HDTenEightyP/NetNews huggingface dataset:
Newsgroups: sci.physics
Subject: Re: Magnetic monopoles?
From: mcirvin@husc8.harvard.edu (Matt McIrvin)
Date: 26 Jan 93 00:21:33 GMT
 <1993Jan20.025101.9082@CSD-NewsHost.Stanford.EDU> <25404@galaxy.ucr.edu>

baez@guitar.ucr.edu (john baez) writes:

>In article <1993Jan20.025101.9082@CSD-NewsHost.Stanford.EDU> pratt@Sunburn.Stanford.EDU (Vaughan R. Pratt) writes:
>>If there are no monopoles then searching for them would indeed be
>>pointless.  But if charge quantization only increases the known lower
>>bound on the number of monopoles in the universe by one, why should the
>>knowledge that charge is quantized change our mind about searching for
>>them?  (Not objecting, just want to learn how to think like an
>>experimentalist.  :-)

>For starters, you are being way too logical.  It goes like this:
>monopoles would explain charge quantization, which is otherwise
>not easy to explain.  So let's look for monopoles!  

I thought until a few days ago that an *alternative* explanation for
charge quantization would be to embed the electroweak gauge group
(including its abelian U(1) subgroup, which does not require particles
to have discrete weak hypercharge) in some nonabelian GUT gauge group,
which would restrict everything to transform as some discrete
representation of the GUT group and therefore force electric charge
to come in discrete units.  However, someone recently told me
that there was a beautiful theorem stating that all such GUTs had
at least the possibility of magnetic monopoles, so one explanation
would, in a sense, imply the other!  Does anyone know how true this is?
 
-- 
Matt McIrvin
Xref: sparky sci.physics:23550 sci.skeptic:22907 alt.paranormal:2853 alt.sci.physics.new-theories:2859 rec.arts.startrek.tech:7789
From: mcgrath@cs.uiuc.edu (Robert McGrath)
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 21:09:44 GMT
Reply-To: mcgrath@cs.uiuc.edu
Organization: University of Illinois, Dept of Computer Science

In article <C1GEpL.4H7@well.sf.ca.us>, sarfatti@well.sf.ca.us (Jack Sarfatti) writes in part:
|> The gossip
|> is that Martin Gardner and the arch-debunker, "The Amazing Randi" take
|> psychic phenomena very seriously. That is why they came down so hard on Uri
|> Geller because they believe him to be an imposter - a stage magician in
|> psychic clothes. It is certainly true that Randi can do everything that
|> Geller can do. It is also true that Geller fails rigorous tests set up by
|> other stage magicians. 

You really shouldn't repeat unsubstantiated gossip about individuals.
However, these comments are pretty slippery.  Yes, MG and JR "take
psychic phenoman very seriously"--why else would they spend so much
time and effort debunking such claims.  And yes they came down hard
on UG because they believe him to be an imposter.  And you state the
essence of the claims against UG.  What exactly are you trying to
say?

And by the way, claims that the military/CIA have successfully used
and believe in remote viewing are most likely lies or mistakes.  Next
thing you'll be telling me is that something is true because Richard 
Nixon said so in a press conference.  Puh-leeeze.

|> On the other hand, I saw topologically intricate
|> twisted metal allegedly bent by psychics in Brazil that is very puzzling.

I can't realy help you being puzzled.  Many things puzzle me, but
most aren't remotely psychic.

--

  Robert E. McGrath
  Urbana Illinois
  mcgrath@cs.uiuc.edu
Newsgroups: sci.physics
From: daryl@oracorp.com (Daryl McCullough)
Subject: Re: hidden variables
Organization: ORA Corporation
Date: Fri, 22 Jan 1993 03:50:56 GMT

preddy@comphy.physics.orst.edu () writes:

>As an aside, it is worth noting here that a "theory" of
>physics is worth nothing until it predicts something not yet
>observed, no matter how aesthetically pleasing said "theory"
>may be. And so much the worse for a theory full of
>superfluous, metaphysical explanations.

I think it is worth noting that theories of physics aren't worth much
whether they predict something or not. Most cutting-edge theoretical
physics is of absolutely no use whatsoever except to other theoretical
physicists. So let's cut out this talk about the "worth" of theories;
they don't have any.

The only motivation there can be in continuing to work in theoretical
physics is simply the driving power of curiosity---the desire to
understand how the world works. And the only criterion for whether a
theory of physics is satisfactory is this: does it satisfy your
curiosity?

Daryl McCullough
ORA Corp.
Ithaca, NY

Organization: Doctoral student, Mathematics, Carnegie Mellon, Pittsburgh, PA
Newsgroups: sci.physics
Date: Thu, 21 Jan 1993 10:49:45 -0500 
From: "Vincent J. Matsko" <vm0h+@andrew.cmu.edu>
Subject: Origin of Limerick?

The following is my advisor's paraphrase of a limerick he once heard. 
We would like to use it in a book we are co-authoring, and would
appreciate a reference.  Has anyone heard of it and/or know its source?

  There was a young lady named Bright,
  Who travelled about faster than light.
     She went away one day
     In a relative way,
  And came back the preceding night.

Thanks for any help,
Vince Matsko
vm0h@andrew.cmu.edu
From: wellison@kuhub.cc.ukans.edu
Newsgroups: sci.physics
Subject: Re: Relativity book for a 9 year old
Date: 27 Jan 93 15:01:28 CST
Organization: University of Kansas Academic Computing Services

> 
> Are there any relativity book(s) that a nine year old could read ?
> I haven't been through any of Gamow's Mr. Tomkin books, but I think they 
> might be a little too much for a child of that age.  A book that
> illustrates relativity in cartoon form would be nice.
> 
> Please email.

My daughter (also nine) is always asking me pointed questions. Considering my
basement is filled from end to end with electronic devices and lasers shooting
beams from one end to the other (except for a little spot I gave the wife for
her washer and dryer ;-)So she is always asking how lasers work, ect. Anyway, 
she asked the same question: 'what is
relativity' or 'how can a black hole change time'. The only book I have on the 
subject is written by the maser himself (Hawkins) and I don't even understand
parts of it ;-) If someone knows of a book written for children that describes
black holes and relativity and quantum theory, please let me know. Then maybe I
could understand it myself ;-) Thanks in advance.

-=-= Wes =-=-
Newsgroups: sci.physics
From: kimball@stsci.edu (Timothy Kimball)
Subject: Re: Space: continuous or discrete?
Organization: Space Telescope Science Institute
X-Newsreader: TIN [version 1.1 PL6]
Date: Wed, 27 Jan 1993 20:29:33 GMT

Haven't read the book, but I'll take a stab...

michael lawley (lawley@kurango.cit.gu.edu.au) wrote:
: 
: Hi,
:    I've recently been read Paul Davies' and John Gribbin's ``The Matter
: Myth''.  In it there is a brief discussion of chaos theory and its
: relevance to physics.  They argue that, since the world is a physical
: system and not the theoretical model the physicists use to describe it, the
: actual values of any quantity (say, the distance between two electrons)
: must be a rational value rather than an irrational one that may be predicted
: by the model...

What if we define a new unit of charge, say the lawley,
where the charge on an electron is defined as pi lawleys?
Now we have a physical quantity, perfectly real, but irrational.
The value you get for a physical quantity depends on the system of
units you use.  Maybe the authors meant that you can never
take a measurement that will be irrational, because no measurement
device will be that precise.  So in our new units, you could define
pi lawleys, and an electron would always have a charge of pi lawleys,
but you'd never be able to measure that quantity with absolute precision.

Besides: Say you have three electrons, placed at the vertices of a triangle
so that a & b are 1 unit apart, a & c are one unit apart, and ab & ac are
at right angles.  What's the distance between b & c if it isn't sqrt(2),
which is irrational?

:             ...Now this seems to imply that space is discrete rather than
: continuous and that would seem to be rather a large claim...

That doesn't follow.  It would require a rational smaller than all others.
But half of such an object would be rational, too.
The rationals aren't discrete.  They're _countable_, but that doesn't
mean discrete.

--

/* tdk -- Opinions are mine, not my employer's. */
Xref: sparky sci.physics:23548 alt.sci.physics.new-theories:2858 sci.skeptic:22906
From: baez@guitar.ucr.edu (john baez)
Newsgroups: sci.physics,alt.sci.physics.new-theories,sci.skeptic
Subject: Re: below absolute zero?
Date: 26 Jan 93 05:08:57 GMT
Followup-To: sci.physics
Organization: University of California, Riverside

In article <C1EEo5.8Jr@well.sf.ca.us> sarfatti@well.sf.ca.us (Jack Sarfatti) writes:
>Thought problem for Star Fleet Academy Cadets from Admiral Sarfatti:
>How does a reversible Carnot heat engine behave if the hot reservoir is
>at a negative quantum temperature while the cold reservoir is at a positive
>classical temperature? What kind of Star Fleet devices can you make with
>this idea? Hint: use the second law of thermodynamics.

I won't answer the above question, but I will give you space cadets out
there a hint.  When you put a body with negative temperature in contact
with one of positive temperature, the temperature of the "cold" one *rises*
while the temperature of the "hot" one *falls*.  This is easy to see (for
physicists) if you recall that 1/kT is beta, which is dS/dE.  So (forgetting
Boltzmann's constant k), dS/dE = T.  Thus a system with negative temperature
gets more entropy if you *decrease* its energy, while a system with positive
temperature gets more entropy if you *increase* its energy.  Systems like
to increase their entropy, so energy will like to flow from the negative
T system to the positive T system.  

This is another reason why it sort of makes sense to think of negative
temperatures as being temperatures that are greater than infinity.

I suppose readers who don't already trust me will think I'm nuts, but
this is really all pretty well known.  I think Scientific American had
a nice article on systems with negative temperature a while back.
From: dseeman@novell.com (Daniel Seeman)
Subject: Re: Home made monopoles
Organization: Novell Inc., San Jose, Califonia
Date: Mon, 25 Jan 1993 17:12:23 GMT

In article <1jr3uiINNcjk@mirror.digex.com> bdoa@digex.digex.com (Barry Adams) writes:
>   
>
>                     Home made magnetic monopoles
>                     ============================
>
>   Contrary to popular belief , magnetic monopoles exist and are easy to
>make . Take a Steel hemisphere and cut a concentric hemisphere cut of the
>middle , now magnetize the hemisphere such that the domains of the object
>are aligned with the north (south) pole pointing outwards. Now stick two of
>the hemispheres together forming a sphere  (glue strong enough to resist
>the magnetic repulsion of the hemispheres is required) you now have your
>magnetic monopole :-) , since any observer will see the object having a north
>pole only (unless they cut it open).
>   Of course the configuration is unstable and the domains will slowly try
>to rearrange themselves to a more stable state. And the magnetic force still
>decays like a dipole. Such objects might to useful as frictionless bearings.
>
>Barry Adams
>
>   
In this experiment, we are to assume that what we cannot diretly "see (ie. the
inside of the sphere)" does not affect the problem.  Just because we "know" the
South Pole exists in the volume cavity inside doesn't mean we can actually
"see" it.  Hmmmm, it seems a bit like an illusion to me (smoke and mirrors to
be sure) but the application may be useful.  The application sure does satisfy
the apparent identifying criterion (compass always points one way near the
monopole).  I would like to hear other opinions (experiences) with this idea.

dks.
From: bweiner@ruhets.rutgers.edu (Benjamin Weiner)
Newsgroups: sci.physics
Subject: Re: photon 'detectors' - how reliable?
Date: 26 Jan 93 19:02:51 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

merritt@macro.bu.edu (Sean Merritt) writes:

>You erased, as others who poited this out, where I specified detectors
>that exploit the the photo-electric effect. I don't know enough
>about Charged Coupled Devices, do they use the photo-electric effect?

Whoops, sorry.  I wasn't trying to correct you, just adding a little
information on something else.  Yes: CCDs consist of semiconductor
layers; an incident photon is absorbed, creating loose charges, which
is confined to its pixel by an ingenious layout of the n and p layers; 
further ingenuity allows you to read the pixels out in order at the end
of your exposure.

>Does anyone know a manufacturer of CCD's, I should like to get a
>databook. Also what are the costs as compared to a photo-voltaic
>cell?

TI and Tek are the biggies, it seems to me.  They are expensive, though,
and it seems to me that CCDs are most useful in imaging or other highly
position-sensitive devices (they usually come in sizes 256x256 to 800x800 
or so pixels) - although I may only think this because of astronomy.
Also they need to be fairly cold, to reduce thermal noise, so the cooling
system adds expense and bulk.
Newsgroups: sci.physics
From: sarfatti@well.sf.ca.us (Jack Sarfatti)
Subject: re: Bass, Sawyer and Zoe Baird
Organization: Whole Earth 'Lectronic Link
Date: Fri, 22 Jan 1993 02:28:48 GMT


There is a parallel between Zoe Baird's fitness for Attorney General and
Bass's and Sawyer's fitness to be objective moderators. There is also,
as the late David Bohm would say, a "significant difference" in that Ms
Baird has publically apologized for her breaking the law she would be asked
to enforce. At the moment, the fact is that these would-be moderators have
put themselves "above the law".
From: barry@arnold.math.ucla.edu (Barry Merriman)
Newsgroups: sci.physics
Subject: Re: Truth vs beauty in physical theories
Date: 24 Jan 93 13:41:37 GMT
Organization: UCLA, Mathematics Department

In article <6aZmXB4w165w@1776.COM> bob@1776.COM (Robert Coe) writes:
> barry@arnold.math.ucla.edu (Barry Merriman) writes:
> > > A... why should our sense
> > > of beauty play a role comparable to experimental data? one reason may be
> > > that behind all phenomena there really is a very beautiful, unified 
> > > theory.
> > 
> > Wishful thinking. It could just as easily get extraordinarily complicated.
> > After all---if string theories are so simple, why are they so difficult
> > to work with?
> 
> Maybe it's because they're wrong.

Sure they're wrong, but thats besides the point.

Obviosuly, we can only work with theories that are simple enough for us to 
understand, and that guarantees a certain level of simplicity, either
in the theory or in its applications. 

But these are all statements about _us_, not the universe. So I still
see no reason to think the universe is simple. Rather, we'll only
ever understand those parts of it that are.

--
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: rbsalgad@rodan.acs.syr.EDU (Rob Salgado)
Subject: Questions on:  Black-Hole Thermodynamics
Organization: Syracuse University, Syracuse, NY
Date: Sat, 23 Jan 93 23:17:42 EST

I am about to carefully study the Bardeen-Carter-Hawking paper
"The Four Laws of Black Hole Mechanics" (Comm.Math.Phys. 31, 161-170 [1973]).

I have a few questions concerning black-hole mechanics and thermodynamics.
For now, I am only interested in the classical theory
(i.e: no Hawking radiation, no statistical mechanics).

REFERENCES would be greatly appreciated.

1) What is the current status of the uniqueness theorems?
   Is there a concise formulation and proof of a general uniqueness theorem?

2) Is there any work being done on non-stationary black-holes?

3) Are there any natural geometric structures living on the event horizon?

4) What is the status of the cosmic censor conjecture?

5) Is the thermodynamic analogy peculiar to (3+1)-Einstein gravity?
   Compare/contrast to, say, (2+1)-Einstein gravity or a scalar-tensor
   theory.

                                        Rob Salgado
                                        salgado@suhep.phy.syr.edu
From: weemba@sagi.wistar.upenn.edu (Matthew P Wiener)
Newsgroups: sci.physics
Subject: Re: Bass and Sawyer have disqualified themselves by flames.
Date: 24 Jan 93 17:21:17 GMT
Reply-To: weemba@sagi.wistar.upenn.edu (Matthew P Wiener)
Organization: The Wistar Institute of Anatomy and Biology
In-reply-to: sarfatti@well.sf.ca.us (Jack Sarfatti)

In article <C17zos.D4z@well.sf.ca.us>, sarfatti@well (Jack Sarfatti) writes:
>[croaking omitted]

I think you've revealed the true etymology of your name--it's from the
Hebrew ts'fard`ee, meaning frog.
-- 
-Matthew P Wiener (weemba@sagi.wistar.upenn.edu)
Newsgroups: sci.physics
From: atems@igor.physics.wayne.edu (Dale Atems)
Subject: Re: hidden variables
Organization: Wayne State University, Detroit, MI
Date: Sat, 23 Jan 1993 23:02:47 GMT

In article <511@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:

>[...] To compute the timing you need to go to the wave function model
>and you need to use the collapse postulate. 

The crucial question, as I see it, is whether the collapse postulate
is mathematically necessary.

>The Schrodinger equation
>is local you cannot use it to model the instantaneous transfer of information
>that you agree is necessary to produce the predictions of QM.

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.

------
Dale Atems
Wayne State University, Detroit, MI
Department of Physics and Astronomy
atems@igor.physics.wayne.edu
Newsgroups: sci.physics
From: wied@animal.sps.mot.com (Bill Wied)
Subject: Debate question of the day!!!!!
Organization: Motorola Inc.
Date: Thu, 21 Jan 1993 21:04:43 GMT

Hello all you physic buffs,

We were having a debate today about what makes a balloon full of air propel.
There were two theories expressed as to what is the major cause of propulsion.

The two theories go as follows:

1) Is it caused primarily by the effect of conservation of momemtum. That is,
   the propelling of the air mass in the ballon out at a high velocity causing
   the ballon to travel in the opposite direction with the same momemtum.

or

2) Is it caused primarily from the air being expelled at a high velocity,
   pushing against the exterior atmosphere thus creating high air pressure
   outside the ballons opening, which thrusts the balloon forward.
   
   

You'll have to forgive us if this question seems absurdly simple but we are
just a bunch of engineers who have long forgotton our physic lessons.

I would appreciate any expert opinions on this topic.

Thanks,

-- 
 _ __	        _     _          #  Bill Wied    #8-)  wied@animal.sps.mot.com
' /__)  o /  / ' )   / o   __/   #  2100 E. Elliot Rd. MD:EL512 Tempe, Az 85284
_/___)_/_/_ /   /_/_/_/_E_/_/_   #  Phone:602-897-4266  Fax:602-897-3822
______________________________)  #  Network Applications Group, Motorola SPS
From: baez@guitar.ucr.edu (john baez)
Newsgroups: sci.physics
Subject: Re: hidden variables
Date: 25 Jan 93 03:56:20 GMT
Organization: University of California, Riverside

In article <510@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:
>However, if the real motivation was curiosity about how
>the world works there would be far more interest and attention to the
>conceptual problems that exist in theoretical physics. People would be
>willing to take on these problems even realizing that they might spend a
>lifetime on them and fail in their quest. It is an entrenched bureaucracy
>that demands one takes on problems for which one can provide results that
>are meaningful in terms the bureaucracy recognizes in a reasonable
>time frame.

You certainly have a valid point here: that the bureaucracy of science
forces scientists towards projects that get done (or fail) in a several-year
time frame.  But I think it is an exaggeration to say that without this
effect "people would be willing to take on... problems even realizing that they 
might spend a lifetime on them and fail in their quest."  Some people would,
but most, I think, still would not.  Most people get depressed working on
something that might take a lifetime and still amount to nothing.  Most
people prefer the sense of accomplishment that results from finishing a
finite and doable task.  Even you might find pondering the interpretations
of QM frustrating if you didn't also have a job that gave you that kind of sense
of accomplishment.  (This could, of course, point to the good old model of
the "amateur scientist" (as opposed to "professional") as the best way to
keep science from getting hidebound.)  

Of course, many people who work on possibly hopeless tasks like theology,
philosophy, foundations of math and foundations of physics seem able to
*fool* themselves into a sense of accomplishment by convincing themselves
they have achieved something solid when they haven't.  (I will not name
names.)  The next generation may declare their work a bunch of rubbish, but
they will die "knowing" they have solved their problem.
From: mkagalen@lynx.dac.northeastern.edu (michael kagalenko)
Newsgroups: sci.physics
Subject: Re: female mentors in science
Date: 28 Jan 93 22:24:28 GMT
Organization: Northeastern University, Boston, MA. 02115, USA

In article <1993Jan28.052031.4258@nuscc.nus.sg> scip2124@nusunix1.nus.sg (MARC PAUL JOREF VAN LOO) writes:
>
>
>   
>       I am Posting Currently yes.
>       No doubt there are ahrian traces in this remark...
>       all you need is some fantasy.
>
>       Making comparisons like yours doesn't prove you have
>       a keen eye for history, it just shows you're obnoxious.

You would do great if you gain understanding that history is studied in
order to be able to make comparisons, my dear friend. 
Newsgroups: sci.physics
From: sarfatti@well.sf.ca.us (Jack Sarfatti)
Subject: re: Nasty people.
Organization: Whole Earth 'Lectronic Link
Date: Thu, 28 Jan 1993 04:40:12 GMT


Topic 279:  Mad Scientists II
# 12: Epigone of Koestler (rcl)      Mon, Sep 14, '92  (17:58)
16 lines

Praising Sarfatti in front of his face certainly won't alter his
character for better or worse, so let me say this. He strikes me
as one of those unusual American originals, The Existential Hero.
Such people don't often exist outside the fiction of Hemingway or
Mailer. Perhaps sarfatti has drunk deeply of the Mailerian spring.
Whatever drew him into this way of life, the fact remains that
he's obeying Nietzsche's maxim, live dangerously; and he's
pursuing Whitehead's ideal of the Adventure of Ideas. This he is
doing not as an insensate sleepwalker, but fully conscious and
aware of the dangers he runs and the glories he might gain.

Too bad that some blockheads among us writhe with envy at the
spectacle of a gifted soul aiming at stardom, and who spit gall
rather than applaud a trapeze artist flying high, netless, over
marble.