HDTenEightyP/NetNews huggingface dataset:
From: bweiner@ruhets.rutgers.edu (Benjamin Weiner)
Newsgroups: sci.physics
Subject: Re: Home made monopoles
Date: 28 Jan 93 00:33:34 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

brahm@cco.caltech.edu (David E. Brahm) writes:

>bdoa@digex.digex.com (Barry Adams) wrote,
>>                     Home made magnetic monopoles
>> [Glue together 2 hemispheres each magnetized with "North" at its pole]

Actually I think Adams meant hemispheres magnetized radially outward,
so that for each one, the field lines point out of the hemispherical 
surface and in through the flat part. 

>dseeman@novell.com (Daniel Seeman) writes:
>> ...Just because we "know" the South Pole exists in the volume cavity
>> inside doesn't mean we can actually "see" it...

>I don't know who's serious and who's joking here, but for the record,
>Adams's construction is not a monopole (I believe it's a quadrupole).
>Field lines outside the sphere emerge from each pole and re-enter at the
>equator; "glue" doesn't stop them!  You can't make something that violates
>Gauss's Law of Magnetism (del.B=0) by superposing things that obey it.

This last statement is quite correct and applies to the radially-magnetized
version as well.  I might as well blow the punchline, maybe some people will
benefit.  Consider Gauss's law of magnetism: usually one writes this as
   div B = 0.
This is true at any point; hence no point can have net outflow/inflow
of magnetic field lines.  But it's also true of surfaces; remember the
integral form of Gauss's law of magnetism.
   integral(B dot dS) = 0,
where the integral is over a closed surface and dS is a surface element, and 
"0" = zero is the enclosed magnetic charge.  (Inspired by my high-school 
calc class using "plus an arbitrary constant, zero" for indefinite integrals.)

Take this integral over a sphere just at the surface of the magnetized
sphere, and you see that if B is everywhere outward then the integral
cannot be zero, so no dice.  In fact given that the arrangement maintains
spherical symmetry the B-field will vanish everywhere, by symmetry
arguments. 
Newsgroups: sci.physics,sci.skeptic,alt.paranormal,alt.sci.physics.new-theories,rec.arts.startrek.tech
From: lindsay+@cs.cmu.edu (Donald Lindsay)
Subject: Re: New Physics, Healing, Paranormal
Organization: School of Computer Science, Carnegie Mellon
Date: Wed, 27 Jan 1993 18:36:33 GMT


sarfatti@well.sf.ca.us (Jack Sarfatti) writes:
>It is also true that Geller fails rigorous tests set up by
>other stage magicians.

You're understating. Geller has been outright caught cheating, by
plural people, plural times.

For example, the reporter who visited Geller in a hotel room.  She
noted that the edge of the coffee table had three notches in it, just
as if someone had bent a key, three times. When Geller "psychically"
bent her key, she noticed that the coffee table had just sprouted a
fourth notch.
-- 
Don		D.C.Lindsay	Carnegie Mellon Computer Science
From: blom@husc15.harvard.edu
Newsgroups: sci.physics
Subject: More POP FIZZ PSI WARS
Summary: More POP FIZZ PSI WARS
Keywords: electric radio waves electromagnetic radiation psychological warfare
Date: 21 Jan 93 18:51:09 GMT
Reply-To: blom@husc.harvard.edu
Followup-To: sci.physics
Organization: Harvard University Science Center

Do high-intensity radio waves of computer-like frequency affect computer
systems?

Would 10-15Hz electric waves mess with people's minds?

Could one make a laser-like device for such electric waves?  Would magnetic
lenses work to direct the beam?

Could one just put a bunch of electric dipole antennae in an electric-wave
reflecting tube?

How does one reflect 10-15Hz electric waves?  I know radio waves can be
reflected with regular materials.

Eric Blom
Harvard U
From: mkagalen@lynx.dac.northeastern.edu (michael kagalenko)
Newsgroups: sci.physics
Subject: Re: female mentors in science
Date: 28 Jan 93 01:26:46 GMT
Organization: Northeastern University, Boston, MA. 02115, USA

In article <1993Jan28.004712.22520@organpipe.uug.arizona.edu> corleyj@helium.gas.uug.arizona.edu (Jason D Corley ) writes:
>In article <1993Jan27.210411.8122@lynx.dac.northeastern.edu> mkagalen@lynx.dac.northeastern.edu (michael kagalenko) writes:
>>In article <1993Jan27.055231.23117@nuscc.nus.sg> scip2124@nusunix1.nus.sg (MARC PAUL JOREF VAN LOO) writes:
>>>michael kagalenko (mkagalen@lynx.dac.northeastern.edu) wrote:
>>>
>>>: All this talk about "female science" looks suspiciously similar to 
>>>: other well known distinctions : "Ariahn" vs "Non-Ariahn", "proletarian"
>>>: vs "bourgeous" science....
>>>
>>>    Are you a nut?
>>>
>>Are you PC ?
>
>Are you working on a PC?

Grave offence ! ;-)
Newsgroups: sci.physics
From: kring@efes.physik.uni-kl.de (\)
Subject: Re: satellite orbits
Organization: FB Physik, Universitaet Kaiserslautern, Germany
Date: Fri, 22 Jan 1993 13:42:13 GMT

In article <376oXB3w165w@netlink.cts.com>, bigbro@netlink.cts.com (Kenneth Sullivan) writes:
>a.)what keeps a satellite in orbit

Kepler's laws.  Or, to put it another way, gravitation.
If the initial conditions are right, the satellite will circle the earth
on an ellipse by itself.  The moon does it too.
The only thing that can't stay in an orbit without using up energy is the
"Enterprise".
(The above assumes there is no friction slowing down the satellite.)

>b.)just how wrong is the idea of centrifugal/centripidal "force"?

Nothing wrong about it (except the spelling of "centripetal").
The centrifugal force appears only if you use the satellite (or any rotating
system) as a frame of reference.  You can avoid it by looking at the system
from far away, using an inertial system as frame of reference.

A non-astronomy example:
On a merry-go-round, you'll experience centrifugal force, pulling you away from
the centre, but that force cancels with the centripetal force, which acts on
you through the chain tying you to the rotating part.  So the sum of all forces
is zero, and you stay where you are - with reference to the rotating part.
But the bystanders see it another way: You are held on a circular orbit by the
chain pulling you to the centre and stopping you from flying away on a tangent
and hurting yourself badly, which you'd do if there were no force (no chain).
They observe only one force.

Some people will tell you that centrifugal force is "not a real force" or
"pseudo force" but I think that's dubious.  The Theory of General Relativity
states that you can choose whatever system of reference you want, laws of
physics will be the same.  Using the standpoint of an observer on the
satellite is as reasonable as any other, only the forces you need are more
complex.  That is, you need more assumptions to explain the same observations.
Therefore, using Occam's razor ("Do not unnecessarily multiply entities" or,
as Einstein put it, "As simple as possible - but not simpler")
one normally chooses the frame of reference with less assumptions.

BTW, that's the only reason why we say that the earth is rotating the sun and
  not the other way around: for simplicity.

Another BTW:  Thus Einstein, with General Relativity, decided the case
  Copernicus vs. Ptolemy by saying "You're both right", as he decided the case
  Newton vs. Huyghens (regarding the wave or particle nature of light) by saying
  a similar thing with his photon idea.

--
thomas kettenring, 3 dan, kaiserslautern, germany
Philosophy is the art of drawing conclusions from definitions that have been
chosen so that one can draw the conclusions one would like to get.
It immediately follows that philosophy is silly.
Xref: sparky sci.physics:23569 sci.skeptic:22928 alt.paranormal:2862 alt.sci.physics.new-theories:2868 rec.arts.startrek.tech:7801
From: brahm@cco.caltech.edu (David E. Brahm)
Newsgroups: sci.physics,sci.skeptic,alt.paranormal,alt.sci.physics.new-theories,rec.arts.startrek.tech
Subject: Re: New Physics, Healing, Paranormal
Followup-To: alt.paranormal
Date: 26 Jan 1993 21:54:47 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: punisher.caltech.edu
Summary: Mentally influencing your random number generator

petitc@nuge105.its.rpi.edu (Christopher Jon Petit) writes:
> I think the head of Stanford's Engineering dept. did some studies which
> showed that, by trying to influence certain statistically valid actions
> (e.g. 100,000 flips of a coin, in one second, by a computer), the
> subjects did have a small but measurable influence.
> Now, I want to see those tests done myself, but I don't have the
> resources.

It seems obvious to me that you do have the resources, namely
  1) A computer,
  2) A human brain.
So go for it!  Mentally influence your random number generator!  Myself,
I'll be trying to mentally influence millions of UseNet readers to keep
this stuff out of sci.physics.

--
Staccato signals of constant information,  |  David Brahm, physicist
A loose affiliation of millionaires and    |  (brahm@cco.caltech.edu)
  billionaires and Baby ...                |---- Carpe Post Meridiem! --
These are the days of miracle and wonder,  | Disclaimer:  I only speak
And don't cry, Baby, don't cry, don't cry. |   for the sensible folks.
From: m14494@mwvm.mitre.org (Mike White)
Newsgroups: sci.physics
Subject: Re: Debate question of the day!!!!!
Date: 22 Jan 93 19:16:22 GMT
Distribution: na
Organization: The MITRE Corporation

David E. Brahm writes:
> There's a story that a major newspaper once printed an editorial 
> ridiculing Goddard for not understanding that..., his rockets could
> never work in space [without air to push against].

It was the New York Times, and in the 1970's during the Apollo 
flights, they printed a tongue-in-cheek retraction admitting
they were wrong.

************************
* These are my opinions only.*
************************
Newsgroups: sci.physics
From: sawyer@utahep.uta.edu (Lee Sawyer)
Subject: re: integrity of moderators
News-Software: VAX/VMS VNEWS 1.41    
Organization: University of Texas at Arlington High Energy Physics Group
Date: Thu, 21 Jan 1993 21:53:00 GMT

In article <C180ps.Drn@well.sf.ca.us>, sarfatti@well.sf.ca.us (Jack Sarfatti) writes...
> 
>sci.physics has been an informal forum for all sorts of half-baked ideas,
>jokes, brawls (flames) etc. Like Prince Hal I can play with Falstaff, or
>even be Falstaff. But I have spend lot's of time in close observation of
>really great physicists like Feynman, Bethe, Heisenberg, Salam etc.
>So if you really want a high quality mderated conference your selection
>of moderators is crucial. I fool around and play with outrageous ideas- but
>I know what it means to be professional and fair when the occasion calls for
>it - not the case with some of the present moderators who are not
>"cultured".

  I think you have confused my deep seated fatigue with this discussion
with a personal flame. I apologize for offending your professional 
sensibilities, and expect a similar apology from you for questioning my
professional expertise. There is more to being "cultured" than high-tech
name dropping.

  Friends and neighbors, I do not have time for this sort of nonsense.
I enjoy reading this forum, and feel that a moderated group for 
research level discussions would a wonderful adjunct to it. (In fact,
I am inclined to agree with Mr. Sarfatti's suggestion of separate theory
and experimental newsgroups, if there is sufficient demand.) But I do 
have other things to do, and will step aside as a comoderator in an instant.

       ================                           
         Lee Sawyer                                  

         Dept of Physics                          
         Univ. of Texas                            
               at Arlington
From: paul@mtnmath.UUCP (Paul Budnik)
Newsgroups: sci.physics
Subject: Re: hidden variables
Date: 23 Jan 93 17:16:47 GMT
Organization: Mountain Math Software, P. O. Box 2124, Saratoga. CA 95070

In article <1993Jan22.133037.6880@oracorp.com>, daryl@oracorp.com (Daryl McCullough) writes:
> paul@mtnmath.UUCP (Paul Budnik) writes:
>
> >One is forced to use phase space because the wave functions for two
> >separate particles will overlap in physical space. One needs some method
> >to represent the probability of finding particle A at location A1 and
> >particle B at location B1. One cannot represent this without using a phase
> >space that includes position coordinates for both particles.
> 
> No, that's not true. In the case of identical particles, one can do
> without phase space by just using the particle density, which gives
> the expected number of particles in a unit volume.

But what about non identical particles? It is not simply
a question of their density but which particles are at which location.

> Phase space is only
> needed for distant correlations between particles.

> It is precisely the
> violation of Bell's inequality that forces the use of phase space for
> describing quantum mechanics.

That's an interresting conclusion since phase space was used for decades
before Bell's result was known. I assume you mean it is the nonlocal nature
of QM that forces the use of phase space.

> If quantum mechanics obeyed Bell's
> inequalities, then there would be a local description of quantum
> mechanics that does not use phase space.

It does not follow that because a theory does not violate Bell's inequality
it is local. There are other forms of locality violation.

I do not think that phase space has anything to do with locality violation
per se. Phase space is used in classical mechanics. It is also easy to
construct nonlocal models that violate Bell's inequality and that do not use
phase space. Phase space is necessary in quantum mechanics because the wave
functions for particles overlap in physical space. We need to represent
the probability of finding any given particle at any given location.

The changes in phase space that are governed by the relativistic
Schrodinger equation are all local and Lorentz invariant in both phase
space and when projected back into physical space. Phase space 
and the linear changes in it from the Schrodinger equation is a local model.

It is only the changes in phase space that result from the collapse postulate
that introduce nonlocal effects in physics. The singlet state correlations
are a completely local model in the sense that the state vector that embeds
this information propagates in a local way. It is only when observations
are mode that nonlocal effects are introduced as a consequence of the singlet
state. It is the collapse postulate that determines the *timing* of these
effects. This timing is the critical issue in deciding if locality is
violated.

Paul Budnik
Xref: sparky sci.physics:23532 sci.skeptic:22894 alt.paranormal:2845 alt.sci.physics.new-theories:2850 rec.arts.startrek.tech:7779
From: lindsay+@cs.cmu.edu (Donald Lindsay)
Newsgroups: sci.physics,sci.skeptic,alt.paranormal,alt.sci.physics.new-theories,rec.arts.startrek.tech
Subject: Re: New Physics, Healing, Paranormal
Date: 26 Jan 93 19:48:55 GMT
Article-I.D.: cs.C1H8Dr.7r3.2
Organization: School of Computer Science, Carnegie Mellon


petitc@nuge105.its.rpi.edu (Christopher Jon Petit) writes:
>there is supposedly (or so I've heard) scientific proof that some
>forms of ESP do in fact exist.  I think the head of Stanford's Engineering
>dept. did some studies which showed that, by trying to influence certain
>statistically valid actions (e.g. 100,000 flips of a coin, in one second, by a
>computer), the subjects did have a small but measurable influence.


That would be interesting IF IT WERE TRUE. But the last I heard, it
just isn't true. 

Since you are the person making the amazing claim, it's up to you to
produce the amazing facts. Find a reference, please.
-- 
Don		D.C.Lindsay	Carnegie Mellon Computer Science
From: ted@physics3 (Emory F. Bunn)
Newsgroups: sci.physics
Subject: Re: Black hole insights
Date: 26 Jan 93 20:31:20 GMT
Followup-To: sci.physics
Organization: Physics Department, U.C. Berkeley
NNTP-Posting-Host: physics3.berkeley.edu

In article <C1FFtH.Gyq@megatest.com> bbowen@megatest.com (Bruce Bowen) writes:

>  Say, we have a black hole of mass M.  We drop a small test mass into
>it.  We wait long enough for it to get within a small distance epsilon
>of the horizon.  We then radially symmetrically dump another amount of
>mass M in on top of it.  Very soon in observer/coordinate time the
>event horizon has moved far above the position of our small test mass,
>so it is well within the event horizon in a finite amount of
>schwartzchild "t".  What now is it's coordinate time to reach the
>central singularity?

It seems to me that you can answer this question by using Birkhoff's theorem.
The theorem says that if you have a spherically symmetric distribution of
matter, you can always ignore the matter outside of a spherical
shell if you want to determine the dynamics inside of that shell.  So
since the extra mass you've dumped in is always outside of the shell
on which the test particle sits, the test particle just falls as if
in a Schwarzschild geometry of mass M.  Of course, it disappears from
the view of a person sitting on the outside looking in, but that's because
the photons that it would have to emit in order for the person to
observe it have their motions altered by the extra mass.

>  Here's another question:
>
>  Kruskal coordinates, etc.  are different parameterizations of
>spacetime that avoid the coordinate singularity at the horizon that
>results in schwartzchild coordinates.  There is of course a mapping
>between the two coordinate systems.  What does one get for "r" and "t"
>when one maps back into schwartzchild coordinates after the particle
>has passed the horizon, and does anyone give these values
>significance?  What is the final value of "t" when an infalling
>particle reaches the central singularity?

You can figure this out, and its not too hard.  The path of the particle
on an r-t diagram looks like this:  It starts at r>R (R is the schwarzschild
radius); then r decreases towards R as t goes to infinity.  Then you
see t coming "back from infinity" as r goes from R to zero.
I don't imagine that the value of t at r=0 is of any physical significance,
since you could alter it by just time-translating the whole coordinate
system.

One rather strange thing is that for r<R, r is a timelike coordinate and
t is spacelike.  So that means that the singularity r=0 is not a 
single point in space that exists at all times; rather, it is a single
point in time that exists at all "distances" t.  This makes it clear
why you can't avoid the singularity once you've crossed the horizon.
Since the singularity is a future point in time, you can't alter your
world line to avoid hitting it, any more than you can alter your world
line to avoid hitting next Thursday.

-Ted
Newsgroups: sci.physics
From: atems@igor.physics.wayne.edu (Dale Atems)
Subject: Re: hidden variables
Organization: Wayne State University, Detroit, MI
Date: Mon, 25 Jan 1993 05:39:21 GMT

In article <515@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:
>In article <1993Jan23.230247.1315@cs.wayne.edu>, atems@igor.physics.wayne.edu (
Dale Atems) writes:
>>[...]
>> I certainly do not agree that it is logically necessary for a theory
>> to regard the violation of the mathematical relationship of Bell's
>> inequality as due to information transfer. I agree only that it is a
>> reasonable thing to require of a theory. If experiment shows that this
>> transfer must be instantaneous, then I am inclined to reject the
>> requirement.
>
>[...]
>I am confused by your statement. Eberhard proved that QM makes
>predictions that require nonlocal effects or influence.
 
No, he proved that some of the predictions of QM require that the
outcome of a measurement must depend on a distant setting.
 
>The Relativistic
>Schrodinger equation is local and Lorentz invariant. One cannot derive
>such effects using that equation.
 
This argument looks like a rather clever sleight of hand to me. The
last statement requires a proof. While it's certainly true that one
cannot use that equation to obtain an instantaneous change in the wave
function at a given location due to a change in a distant polarizer
angle, it's not at all obvious to me that you need this in order to
describe what is happening. Maybe I'm missing something.
 
I've already shown that the nonlocal dependence required by Eberhard's
proof is implicitly contained in the rotational invariance of the
singlet state. Thus the singlet state vector already knows how it will
be affected by any possible combination of polarizer angles. I believe
the effect can be described entirely in terms of local interactions.
See my next post.

------
Dale Atems
Wayne State University, Detroit, MI
Department of Physics and Astronomy
atems@igor.physics.wayne.edu
Newsgroups: sci.physics,sci.skeptic,alt.paranormal,alt.sci.physics.new-theories,rec.arts.startrek.tech,alt.religion.kibology
From: kibo@world.std.com (James "Kibo" Parry)
Subject: Re: New Physics, Healing, Paranormal
Followup-To: alt.religion.kibology
Organization: Two rooms filled with typography, in downtown Boston
Date: Wed, 27 Jan 1993 06:13:41 GMT

In article <C1GEpL.4H7@well.sf.ca.us> sarfatti@well.sf.ca.us (Jack Sarfatti) writes:
>
>I am being paid a significant amount of money to write this by an
>influential European corporation. If you want to make
>corrections,suggestions etc. with no monetary compensation from me,feel free
>to do so. I will include opposing points of view in footnotes with your
>names if you like. All I can say is that this document is going to be
>translated into Spanish, French, Portuguese,Russian, Hindi and will be
>read by some of the most powerful people (politicians, CEO's of multi-
>nationals etc.) in the world who are about to set up a satellite based
>multi-media world wide university in which I have been asked to play a
>major role with major funding.
>
>This is no joke! I have been told that I am a "super star" in some powerful
>circles that have decided that traditional universities are "brain dead"
>and that something new-age is needed.
[...]
>to be continued (the above is one evening's work).
>
>Admiral Sarfatti
>Star Fleet Academy
>Star Fleet Command
>Presidio
>San Francisco
>Federation of United Planets.

No joke indeed.  DOO DAH, DOO DAH, DOO DAH, DOO DAH!
							-- K.
From: bruce.weaver@nitelog.com (Bruce Weaver)
Newsgroups: sci.physics
Subject: HELP Wanted!
Date: 24 Jan 93 20:54:00 GMT
Reply-To: bruce.weaver@nitelog.com (Bruce Weaver)
Organization: Nitelog BBS - Monterey, CA - 408-655-1096

DTL>From: davidlai@unixg.ubc.ca (David TW Lai)
DTL>Newsgroups: sci.physics
DTL>Subject: HELP Wanted!
DTL>Date: 20 Jan 93 01:33:24 GMT
DTL>Message-ID: <davidlai.727493604@unixg.ubc.ca>

DTL>Hi netters,

DTL>        I'm puzzling around the following questions.  If you have some
DTL>hints to the questions, could you give me some help?  Thanks in
DTL>advance.

DTL>(1) Why are Earth age estimates based on sedmentation and erosion rates
DTL>so poor?

if you mean total age, because uplift and vulcanism are frequent
compared to the age of the earth

DTL>(2) A rock specimen contains precisely ten times less potassium-40 than
DTL>its radioactive decay product (half-life 1.3 billion years) argon-40.  How
DTL>old is this rock and where did it come from?

DTL>(3) Give four reasons, in order of important, why the
DTL>Earth appears to have fewer huge impact scars than
DTL>The Moon.

One answer dominates: because uplift and vulcanism are frequent compared
to the age of the earth.  From the geologist's point of view, the
surface of the earth is like a bubbling cauldron.  Finding craters on
the earth is hard and they are all (relatively) young.  The moon, on the
other hand, is relatively inactive.  It did have a major melting event
(hence, the lunar maria on which are relatively few craters).  Also, the
garbage is swept up with time so that the impact rate will decay with
time from formation.  This accentuates the cratering difference between
the two planets (pop quiz: is the orbit of the moon ever convex towards
the sun ? )

DTL>        Thanks a lot!

DTL>David.
---
 . SLMR 2.1a . Physics is a subset of astronomy