HDTenEightyP/NetNews huggingface dataset:
From: paul@mtnmath.UUCP (Paul Budnik)
Newsgroups: sci.physics
Subject: Re: QM non-causal?
Date: 12 Dec 92 16:15:24 GMT
Organization: Mountain Math Software, P. O. Box 2124, Saratoga. CA 95070

In article <1992Dec11.231940.28759@newshost.lanl.gov>, jlg@cochiti.lanl.gov (J. Giles) writes:
] In article <433@mtnmath.UUCP>, paul@mtnmath.UUCP (Paul Budnik) writes:
] |> 
] |> Unless you say what principles you are calling into question it is not
] |> possible to debate the issue. Any claim *might* be false if *all* principles
] |> of mathematics and science are called into question.
] 
] But, I'm not making a scientific point - I'm making a 
] philosophical one.  Namely that mathematics is a formal system 
] invented by humans and its only connection with science is
] whatever properties can be verified independently.  Those
] properties of mathematical models which do not correspond
] to verifiable properties of reality are simply not demonstrably
] real and should not be touted as facts.

Yes, but one cannot carry on any scientific debate unless one assumes
that some mathematical models apply to physical reality. The basic
mathematics in Bell's result has been verified and is implicitly assumed
in most physical models. It is little more then elementary statistics and
some basic geometrical assumptions about space and time. Your point is true
trivial and irrelevant. If you want to debate a question such as this you
have to say what principles you are rejecting. Otherwise no rational
argument is possible. 

Paul Budnik
Newsgroups: sci.physics
From: draper@sscvx1.ssc.gov
Subject: Attraction & repulstion Re: The answer to not so fundamental questions?
Organization: Superconducting Super Collider Laboratory
Date: Fri, 11 Dec 1992 21:22:27 GMT

In article <BCR.92Dec11004605@hfl3sn02.cern.ch>, bcr@cernapo.cern.ch (Bill Riemers) writes:
> 
>> why should be attracted to creator of positive charge property and repeals from
>> negative charge
> 
> Like charges exchange more posative momentum photons, while negative charges
     							      ^^^^^^^^
							     "unlike",right?
> exchange more negative momentum photons.
> 
This is extremely interesting! I asked a similar question a while ago, viz.,
what information does a photon carry that conveys whether it sprang from a
positive or negative charge, and hence tells it whether to attract or repel a
charge of unlike or like sign. I got all the proper admonitions about trying to
derive a static field result with Feynman diagrams. But you seem to have an
insight I'm lacking. Please clarify, expand, explain.

Paul Draper
University of Texas at Arlington
Mythink, not UTAthink, not SSCthink, not GOVthink.
Newsgroups: sci.physics
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: Richard P. Feynman
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Mon, 14 Dec 92 00:11:33 GMT

In article <Dec.13.18.15.03.1992.6526@ruhets.rutgers.edu> bweiner@ruhets.rutgers.edu (Benjamin Weiner) writes:

>Sorry Dale, couldn't resist.  To stay close to drifting from the
subject,

Ah yes, staying close to drifting, that's usenet at it's best...

>I was wondering why physicists often feel compelled to put down engineers,
>and I thought of a few reasons:

[various reasons deleted]

Here's my theory.  Physicists are sick of being teased about being
nerds, so they (subconsciously) want to deflect the barbs, thinking,
it's not ME who's a boring grind, I am tremendously creative and love to
ponder the inner mysteries of the universe - it's HIM, that guy over
there, who fits the stereotype!
Organization: Penn State University
Date: Tue, 15 Dec 1992 13:38:19 EST
From: <CCB104@psuvm.psu.edu>
Newsgroups: sci.physics
Subject: Spin-2 ===> Attractive Force ??

Why are spin-2 "exchange particles" supposed to imply attractive---rather
than EITHER attractive or repulsive, as with electromagnetism---forces? In
other words, why can't spin-2 "exchange particles" represent repulsive
forces?
Thanks!
Carey
ccb104@psuvm.psu.edu
ccb104@psuvm.BITNET
Xref: sparky sci.physics:21083 sci.math:16834
From: bhoughto@sedona.intel.com (Blair P. Houghton)
Newsgroups: sci.physics,sci.math
Subject: Re: Bayes' theorem and QM
Date: 14 Dec 1992 05:11:04 GMT
Organization: Intel Corp., Chandler, Arizona
NNTP-Posting-Host: alfalfa.intel.com

In article <SRCTRAN.92Dec13221623@world.std.com> srctran@world.std.com (Gregory Aharonian) writes:
>follows (in a very pretty argument) that statements about reality are 
>all probabilistic, that any theory that uses the integers implicitly

What do you mean by "uses the integers?"

				--Blair
				  "Is this mathematical harrassment?"
Newsgroups: sci.physics,sci.math
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: Can space-time intersect itself?
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Tue, 15 Dec 92 06:54:13 GMT

Toon Moene writes:

Well, ok, I know (and appreciate) that one. I, however, still don't  
understand why it is a question *whether* the manifold describing *our*
space-time structure wouldn't be embedded in some R^n. I read the  
aforementioned theorem as saying: Either you prove that your manifold  
isn't seperable, or it *is* embedded in some R^n. Whether there is a  
constructive proof of it doesn't interest me. Besides, it bothers me that  
one needs this to be able to prove or disprove that a manifold can 'bump
into itself'. This somehow contradicts your last paragraph.

---
The spacetime manifold might as well be assumed to be separable.  That's
not the point.

We're getting mired in semantics here.  The mathematical theorem says
any separable manifold CAN BE embedded in some R^n.  It doesn't say it
IS embedded in some R^n.  It's also easy to prove that any separable
manifold CAN BE embedded in an infinite-dimensional Hilbert space.
That's different than saying it IS so embedded.  If you can't see the
distinction, I hope someone else can explain it to you.  I'm afraid I
won't have the patience.

More to the point, we're doing physics here, not math.  Just because our
spacetime CAN BE mathematically embedded in some R^n does not mean we
HAVE TO think of it as being so embedded, and physically it makes not a
whit of difference whether we think of it as being so embedded or not,
unless these two viewpoints give us different physical predictions.  In
bringing up the issue of whether our spacetime could "bump into itself,"
I was trying to imagine a sort of theory that might take advantage of
the idea of our spacetime being embedded in a higher-dimensional space.
Newsgroups: sci.physics
From: lordSnooty@cup.portal.com (Andrew - Palfreyman)
Newsgroups: sci.physics
Subject: Re: Another antigravity device
Date: Tue, 15 Dec 92 01:28:44 PST
Organization: The Portal System (TM)
Distribution: world

John Baez poses:
: Imagine an extremely (although not infinitely) rigid crystal.  It takes
: a huge amount of energy to deform the crystal lattice ever so slightly.
: Thus if this crystal is placed in the earth's gravitational field at sea
: level, the curvature of space due to the gravity prevents the
: lattice from being perfectly regular, at the cost of a large amount of
: energy.  The crystal would have much less energy if it were far away
: from the earth where the curvature of space is less.  If we make the
: crystal rigid enough it will actually be energetically favorable for the
: crystal to float upwards - since the decrease in its internal energy
: will more than compensate for the increase in gravitational potential
: energy.
: 
: Now, I *know* that this material would have to be insanely rigid for
: this effect to be noticeable at all -- far more rigid than any actual
: stuff.  However, we're talking questions of principle here.  Is there 
: any reason *in principle* why a sufficiently rigid material wouldn't
: levitate to get out of the earth's gravitational field - that's what I'm
: asking.  

I usually get this stuff wrong, but here's my answer.
The rod will flex infinitessimally, offsetting its internal energy gain
by the reduction in gravitational potential energy. This is a local energy
minimum, and that's where it'll be trapped. The space stuff is a red
herring, since there is no mechanism to get it there.
 --------------------------------------------------------------------------
| lord snooty @the giant |  Would You Like Space Potatoes With That?       |
| poisoned electric head |              andrew_-_palfreyman@cup.portal.com |
 --------------------------------------------------------------------------
From: brandt@cco.caltech.edu (William N. Brandt)
Newsgroups: sci.physics
Subject: FEYNMAN GRAPH EXPANSION QUESTION
Date: 20 Dec 1992 10:49:16 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: sandman.caltech.edu
Summary: FEYNMAN GRAPH EXPANSION QUESTION

Does anyone know of a way to systematically generate all the Feynman
graphs to a given order for a certain process, say e-e+ ---> e-e+?
Or at least a method for predicting how many graphs there will be?
(I am interested in connected distinct Feynman graphs only). Any
references would be appreciated.

For electrons off positrons, as above, I count

order e-squared    2
order e-cubed      0
order e-fourth    18

and it gets quite tricky after this point. Also, how far our have
the graph expansions been done, say for electron-positron scattering?
Do there exist computer programs which systematically generate and
compute the s matrix contributions or is this usually done by hand?

I would be grateful for any information on this issue. Especially references
which I could trace back.

I would be grateful if you could send me email (as well as posting, if you
like).

Thank you, Niel Brandt
Newsgroups: sci.physics
From: andrew@rentec.com (Andrew Mullhaupt)
Newsgroups: sci.physics
Subject: Cappucino Noise
Date: 16 Dec 92 00:27:43 GMT
Organization: Renaissance Technologies Corp., Setuket, NY

When you run steam through milk with a cappucino machine, you get a
characteristic noise which steadily drops in pitch.

Explain this noise. Is it the same noise as you get running hot water
from the tap?

1. This isn't homework.

2. I actually don't know.

Later,
Andrew Mullhaupt
From: baylissb@topaz.ucq.edu.au
Newsgroups: sci.physics
Subject: TIME HAS INERTIA, CHALLENGE
Date: 14 Dec 92 20:41:13 AET
Organization: University of Central Queensland, Australia


Abian,


As email (in your case), may be unreliable, I place this challenge to you in
this news group.

This discussion has been going on long enough, and as a result your theory has
grown in size (which is good).  However it is time to place it to the test,
where the crediblity of the editors is known, as opposed to the people in this
group.

The challenge is to PUBLISH this idea in a scientific journal which deals with
cosmology (if there is one), or one in which this is an area of research. 
After the article has been published, or accepted, let the NET group know so
that they may get a copy.  If it has been published, then the problems which
people complain about will be mostly answered in one go.

It is quite possible that it may not be accepted, if so, try publishing it in
the (forgetten proper title), but it is for the sceptics society.  This is not
a step down, as you are sceptical about the ideas upon which physics is based. 

I don't see how this accomplishs your (A3), and I'm not interested in how it
does so.

barry...

p.s. if possible use LaTeX, as this can be sent via email, that way placed in
this news group.  This however will not prove that the article has been
accepted, so a cite may be required as well.

========================================================================
The above are only ideas, treat them as such.
========================================================================
Do not condemn the judgement of   |  If it can't be understood, it's not     
another because it differs from   |  finished yet.                             
your own. You may both be wrong.  |                                             
                                  |                -Paul Herbig              
		-Dandemis         |                                     
                                  |
-----------------------------------------------------------------------------
Newsgroups: sci.physics
From: dnash@uxa.cso.uiuc.edu (Dave Nash)
Subject: Annual Unintentional sci.physics Humor Award
Organization: University of Illinois at Urbana
Date: Sat, 12 Dec 1992 06:44:35 GMT

Envelope please...thank you.  And the winner is... (rip):  Geez, can't you 
guess by now?

I have, in the past, wondered whether Abian was serious, a dreadful practical
joker, merely bizarre, or the result of an AI experiment gone amuck.  Nope.
None of the above.  In fact, the following paragraph dispells all doubt:

>  You have to surrender to (A3), you have to introduce (A3) as the prime
>principle of Physics as the CORNERSTONE of modern PHYSICS .  You have no
>other choice!  No matter how you twist and twirl around to bend the inter-

Ah!  It becomes clear now.  Abian is a Borg.  (Molecules are irrelevant! 
Physics is futile!)

>I am offering you the Light of knowledge .  Accept  (A3) and you will see that
>all your fundamental questions will be answered in a convincing way and 
>Physics will grow on firm, solid Rock of the truth that (A3)  or even (A1) 
>offers.

No!  Abian the tent preacher!  (Do you beleive in the Rock of the Truth?  Amen,
brother!  Say hallelujah!)

Keep up the good work, Brother Alex!

>P.S. Please keep a complete file of  TIME HAS INERTIA postings they will
>     be extremely valuable!

Doubtlessly so -- but not for the reasons you suppose.
-- 
David Nash                  | Gradual Student, Chemistry
                            | University of Illinois (Urbana)
(dnash@uxa.cso.uiuc.edu)    | This .sig is made of 100% recycled electrons.
(nash@aries.scs.uiuc.edu)   | No binary trees were killed to make it.
From: bweiner@ruhets.rutgers.edu (Benjamin Weiner)
Newsgroups: sci.physics
Subject: Re: Where is background energy going?
Date: 17 Dec 92 01:14:01 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

ucap22w@ucl.ac.uk (Martin S T Watts) writes:

>Isn't it the *frequency* that isn't significantly affected? I thought that
>wavelength changed in accordance with velocity.

True.  I should have said frequency.  But the wavelength returns to its
usual value once you leave the material, so if you do observations
in a telescope with air in the tube you should be OK  (we spend most
of our time wishing we could get the air out of the tube, but never
mind)
Newsgroups: sci.physics
From: crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass)
Subject: Dark Matter
Originator: crb7q@kelvin.seas.Virginia.EDU
Organization: University of Virginia
Date: Fri, 18 Dec 1992 21:22:09 GMT


     I just read a rather interesting article in Nature that suggests
     that the rotation curves of gas orbiting spiral galaxies can
     be explained by magnetic stresses (Battanger, /etal 
     Nature, 360:613 (1992), News and Views p. 624 of the same issue).
  
     From the News and Views portion (by J. Binney), the main argument goes

           ... by arguing that tens of kiloparsecs from the center
           of a galaxy, where the gas density is usually very low, the
           dynamics of the gas may be strongly affected by a magnetic
           field of 1 picotesla.  We know that the interstellar
           field tends to wind around galactic disks, so that to a first 
           approximation one can imagine that the field lines form a
           series of gas-filled hoops within the plane of the disk.
           The magnetic field B imposes two kinds of forces on the
           hoop; a tension 1/2 B^2/\mu_0 runs the long way around the
           hoop, pulling it more snugly around the galaxy, while in
           the two perpendicular directions, the field exerts pressure
           1/2 B^2/\mu_0, tending to cause the hoop to fatten into
           a doughnut.

           The magnetic tension in the hoop must be counteracted by
           some combination of a net outward force on the hoop due
           to a radial gradient in the perpendicular magnetic pressure,
           and an excess of the centrifugal force on the spinning
           hoop over the inward gravitational pull of the galaxy.

     In any case, Battinger \etal use M31 to show that the rotation
     curves would be satisfied if there is a field of about 0.8 picotesla
     between 10 and 30 kiloparsecs.  Apparently observations of 
     synchrotron emission are being used to claim that the field strength 
     is correct for this mechanism in M31.  However, from our own galaxy at 
     our position the component of the magnetic field along the azimuthal
     direction is roughly four times smaller than 0.8 picotesla.  So, at
     our position, magnetic forces would be about an order of
     magnitude smaller than necessary for their mechanism to work.

     Anyway, it is an interesting paper.

                              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: palmer@sfu.ca (Leigh Palmer)
Subject: Re: Metals in liquid Nitrogen !!
Organization: Simon Fraser University
Date: Fri, 11 Dec 1992 19:52:40 GMT

In article <10DEC199219275429@trentu.ca> lchardon@trentu.ca (PETIT PAPA NOEL.)
writes:

>        In my thermodynamics class, we were all happily playing with liquid 
>nitrogen, freezing squash balls, making erasers explode (BTW, why do 
>plastic erasers explode when in liquid nitrogen?) and all that kind of 
>things that you do when you have 10 litres of nitrogen to waste, when a 
>prof dropped by and told us to try to immerge some piece of metal in the 
>nitrogen. Sure enough, somebody pulled out a penny and dropped it in a 
>full styrofoam cup. What happens is the following:
>The nitrogen will boil for some time, like it boils when you drop anything 
>in it, but then suddenly it will boil really hard, about 3 times more 
>violently than it did before, for about half a second, and then it will 
>just gently bubble away (When the metal is in thermal equilibrium with it, 
>i guess...).
>
>        WHY ???????????????
>        WHY JUST METALS ???

As Michael Kagalenko has beat me to the punch in answering the first question,
that the so-called "Leydenfrost effect" is exemplified by this demonstration, I
will answer the second question. The effect you have described is seen in
metals because they are thermal conductors. The entire surface of a conducting
object is approximately at the same temperature. Thus the critical temperature
for the breakdown of the vopor barrier is reached simultaneously over the
entire surface, resulting in a large sudden increase in the heat transfer rate
from the metal to the liquid nitrogen. For a thermally insulating material this
breakdown occurs at different times for tifferent places on the surface, and
the heat transfer within the object limits the rate of transfer as well.

I might opine that your thermodynamics professor is a piker. Here in western
Canada I do that demonstration with a machined one-kilogram copper cylinder.
The effect is much more dramatic. Your prof could, at the very least, spring
for a silver dollar! :-))

Finally, I will reveal a demonstration similar to one you did which I
originated, and which I have never explained satisfactorilly. If you take a
Pink Pearl eraser and immerse it for one minute in liquid nitrogen, and then
remove it and place it on an insulating stand in the ambient open air, it will
*subsequently* explode. This demonstration is not highly reproducible, and it
will not work at all with other brands of erasers in my limited experience, but
it works with more than one size of the correct brand. If any kid out there
with access to a liquid nitrogen source would like a nice science fair project
I'd be glad to collaborate. Optimization of time and conditions, examination of
probable effects, etc., are still to be done. Somehow I felt that this project
would be inappropriate for me to undertake myself, and I think no graduate
student would find it attractive.

Merry fig day,

Leigh
Newsgroups: sci.physics
From: barry@arnold.math.ucla.edu (Barry Merriman)
Subject: Re: KIRLIAN PHOTOGRAPHY...
Organization: UCLA, Mathematics Department
Date: Sun, 13 Dec 92 02:33:01 GMT

In article <12DEC199217193643@trentu.ca> lchardon@trentu.ca (LAURENT CHARDON)  
writes:
> A few years ago I came across Kirlian photography. What is the latest 
> explanation?
> 
> I'm quite surprised that we hear so little of it, since the effects are so 
> remarkable. 

From this, you should draw the conclusion that the effects are
not remarkable.

As for the explanation, can you say "coronal discharge". Kir. photos
are taken with the object under high voltage, which causes myriad
breakdown effects, and it heavily dependent on factors like
humidity, surface roughness, impurities, etc.

Some actual scientists have done a few experiments to verify that
it is coronal discharge---check your back issues of the 
Skeptical Inquirer for details.

There is no reason whatsoever to suspect any supernatural phenomena.
Is it so remarkable that one gets breakwdown effects under high voltage?


--
Barry Merriman
UCLA Dept. of Math
UCLA Inst. for Fusion and Plasma Research
barry@math.ucla.edu (Internet; NeXTMail is welcome)


Newsgroups: sci.physics
From: kkretsch@unix1.tcd.ie (kevin patrick kretsch)
Subject: Re: Richard P. Feynman
Organization: Trinity College, Dublin
Date: Mon, 14 Dec 1992 12:46:17 GMT

In <schumach.724117382@convex.convex.com> schumach@convex.com (Richard A. Schumacher) writes:

>>but I was.  I don't see why I can't enjoy (and understand) both Hannah 
>>Arendt and Oppenheimer or Feynman.  Please recall that Mr. Feynman 
>>specialized in physics but also painted and played the bongos, among many 
>>other endeavours not normally associated with 'scientists'.

>Not true!. Many scientists are interested in and appreciative of the arts.
>You must be thinking of engineers.

Absolutelty right!!
I play the guitar, badly but I play and paint and I even tried the
bongos once! In fact Feynman has/had a lot in common with 'normal'
everyday physicists, including bongos and painting and even strip clubs
(don't forget that Feynman spent time in strip clubs too).
As a matter of fact, a helluva lot of physicists write to newsgroups
like rec.music.makers , alt.guitar etc. and most of the replies I get
from these newsgroups are in fact physicists (about 80%).

Scientists are normal 'I pick my nose too!' people. We bleed when were
cut, cry when we listen to Stevie Ray Vaughan records, WE ARE HUMAN!
Why shouldn't we paint or play music or whatever??
Just because we count neutrinos or talk Q.M. eight hours a day??

Let us not remove ourselves from society and then wonder why nobody
considers us normal or interesting because we are scientists. If we do,
then all we do for humanity is in vain.

Kev.

--
________________________________________________________________________________
kkretsch@unix1.tcd.ie
also  dept.of pure and applied physics

Newsgroups: sci.physics