Barbara A Cohen)
Subject: Re: test -- From: john@mail.petcom.com. (John S.)
Subject: Re: Using C for number-crunching (was: Numerical solution to Schrodinger's Eq) -- From: Alexey Goldin
Subject: Re: minimun energy of a photon -- From: lrmead@ocean.st.usm.edu (Lawrence R. Mead)
Subject: Re: Is glass a solid? -- From: Stephen La Joie
Subject: Re: Gravity In Intervals? -- From: lrmead@ocean.st.usm.edu (Lawrence R. Mead)
Subject: Re: Need help: Physics education on-line -- From: onscrn@aol.com (Onscrn)
Subject: Re: When will the U.S. finally go metric? -- From: Robert Burgman
Subject: "Nutty Physicists?" -- From: F.Ali@lboro.ac.uk (F Ali)
Subject: Re: Anti-Gravity Device? Riemanns theory of gravitation -- From: nervous@netrover.com (nervous)
Subject: Maxwell's Equations in anisotropic media (was Re: Using C for number-crunching (was: Numerical solution to Schrodinger's Eq) -- From: adler@pulsar.wku.edu (Allen Adler)
Subject: Re: Reducibility (was: Science and Aesthetics) -- From: jti@santafe.santafe.edu (Jeff Inman)
Subject: dimensions other then our usual 4 -- From: bmorriso@netcom.ca(Barry E. Morrison)
Subject: Re: A photon - what is it really ? -- From: laradex3@sj.znet.com (Larry Adams)
Subject: Re: When social critics wimp out ... (was: Nietzsche) -- From: mkagalen@lynx.dac.neu.edu (Michael Kagalenko)
Subject: Re: Increasing RADAR cross section or visibility -- From: borism@interlog.com (Boris Mohar)
Subject: Java-powered dynamics course -- From: Mark Sutherland
Subject: Re: This Week's Finds in Mathematical Physics (Week 93) -- From: baez@math.ucr.edu
Subject: Believe it or not, Correct Proof of Fermat's Last Theorem (text) -- From: James Harris
Subject: Re: probability is relativistic -- From: Christopher McKinstry

Articles

Subject: Re: What is the Cause of Time Dilation?
From: throopw@sheol.org (Wayne Throop)
Date: Mon, 28 Oct 1996 17:33:13 GMT
:: savainl@pacificnet.net (Louis Savain)
:: The most sensible solution to this conundrum that I can see is that
:: the earth-bound twin is moving *absolutely* much slower than the
:: absolute speed of light than the traveling twin.  OK.  Calm down now,
:: guys and gals.  :-) It's just a partially baked idea I've been
:: thinking about recently.  I haven't thought it through completely. 
:: I'm working on it.  Be cool. 
Well, OK, go ahead and assume an "absolute velocity", an "absolute rest
frame" for all objects.  Then work the problem through (remembering to
use relativistic velocity composition to get the outbound and
returnbount velocities for the spacecraft). 
And when you've worked it through, if you do it correctly, you'll
find that the twin so-called-paradox has exactly the same result if
the "earth" is taken to move at a constant "absolute" velocity of 
0.9999999999999999 lightspeed throughout.  As long as you assign
a constant "absolute" velocity to earth, you'll get the same results,
no matter what this "absolute" velocity is.
Since this is so, I think the fact that SR involves no concept
of "absolute velocity" to be quite reasonable.
: bjon@ix.netcom.com (Brian Jones)
: In SRT, clocks must slow with their absolute speeds because otherwise
: one could easily truly set clocks by using simple clock transport. 
SRT involves no such concept.  Bjon may argue that clocks "must" have
an "absolute speed", but that's just his philosophical prejudice, and
has nothing to do with the formalism of special relativity, nor does
it actually establish the need for an "absolute" frame.
Bjon always claims that "time dilation" etc "wouldn't happen" if
there weren't an absolute frame, because if there weren't, there
wouldn't be an objective, "real" cause for it.  But it is fairly
clear that bjons alleged "reasoning" to support this is a
classic in stance of proof by emphatic assertion.
The reason I'm so certain bjon's argument is faulty is because
it's geometrically the same argument as the claim that there must
be a real, absolute direction "left", because if there weren't
things couldn't be foreshortened by rotation.
--
Wayne Throop   throopw@sheol.org  http://sheol.org/throopw
               throopw@cisco.com
Return to Top
Subject: Re: Magnetic symmetry supports new ocean ridge model
From: jnhead@anaxamander.lpl.arizona.edu (James Head)
Date: 28 Oct 1996 17:45:57 GMT
The first attempt to post this article apparently failed.  Apologies if
this is a duplication...
In article  S Krueger  writes:
>
>Jupiter is an enormous gaseous planet with a nuclear furnace in it's core
>(hence the radiation). What's this got to do with the Earth?
An enormous gaseous planet with a nuclear furnace is called a star.  J
is too small to iniate fusion reactions--you need about 80 Mjup at least.
Js excess radiation is from the conversion of gravitational energy--
either from accretion or differentiation.
For the hair-splitters out there, earth also gives off more radiation 
than it receives from the sun--by ~80 milliwatts/sq. meter (out of
~1300kW/m^2, so big deal). 
-- 
James N. Head                    |        IMP Calibration Team
Lunar and Planetary Lab          |        So many pixels
jnhead@lpl.arizona.edu           |        So little time
Return to Top
Subject: Some simple questions
From: "James W. Kincaid III"
Date: Mon, 28 Oct 1996 10:15:26 -0800
Here are a few questions that have been bothering me.  Hopefully 
someone out there will take heart and give me some guidance.  I'm not "in 
the know" in regards to advanced physics so please go easy on me.
  Let's say we have a metal sphere that is a few cm in diameter and 
negatively charged to capacity.  We get out into deep space and make sure 
we are traveling in a strait line.  Then we make sure were not 
accelerating, decelerating or rotating in relation to the distant stars 
and galaxies.  So we are moving along and I have you hold the charged 
sphere perfectly still.  As you do this, we both observe the hairs on the 
back of your hand standing out and note the electrostatic charge.  At 
this point I whip out a gauss meter and try to determine if there is any 
magnetic field present around the charged sphere.  My question is, will I 
find a magnetic field?  If there would be a magnetic field under these 
conditions then there is no reason to read further, but please let me 
know.  Now I know that if we decelerate or accelerate we will see a 
magnetic field.  However, what I don't know is, will the magnetic field 
direction change in relation to whether we're accelerating or 
decelerating?  In other words, would the magnetic field direction be 
oriented one way for accelerating and oppositely oriented for 
deceleration?  I wish I had some sensitive equipment!  Then I could just 
do the experiments and I wouldn't have to bug you guys.  Speaking of 
bugging, here's another question.
  Same situation as above, but this time we have several charged spheres 
attached to a dielectric disk equipped with a central axis and a means of 
applying rotational torque.  The Rowland experiment should come to mind 
as you imagine this set up.  Ok, we apply some rotational torque and 
disengage the torque, allowing the disk arrangement to spin freely.  I 
know that there is now a magnetic field present around the disk as a 
result of the free rotation.  I also know that this magnetic field 
requires no extra power to exist and that the rotation and magnetic field 
can exist forever provide there are no frictional losses.  What I don't 
know is, if we apply rotational torque to speed it up, will there be an 
increase in the magnetic field that is greater than the field that will 
be present at the moment we disengage the torque.  Of course there will 
be a much greater magnetic field when we stop applying torque, because 
the disk is spinning much faster now.  What I want to know is, will the 
torque when applied increase the magnetic field to a point greater than 
the ending speed?
  To anyone willing to spend the time answering any of these questions, I 
am eternally greatful.
James
Return to Top
Subject: off-topic-notice spncm1996301073708: 8 off-topic articles in discussion newsgroup @@sci.physics
From:
Date: Mon, 28 Oct 1996 07:37:08 GMT
-----BEGIN PGP SIGNED MESSAGE-----
These articles appeared to be off-topic to the 'bot, who posts these notices as
a convenience to the Usenet readers, who may choose to mark these articles as
"already read".  It would be inappropriate for anyone to interfere with the
propagation of these articles based only on this 'bot's notices.
You can find the software to process these notices at CancelMoose's[tm] WWW
site: http://www.cm.org.  This 'bot is not affiliated with the CM[TM].
Poster breakdown, culled from the From: headers:
  8 Archimedes.Plutonium@dartmouth.edu (Archimedes Plutonium)
The 'bot does not e-mail these posters and is not affiliated with the several
people who choose to do so.
@@BEGIN NCM HEADERS
Version: 0.9
Issuer: sci.physics-NoCeMbot@bwalk.dm.com
Type: off-topic
Newsgroup: sci.physics
Action: hide
Delete: no
Count: 8
Notice-ID: spncm1996301073708
@@BEGIN NCM BODY
<550vg3$7ga@dartvax.dartmouth.edu>	sci.physics
	sci.bio.microbiology
	sci.bio.misc
	sci.med
	sci.med.diseases.cancer
<5510pr$b6j@dartvax.dartmouth.edu>	sci.astro
	sci.physics
<5513vo$snu@dartvax.dartmouth.edu>	sci.physics
	sci.chem
	talk.philosophy.misc
	sci.misc
	sci.bio.misc
	sci.math
	misc.invest.stocks
	alt.president.clinton
<54tpkp$4ee@dartvax.dartmouth.edu>	sci.physics
	sci.math
<54u84n$o3n@dartvax.dartmouth.edu>	sci.physics
	sci.math
<54uarn$gqr@dartvax.dartmouth.edu>	sci.chem
	sci.physics
<54tvni$ma5@dartvax.dartmouth.edu>	sci.physics
	sci.math
<54udr8$1pq@dartvax.dartmouth.edu>	sci.chem
	sci.physics
@@END NCM BODY
Feel free to e-mail the 'bot for a copy of its PGP public key or to comment on
its criteria for finding off-topic articles. All e-mail will be read by humans.
-----BEGIN PGP SIGNATURE-----
Version: 2.6
iQCVAwUBMnRipYz0ceX+vLURAQE1cAP/TieN8y3pdj4COmX2jbmZ8RahcjC/Kejs
Dt6DB1FCNWahoGH0/tIqfaC+n2Mx3D9K/8XUVMFw1Wy4+2Z78YCmqX1Jmjpxo/2s
ayc6aR17ri23BhllzFjkV1P6VOqZEkP2eCX0o2rfX3opxuibITrKlO4K80/NorYv
PYhpYnJAjSc=
=3MN6
-----END PGP SIGNATURE-----
Return to Top
Subject: Re: "Essential" reality (was: When did Nietzsche wimp out?)
From: cri@tiac.net (Richard Harter)
Date: Mon, 28 Oct 1996 19:16:34 GMT
Steven Hines  wrote:
>Russell Turpin wrote:
>> 
>> There is no comparable passage of faith in the sciences.  If a
>> student learns how to engage the relevant questions, perform the
>> relevant research, intelligently analyze the results, and write
>> up the results (all issues of performance, not belief), it does
>> not matter whether he is some kind of Platonist who believes that
>> he is investigating the ultimate Reality or a Buddhist who thinks
>> it is all illusion or a science skeptic who thinks it is just a
>> meaningless game.  Whatever one's metaphysics and epistemology,
>> as long as they do not reduce a person to dysfunction (hence, the
>> requirement about finding their way to the classroom), they are
>> enough to learn and do science.  There is no faith to which one
>> must leap, no metaphysical tenets that one must accept.
>Don't you have to believe that every event has a cause? Doesn't
>acceptance of this proposition constitute a "passage of faith"?
Urk.  Not only do you not have to believe that every event has a
cause, you'll do well to lay any such notion firmly aside if you're
going to come to terms with modern physics.  What you do have to "do"
is accept *as a working hypothesis* that the universe is lawful.  If
it isn't, it will let you know that you are wrong in its own way.  As
it happens, proceeding on the presumption that one can make sense out
of the universe has been extraordinarily productive and successful.
But to make that presumption does not require a passage of faith.
>I'm not saying that I haven't made this "passage", since I have
>experienced many events and believe that all of them were caused.
>But of course many times I have just assumed that they were...
>-----------------
>Steve Hines
>shines@sdd.hp.com
Richard Harter, cri@tiac.net, The Concord Research Institute
URL = http://www.tiac.net/users/cri, phone = 1-508-369-3911
Life is tough. The other day I was pulled over for doing trochee's
in an iambic pentameter zone and they revoked my poetic license.
Return to Top
Subject: Re: THE INDUSTRIAL RELIGION
From: yqg023@mrbig.rockwell.com (Jim F. Glass x60375)
Date: 28 Oct 1996 16:27:29 GMT
In article <326AC2E1.7553@easynet.co.uk>, "sdef!"  writes:
|> Adam Ierymenko wrote:
|> 
|> > 
|> > Colonization is almost a reality.  The real problem is getting the stuff
|> > up there.  That is the biggest obstacle, which may be about to be solved.
|> > Once we actually get up there, our technology right now is more than adequate
|> > to construct an artificial environment that is self-sustaining.
|> 
|> We already have an infinitely complex and beautiful REAL environment which 
|> requires no technology from us to sustain both itself and us. These pathetic 
|> madcap schemes are what is destroying it. It is a shame that these people don't do 
|> something useful with their lives rather than screwing things up for the rest of 
|> life on earth, including other humans.
|> Those who need artificial environments and 'virtual reality' do so because they 
|> cannot handle the real world. This does not give them the right to destroy it in 
|> their futile attempts to dominate it. there is a growing movement in the world 
|> that is prepared to actively oppose this minority of mad (mostly)men.
|> Andy
|> -- 
|> http://www.hrc.wmin.ac.uk/campaigns/earthfirst.html
|> South Downs EF!,  Prior House      
|> 6, Tilbury Place, Brighton BN2 2GY,  UK
|> "Happy is he who dares to defend passionately
|> that which he loves" -Ovidius
The "movement" is called "Ludditism", and it is they who are mad;
they want us to return to mud huts and digging for grubs in the
dirt.
Tell you what.  YOU go live a subsistence lifestyle; enjoy the
termites.
While you are at it, kindly forego the evil results of our "mad"ness,
including computers, electricity, modern medicine, aircraft, etc.
THEN we might not call you a bunch of ignorant hypocrites.  The irony
of seeing such blather as your posting on an internet newsgroup must
escape you.
The rest of us will colonize space and keep working toward the stars.
Jim Glass
Opinions my own, and my own only--as if you could doubt it.
Return to Top
Subject: Re: Using C for number-crunching (was: Numerical solution to Schrodinger's Eq)
From: pausch@electra.saaf.se (Paul Schlyter)
Date: 28 Oct 1996 17:47:50 +0100
In article <54nld7$hqv@zephyr.cerfacs.fr>,
Muller Jens Dominik  wrote:
> In article <54lftc$qr8@thorn.cc.usm.edu>, lrmead@ocean.st.usm.edu (Lawrence R. Mead) writes:
>>Maple can easily handle this; its language is very Pascal-like. C is not
>>really a language one should do numerical number crunching in.
> 
> What? I think I have to strongly disagree. You can code "FORTAN-style"
> in C where efficiency is at a prime and recover the speed of FORTRAN
> without any problems. Even if you don't restrict your programming
> style, your basic C-code will run at some 90% of FORTRAN. Jens.
I agree.  Only FORTRAN and Ada have better support and/or efficiency
for numerical programming than C/C++ does.  Thus C/C++ is a better
choice than almost any other programming language for
number-crunching programs.
-- 
----------------------------------------------------------------
Paul Schlyter,  Swedish Amateur Astronomer's Society (SAAF)
Grev Turegatan 40,  S-114 38 Stockholm,  SWEDEN
e-mail:  pausch@saaf.se        psr@home.ausys.se
Return to Top
Subject: Re: Fullerene
From: mseewald@lakeforest.franken.de (Michael Seewald)
Date: 27 Oct 1996 22:54:00 +0200
In article <6Jaf67Q2CvB@smello.ruhr.de> GiZMO@smello.ruhr.de (Christian  
Schur)  writes:
> Sie werden auch in der Leichtbauweise angewandt. Sie ersetzen die
> Kohlefaser, da sie eine bessere Stabilitaet besitzen.
Wo??? Leichtbauweise? Bauindustrie womöglich? Das halte ich - ehrlich gesagt  
- für ein Gerücht! Technische Anwendungen der Fullerene gibt es noch nicht,  
einige exotische Anwendungsmöglichkeiten hat man gefunden (Vakuumschmier- 
mittel), aber mehr noch nicht.
Ciao,
Michael
--
Michael Seewald  at his WinNT site in Bavaria: mseewald@lakeforest.franken.de
PGP Mail Welcome!      at Bayreuth University: Michael.Seewald@uni-bayreuth.de
Return to Top
Subject: Re: What is the Cause of Time Dilation?
From: Cees Roos
Date: Mon, 28 Oct 1996 19:35:14 +0000 (GMT)
In article <3274194c.11422953@news.pacificnet.net>, Louis Savain
 wrote:
> Does anyone here know whether
> or not the SRT paper was submitted before of after the MM experiment?
> Louis Savain
1881-1887 Michelson-Morley experiments.
1893      Hypothesis of Lorentz-contraction by Lorentz and Fitzgerald
          simultaneously, to explain the MM results.
1905      Einstein publishes his SRT, giving the Lorentz-contraction
          a sound theoretical basis.
-- 
Regards, Cees Roos.
I know that all I know is what I know, including that I
do not know what I do not know.
Return to Top
Subject: Re: Can Science Say If God Exists?
From: mrjones@yoss.canweb.net (Jones)
Date: Mon, 28 Oct 1996 18:28:23 GMT
On Sun, 27 Oct 1996 11:54:01 GMT, soliver@capecod.net (Suzane Oliver)
typed something like:
>On Sun, 27 Oct 1996 02:09:15 -0700, jsnodgrass  wrote:
>
>>-Einstein said GOD exists...
>
>1)  Exact quotes and refrences please.
>
>2) What did Einstein mean by 'god'
>
>3) So what? Why do you believe what Einstein said anyway??
Lets not get anal here, Einstein was a jew and it was because of his
belief in god that he could not reconcile things like quantum theory.
This should not be news to anyone who knows anything about the man.
As to what he meant, probably not what you would like and...
so what? Well I think the original poster was relying on his rep as
the greatest thinker of our time as support for belief in god. 
I thought it was rather clear, if not convinicing, so I hope you were
being sarcastic.
Can anyone say: Duh?
Return to Top
Subject: Re: Increasing RADAR cross section or visibility
From: "Paul Kisatsky"
Date: Mon, 28 Oct 1996 17:54:56 GMT
In order to increase radar cross section, you need to utilize a highly
reflective substance on the objcet.  Wrapping it in a smooth aluminum foil,
for example.  But this is not the best way.  Using a corner reflector made
of the same, lightweight aluminum foil, works much better.  A corner
reflector has the unique property of retroreflection, ie it will return the
reflected radar energy back into the direction from which it was
illuminated rather than scattering it in multiple directions.  Doing a
little ray bounce drawing in a right angle will convince you of this.  You
did not say what frequency your radar is, since the size of the corner
reflector needed must be bigger at lower frequencies but can be smaller as
the freq increases and wavelength decreases.  The corner reflector in radar
is the equivalent of the "cats eye" in optics that we see at night on road
signs.  Notice how strongly they reflect back to you.  I am a physicist in
R&D; for the Dept of Army.  I hope this helps you.
Paul Kisatsky
Richard Weideman  wrote in article
<3274B7E6.D3B@realtime.co.za>...
> Hi,
> 
> I'm trying to find a lightweight material with a high radar cross
> section, or any other information about increasing the radar visibility
> of a small object.
> 
> Can anyone point me in the right direction ?
> 
> All the stuff I find on the net is about REDUCING the cross section for
> the purpose of hiding things away ...
> (various mass destruction devices etc.)
> 
> I'm trying to make something MORE visible, not less
> (for recreational purposes, not mass destruction)
> 
> Cheerz
> Richard
> 
Return to Top
Subject: Re: [Fwd: Re: The Conscious Mind -- David Chalmers]
From: andersw+@pitt.edu (Anders N Weinstein)
Date: 28 Oct 1996 19:02:43 GMT
In article ,
David Yeo   wrote:
>By "simplifies the physical stance" I mean that it acts as a sort of
>shorthand for processes which, if one cared to, one could describe in
>terms of the physical stance (assuming it was known). 
This I disagree with. It's like saying "there's a chair in my office"
is a shorthand for "there are a bunch of molecules of such and such an
arrangment at a certain location". The latter does not carry as much
information as the former -- it does not say that there is a chair in
my office. 
So a physicist who predicts motions of molecules under basic physical
descriptions does not thereby predict things under other descriptions,
such as the intentional -- not unless the higher-level description can be
reductively defined in terms of the lower level one. Which is what I
doubt.
Better to think of the intentional facts as a distinct realm of fact
inhering in the physical facts like form in matter, I think. So
physical science gets to deal with the matter, while being blind to the
forms (meanings) carried therein. For the latter, something like
ecological psychology or even existential phenomenology might be the
right discipline, not basic physics or anything that can be defined
using it as a basis.
Return to Top
Subject: Re: Increasing RADAR cross section or visibility
From: "Paul Kisatsky"
Date: Mon, 28 Oct 1996 17:33:57 GMT
In order to increase radar cross section, you would like to have your
object made of or coated with a highly reflecting material, such as
aluminum foil.  But this is not the best way.  A "corner reflector" has the
unique property of reflecting the radar rays that hit it back to the
direction from which they originally came.  This is called a
"retroreflector" and the radar equivalent to the familiar "cats eye" in
optics that you see attached to sign posts.  Notice how brightly they glow
in your headlights at night.  They are a multitude of corner reflectors. 
Drawing a little ray diagram on a right angle corner will convince you of
this.  You did not say what the frequency of your radar was because this
will affect the size of the corner reflector you need.  The higher the
freq, the smaller the corner reflector you can use...and you can make it of
a light weight metal such as heavy al foil or flashing.  I am a physicist
for the Dept of Army...I hope this helps you.
Paul Kisatsky
Richard Weideman  wrote in article
<3274B7E6.D3B@realtime.co.za>...
> Hi,
> 
> I'm trying to find a lightweight material with a high radar cross
> section, or any other information about increasing the radar visibility
> of a small object.
> 
> Can anyone point me in the right direction ?
> 
> All the stuff I find on the net is about REDUCING the cross section for
> the purpose of hiding things away ...
> (various mass destruction devices etc.)
> 
> I'm trying to make something MORE visible, not less
> (for recreational purposes, not mass destruction)
> 
> Cheerz
> Richard
> 
Return to Top
Subject: Re: A photon - what is it really ?
From: lrmead@ocean.st.usm.edu (Lawrence R. Mead)
Date: 28 Oct 1996 19:08:05 GMT
Larry Adams (laradex3@sj.znet.com) wrote:
: 
: A photon is the combination of two spin
: waves of opposite helicity within matter
: undergoing magnetic resonance.
: 
: L.A.
While a *plane* polarized wave is indeed a superposition of right and left
circularly polarized waves of the amplitude, this is a mathematical
identity which follows from the principle of superposition - it has nothing
whatever to do with magnetic resonance.
-- 
Lawrence R. Mead (lrmead@whale.st.usm.edu) 
ESCHEW OBFUSCATION ! ESPOUSE ELUCIDATION !
http://www-dept.usm.edu/~scitech/phy/mead.html 
Return to Top
Subject: Re: A photon - what is it really ?
From: lrmead@ocean.st.usm.edu (Lawrence R. Mead)
Date: 28 Oct 1996 19:09:56 GMT
Lloyd Johnson (johnson@mintaka.sdsu.edu) wrote:
: It has been stated very clearly in this discussion that photons of
: different energies travel at different velocities through glass and
: other transparent media.  This claim is contrary to wave phenomena.
No. This phenomenon is *expected* from wave characteristics.
: This claim should then be tested in a laboratory using lasers of very
: different frequencies to direct light through a significant length of
: glass to measure the speed of light.  Make sure that it is a straight
: path so internal reflections don't interfere with the experiment.  Is
: there a difference between the speed measured using the red laser and
: the green laser?
Yes, indeed and the difference is given precisely by the indices of
refraction at those wavelengths.
-- 
Lawrence R. Mead (lrmead@whale.st.usm.edu) 
ESCHEW OBFUSCATION ! ESPOUSE ELUCIDATION !
http://www-dept.usm.edu/~scitech/phy/mead.html 
Return to Top
Subject: Re: Does X = Biblical God Exist (was DOES X ESIST?)
From: Les Cargill
Date: Mon, 28 Oct 1996 13:05:35 -0600

> Since I have defined God as an consistent formal system (with a
> few additions) then there is a statement and its converse which
> are undecidable in that formal system.  That is, God does not
> understand them.  For God to remain a consistent formal system and
> grow, He cannot adopt both of these statements.  If, however,
> one statement were true at some places in the universe and the other
> were true in other places, then this problem could be solved.  Note
> how we have easily arrived at the same place as one of the more
> popular inflationary models of the universe which also has the
> fundamental properties of space/time changing over vast distances.
> Maybe someone can give us the name of this theory, as I forget.
> 
Formal systems are inherently less powerful that intelligent 
entities. Read "Godel, Escher, Bach". In it, Hofstaedter (sp?) states 
"Proof is less powerful that truth". 
> > Secondly there is a mental trap if we refer to the entity that you
> > describe as the Biblical God. Most people think of a 'Person' or
> > a personal god of a particular sort when we speak of the Biblical
> > 'God'. The entity that you describe does not seem to be a person.
> 
> The word "person" has no operational definition (that is, I have
> no procedure for testing an individual to see if he is a person or
> not).  I asserted the God I defined acts in a manner very
Funny, I do. If an entity has the same number of chromosomes as I do,
then it is a person. Of course, you have to allow for Mongolism, but
this should work.
< mo' snippage >
-- 
Les Cargill   		    Optical Data Systems, Inc.
lcargill@ods.com            1101 E. Arapaho Road
(214) 238-5351              Richardson, Tx 75081
Return to Top
Subject: Re: Looking for a book on x-ray
From: meron@cars3.uchicago.edu
Date: Mon, 28 Oct 1996 19:02:14 GMT
In article <32747A3C.41C67EA6@mp-sun1.informatik.uni-mannheim.de>, Georg Gutermuth  writes:
>Hello out there!
>
>Perhaps someone can help me with my problem.
>
>I am looking for literature on x-ray. To be more precise, a formular
>describing the form of an artificially produced x-ray spectrum as well
>as a formular for the interaction cross section of x-ray with matter
>(photo-effect, compton-effect and e+/e- production)
>
>Thank you very much in advance
>
For some general info you may look up 
X-ray Diffraction, by B.E. Warren.
A bit dated but quite relevant and dirt cheap.  You can get it from 
Dover Publications, for $10.
For all you ever wanted to know and more, I would suggest
Handbook on Synchrotron Radiation, Published by North Holland.  Huge 
multi volume work and very expensive, but I'm sure that you can find a 
university library carrying it.
Mati Meron			| "When you argue with a fool,
meron@cars.uchicago.edu		|  chances are he is doing just the same"
Return to Top
Subject: Re: can value of pi change?
From: meron@cars3.uchicago.edu
Date: Mon, 28 Oct 1996 19:13:01 GMT
In article <552lk2$nv7@sjx-ixn10.ix.netcom.com>, Alan \"Uncle Al\" Schwartz  writes:
>
>meron@cars3.uchicago.edu wrote:
>>In article <550d1q$suv@herald.concentric.net>, Hitech@cris.com (Hitech) writes:
>>>In article <54u957$bf1@geraldo.cc.utexas.edu>,
>>>Jeff Candy  wrote:
>>>>
>>>>exp(i pi) = -1 has no intrinsic physical content.  e=mc^2 does.
>>>>This is not to say that exp(ix) is an unimportant function in the 
>>>>physical sciences.  
>>>
>>>Great explanation!  I take it from your response there is no reasonably
>>>fundamental physical understanding of e^(i Pi) = -1 or else you would have
>>>provided it.
>>>
>>Why do you think there should be a physical understanding.  This is a 
>>mathematical statement, not a physical one.
>
>
>Euler's Equation unites algebra and analytic geometry. I'd be >real< 
>curcumspect about minimizing that.
>
I would not even dream of minimizing that.  It is one of the most 
beautiful (and surprising) things that ever came from math.  But it is 
not a statement about physical quantities, thus asking for 
"fundamental physical understanding" is missing the mark.  What is the 
fundamental physical understanding of x^2 - y^2 = (x - y)*(x + y) ?
Mati Meron			| "When you argue with a fool,
meron@cars.uchicago.edu		|  chances are he is doing just the same"
Return to Top
Subject: Re: "Essential" reality (was: When did Nietzsche wimp out?)
From: meron@cars3.uchicago.edu
Date: Mon, 28 Oct 1996 19:19:57 GMT
In article <3274E91F.5247@sdd.hp.com>, Steven Hines  writes:
>Russell Turpin wrote:
>> 
>> There is no comparable passage of faith in the sciences.  If a
>> student learns how to engage the relevant questions, perform the
>> relevant research, intelligently analyze the results, and write
>> up the results (all issues of performance, not belief), it does
>> not matter whether he is some kind of Platonist who believes that
>> he is investigating the ultimate Reality or a Buddhist who thinks
>> it is all illusion or a science skeptic who thinks it is just a
>> meaningless game.  Whatever one's metaphysics and epistemology,
>> as long as they do not reduce a person to dysfunction (hence, the
>> requirement about finding their way to the classroom), they are
>> enough to learn and do science.  There is no faith to which one
>> must leap, no metaphysical tenets that one must accept.
>
>Don't you have to believe that every event has a cause? Doesn't
>acceptance of this proposition constitute a "passage of faith"?
>
Assume, yes, believe, no.  There is a difference.  Science is self 
checking and self correcting.  It makes assumptions, draws conclusions 
and checks the conclusions versus experimantal data.  But the 
assumptions aren't sacred and if the data fails to support your 
conclusions you may be forced to modify your assumptions.  It is the 
continuous cross checking that distinguishes assumptions from beliefs.
Mati Meron			| "When you argue with a fool,
meron@cars.uchicago.edu		|  chances are he is doing just the same"
Return to Top
Subject: Re: A photon - what is it really ? (Question for Mr. Potts)
From: lrmead@ocean.st.usm.edu (Lawrence R. Mead)
Date: 28 Oct 1996 19:25:55 GMT
Ken Seto (kenseto@erinet.com) wrote:
: Christopher R Volpe  wrote:
: 
: >magnus.lidgren wrote:
: >> 
: >> A short summary of some of the questions and answers:
: 
: >> 
: >> Q3. As I understand it, Quantum mechanics states that when a photon makes
: >> its way through a glass body, it is absorbed and (a new?) (re?)-emitted a number of
: >> times before it passes through. Every time "the photon" actually is a "real" photon it
: >> travels at c speed and during "the absorption period" "it" stands still ??
: >> 
: >> Majority opinion was that the photon goes through repeated absorbtions
: >> and re-emissions (in the forward direction) thus delaying "its" passage
: >> through the glass in correlation with the index of refraction for glass.
: 
: >Anthony Potts disagrees with this. I thought the same thing, until he
: >offerred me the following explanation in email (which I hope he doesn't
: >mind my sharing)
: 
: >++++++++++++++++++++Begin included message++++++++++++++++++++++++
: >On Wed, 9 Oct 1996, Christopher R Volpe wrote:
: 
: >> Anthony Potts wrote:
: >> >
: >> >
: >> > The net effect is to make the photons travel slower, even though they are
: >> > not being absorbed and reemitted by the medium.
: >>
: >> Interesting. I was told that this absorbtion and reemission is precisely
: >> why it is slower.
: >>
: >Well, I don't know who told you that, but it seems to be a very dodgy
: >way
: >of looking at it. For a start, without the light being absorbed by a
: >single atom, maxwell's equations tell us that it will be slowed, because
: >of the change in the permittivity and permeability.
: 
: >Secondly, if the light were absorbed, and reemitted, why on earth would
: >it
: >keep going in the same direction? The atoms have no reason to emit the
: >light in the same way that it first hit them, so you would just get the
The atoms *do* have good reason to emit preferentially in the forward
directon: conservation of momentum. Remember that the abosorbtion/reemission
process is not done by a stationary atom.
But nonetheless, his point is well-taken; the elastic scattering of
waves is the main effect.
To quote J. D. Jacson [page 683]: [scattering by quasi-free charges]
" But in the forward direction the scattering per electron increases 
rapidly to quite large values compared to the Thomson (free charge)
cross section."
Also, see the remarks following eqn. 14.110 .
-- 
Lawrence R. Mead (lrmead@whale.st.usm.edu) 
ESCHEW OBFUSCATION ! ESPOUSE ELUCIDATION !
http://www-dept.usm.edu/~scitech/phy/mead.html 
Return to Top
Subject: Re: Mars life: First a few things need explaining...
From: bcohen@lpl.arizona.edu (Barbara A Cohen)
Date: 28 Oct 1996 19:35:36 GMT
tadchem (tadchem@arn.net) wrote:
: On Sun, 11 Aug 1996 05:00:17 GMT, Alan Douglas said...
: 
: >From what I've heard from those who know of such things, there has
: >been work done on this, but the results suggest Earth's gravity is too
: >great and the atmosphere too thick to make it likely that an impact
: >could propel a rock to escape velocities without vaporising it. 
: There is a theory running around that, in the early years of planet Earth, a 
: Mars-sized object struck it, seriously rearranging the crust, mantle ,and 
: even the core, and splashing a lot of mantle rock up into high orbit,  Thos 
: rock eventually cooled and solidified into the Moon.  I've even seen video 
: of a computer simulation of this.  Didn't get out of the gravity well, 
: however.
: 
: >Theoretical arguments aside, the question has been floated on usenet
: >as to whether there has ever been a meteorite found which was known to
: >have come from Earth in the first place.  I've not seen an answer to
: >that yet, but I strongly suspect it would be "no".
: Would you accept tektites (terrestrial impact ejecta that achieves 
: sub-orbital trajectories like Alan Shepard's)?
At the AAS Division for Planetary Sciences meeting last week here
in Tucson, there was a fair bit of this kind of discussion.  There is no
meteorite in our collections (that we know of) that originated
on the earth, got blown into interplanetary space for a few Ma,
then came back down to earth.  Tektites aren't classic "meteorites"
in that sense.  Most people attribute this fact to the Earth's thick
atmosphere and it's comparatively large escape velocity.  There
should be even fewer Venusian meteorites.
There's also the queston of orbital dynamics, where it is much easier
for material to go towards the sun than away from it, so Mars ejecta
has an easier time getting to the Earth, Venus, Mercury, etc. than
Earth ejecta (if any) has of getting to Mars.  Perhaps we could sample
the entire inner solar system by roving around Mercury for a while? :)
                Barbara Cohen
     Cosmochemical Cocktail Mixer, PhD to be
     ---------------------------------------
Madness takes its toll. Please have exact change.
Return to Top
Subject: Re: test
From: john@mail.petcom.com. (John S.)
Date: 28 Oct 1996 19:27:37 GMT
In article <54vsgo$e7d@sjx-ixn7.ix.netcom.com>, uncleal0@ix.netcom.com 
says...
>
>nhb003@lightspeed.net wrote:
>>making sure I can post
>>
>
>Clueless newbie twits should be multiply posting to  news:alt.test  lest 
>those of us with some concept of netiquette and vigilante justice be 
>making sure we can flame.
>
>-- 
>Alan "Uncle Al" Schwartz
>UncleAl0@ix.netcom.com ("zero" before @)
>http://www.ultra.net.au/~wisby/uncleal.htm  (lots of + new)
> (Toxic URLs! Unsafe for children, Democrats, and most mammals)
>"Quis custodiet ipsos custodes?"  The Net!
>
Welcome- UncleAn-style. :-)
We're not all so bilious.
Return to Top
Subject: Re: Using C for number-crunching (was: Numerical solution to Schrodinger's Eq)
From: Alexey Goldin
Date: Mon, 28 Oct 1996 20:09:01 GMT
pausch@electra.saaf.se (Paul Schlyter) writes:
>  
> I agree.  Only FORTRAN and Ada have better support and/or efficiency
> for numerical programming than C/C++ does.  Thus C/C++ is a better
> choice than almost any other programming language for
> number-crunching programs.
Last time I checked FFT benchmark in CMU Common Lisp on my Linux
machine was 30%-20% faster than in C (both double precision with heavy
optimization)
Return to Top
Subject: Re: minimun energy of a photon
From: lrmead@ocean.st.usm.edu (Lawrence R. Mead)
Date: 28 Oct 1996 20:59:53 GMT
David A. Cary (d.cary@ieee.org) wrote:
: In article <51kc4l$aga@thorn.cc.usm.edu>,
: lrmead@ocean.st.usm.edu (Lawrence R. Mead) wrote:
: +[snip]
: +: The uncertainty principle relates to measuring the values of variables
: +                                       ^^^^^^^^^^^^^^^^^^^^
: +: rather than the values that they can take.
: +                   ^^^^^^^^^^^^^^^^^^^^^^^^^
: +
: +What - operationally - is the difference ??
: 
: Operationally, one may measure that a particle has a position (x) 20 mm
: above the table. The uncertainty principle relates to how accurately (dx)
: (+-1 mm ? +-1 nm ?) that can be measured.
: 
: The Heisenberg uncertainty principle(s)
:   dE*dT =< hbar
:   dx*dp_x =< hbar
: 
: say nothing about what particular Energy, Time, Position, and Momentum will
: be measured. It only states to what accuracy (dE, dT, dx, dp_x) they can be
: measured.
I repeat my question: what is the *operational* difference? [note the
word operational - look up its meaning if you do not know it]
: Some people believe that particles and photons actually do have some exact
Some people "believe" in fairies too. In science, we believe in what we
can *measure* .
-- 
Lawrence R. Mead (lrmead@whale.st.usm.edu) 
ESCHEW OBFUSCATION ! ESPOUSE ELUCIDATION !
http://www-dept.usm.edu/~scitech/phy/mead.html 
Return to Top
Subject: Re: Is glass a solid?
From: Stephen La Joie
Date: Mon, 28 Oct 1996 20:08:13 GMT
Kelly Miller wrote:
> 
> davidelm  writes:
> 
> >Glass is one of those things which is always a liquid at any
> >temperature.
> 
> just another example that gross ignorance does not prevent the use of
> fingers on a keyboard...
> 
> Kelly Miller
> miller@aries.scs.uiuc.edu
Insults don't prove your point. The do make a point about you.
Take your insults elsewhere, flame-boy.
There are plenty of references to support both sides of this
argument. This is a matter of definition.
Return to Top
Subject: Re: Gravity In Intervals?
From: lrmead@ocean.st.usm.edu (Lawrence R. Mead)
Date: 28 Oct 1996 20:53:20 GMT
Darren Swersky (swersky@compusmart.ab.ca) wrote:
: A beam of light spreads by its distance squared. Therefore, its intensity
: must decrease by its distance squared. At some distance, the beam will be
: so spread out that the individual photons will no longer be touching.
What makes you think the photons were "touching" near the source? And
what does it *mean* to have photons touching??
: Relativists believe photons are indivisible, and while I don't agree, I
: don't see any reason for photons to split up in a beam anyhow. Therefore,
"Relativists" do not "believe" photons are indivisible: they note how
real photons behave and we never experience *half* of a photon or
*1/3* of a photon - always one or two or ... .
[long polemic deleted] According to GR at least, do travel in waves
at lightspeed. The waves of which you spoke [item deleted] is a
*spherical* wave from a *point* source. Indeed those can be broken up
into a superposition of "photons" (right and left cirularized waves) - but
the superposition is rather complicated: the description of what happens
to a spherical wave from the quantum (photon) point of view is not
easily stated in the simplified viewpoint you wish to espouse. The situation
is similar for gravity waves, and a bit more complicated still because 
gravitons are expected to carry spin two, rather than one (with its two base 
states) as for the photon.
: 	Let me know what you think.
: 
: Darren Swersky
: 
: 
-- 
Lawrence R. Mead (lrmead@whale.st.usm.edu) 
ESCHEW OBFUSCATION ! ESPOUSE ELUCIDATION !
http://www-dept.usm.edu/~scitech/phy/mead.html 
Return to Top
Subject: Re: Need help: Physics education on-line
From: onscrn@aol.com (Onscrn)
Date: 28 Oct 1996 15:48:15 -0500
Mike,
If you're interested in particle physics take a look at the OnScreen
Science site at . It's mainly devoted to
Chamber Works, our particle-chamber simulation that requires no advanced
math; but it also has a page of annotated links to other sites of
interest.
Bob Estes
OnScreen Science, Inc.
800-617-6416
onscrn@aol.com
Return to Top
Subject: Re: When will the U.S. finally go metric?
From: Robert Burgman
Date: Mon, 28 Oct 1996 12:37:33 -0800
> 
> >By the way, in _French_ meter is spelled metre _not_ in English.
> 
> In English metre is spelled metre (at least in most places where English
> is spoken/written).  In America they spell the same word meter.
> In Canada, both French and English write "metre". In the late 70's, when
Canada began its metrification, the decision on how to spell metre was
made with the idea that by spelling it "metre", you could distinguish it
from a meter ( parking or volt variety ) by the spelling rather than the
context of the sentence.
Having both languages spell it the same way has its advantages also.
By the way, Canada is a "half and half" country. Part imperial and part
metric. Since our economy is so closely intertwined with the US, the country
could not go 100% metric. We are waiting for our southern neighbour to join
the rest of the world before we switch over 100%. As an engineer, I use both
systems of measurement each day. I much prefer to do calculations in metric.
-- 
           Robert Burgman, P. Eng.
           Sr. Project Engineer - Systems
           Avenor Pulp Mill - Gold River, BC
Return to Top
Subject: "Nutty Physicists?"
From: F.Ali@lboro.ac.uk (F Ali)
Date: 28 Oct 1996 20:37:33 GMT
Hello readers,
Though I am not a physicist, I am very interested in the behaviour of 
physicists, especially the stereotypical, eccentric, absent minded Professor. 
I am doing a study on academics and the odd or unusual things they have got 
up to, and overall general nutty behaviour and attitudes.
Has anyone out there got any amusing/humorous anecdotes of their 
lecturers/professors/researchers which they would share with me? 
Alternatively, if you are one of the above, have you ever done anything which 
has raised a laugh (if only to yourself) and perpetuated the great Nutty 
Professor tradition?
All responses, however short or long, gratefully received -- I'll post some 
of the best back to the group.
Please send all replies to: F.Ali@Lboro.ac.uk
Many thanks,
Farooq Ali
Return to Top
Subject: Re: Anti-Gravity Device? Riemanns theory of gravitation
From: nervous@netrover.com (nervous)
Date: Mon, 28 Oct 1996 16:02:04 -0500
In article <54r4h4$him@udevdiv.Unibase.COM>, john@petcom.com wrote:
-> Why do I never see Simon's posts first-hand? And I never seem to receive a Cc
-> either. Hmmph. Maybe my program needs debriefing.
-> Yes, thank you Simon. I'm sorry for the finger-bite. :-) Keep it out there,
-> please.
-> My statement that there are no black holes is not to say that there aren't
-> some extremely massive objects out there. The atomic model that I have
-> developed, and from which my concept of gravity just seemed to drop out,
-> postulates that energy assumes similar patterns at certain points as one
-> moves up the scale. Just like one finds the same musical note as one 
-> goes from one octave to the next. So, in comparing galaxies to atoms,
-> I developed my Galaxy Model, which treats the arms of a galaxy as if
-> they were the electrons of an atom. This means that the centers of
-> galaxies compare to us as aggregations of protons compare to electrons-
-> 1000 times denser and of opposite charge. Certainly these will be
-> extremely massive bodies, but they are not such because gravity is
-> crushing something which would otherwise be less dense- rather they
-> are dense because that is their nature. Call them black holes if you
-> want, but gravity will reach a limit before it breaks down atoms.
Don't you high-school kids have anything better to talk about?  Galaxies as
atoms! Hahahahah!!! Nice.
-- 
Return to Top
Subject: Maxwell's Equations in anisotropic media (was Re: Using C for number-crunching (was: Numerical solution to Schrodinger's Eq)
From: adler@pulsar.wku.edu (Allen Adler)
Date: 28 Oct 1996 14:52:27 -0600
What would be the best way to obtain numerical solutions of
Maxwell's equations in an anisotropic medium?
Allan Adler
adler@pulsar.cs.wku.edu
Return to Top
Subject: Re: Reducibility (was: Science and Aesthetics)
From: jti@santafe.santafe.edu (Jeff Inman)
Date: 28 Oct 1996 21:07:06 GMT
Mikenew2@aol.com (Mike Birtel) writes:
>jti@santafe.edu (Jeff Inman) wrote:
[re: people who fear "ontological reduction" really just fear determinism]
>>  This needn't be a fear that "spirit" is
>> ultimately deterministic but might quite reasonably be a concern that
>> such a reduction to the inadequate tools and concepts that physicists
>> currently employ constitutes a loss of important aspects of the
>> original.
>> 
>> So, the complaint might quite well be that the inadequacy of reducing
>> experience to the kind of "material" that scientists typically mean,
>> seems to suggest that "material" is poorly understood.  In other
>> words, one can be a materialist without being reductive.  This
>> represents one kind of critique of physics.
>
>I think we essentially agree. I certainly didn't want to imply that any
>physics we have is capable of modeling the "ontological facts," simply that
>the assumption that it someday could is essential to the belief that there
>is nothing special about "experience" except that we aren't capable of
>modeling it with our limited tools and processing power.  
But this blurs your distinction between "ontological" and
"epistemological" reduction.  Changes in what can be known and
observed by science are accompanied by changes in the quality of what
is being observed, that is, in what "matter" is, etc.  Science is not
merely extended its power to explain somthing that remains unchanging,
it is describing a changing thing.
>The fact that we
>can't understant reductive models well says nothing about the world, but
>teels us a great deal about ourselves - this was the point of
>distinguishing epistemological from ontological reduction: I fully believe
>in ontological reduction but not epistemological reduction - we simply
>can't work with models when their complexity approaches that of even
>today's physics.
But vice versa, too.  As far as I know, for all the supposed
sophistication of the models, the theories of the *ontos* currently
entertained by scientists don't "expand" (i.e. the opposite of
reduction) to theories of experience, except through the premise you
make, that it might be (or must be) possible.  Hence "ontological
reduction" of experience remains for now untenable.  One werely offers
a promise, by suggesting that this is the result of epistemology.
Presumably, a transformation of the ontology will accompany any
advances against the epistemological limitations.
-- 
"But among those whom this story reached were were also the woman's
 in-laws, and they decided, without telling her a word, to find this
 angel and to see if knew how to fly ..."
Return to Top
Subject: dimensions other then our usual 4
From: bmorriso@netcom.ca(Barry E. Morrison)
Date: 28 Oct 1996 21:12:21 GMT
I have seen references in books and articles that there are more
dimensions than our "normal" four. Maybe as many as 13 or 16; and that
perhaps the others "shrunk," or curled up on themselves, and are tiny
now. I would like to know how the dimensions and the number were
identified; how and why they shrunk; and what the implications are; can
something exist in these other dimensions as well as our own; will our
4 dimensions shrink? Where else might I find information on the
subject? Thanks.
BEM
Return to Top
Subject: Re: A photon - what is it really ?
From: laradex3@sj.znet.com (Larry Adams)
Date: 28 Oct 1996 22:01:06 GMT
In article <55232g$cus@newton.cc.rl.ac.uk>, tony.richards@rl.ac.uk says...
>
>laradex3@sj.znet.com (Larry Adams) wrote:
>>
>>A photon is the combination of two spin
>>waves of opposite helicity within matter
>>undergoing magnetic resonance.
>>
>>L.A.
>>
>BS
>-- 
>Tony Richards
So you haven't read Ferromagnetic Resonance by Vonsovskii,
so what?  L.A.
Return to Top
Subject: Re: When social critics wimp out ... (was: Nietzsche)
From: mkagalen@lynx.dac.neu.edu (Michael Kagalenko)
Date: 28 Oct 1996 14:53:09 -0500
Silke-Maria  Weineck (weinecks@mail2.sas.upenn.edu) wrote:
]Michael Kagalenko (mkagalen@lynx.dac.neu.edu) wrote:
]: Silke-Maria  Weineck (weinecks@mail1.sas.upenn.edu) wrote:
]: ]Michael Kagalenko (mkagalen@lynx.dac.neu.edu) wrote:
]: ]: Silke-Maria  Weineck (weinecks@mail2.sas.upenn.edu) wrote:
]: ]: ]guilt. But here we have the "science" community, intoning in near-unison
]: ]: ]and near-ignorance, "where there's smoke, there must be fire."  
]: ]
]: ]:  You are lying. 
]: ]
]: ]Am I? You have so far demonstrated neither knowledge nor originality i 
]: ]your detractions of Derrida.
]
]:  Actually this is true sentence. since I have not posted any
]:  "detractions of Derrida", I have not "demonstrated either 
]:  knowledge or originality" by them.
]
]: ] Perhaps I'm "lying" about others -- I'm 
]: ]certainly right about you.
]
]
]:   That is false. I challenge you to produce a single post, claiming
]:   that Derrida must be wrong, because
]:  "where there's smoke, there must be fire." Failing that, I 
]:  expect  you to publically apologize for your lying.
]
]
]If you think you're worth an hour spent at altavista, your self-image has 
]re-inflated to an amazing degree. You have never posted a derogatory 
]remark about Derrida? If you say so. I apologize for having 
]misjudged you.
 That's welcome development, but it's not nearly good enough. Here's your 
 claim again:
 ]guilt. But here we have the "science" community, intoning in near-unison
]: ]: ]and near-ignorance, "where there's smoke, there must be fire."
 Produce the post(s) advancing such an argument, or apologize.
-- 
LAWFUL,adj. Compatible with the will of a judge having jurisdiction
                -- Ambrose Bierce, "The Devil's Dictionary"
Return to Top
Subject: Re: Increasing RADAR cross section or visibility
From: borism@interlog.com (Boris Mohar)
Date: Mon, 28 Oct 1996 21:57:54 GMT
On Mon, 28 Oct 1996 15:40:54 +0200, Richard Weideman
 wrote:
>Hi,
>
>I'm trying to find a lightweight material with a high radar cross
>section, or any other information about increasing the radar visibility
>of a small object.
>
>Can anyone point me in the right direction ?
>
>All the stuff I find on the net is about REDUCING the cross section for
>the purpose of hiding things away ...
>(various mass destruction devices etc.)
>
>I'm trying to make something MORE visible, not less
>(for recreational purposes, not mass destruction)
>
>Cheerz
>Richard
 Look up cornercube or retroreflector.  It reflects the signal back to
ita source regardless of relative orientations of the two.
Boris Mohar
Boris
Return to Top
Subject: Java-powered dynamics course
From: Mark Sutherland
Date: Mon, 28 Oct 1996 13:50:56 -0400
*****  FUN@LEARNING.PHYSICS  *****
        o an on-line course - subject matter: dynamics
        o university level, with calculus
Features:
        o Lessons - richly illustrated, colorful, screen-optimized
        o Java applets - interactive simulations of physical processes
        o Animations - illustrations of topics discussed in lessons
        o Tutorials - multiple-choice questions with responses
Ideas for use:
        o Students can use it as a supplement to traditional texts
        o Professors can serve it over a local network to their class,
            use it to illustrate lectures, integrate it with their own 
						on-line materials,...
Advantages:
        o Available in standalone Web-based versions
        o Fast delivery by ftp
        o Easy setup
        o Platform independent - runs the same on all computers
For free samples and further info, go to the World Wide Web address
        http://medb.physics.utoronto.ca/Web/website/fun.html
Return to Top
Subject: Re: This Week's Finds in Mathematical Physics (Week 93)
From: baez@math.ucr.edu
Date: 28 Oct 1996 21:59:57 GMT
Joshua Burton and others have caught some errors:
In article <55153l$r58@charity.ucr.edu>, John Baez  wrote:
>    ELECTROMAGNETIC FORCE          WEAK FORCE         STRONG FORCE
>        
>    photon                          W+                  6 gluons 
>                                    W-
>                                    Z  
There are 8 gluons.  
>Right now, we believe that neutrinos only exist in a
>left-handed form, rotating one way but not the other around the axis
>they move along.  This is intimately related to their apparent
>masslessness.  In fact, for reasons that would take a while to explain,
>the lack of parity symmetry in the Standard Model forces us to assume
>all fermions acquire their mass only through interaction with the Higgs
>particle!  
Joshua notes that were there a right-handed neutrino, it would be
an SU(3) x SU(2) x U(1) singlet (or in math lingo: it'd transform
in the trivial representation), so it could acquire a Majorana mass.
One proposed method is the "seesaw mechanism".  For more on this sort
of thing see the recent thread on sci.physics.research entitled 
"Proof of neutrino rest mass?" and also 
Paul Langacker, Implications of neutrino mass,
http://dept.physics.upenn.edu/~www/neutrino/jhu/jhu.html 
>The Standard Model [...]
>would be ruined by "anomalies" --- certain nightmarish problems that
>can beset a quantum field theory --- if one idly tried to mess with the
>generations by leaving out a quark or the like.  Indeed, this is why the
>charm quark was first predicted, before the generation pattern was fully
>apparent.  
This is wrong.  Joshua notes that while the famous 1969 Adler-Bell-Jackiw
paper on anomalies predates the discovery of the charm quark, and perhaps 
*could* have been used to predict the charm quark, the actual prediction 
of the charm quark by Glashow-Iliopoulos-Maiani in 1970 was made for 
other reasons.  
They proposed this quark, and the so-called "GIM mechanism", to solve some
problems concerning kaon decay.  In the Standard Model as it then stood,
a neutral K-bar meson could decay into a muon-antimuon pair like this:
             W+
dbar--<----~~~~~~~----<---mu+ 
           |     |
          u^     V nu
           |     |
   s-->----~~~~~~~---->---mu-
            W-
(The neutral K-bar is a strange-antidown pair.)   But this decay was
not observed.  Glashow Iliopoulos and Maiani posited the new c quark
so that the process would be cancelled, or almost cancelled, by 
             W+
dbar--<----~~~~~~~----<---mu+
           |     |
          c^     V nu
           |     |
   s-->----~~~~~~~---->---mu-
            W-
Actually Joshua spoke of "neutral kaon mixing" rather than kaon decay,
and I'm getting the above stuff from Kerson Huang's book "Quarks Leptons
and Gauge Fields".  Perhaps the same general problem shows up in something
like the following? 
            W+
dbar--<----~~~~~~~----<---sbar
           |     |
          u^     V u 
           |     |
   s-->----~~~~~~~---->---d
            W-
In any event, Joshua says that his advisor, Mary Gaillard, noted that
the cancellation wouldn't be complete, since the up and charm have
different mass, and used the observed left-over kaon mixing to successfully
predict the charm mass six months before the charm quark --- or more
precisely, the J/psi, which is a c-cbar bound state --- was discovered
by Richter and Ting in 1974.  Ah, the good old days!  
>The Standard
>Model makes no attempt to explain this, although it does suggest that
>there had better be more than 17 quarks --- more, and the strong force
>would not be "asymptotically free" (weak at high energies), which would
>cause lots of problems for the theory. 
There had better NOT be more than 17 of something.  Joshua says
there had better not be more than 17 generations, but Huang's book
says there had better not be more than 17 flavors of quark.  In any
event, we are pretty sure there are no more than 3 generations, unless
the next generation has a darn heavy neutrino or something else really
weird like that happens.
>Gauge
>bosons have n - 2 physical degrees of freedom in n dimensions: for
>example, in dimension 4 the photon has 2 degrees of freedom, the spin-up
>and the spin-down states.  
It would be better to say, "the left and right polarized states".
A corrected version is now at
http://math.ucr.edu/home/baez/week93.html
Return to Top
Subject: Believe it or not, Correct Proof of Fermat's Last Theorem (text)
From: James Harris
Date: Mon, 28 Oct 1996 05:26:10 -0800
Even though I've yet to get email, I suspect that someone is reading
this, at least I hope so.  Here is the correct proof without that
strange muddled ending that was in the first one.  I didn't have to
reach for this one either.  Like the rest of the proof it was just
staring at me in the face.
James S. Harris
Georgia, USA
--------------------------------------------
Introduction.
Fermat's Last Theorem has long been a magnet to the amateur and
professional mathematician alike because of its seeming simplicity; yet,
extraordinary difficulty.  Although there is a proof by Andrew Wiles, I
think it is understandable that the problem still would incite
curiosity.  I would also assume that a simpler solution would also be of
interest.
Note:  The following proof makes extensive use of Fermat's Little
Theorem which isn't usually stated.  I also make use of accepted results
which have came up in my previous posts on sci.math without going over
them in detail again.  
1.  Statement of the Problem:  Fermat's Last Theorem
Given x,y,z, relatively prime, n odd prime 
no solution exists for the equation x^n + y^n = z^n 
2.  Proof for Cases where x,y or z are divisible by n.
Let x=af, y=bg, z=ch  means that
 x+y=h^n or n^{n-1}h^n, z-x=g^n or
 n^{n-1}g^n, and z-y=f^n or n^{n-1}f^n.  
   For example, 
  x^n + y^n = (x+y)(x^{n-1}-x^{n-2}y+...+y^{n-1}) = z^n
Since x,y and z are relatively prime, (x+y) can only be divided out once
and the term it is      multiplied times can have no factors of (x+y)
except for maybe one n factor. 
And,
 (x+y-z)^n = n(z-x)(z-y)(x+y)Q 
where Q 
represents 
all those other terms that are hard to write out for the general case. 
For
 n=3 it is one.  And for n=5
  Q = z^2 - (x+y)z + x^2 + xy + y^2
.  
Using the above the following is always true.
  (x+y-z) = nfghq    (Using Q=q^n)
I can then use my earlier relations to write my equation in terms of
f,g,h,q, n only.  An intermediates step with z divisible by n is
   x + y-z = af - f^n = bg - g^n = n^{n-1}h^n - nch  = nfghq
From which I get
 f^n + 2nfghq + g^n = n^{n-1}h^n   and subtracting   f^n + nfgp + g^n =
(f+g^)n  
(p used for ease of writing the general case, for example, with n=3,
p=f+g)
  gives
   nfg(p-2hq) = (f+g)^n - n^{n-1}h^n
p is always divisible by (f+g) because nfgp=(f+g)^n - (f^n + g^n) 
Since (f+g) must be divisible by n, because in this case z is divisible
by n, requires that f,g,h or q be divisible by n which creates an
infinite regression similar to the one in Fermat's proof for n=3.
The same comes up with x or y divisible by n since you get
  g^n + 2nfghq - h^n = n^{n-1}f^n    subtracting 
  g^n + nghp - h^n = (g-h)^n
gives 
     ngh(p-2fq) = (g-h)^n - n^{n-1}f^n
which requires that f,g,h or q be divisible by n because (g-h) is
divisible by n which is again a contradiction for the reason given
before.
3.  Proof for Case x,y,z not divisible by n 
Extension of Fermat's Little Theorem:
Given a-b divisible by n, a^n - b^n must be divisible by n^2
So Fermat's Last Theorem can be written as
  Given x,y,z relative prime, none divisible by n; n odd prime
 for a solution to exist  (x+y)^n - (x^n + y^n) must be divisible by
n^2.
Now notice that x and y can be written in terms of n like 
x=jn+r and y=kn+s with r,s < n 
 If (x+y)^n - (x^n + y^n)
 were divisible by n^2 from a substitution it can be seen that this
would require that 
     (r+s)^n - (r^n + s^n)   be divisible by n^2  but we can also write
  u+r = c1n, v+s = c2n   which still requires that    (u+v)^n - (u^n +
v^n)   be divisible by n^2 .
But by varying c1 and c2 one can create u's and v's with any desired
modulus with respect to n.  Therefore, the above requires that for any
integers a,b
   (a+b)^n - (a^n + b^n)  must be divisible by n^2  
But  then I can use a=f, b=g which requires that (f+g)^n - (f^n + g^n)
must be divisible by n^2
(in working out the text version I've noticed that all of this isn't
required because f has the same modulus as x and g the same as y anyway)
Which from before equals nfgp and requires that p be divisible by n
But like before I can write
f^n + 2nfghq + g^n = h^n  and again subtract    f^n + nfgp + g^n =
(f+g)^n  
which gives
 nfg(p-2hq) = (f+g)^n - h^n
which conflicts with the requirement that x,y and z be relatively prime,
as before.
It is then seen that  (x+y)^n - (x^n + y^n)
   is not divisible by n^2  which completes the proof of Fermat's Last
Theorem.
Here is one example with an alternate proof of the above for one n.
Notice that for n=5,   (x+y)^n - (x^n + y^n) equals 5xy(x+y)(x^2 + xy +
y^2) 
which would mean that x^2 + xy + y^2 must be divisible by 5.  It's easy
enough
 to see that it can't be just by trying different r's and s'  with 
(r+s)^n - (r^n + s^n).
James S. Harris
Return to Top
Subject: Re: probability is relativistic
From: Christopher McKinstry
Date: Mon, 28 Oct 1996 16:15:04 -0600
if you write pi in base pi, i'm not going to have much trouble guessing
it now am i?
-- 
-K. Christopher McKinstry : Homepage
 http://www.clickable.com/employees/chris/index.html
-Join In The World's Largest AI Effort
 http://www.clickable.com/mist_corpus.html
Return to Top

Downloaded by WWW Programs
Byron Palmer