HDTenEightyP/NetNews huggingface dataset:
From: schiller@prl.philips.nl (schiller c)
Subject: Why is the letter Q used for electrical charge ?
Originator: schiller@prles11
Organization: Philips Research Laboratories, Eindhoven, The Netherlands
Date: Wed, 29 Jul 1992 13:28:57 GMT


The title says it all. Does anybody have a clue ?

Christoph Schiller

schiller@prl.philips.nl
From: gilligan@bldrdoc.gov (Jonathan Gilligan 303-497-3861)
Newsgroups: sci.physics
Subject: Re: scientific literature
Date: 28 Jul 92 23:42:30 GMT
Distribution: na
Organization: National Institute of Standards and Technology

In article <1992Jul26.192348.19076@wpi.WPI.EDU> phillies@wpi.WPI.EDU (George D. Phillies) writes:
|>[... Sci. Am. is not part of the scientific literature because
|>     it doesn't satisfy the following definition ...]

|>Under the orthodox definition of a scientific journal, as one whose 
|>articles are documented in a scholarly way and whose pages are 
|>generally open to debate, Scientific American (no matter its 
|>extensive merits as a refined match to Popular Mechanics) is not a 
|>scientific journal, and publication in its (undoubtedly culturally 
|>valuable) pages should not be described as publication in the 
|>scientific literature.  

Then is Reviews of Modern Physics not part of the scientific
literature because debates are not published there?

---Jon
-- 

Disclaimer --- The government probably disagrees with my opinions.
Organization: University of Illinois at Chicago
Date: Monday, 27 Jul 1992 15:13:14 CDT
From: <U53644@uicvm.uic.edu>
Newsgroups: sci.physics
Subject: Re: Earthquake's amplified?

The explanation that I'm familiar with (and please check this with a
geophysicist) is that stresses build up along a fault line because there are
both forces trying to move the rocks on either side in different directions
(or one side in one direction, and the other not at all), there is some
resistance to motion (friction; in the case of the San Andreas fault, the edge
between the Pacific and North American plates runs past the end of a mountain
chain, which acts as a ratchet, if you think of the slowly rotating Pacific
plate as a wheel). Stresses build up until a slip occurs, rock formations
break, etc. The violence occurs because it takes a lot of force to initiate
slippage, but once it starts, the resitance to further motion is reduced.

       For example : Suppose that you have a wooden block covered with
       sandpaper, and you are trying to push it across a floor. You
       gradually shove harder and harder, until you overcome the static
       frictional force, and it starts sliding. You'll feel a little
       jerk as the block picks up speed - it's sliding more freely now,
       and the force you are putting on it (the force needed to start
       motion) is now greater than the force needed to maintain a constant
       velocity, allowing for a slight acceleration.

       That slight jerk is analagous to an earthquake.

Predictable ? To some extent, if you know how much stress it takes to break
the relevant rock formations, and at what rate stress is buliding up, you
can make some educated guesses (expressed as probabilities). In my part of
the country (Midwestern US), it takes >a lot< of force to break those rocks,
and it builds up slowly, so major earthquakes are very infrequent (centuries
apart), but on the one time in recorded history when they hit (1811-1812, if
I recall correctly, epicenter near New Madrid, Missouri) they were extremely
powerful.

But like I said, please check this out with a professional, I might have gotten
this wrong. (There is a geology group, right?)

                                                   Joseph B. Dunphy
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: Defining Photons
Keywords: Relating photons E=MC^2 criticism
Organization: MIT Department of Mathematics, Cambridge, MA
Distribution: na
Date: Mon, 27 Jul 92 22:52:49 GMT

In article <24910@dog.ee.lbl.gov> sichase@csa2.lbl.gov writes:
>Photons behave classically when there are alot of them around.  Electrons
>behave classically when one of them is at high energy.  This is a fundamental
>difference, which emerges directly from the different methods of quantization
>used for fermion and boson fields, and directly leads to the dramatic
>classical difference between EM fields and lumps of matter.  But in the
>quantum regime this distinction blurs considerably, leading physicists to 
>class all these objects - photons and electrons and everything else, together
>as particles.
>
>Notice that masslessness have nothing to do with these questions.  

While my reply to the same query talked about mass rather than the
fermion/boson distinction, I should add for Jim's benefit that Scott's
reply does not contradict mine -- his just makes it a lot clearer what
about photons makes them seem so "weird" compared with ordinary
particles -- it's that they're bosons.
From: sichase@csa2.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Re: The Future of Physics
Date: 22 Jul 92 19:40:31 GMT
Reply-To: sichase@csa2.lbl.gov
Distribution: na
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
NNTP-Posting-Host: 128.3.254.197
News-Software: VAX/VMS VNEWS 1.3-4

In article <1992Jul22.160138.25400@galois.mit.edu>, jbaez@riesz.mit.edu (John C. Baez) writes...
> 
>Indeed, if you check, plasma research, solid state physics, and
>"chaos theory" (better to say "nonlinear dynamical systems theory") are
>all avid consumers and producers of fairly fancy mathematics.    

Not only that, but it's the same mathematics in many cases that makes 
particle physics seem so obscure to the uninitiated.  Group theory, 
renormalization, Lie algebras, etc., are all just as at home in solid 
state physics as particle physics.  Nonlinear dynamics is just a fact 
of life, which manefests itself in all interesting branches of physics.

The only reason that particle physics gets singled out in this regard, IMHO,
it that it gets more air play in general than, say, solid state physics.
How many laypeople who know about Feynman or Carlo Rubia also know about
Wilson, Migdal, Kadanoff, etc.  These guys just don't do PBS specials.

-Scott
--------------------
Scott I. Chase			"The question seems to be of such a character
SICHASE@CSA2.LBL.GOV		that if I should come to life after my death
				and some mathematician were to tell me that it
				had been definitely settled, I think I would
				immediately drop dead again."      - Vandiver
Newsgroups: sci.physics
From: clarke@acme.ucf.edu (Thomas Clarke)
Subject: Re: Re^2: Twins Paradox Resolved
Organization: University of Central Florida
Date: Wed, 22 Jul 1992 15:54:22 GMT

In article <1992Jul22.144745.24854@email.tuwien.ac.at>  
gast@next.ben-fh.tuwien.ac.at (Gast) writes:
> In article <1992Jul22.130948.18912@cs.ucf.edu> clarke@acme.ucf.edu (Thomas  
> Clarke) writes:
> > In article <BrrztE.J4u@well.sf.ca.us> metares@well.sf.ca.us (Tom Van  
> Flandern)  
> > writes:
> > > 
> > > {reiteration deleted}
> > >     For those unfamiliar with SR, SR implies that events synchronized  
> in one
> > >frame will not be synchronized (= simultaneous) in a relatively moving  
> frame.
> > 
> > Not true.
> 
> It is true. Two events that happen simultaniously in one system don't in a  
> system which is moved in respect to the former system.
> 
> Harry

Apologies, egg-on-face etc. etc.

I read TVF's statement without the "not".  His argument didn't make
sense unless he was erroneously claiming that it made sense to compare
ages on T1 and E1 relative to event of T2 meeting E2.  This comparison
makes sense if you assume once simultaneous then always simultaneous.

--
Thomas Clarke
Institute for Simulation and Training, University of Central FL
12424 Research Parkway, Suite 300, Orlando, FL 32826
(407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu
Newsgroups: sci.physics
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: Twins Paradox Resolved
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Thu, 23 Jul 92 16:38:26 GMT

In article <1992Jul23.050957.6557@nuscc.nus.sg> matmcinn@nuscc.nus.sg (Mcinnes B T (Dr)) writes:
>John Baez: What, more reticence? I'm sure I speak for many when I say
>that I would be very interested to hear about those 3 hours of debate on
>the twins. Please post a summary. Thanks rett 

My reticence is never more than momentary.  We started out talking about
relativistic free particles and got into the twin "paradox".  I think
the upshot was what I described in a previous post.  Namely, the only
reason why one might expect the twins to have the same age upon
meeting each other again is some sort of symmetry argument.  When you
realize that one computes a twin's age by calculating the length of his
worldline using the Minkowski metric, one should realize that a symmetry
argument is only applicable when there is an isometry of Minkowski space
mapping one twins worldline to the other.  I.e., when their worldlines
look the same up to translations, rotations, and Lorentz boosts.
There's never any way to map a geodesic (unaccelerated worldline) to a
nongeodesic (accelerated worldline) so if one twin has felt acceleration
and the other not it's clear that no symmetry argument applies.
However, in fancier spacetimes like the torus world there may even be
two timelike geodesics that cannot be mapped to one another via
isometries, so one can have two unaccelerated twins who meet with
different ages.

We also discussed the version of the twin paradox that von Flandern likes so
much.  Here of course the trick is that simultaneity is an
frame-dependent concept.  We also went over the extra things you have to
do to take into account what relativistic observers actually SEE -
namely, take into account the time it takes light to get there.  (All
the things we SEE at t=0 is a different notion than all the
things happening at t=0 in our frame.)  Here the famous case is the fact
that one will SEE a rapidly moving sphere as having a perfectly round
profile, despite the Lorentz length contraction.  

I also showed them how to rapidly draw Lorentz-boosted coordinate
systems in 2-d spacetime diagrams, an invaluable skill.  Hint: call your
coordinates t and x.  A Lorentz boost will map the diagonal lines t = x
and t = -x to themselves.  Since a Lorentz boost is volume preserving,
it simply stretches out the line t = x by some factor k while squishing
in the line t = -x by the factor 1/k.  I.e. in lightcone coordinates
u = x+t, v = t-x, we get something like

u -> u/k
v -> kv

Everyone who hasn't done this twice already is advised to take the
situation von Flandern describes and draw a spacetime diagram of it
first in "our" coordinate system and then the coordinate system in which
the astronaut is at rest, to see his explanation of why he's so much
younger than us stay-at-homes.
Xref: sparky sci.physics:11299 sci.astro:8205
From: freitag@elrond.toppoint.de (Claus Schoenleber)
Newsgroups: sci.physics,sci.astro
Subject: Re: Structure of Time
Date: 21 Jul 92 19:21:58 GMT
Organization: Claus Schoenleber, Kiel, Germany (3-926986)

phfrom@nyx.uni-konstanz.de (Hartmut Frommert) writes:

>  Univ of Constance, P.O.Box 55 60,     |     or  <phfrom@nyx.uni-konstanz.de>
>  D-W-7750 Constance, Germany  | + SAVE THE WHALES ! BOYCOTT NORWAY !        +
            ^^^^^^^^^
I think, "she" is spelled "Konstanz", isn't it? Or do you spell N.Y. like
"Nju Jork"?  ;-)

Claus.

-- --------------------------------------------------------------
Claus Schoenleber             I  UUCP  freitag@elrond.toppoint.de
=================================================================
The Galaxy shall miss you! I "What's the matter?" - "Never mind!"
Isaac Asimov died 06Apr92. I  ;-)  "What's mind?" - "No matter!"
=================================================================
Newsgroups: sci.physics
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: Defining Photons
Keywords: Relating photons E=MC^2 criticism
Organization: MIT Department of Mathematics, Cambridge, MA
Distribution: na
Date: Mon, 27 Jul 92 23:39:34 GMT

In article <24927@dog.ee.lbl.gov> sichase@csa3.lbl.gov writes:
>You will find that serious attempts at quantizing photons in a rigorous way
>actually treat the photon as massive (to elimate certain problems which 
>arise from gauge transformations) and then discard the unphysical part of the
>resultant fock-space which results from the unphysical degrees of freedom.
>(The phrase "Buela-Gupta quantization" pops into my head.) 

Bleuler-Gupta pops into mine.

>The massiveness
>in no way interferes with the photon's quantization or its behavior in the
>classical limit.

Indeed, if one is only worried about free photons there's not even any
need to treat the photon as massive at any stage, or screw around with
"indefinite metrics" in Hilbert space and such.   It's just another
unitary irreducible representation of the Poincare group and one just
pops it into the general machinery for quantizing unitary
representations.  If one is worried about interacting photons then of
course there is no rigorously worked out theory, since there's no fully
worked theory of interacting QFT's in 4-d.  But there is a workable
perturbation theory and while the masslessness of the photon causes
nasty infrared divergences the experts tell me this doesn't faze them.
Newsgroups: sci.physics
From: cramer@phys.washington.edu (John Cramer)
Subject: Re: Communication using non-local quantum correlation
Organization: University of Washington
Distribution: na
Date: Fri, 24 Jul 1992 14:34:27 GMT

Argh!  I strongly object to Jack Sarfatti bringing the transactional
interpretation of quantum mechanics (see Reviews of Modern Physics, July-1986)
into his latest non-local FTL communication scheme.  The transactional
interpretation is just that, and INTERPRETATION of the formalism of
the standard mathematics of quantum mechanics, and as such it does not provide
any mechanism for non-local communication.  The reason is fairly simple:
in the mathematics of quantum mechanics, spatially separated measurements
performed on the same quantum system are represented by operators that
always commute, so nothing that one operator does can change, in the sense of
signalling, the response of the other measurement.  The non-local quantum
correlations are there, but they are so subtle that no non-local observer
to observer communication is possible, UNLESS YOU GO BEYOND THE STANDARD
FORMULATION OF QUANTUM MECHANICS.

Therefore, I would not worry much about Sarfatti's latest broadside.  If you
are interested in non-standard quantum mechanics, Steve Weinberg's recent
investigations of the possibility of small non-linear effects in quantum
systems is a much better place to look.  There is also some discussion of
"extensions" of the formalism in various directions in my paper on the
transactional interpretation, as cited above.

John G. Cramer
University of Washington
cramer@phast.phys.washington.edu
From: ted@physics1 (Emory F. Bunn)
Newsgroups: sci.physics
Subject: Re: Quantum Cosmological Boundaries and Determinisim?
Date: 22 Jul 1992 02:16:58 GMT
Organization: /etc/organization
NNTP-Posting-Host: physics1.berkeley.edu
Keywords: Quantum cosmology

In article <jtwamley.711766649@adelphi> jtwamley@physics.adelaide.edu.au (Jason Twamley) writes:
>Question:
>Assume the the while universe can be described by a quantum theory....
(Lots of stuff deleted here.  Let me summarize.)

The question, as I understand it, is this:  If we had a theory that predicted the
wavefunction of the Universe uniquely at time t=0, would that mean that the 
evolution of the Universe thereafter was completely deterministic?

Admittedly, we're in somewhat murky waters here, but I'll give an opinion.

No.  The indeterminism of quantum mechanics would still apply.  Let's suppose
that either the standard "collapse" interpretation or the so-called "many-worlds"
interpretation of quantum mechanics is right.  In the first case, observations
will (frequently) cause the collapse of the wavefunction, and this collapse
will be a nondeterministic event.  It is perhaps even more unclear than usual
what counts as an "observation" that can collapse this wavefunction, but the
fact that the wavefunction collapses under some circumstances is certain.

I'm not really up on the many-worlds interpretation, but my understanding of it
is that the evolution of the wavefunction is deterministic, but that the results
of any particular quantum experiment will still be random.  This is true whether
the wavefunction in question belongs to a single electron or the entire Universe.
If anybody wants to do a better job explaining this, be my guest.

-Ted
(ted@physics.berkeley.edu)
From: sichase@csa3.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Re: Radionuclide Half-Lives
Date: 21 Jul 92 20:48:23 GMT
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
Distribution: na
Reply-To: sichase@csa3.lbl.gov
NNTP-Posting-Host: 128.3.254.198
Summary: I'll bite
News-Software: VAX/VMS VNEWS 1.3-4   

In article <1992Jul21.172715.3167@murdoch.acc.Virginia.EDU>, crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass) writes...
>In article <92203.121247CCB104@psuvm.psu.edu> <CCB104@psuvm.psu.edu> writes:
>>For want of a sponsor or potential "licensee," an official "Invention
>>Disclosure" outlining an unconventional method of forcibly changing
> 
>    What would be the 'conventional method'?  Acceleration to high
>    energy?

As you know, that would not change the decay rate in the nucleus' rest
frame.  There is however a way to modify some decay rates, though most
people don't realize it because they are incorrectly taught that nothing
environmental can affect the decay rate of a radioactive nucleus.

For nuclei which decay by K capture, the decay rate is sensitive to the
electronic structure of the atom.  This is obvious, because any capture
matrix element will have to include the electron's wave function.  So if
you take such an atom and bind it in a molecule so that it's electronic
orbitals are perturbed, you affect the decay rate of the nucleus.

You can look up the details in Segre's book _Nuclei and Particles_.  The
effect has been experimentally verified.  Although I don't know if it has
ever been done, you can easily imagine that very high pressures will also
change the decay rate of a solid lump of such an element, for the same 
reasons.

I can also imagine that putting a nucleus which is gamma unstable between
two plates, ala Casimir, would affect the decay rate by changing the 
allowed photon spectrum in the gap.  But because of the very high frequency
the plates would have to be much closer than is typical for the kind
of cavity experiments you read about nowadays.


-Scott
--------------------
Scott I. Chase			"The question seems to be of such a character
SICHASE@CSA2.LBL.GOV		that if I should come to life after my death
				and some mathematician were to tell me that it
				had been definitely settled, I think I would
				immediately drop dead again."      - Vandiver
Newsgroups: sci.physics
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: The Future of Physics
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Thu, 23 Jul 92 16:48:24 GMT

In article <phfrom.219@nyx.uni-konstanz.de> phfrom@nyx.uni-konstanz.de (Hartmut Frommert) writes:

>>[..] tachyons (which do not exist) [..]
>               ^^^^^^^^^^^^^^^^^^^^
>               Can you prove this ?

If you prefer, I can say they "seem like they probably don't exist".
Then I also have to say that unicorns "seem like they probably don't
exist."  They have not been observed despite some effort.
Newsgroups: sci.physics
From: jamesm@helios.physics.utoronto.ca (James Mihaychuk)
Subject: Re: What are those things called...
Organization: University of Toronto Physics/Astronomy/CITA
Date: Sun, 26 Jul 1992 18:10:07 GMT

In article <1992Jul23.214214.8574@microplex.com> hsk@microplex.com (Harjeet Kalsi) writes:
>I know I've seen them in physics labs (including mine when I was in school) 
>but forgotten what this "box" with two antennas, that has a high
>voltage spark travelling between the antennas from bottom to top,
>is called.
>
>hsk@microplex.com

My high school physics teacher told me it was called a Jacob's Ladder, although
there might be other names.
---
James Mihaychuk, indentured servant  You say your moon's in the seventh house,
(lowly physics grad student)         But your butt spent three days on my couch
jamesm@helios.physics.utoronto.ca    "Eternal Fatalist," the Lowest of the Low
From: jac@ds8.scri.fsu.edu (Jim Carr)
Newsgroups: sci.physics
Subject: Re: Space Station & APS
Keywords: infrastructure infrastructure infrastructure
Date: 29 Jul 92 20:50:13 GMT
Reply-To: jac@ds8.scri.fsu.edu (Jim Carr)
Organization: SCRI, Florida State University

In article <1992Jul29.175816.29663@murdoch.acc.Virginia.EDU> crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass) writes:
>In article <29JUL199213170451@stars.gsfc.nasa.gov> dc@cobi.gsfc.nasa.gov writes:
>>
>>I have seen statements flying by that the APS opposes the Space Station.
>>However, if you read the statement you can see that the APS only opposes
>>the justification of SSF on the grounds of scientific research.
>>Basically, the supporters of SSF told the public "This will be great for
>>science" and the scientists have responded "It won't either".  The APS
>>does not comment on other purported justifications of the SSF.
>
>     Exactly.  However, if the APS is just concerned about the purity of 
>     science, why do we not see large campaigns to eliminate quackery, a much
>     more important misuse of scientific justifications?

The APS has not mounted a "campaign" to halt SSF.  It has merely issued a 
formal policy statement, as have other organizations, as a result of a 
vote by its elected counselors.  In accordance with its bylaws, the 
president of the APS read that statement at various public hearings. 

The APS has taken formal positions on the other issues that concern you, 
most notably fraud in science, the only form of quackery that falls under 
its purview.  In addition, it gave a major award to James Randi for his 
work in helping debunk the homeopathy claims of Benveniste.  It is not 
the sort of organization that takes such stands on many issues (it is 
a relatively recent change in what had been a policy of utter neutrality 
on everything) or that "campaigns" on anything.  Its public affairs 
office has, however, helped coordinate the actions of individuals who 
wish to bring their views to the attention of local officials -- but 
does not dictate the position those individuals might wish to take. 

--
J. A. Carr                                    |  "The New Frontier of which I  
jac@gw.scri.fsu.edu                           |  speak is not a set of promises
Florida State University  B-186               |  -- it is a set of challenges."
Supercomputer Computations Research Institute |   John F. Kennedy (15 July 60)
Newsgroups: sci.physics
From: scip1061@nuscc.nus.sg (Marc Paul Jozef)
Subject: [Experiments violating relativity?]
Organization: National University of Singapore
Date: Wed, 29 Jul 1992 06:20:12 GMT

   Is there anybody who disputes Hayden's interpretation
of the Brillet-Hall improved Michelson-Morley experiment?
[Hayden: Is the velocity of light isotropic in the frame
of the rotating earth?; in: Physics Essays, vol. 4, nr 3, 1991].

This experiment, and others (Sagnac, Michelson-Gale etc)
are able to detect the daily rpotation of the earth, but
NOT the rotation around the sun.

Now Hayden suggests that relativity is not capable of
furnishing a satisfying explanation for this. I thinkk it
can, but at the cost of the Einstein idea that rods on
a rotating circle are `contracted'.

So secondly, I would like to know if there is concensus
on whether or not special relativity REQUIRES the
circumference of rotating circles to change. If there
is concensus, is that written down in some published
paper?

Marc val Loo, national university of Singapore.
scip1061@nuscc.nus.sg


Newsgroups: sci.physics