HDTenEightyP/NetNews huggingface dataset:
From: usenet@crd.ge.com (Required for NNTP)
Newsgroups: sci.physics
Subject: Re: Question about dimmer switch and lamp.
Date: 11 Apr 92 11:29:52 GMT
Organization: GE Corporate R&D Center

In article <STEINLY.92Apr6175636@topaz.ucsc.edu> steinly@topaz.ucsc.edu (Steinn Sigurdsson) writes:
>In article <1020006@hpdmd48.boi.hp.com> rrr@hpdmd48.boi.hp.com (Rudi Rynders) writes:
>
>
>    Can someone versed in physics please explain this phenomenon?
>    Given an incandescent lamp with a dimmer switch. The lamp is on.
>    One can then slowly turn the dimmer knob and reduce the light
>    intensity until the filament is just barely glowing.
>    If , however the lamp is off, and one slowly turns the dimmer
>    switch up, no matter how slow, the light always comes on rather
>    suddenly and much brighter than in the reverse process .
>    Why is that so ?
>
>No one tackled this one?
>I'd say because the filament resistance is a function of temperature,
>that should suffice...
>

This is not a physics problem, it is an electrical engineering problem.
If you were the incandescent lamp with a Variac, it would turn off and on
at the same point, smoothly and without hysteresis. The reason it behaves
as described by Rudi is that residential dimmers do not use variable
transformers, but do use a semiconductor switch called a Triac to apply
the 60Hz power to the lamp for variable portions of the cycle. That is, at
half power, full voltage is applied for half of each 60Hz cycle. The
triggering circuit for this Triac has considerable hysteresis, which
accounts for the behavior documented above.

Vic Roberts
GE Research and Development Center, Schenectady, NY
roberts@crd.ge.com
Newsgroups: sci.physics,sci.aeronautics
From: serafini@amelia.nas.nasa.gov (David B. Serafini)
Subject: looking for CFD code
Keywords: CFD 
Organization: Rose Engineering & Research, @ NASA/Ames R.C.
Date: Sat, 11 Apr 92 01:44:35 GMT
Summary: anyone with a simple finite-volume N-S solver?

I'm looking for the source code for a finite-volume Navier-Stokes flow
solver.  More for education purposes than engineering use, so bells
and whistles are not required.  I haven't checked COSMIC yet, but I
will, so don't suggest that route.

Send email (serafini@nas.nasa.gov) and I'll summarize.

Thanks in advance.

-David

--
David B. Serafini			serafini@ralph.arc.nasa.gov
Rose Engineering and Research		   or   @amelia.nas.nasa.gov
NASA/Ames Research Center MS 227-6	(415)604-6233   FTS: 464-6233
Moffett Field, CA 94035-1000		==<all standard disclaimers apply>==



--
David B. Serafini			serafini@ralph.arc.nasa.gov
Rose Engineering and Research		   or   @amelia.nas.nasa.gov
NASA/Ames Research Center MS 227-6	(415)604-6233   FTS: 464-6233
Moffett Field, CA 94035-1000		==<all standard disclaimers apply>==
Newsgroups: sci.physics
From: richard@locus.com (Richard M. Mathews)
Subject: Re: My objections to the collapse postulate
Organization: Locus Computing Corporation, Los Angeles, California
Date: Tue, 07 Apr 1992 19:43:58 GMT

<U53644@uicvm.uic.edu> writes:
>Please pardon me if this is a silly question (I'm a Math/Elec.Eng. grad, not
>physics), but can one tell that a wave function has collapsed at a certain
>distant point before light from that point would have arrived?

No.  Two events separated by a space-like interval may be correlated, but
observers at either point cannot confirm the correlation until enough time
passes to "see" the other event.  Prior to observing either event, there
is no way to observe whether the wave function has already collapsed in
such a way that it will force the outcome of that event.  The result you
get is a certain outcome if you assume the collapse already took place
and a possible outcome if you assume the collapse did not already take
place.  It is the same outcome in either case, so you can't distinguish
those.

>If not, then
>does the simultaneous collapse of that wave function everywhere transmit
>information at faster than light speeds?

No information is passed, and it does not matter which event you consider
to have occured first.

>If not, what's the paradox?

The fact that Paul Budnik keeps this debate going for years.   ;-)

Richard M. Mathews			Lietuva laisva = Free Lithuania
Internet:   richard@locus.com		Brivu Latviju  = Free Latvia
UUCP:	    ...!uunet!lcc!richard	Eesti vabaks   = Free Estonia
MIL/BITNET: richard%lcc@UUNET.UU.NET	        WE  DID  IT!!!
From: mbk@lyapunov.ucsd.edu (Matt Kennel)
Newsgroups: sci.physics
Subject: Re: Yes, Virginia, there's no superluminal communication
Date: 14 Apr 92 07:40:41 GMT
Organization: University of California, San Diego
NNTP-Posting-Host: lyapunov.ucsd.edu

bweiner@ruhets.rutgers.edu (Benjamin Weiner) writes:
: The reason why I don't believe in Lorentz invariant quantum
: "collapse" is that no one's come up with a theory of it, OK?
: You can throw words around: mechanistic, nonlinear, chaotic,
: but it makes no progress.  Just go off and invent the theory,
: please.

Oh, I admit it's an outrageous suggestion and an immensely daunting task.
But what is the present "theory"?  "It happens by magic and there's no other
explanation and there's nothing else there."  Not so hot.

:  mbk@lyapunov.ucsd.edu (Matt Kennel) writes:
: >It's almost as if people don't want to bother to really look.  (Why?
: >Might small science actually get a Nobel Prize by accident?)
: 
: Why?  Because the chances of getting anything done are
: minimal and you will have a tough time convincing anyone to
: give you a job.

Why?  Because everybody is sure that there's nothing else there.

Acutally, it's my opinion that the experimental evidence _for_ superluminal
collapse is weak, and experiments testing any sort of collapse phenomena not
too numerous.  Most physical experiments don't depend on how collapse
&cetera work, only on things like energy spectra and cross sections.

Sure money's tight, but compared to space missions, and any particle
physics, some small experiment with fast electronics & photomultipliers
is chickenshit.

:  Here let us remember some advice attributed
: to David Mermin: "No one should work on Bell's theorem until
: after they have tenure."

True.  Forgetting about GR, I don't think that any sensible theory could
reasonably be expected without new experimental results, though.

: Ben Weiner

Matt Kennel
mbk@inls1.ucsd.edu
From: 92marsh@gw.wmich.edu
Newsgroups: sci.physics
Subject: Time
Date: 10 Apr 92 04:18:52 EST
Organization: Western Michigan University

         Cheers,

           1. What do we mean by saying 'empty space at given time'? 
         When we say "nothing is there [pointing] now," the now is
         unable to refer to any time reference except where we are,
         but where-when we are pointing.

           2. Can time truly be the transportation of energy?  A point
         object with zero energy "movement" still exists.  Time
         continues.  Unless I am greatly misunderstanding the 'time as
         energy vehicle' approach, it doesn't make sense in this
         respect.

           3. What do we mean by space-time?  We say it means every
         object at every moment is given four unique coordinates. 
         This vector has x, y, z for physical position and t for
         temporal position.  Let us examine (x',y',z',t') and let us say
         there is not an object or energy "there."  Meaning, E=mc^2=0
         for said point/perspective.  The sentence "The point
         (x',y',z',t') exists." has no meaning.  There is no
         perspective of the rest of the universe--no photons are
         relaying information or connecting that point to the universe
         by light cones.  There is apparently no way to get to that
         place-time or to leave that place-time.

           4. A PARADOX!!  It would seem that #3 leads us to believe
         that empty space cannot exist.  Return of the ether theory? 
         (Oh no!)

           5. It would seem that the space-time theory limits all
         knowledge to the here-and-now.  I can't even figure out what
         my friends are saying to me because they are over THERE.  I
         cannot remember what I was just doing because that isn't NOW.


           Someone asked for general ideas about time and I think,
         generally.  Take my ponderings for what they are worth, but
         not arguments toward anything.  Does this paradox seem
         similar to Zeno's?

         Charles
         92marsh@gw.wmich.edu
From: sawyer@sscvx1.ssc.gov (Lee Sawyer)
Newsgroups: sci.physics
Subject: Re: Hawking speaks out ...
Summary: UK politics
Date: 8 Apr 92 20:00:00 GMT
Distribution: world,local
Organization: Superconducting Super Collider Laboratory
News-Software: VAX/VMS VNEWS 1.4-b1

In article <1992Apr8.093810.1@milori.ccit.arizona.edu>, bob@sclera.physics.arizona.edu     writes...
>The Einstein/Sakharov/Li-Zhi tradition is apparently alive and
>well.  Something about cosmology, I guess :)
> 
>C.S. Cornuelle
>bob@sclera.physics.arizona.edu

  "Alive and well" somewhere, no doubt. However can you imagine the response
 if Leon Lederman or Phillip Anderson spoke on the presidential race ?
 He would be crucified by the media, if they paid any attention at all.

 ==============================================================================
         Lee Sawyer     | Dept of Physics          
       (SSCVX1::SAWYER) | Univ of Texas - Arlington    
                        | Arlington, TX            
 ==============================================================================
From: jscott@winvmc.VNET.IBM.COM (Jonathan Scott)
Newsgroups: sci.physics
Subject: Baryon quark idea
Date: 16 Apr 92 16:25:45 GMT

If you roll a ball without slipping or twisting over the surface of
another ball of the same size, the orientation of the rolling ball is a
single-valued spherically symmetrical function.  Another way of looking
at this function is to say that the orientation of the rolling ball may
be obtained by rotating it by half a turn about the original radial
direction, sliding it to the new position keeping the same orientation,
then rotating it by half a turn about the new radial direction.

I reckon that the function which is the "square root" of this rotation
has spin 0, isospin 0 and charge +2 (with opposite signs for the other
square root).  In four-vectors, the function is (cos pi/4 + iu sin pi/4)
where u is a unit vector in the radial direction, so this is simply iu.
(To see how I get the charge, note that the div of this is 2i/r).

If every baryon was held together by one of these functions (call it a
"baryon quark") with charge Q = +2 and baryon number B = 1, rather than
"gluons", then the ordinary quarks could be identical to the leptons and
would not need fractional quantum numbers.  The "baryon quark" could
also act as a marker to distinguish the sequence of otherwise identical
quarks, avoiding the need for "colour".

The quantum numbers need redefining a little to allow leptons to share
quark properties such as isospin, and quarks to have lepton numbers.
This gives an absolutely conserved quantum number equal to Q - 2B + L/2
which seems to fit correctly as the timelike scalar part of the
intrinsic spin, a generalization of I3.  (Q, B and each type of L are
also conserved separately).  It also equals I3 + (S + C + B* + T)/2
where those stand for Isospin3, Strangeness, Charm, Bottom and Top.

To avoid baryons having unbalanced lepton number +3 in this scheme, the
"baryon quark" could alternatively be assigned a new type of lepton
number Ln = -3 (conserved independently) in which case the generalized
I3 quantum number would become Q - B/2 + L/2.

Does this idea seem reasonable?  I'd like to know about any theoretical
or experimental results which might be relevant.

(For those with long memories, this was one of the less weird ideas I
had when I last had write access to the net in 1987.  I don't have
access to the alt group which I assume to be for REALLY weird new
theories, so I'm trying to avoid being TOO controversial).

Jonathan Scott
jscott@winvmc.vnet.ibm.com
Newsgroups: sci.physics.fusion
From: jtchew@csa3.lbl.gov (JOSEPH T CHEW)
Newsgroups: sci.physics.fusion
Subject: HIF Proceedings in print at last
Date: 7 Apr 92 20:14:59 GMT
Article-I.D.: dog.22554
Reply-To: jtchew@csa3.lbl.gov
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
NNTP-Posting-Host: 128.3.254.198
News-Software: VAX/VMS VNEWS 1.3-4

The Proceedings of the International Symposium on Heavy Ion
Inertial Fusion (Monterey, CA, December 1990) have finally
arrived (shades of Jim Carr's posting!).

Mostly it's about the guts of accelerators, but there are 
some papers of broader interest on topics that have come up 
on this newsgroup, like target physics, muon-catalyzed fusion, 
and reactor design.  And there's a paper which holds that the 
real usefulness of heavy-ion inertial fusion will be as a
neutron source for cooking fission wastes.

It's published as Volumes 37-38 of Particle Accelerators,
which is put out by Gordon and Breach Science Publishers.
I don't have copies to give out, but your friendly neighborhood 
technical library should be able to tell you where to get it.

--Joe
"Just another personal opinion from the People's Republic of Berkeley"
From: Dieter Britz <BRITZ@kemi.aau.dk>
Subject: RE: Re: TRITIUM AT HARWELL
Reply-To: Dieter Britz <BRITZ@kemi.aau.dk>
Organization: Sci.physics.fusion/Mail Gateway
Date: Mon, 6 Apr 1992 13:25:19 GMT


Originally-From: cary@esl.com (Cary Jamison)

>In article <78B36487C49F007754@vms2.uni-c.dk>, BRITZ@kemi.aau.dk (Dieter Britz)
> writes:
>> Date: 1 Apr 92 14:30:48 GMT
>>
>> I have it from a source who prefers not to be named, that tritium has been
>> found at Harwell.
>[...]
>> Make what you will of this.
>>
 ------------------------------------------------------------------------------
>> Dieter Britz alias britz@kemi.aau.dk
>> Kemisk Institut, Aarhus Universitet, 8000 Aarhus C, Denmark.
>>
 ==============================================================================
>
>April Fool!!

Full marks, Cary. Must have been too obvious, though, judging by the lack of
response. How about this, Scientists Making Jokes? What will Prof. Farrell
think of us?
------------------------------------------------------------------------------
Dieter Britz alias britz@kemi.aau.dk
Kemisk Institut, Aarhus Universitet, 8000 Aarhus C, Denmark.
==============================================================================
From: edwlt12@lims02.lerc.nasa.gov (MIKE JAMISON)
Newsgroups: sci.physics.fusion
Subject: Filament Fusion
Date: 9 Apr 92 17:37:00 GMT
Article-I.D.: lims02.9APR199212371333
Organization: NASA Lewis Research Center
News-Software: VAX/VMS VNEWS 1.41

I just received my latest Electronic Engineering Times (Monday, Apr. 6, 
Issue 687).  On page 39 there's an article that might be interesting to all 
you non-EEs, as well as us EEs.  The title is "Fusion trials challenge EM 
theory".

The thrust of the article is toward the Ampere force, which supposedly acts 
in the direction of current flow, proportional to the square of the current
, not predicted by Maxwell's equations.  Some of the experiments in which 
this (possible) force *may* be seen are filament fusion experiments.

According to the article, Deuterium is frozen into a solid "wire".  The 
"wire" is then subjected to a large current (1E6 Amperes, for ~1 ns, 
according to the article) and some of the D fuses.  No information is given 
on power out vs power in, etc.

Anyone have any more information on this?


Mike Jamison

Disclaimer:  NASA and I aren't responsible for each other.

"Believe in your limitations, and sure enough, they're yours"
						-Richard Bach
From: dietz@cs.rochester.edu (Paul Dietz)
Newsgroups: sci.physics.fusion
Subject: Re: Deuteron induced fission
Date: 14 Apr 92 00:35:14 GMT
Organization: Computer Science Department University of Rochester

In article <167C810A71.M21742@mwvm.mitre.org> M21742@mwvm.mitre.org writes:

> One of the real problems in science today is the paucity of mentors.
> Mentors could be counted on to know the old literature.  How many
> nuclear physicists are aware of Segre's paper on deuteron induced
> fission of molybedenum to produce (for the first time) technicium?
> And it was published in the relatively high prestige journal Nature.

Fission of molybdenum to make technetium would be a neat trick, since
technetium has a higher atomic number!

What you are garbling is the creation of Tc-99 from Mo-98 by the (d,p)
reaction, followed by beta decay of Mo-99.  This is covered in some
detail in nuclear physics texts.

For example, in the well-known text "Nuclei and Particles".

The author of which is Emilo Segre.

	Paul F. Dietz
	dietz@cs.rochester.edu



	
Newsgroups: sci.physics.fusion
From: ames!FNALD.FNAL.GOV!DROEGE
Subject: Current Experiment Status
Reply-To: ames!FNALD.FNAL.GOV!DROEGE
Organization: Sci.physics.fusion/Mail Gateway
Date: Wed, 15 Apr 1992 02:46:27 GMT

This is the status of the current P&F experiment.

Cathode Electrode: 0.037 cc, 0.58 sq cm, cylinder with spherical ends.
Anode Electrode: Approximately 3 sq cm of .25 mm Pt wire.
Electrolyte: 2N D2SO4 + 0.1N Li2SO4
Charging Profile: Ramp from 40 ma per sq cm to 600 ma per cq cm over 1/2 hour
Duration: Day 35
Initial D/Pd ratio: 0.93
Heater + Cell Power: 9.23 watts
Cell Voltage: Low of approximately 1 to high of 3 volts.  
Temperature: 10 C

Calorimeter balance over the last 6.25 hours was -4.7 joules.  Note this is 
out of 207675 joules which passed through the calorimeter (9.23*3600*6.25).

Calorimeter balance since day 0 is 22,500 joules.  But this includes 
approximately 25000 joules picked up when we changed the operating temperature 
from 20 C to 10 C, and 500 joules lost in charging the sample.  This puts us 
about 3000 joules away from perfect balance over 35 days or a negative drift 
of about 1 mw.   Much of this error is due to not correcting calibration 
properly as changes were made.  We calibrate with a slight negative drift to 
be conservative. 

Skeptics:  Take heart.  We have no heat output to within -4.7 joules in 6.25 
hours or within 0.005 watt per cc.  P&F in a typical experiment claim 20 watts 
per cc so our measurement would place a "Morrison upper limit" 4000 times 
below the P&F claim. 

True Believers:  Take heart.  The average time to first heat from the P&F 
patent is 70 days.  You have 35 more days of hope.  But much longer if we 
use statistics and several samples.  

Others:  Take heart.  It is possible to keep a kludge like this running for 
long periods of time in spite of thunderstorms and flooding of the Board of 
Trade.  What will I ever do with 13.6 Mb of data so far?

Tom Droege
From: alexo+@cs.cmu.edu (Alex Orenshteyn)
Newsgroups: sci.physics.fusion
Subject: Low Temperature Electrolysis.
Date: 15 Apr 92 13:32:26 GMT
Organization: Sinectonalysis, Inc.

If I had the means I would try the experiment myself, but since I
do not I decided to propose it here. Has anyone tried to load Pd
by doing electrolysis in liquid D2 (actually the proper name might
not be "electrolysis"). Since the boiling T of D2 is well known at
1 Atm and room T of, say, 20C and will remain constant throughout
the boiling out process which would simplify lots of calculations.
Keeping Pd electrodes at very low T may put into superconducting state
(I am not sure, I would have to look it up). At these temperatures all
kinds of unusual QM effects may kick in. If D2 does not happen to conduct
(but I think it should) it could be fixed by adding doppants. Measuring
heat evolution can done by continously monitoring the weight of the
entire apparatus.

If someone has the necessary materials, I would very much like to
hear of any results.

Cheers.
From: jac@ds8.scri.fsu.edu (Jim Carr)
Newsgroups: sci.physics.fusion
Subject: Re: Deuteron induced fission
Date: 14 Apr 92 15:16:14 GMT
Reply-To: jac@ds8.scri.fsu.edu (Jim Carr)
Organization: SCRI, Florida State University

In article <167C97CE1.M21742@mwvm.mitre.org> M21742@mwvm.mitre.org writes:
>
>In article <1992Apr14.003514.9862@cs.rochester.edu>
>dietz@cs.rochester.edu (Paul Dietz) writes:
> 
>>In article <167C810A71.M21742@mwvm.mitre.org> M21742@mwvm.mitre.org writes:
>>
>>> Mentors could be counted on to know the old literature.  How many
>>> nuclear physicists are aware of Segre's paper on deuteron induced
>>> fission of molybedenum to produce (for the first time) technicium?
>>> And it was published in the relatively high prestige journal Nature.

 I do not need to be aware of it, or any of the many thousands of similar 
 facts published in the past 50+ years of nuclear physics and nuclear 
 chemistry.  These data, and all other data for deuteron induced reactions 
 on Mo isotopes, are summarized and indexed in a number of ways so that 
 I can access them easily if I need to work in that area.  Some of these 
 indexes are on-line (BNL NNDC), others are the Nuclear Data Tables and 
 Nuclear Data Sheets, plus the data compilations published in Nuclear 
 Physics.  Finally, simple summaries are given in the Table of the 
 Isotopes.  Where one looks first depends on the mass region.

>>Fission of molybdenum to make technetium would be a neat trick, since
>>technetium has a higher atomic number!
>>
>>What you are garbling is the creation of Tc-99 from Mo-98 by the (d,p)
>>reaction, followed by beta decay of Mo-99.  This is covered in some
>>detail in nuclear physics texts.
>>
>>For example, in the well-known text "Nuclei and Particles".
>>The author of which is Emilo Segre.
>
>Sorry, I have never seen that book. 

 So what do you use for a reference on nuclear physics?

>                                     It was my understanding that there
>were also some other Tc isotopes.  

 There are quite a few.  My wallet card lists 23 of them, plus 9 metastable 
 states.  All of them have 1 more proton than any Mo isotope, hence none 
 could be reached by "fission" of Mo.

>                                   Also, how does Mo(d,p)Tc reaction differ
>black box process of Mo + d = Tc + radiation products.  That is, if I
>don't know the answer because I understand the nuclear physics, why isn"t
>it just like the P&F stuff.  I have input of Molybdendum and deuterons
>and fusion occurs.  Or is it fission since I get radiation products out
>after the decay of the intermediate state?  Thanks for the mentoring
>anyway.

 Neither.  It is a transfer reaction, followed by beta decay.

 I am baffled as to what any of this has to do with sci.physics.fusion.

--
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)