HDTenEightyP/NetNews huggingface dataset:
From: mkagalen@lynx.dac.northeastern.edu (michael kagalenko)
Subject: Re: photon 'detectors' - how reliable?
Organization: Northeastern University, Boston, MA. 02115, USA
Date: Sat, 23 Jan 1993 23:29:14 GMT

In article <1993Jan21.162025.23220@novell.com> dseeman@novell.com (Daniel Seeman) writes:
>In article <wwadge.727584610@csr> wwadge@csr.UVic.CA (Bill  Wadge) writes:
>>I was browsing through one of the many 'pop' physics books,
>>where they are describing one of the stock quantum mechanics
>>experiments, and noticed something along the lines of
>>
>> .. towards a detector which records every photon ..
>>
>>Is this possible? Can one really build a device so sensitive that it will
>>detect 100% reliably every photon that enters it, and never
>>go off by accident?
>>
>>Seems unlikely, but then I'm not a physicist ...
>>
>It is not unlikely at all.  Do this experiment:
>
>Enclose yourself in a room with a light that is controlled by a dim switch.  Dim
>the light until you can barely see your hand.  Then, look at the bulb.  At this
>point, your eye is detecting every photon that is comming your way (from the
>bulb).  True, the eye is pretty unique in that its design is ---well pretty
>good.  Apparently our designer (nature,evolution, god---arguably all are one in
>the same) was quite "skilled."  However, there are other devices (natural and
>man-made) that have the same (and better) efficiency.
>
>One thing that may help you consider this is that a light bulb emits photons in
>all directions (except down into the socket---the metal circuit casing stops the
>photons).  But you only see the ones that are directly along your line of sight.
>All other photons in the room are detected or felt by something else (like the
>walls of the room heat slightly etc...).  So, you do not (nor does any other
>singular detector) see ALL the photons emitted by a light source unless that 
>source is directing all its photons toward the detector.  When you look at it
>in that "light---pun intended" these detectors do not seem so awesome.
>
>Hope this helps...
>^^^^^^^^^^^^^
>dks.


Vain hope, since what you're saying is wrong.
From: glipton@lafcol.lafayette.edu (Gary Lipton)
Newsgroups: sci.physics
Subject: Re: Magnetic monopoles?
Date: 23 Jan 93 03:24:45 GMT
Reply-To: glipton@po.CWRU.Edu
Organization: Dept. of EE, Lafayette College, Easton, PA

Some odds and ends about monopoles:

Grand Unified Theories popular in the early 80's predicted the
existence of *very* massive monopoles - sorry I don't have figures,
but I recall that the mass was on the order of micrograms - pretty
hefty.  Some GUTs also predicted that monopoles could "catalyze"
proton decay - needless to say, none of this was verified experimentally.

In 1983 (I think) Cabrera of Stanford ran an experiment to detect
monopoles.  The experiment detected one event which had a virtually
perfect signature for a monopole.  This event occurred on a Sunday
when no one was monitoring the apparatus.  The event was, as far as
I know, never explained and never repeated.

-- 
***************************************
* Gary Lipton, Dept. of EE            *
* Lafayette College, Easton, PA 18042 *
***************************************
From: mcirvin@husc8.harvard.edu (Matt McIrvin)
Newsgroups: sci.physics
Subject: Re: female mentors in science
Date: 27 Jan 93 22:08:55 GMT
Article-I.D.: husc.mcirvin.728172535

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?

I don't think he is.  On the other hand I think he might have
misinterpreted the original post.  The poster was talking about the
possibility of female mentors encouraging scientific participation by
other women, and brought up the possibility (hotly debated) that
women might have, on average, different kinds of scientific abilities
than men.  I have no strong opinion on that subject, but I think it's a
very different proposition from the idea, championed by a tiny number
of radical feminists, that the entire corpus of scientific knowledge
is a patriarchal scam perpetrated by male scientists, to be toppled
by a new "female science."  The latter is just ridiculous, and
indeed raises the specter of past efforts to ideologically drive
scientific inquiry.  The former is the subject of legitimate controversy
over whether it's supported by the data.  I don't think the original
poster was an advocate of "female science" as a separate entity.
-- 
Matt McIrvin
From: bweiner@ruhets.rutgers.edu (Benjamin Weiner)
Newsgroups: sci.physics
Subject: Re: Nickel metal hydride cells in standard form factors
Date: 26 Jan 93 18:42:52 GMT
Distribution: usa
Organization: Rutgers Univ., New Brunswick, N.J.

m14494@mwvm.mitre.org (Mike White) writes:

>The B battery was the high-voltage battery for the tube
>plates; they came in various voltages, starting at 22.5 volts.
>You still see them around some, but they're not very common.

Tip for lab designers: B batteries can be very useful for certain
undergraduate lab uses; for example, running neon lamps, and other
things I forget.  They're not cheap, but they're cheaper than Hewlett-
Packard power supplies if you need one for each of 25 lab workstations!
I used to manage equipment for a teaching lab and I had nearly half a
shelf of B batteries (the 45 volt kind, I think).
Newsgroups: sci.physics,alt.sci.physics.new-theories,sci.skeptic,alt.paranormal,alt.conspiracy,alt.pagan,alt.magick,alt.alien.visitors,rec.arts.startrek.tech
From: erc@unislc.uucp (Ed Carp)
Subject: Re: New University - Call for Faculty and Students
X-Newsreader: TIN [version 1.1 PL6]
Organization: Unisys Corporation SLC
Date: Thu, 28 Jan 1993 17:26:20 GMT

Interesting that the headline didn't have anything to do with the "press
release", which was (for the most part) composed entirely of unintelligible
gibberish.

And why the hell post this garbage all over the net?
-- 
Ed Carp			erc@apple.com, erc@saturn.upl.com	801/538-0177

"It is your resistance to 'what is' that causes your suffering."   -- Buddha
From: bweiner@ruhets.rutgers.edu (Benjamin Weiner)
Newsgroups: sci.physics
Subject: Re: ATOMS & ELECTRONS
Date: 25 Jan 93 04:44:35 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

sichase@csa1.lbl.gov (SCOTT I CHASE) writes:

> mkagalen@lynx.dac.northeastern.edu (michael kagalenko) writes...

>>Why Earth is not crushing into the Sun ? Your answer really applys to
>>the question "Why electron in the ground state doesn't radiate"  

>Completely untrue.  The Earth probably has a net charge ...

Scott, I think you're misinterpreting him.  If one assumes that the
electron in the ground state doesn't radiate for some mystical reason,
then you can pretend that it's on a "Bohr atom" circular orbit, and the
reason it doesn't crash into the nucleus is the same reason that the
Earth doesn't crash into the Sun: conservation of angular momentum
(or energy or whatever).  If the electric coupling constant was as
small as the gravitational coupling constant the radiation would be
negligible and we wouldn't worry about it (why I am even suggesting this?
It's silly.)  I don't think Michael Kagalenko's comment was particularly
useful as pedagogy, though.
From: mbk@lyapunov.ucsd.edu (Matt Kennel)
Newsgroups: sci.physics
Subject: Re: What does quantum have to do with it?
Date: 22 Jan 1993 19:10:45 GMT
Organization: Institute For Nonlinear Science, UCSD
NNTP-Posting-Host: lyapunov.ucsd.edu
X-Newsreader: Tin 1.1 PL3

paul@mtnmath.UUCP (Paul Budnik) writes:
: In article <1jmlssINN4v8@gaia.ucs.orst.edu>, preddy@comphy.physics.orst.edu writes:
: > daryl@oracorp.com (Daryl McCullough) writes:
: [...]
: > This "incoherent mess" is nothing more than a failure to
: > separate a classical notion of the way things are "out there"
: > from what QM predicts about experiments done on systems.
: > 
: > > That's enough for some people, but not for everyone.
: > 
: > Then "everyone" will have to look elsewhere for the answer
: > he/she seeks (like metaphysics, perhaps, or religion).
: > 
: 
: This last statement is the point where physicists go from simply being
: too complacent to committing a serious sin against science. You are saying
: that is impossible to come up with a more complete physical theory that
: could be experimentally verified. What is the scientific basis for this
: metaphysical claim? 

Exactly. 

What is it about quantum mechanics that convinces otherwise reasonable
scientists to proclaim it to be 'a meaningless, unscientific question' to
even question whether there's something more.  Theoretical difficulties
in other models are taken as a sign that they don't quite have
the physics or the math right.

QM is explicitly and implicitly limited in the things that it predicts.
Is there any reason to believe that there cannot possibly be anything else?
Or just that QM simply has no say in the matter.

And if the wavefunction is so unphysical, why does it interfere, and scatter
like 'real' physical electromagnetic fields?

: Paul Budnik

--
-Matt Kennel  		mbk@inls1.ucsd.edu
-Institute for Nonlinear Science, University of California, San Diego
-*** AD: Archive for nonlinear dynamics papers & programs: FTP to
-***     lyapunov.ucsd.edu, username "anonymous".
From: daniel@raphael.acpub.duke.edu (Daniel Crawford)
Newsgroups: sci.physics
Subject: Summer Undergraduate Research Fellowships
Date: 27 Jan 93 22:22:57 GMT
Organization: Center for Computational Quantum Chemistry


                       The University of Georgia

               CENTER FOR COMPUTATIONAL QUANTUM CHEMISTRY

             Summer Research Fellowships for Undergraduates

LOCATION: The Center for Computational Quantum Chemistry, The University
of Georgia in Athens, Georgia.

DIRECTOR: Dr. Henry F. Schaefer, III.

RESEARCH: Each Summer Research Fellow will conduct an independent
research project under the guidance of a Senior Scientist and will
receive adequate training (lectures and computer workshops) in molecular
quantum mechanics and spectroscopy.  Research at the CCQC involves the
use and development of state-of-the-art theoretical methods to describe
the electronic structure of molecules.  A wide variety of chemical
problems have been examined using _ab initio_ methods such as
Self-Consistent Field, Configuration Interaction, and Coupled Cluster.

Some examples include: 
(1) silicon analogs of common hydrocarbon compounds;
(2) potential energy hypersurfaces governing elementary gas-phase
    chemical reactions;
(3) problems in physical organic chemistry, including carbenes and
    biradicals;
(4) hydrogen-bonded systems.

QUALIFICATIONS: Applicants should have completed their junior
undergraduate year and have outstanding academic credentials.
Successful candidates invariably have an interest in pursuing Ph.D.
studies in theoretical physical chemistry in the United States.

STIPENDS: $1300 per month for a 10-12 week period.  Up to $400 in travel
assistance will be provided.

APPLICATION DEADLINE: April 1, 1993


   Send Resume, Academic Transcript and Two Letters of Reference to:

		       	T. Daniel Crawford
	     Center for Computational Quantum Chemistry
	             The University of Georgia
		     Athens, Georgia 30602-2556

Note: Resumes will be accepted via E-mail; transcripts and letters of
reference must be sent via U.S. mail.

For e-mail replys and further information, write to:

           crawdad%sherman.ccqc.uga.edu@athena.cs.uga.edu
From: brahm@cco.caltech.edu (David E. Brahm)
Newsgroups: sci.physics
Subject: Re: Debate question of the day!!!!!
Date: 21 Jan 1993 23:42:27 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: punisher.caltech.edu
Summary: Balloons would propel even in space

wied@animal.sps.mot.com (Bill Wied) writes:
> ...what makes a balloon full of air propel...The two theories go:
> 1)... the effect of conservation of momemtum.
> 2)... 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.

The short answer is (1).  To conserve momentum, when expelled air goes one
way the balloon goes the other.  Another perspective is that the inner
surface of the balloon has a uniform pressure on it over _almost_ all 4pi
steradians, except for a small area on one side where the air is escaping,
so the net force is to the opposite side.

If (2) were correct, balloons and rockets would not propel in space.
There's a story that a major newspaper once printed an editorial ridiculing
Goddard for not understanding that by principle (2), his rockets could
never work in space.

On the other hand, the effect (2) probably does exist, and I don't know
just how small it is, or how important it may be under other circumstances.
Any experimentalists want to try releasing a balloon in molasses?

--
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: sichase@csa2.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Re: Warping???
Date: 26 Jan 1993 17:02 PST
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
Distribution: world
NNTP-Posting-Host: 128.3.254.197
News-Software: VAX/VMS VNEWS 1.41    

In article <1993Jan26.202531.21159@galois.mit.edu>, jbaez@riesz.mit.edu (John C. Baez) writes...
>Hinson writes:
> 
>Now I introduce you to an important postulate that leads to the 
>concept of relativity that we have today.  I believe it will seem quite 
>reasonable.  I state it as it appears in a physics book by Serway: "the 
>laws of physics are the same in every inertial frame of reference."  
>What it means is that if you observer any physical laws for a given 
>situation in your frame of reference, then an observer in a reference 
>frame moving with a constant velocity with respect to you should also 
>agree that those physical laws apply to that situation.  
> 
>---
>This principle also holds in the classical mechanics of point particles,
>so it is NOT enough to assume this principle to get special relativity.
>In fact, classical mechanics satisfies what is known as "Galilean
>relativity" in which the Galilei group replaces the Poincare group.  It
>is the *combination* of this principle with the fact that light is
>observed to have the same velocity in every inertial frame that gets us
>special relativity.  (It would be consistent with classical mechanics if

The way that I like to look at things (which as you know is often different
than everyone else :=)) is this:  The fact that Maxwell's Eq.s explicitly
contain the speed of light, such as curl E = -(1/c) dB/dt, along with the
requirement that this law be the same in all inertial frames, is enough
to convince me that the speed of light should be the same in every inertial
frame, from which SR follows directly.  

Of course, this requires the implicit assumption that the constant, c, which
appears in Maxwell's Eq.s is, in fact, the speed of light.  It is this fact
which seems to me to sit at the center of both electrodynamics and SR, as
the starting point from which most all else follows.

-Scott
--------------------
Scott I. Chase			"It is not a simple life to be a single cell,
SICHASE@CSA2.LBL.GOV		 although I have no right to say so, having
				 been a single cell so long ago myself that I 
				 have no memory at all of that stage of my 
				 life." - Lewis Thomas
From: mcirvin@husc8.harvard.edu (Matt McIrvin)
Newsgroups: sci.physics
Subject: Re: Heavy boots, Light luggage
Date: 21 Jan 93 23:58:12 GMT
Distribution: usa

jac@ds8.scri.fsu.edu (Jim Carr) writes:

>We have new evidence of (as if we needed any) of science ignorance.  Last 
>night, while waiting for aging rock stars to get on stage with their walkers, 
>we were presented with an ad for Samsonite luggage where the luggage was 
>arriving on the moon.  We were told that the weight of the bag did not 
>matter on the moon, as we watched it float around, although it would matter 
>to us on earth.  We then had a closeup of a heavy boot leaving a nice 
>footprint in moon dust. 

>                                  I loved it.

Nice.  I suspect the popular media have a lot to do with the "heavy
boots" belief-- I remember once seeing an episode of "Laverne and
Shirley" in which they're working in some kind of space-equipment
factory testing "gravity boots" which "hold you down on the moon."
They would set a boot on a spring scale, turn it on, and watch the
needle swing.

I'll take ten pairs, only wire them up in reverse...
-- 
Matt McIrvin
From: physcaw@cwis.unomaha.edu (Glenn Sowell)
Newsgroups: sci.physics
Subject: Physics summer workshop announcement
Summary: An NSF summer workshop for computer algebra use in physics
Keywords: Physics, computer algebra
Date: 26 Jan 93 15:59:09 GMT
Organization: University of Nebraska at Omaha


                       Using Computer Algebra Software 
                        To Teach Undergraduate Physics
 
                      A Leadership Development Workshop
                   at the United States Air Force Academy
                           Colorado Springs, CO
          
                             July 11-23, 1993


Computer algebra software can symbolically solve equations, integrate, 
differentiate, solve differential equations, manipulate matrices and much more. 
Its incorporation into the physics classroom is only just beginning. This 
workshop will provide participants an opportunity to master a computer 
algebra program and develop strategies for its integration into the 
undergraduate physics curriculum. Workshop participants will then be able to 
lead workshops of their own in local and regional settings.

Four powerful computer algebra packages will be available at the workshop:
      Derive
      Maple
      Mathematica
      Theorist

Workshop participants may work on either Apple Macintoshes or PC's (DOS or 
Windows). Participants must be college faculty involved in undergraduate 
physics programs.

      The workshop will provide expenses and a stipend for all participants.

      The application deadline is March 5, 1993.

The workshop faculty:

      Glenn Sowell
      University of Nebraska at Omaha
      Marvin De Jong
      College of the Ozarks
      Patrick Tam
      Humboldt State University  

This workshop is sponsored under a National Science Foundation faculty 
enhancement grant #USE-9255505

If you would like more details and an application, please send the following 
information by mail, fax or e-mail to the appropriate address below:

Name__________________________________________________  
Institution_____________________________
Address_________________________________________________________________
City, State, Zip________________________________________.      
      
      Mail to:    Glenn Sowell
                  Department of Physics
                  University of Nebraska at Omaha
                  Omaha, NE 68182-0266
      Fax:        (402) 554 - 3100
      email:      physcaw@unomaha.edu
Newsgroups: sci.physics,alt.sci.physics.new-theories
From: bruce.weaver@nitelog.com (Bruce Weaver)
Newsgroups: sci.physics
Subject: HELP Wanted!
Date: 23 Jan 93 19:20:00 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
                                        
Newsgroups: sci.physics
From: davidm@questor.Rational.COM (David Moore)
Subject: Re: Physics of an Air bag?
Organization: Rational
Distribution: na
Date: Tue, 26 Jan 1993 22:41:27 GMT

rbatra@uceng.uc.edu (Rajesh Batra) writes:


>Hi,


>	I am looking at the possibility of catching an object with
>	some speed (1700 m/s) and some mass (120 kg) with a stuntman
>	air bag.  

I want to be there when this happens (but standing well back)!

The biggest problem with the analysis will be that, given the size
of the bag that will be needed to decelerate an object from
almost Mach 6 with reasonable rates of deceleration, the bag
is not going to act as a lumped object. The bag is going to 
have to be real strong if the shock is not going to tear it.