HDTenEightyP/NetNews huggingface dataset:
From: daryl@oracorp.com (Daryl McCullough)
Subject: Re: What does quantum have to do with it?
Organization: ORA Corporation
Date: Sun, 24 Jan 1993 19:27:41 GMT

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

>A very common mistake in philosophical discussions of quantum
>mechanics is the assumption that QM somehow rules something that sits
>"out there," waiting to be tested. QM affords us predictions of
>experiments on systems, but says nothing about a system independent of
>the observer. To force it to do so goes beyond its intent (and beyond
>physics in general, for that matter).

What is it that makes people want to make oracular pronouncements
about the "intent" of physics, and the "mistakes" of people who don't
understand its intent? How about phrasing your beliefs a little more
humbly: such as "I think that people make a mistake in assuming that
QM somehow rules ...", or "I don't think that QM is capable of going
beyond making predictions"?

I believe that science is *not* about making predictions, it is
primarily about satisfying our curiosity about the world. A more
recent goal is to allow us to manipulate nature and have it serve our
end, but that is hardly applicable to quantum gravity or string theory
or General Relativity.

>> The bottom line for physicists is of course prediction, and
>> in spite of the incoherent mess that quantum theory is, one
>> can identify a solid enough core to make uncannily accurate
>> predictions. 
>
>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.

Well, my apologies for being so dim-witted, but I consider your
response to be a prime example of an incoherent mess. I just don't
know what phrases like "a classical notion of the way things are `out
there'" mean.

>> 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).

Well, I consider your pronouncements about the "intent" of physics to
be metaphysics, and they certainly aren't of much help. And do you
really think that religion helps people to resolve philosophical
questions about quantum theory? Pardon me, but your advice doesn't
sound very useful to me.

Daryl McCullough
ORA Corp.
Ithaca, NY
From: mcirvin@husc8.harvard.edu (Matt McIrvin)
Newsgroups: sci.physics
Subject: Re: gravitons
Date: 24 Jan 93 20:09:33 GMT
Article-I.D.: husc.mcirvin.727906173
 <mcirvin.727660223@husc.harvard.edu> <1993Jan23.225446.17541@lynx.dac.northeastern.edu>

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

 (I wrote:) 
>>
>>Contemplating this further, I think that this statement is a little
>>misleading.  I don't know what the graviton propagator really looks 
>>like (I haven't seen the expression recently), but if you work in
>>Feynman gauge and examine the propagator of a *massless* spin-1
>>boson like a photon, I think that in spacetime (rather than in
>>momentum-energy space) it is confined to the light cone.  If gravitons

>You're wrong here : propagator is not zero outside light-cone.

Okay, I was deluded again.  Never mind.

-- 
Matt McIrvin
From: weemba@sagi.wistar.upenn.edu (Matthew P Wiener)
Newsgroups: sci.physics
Subject: Re: How to write integrals (was Re: The confusion of tongues (was ...))
Date: 24 Jan 93 17:02:28 GMT
Reply-To: weemba@sagi.wistar.upenn.edu (Matthew P Wiener)
Distribution: usa
Organization: The Wistar Institute of Anatomy and Biology
In-reply-to: jac@ds8.scri.fsu.edu (Jim Carr)

In article <11806@sun13.scri.fsu.edu>, jac@ds8 (Jim Carr) writes:
>Well, I got my BS in math and my PhD in physics, so no wonder I feel 
>schizophrenic when I work with integrals.

How do you handle spherical coordinates? 
-- 
-Matthew P Wiener (weemba@sagi.wistar.upenn.edu)
From: mkagalen@lynx.dac.northeastern.edu (michael kagalenko)
Newsgroups: sci.physics
Subject: Re: female mentors in science
Date: 26 Jan 93 23:04:11 GMT
Organization: Northeastern University, Boston, MA. 02115, USA

In article <1993Jan26.185720.8055@netcom.com> barinaga@netcom.com (Marcia Barinaga) writes:
>I am a reporter with Science magazine, and am preparing articles
>for an upcoming special news section on women in science. 
>
>I am looking for an example of a female scientist who has left 
>her mark on a field by attracting, inspiring and training female 
>scientists. I have heard that in some fields, particularly those 
>              .......................
>Also, for a related article in the same issue, I am seeking
>comments from both male and female scientists on the 
>question of whether women approach science differently than
>men. I know this is a controversial question, and am hoping
>to present a range of views on it. Do women have different 
>styles of conducting science, or even different intellectual 
>approaches that may enrich their fields either through 
>added diversity, or as an example men might learn from?
>
All this talk about "female science" looks suspiciously similar to 
other well known distinctions : "Ariahn" vs "Non-Ariahn", "proletarian"
vs "bourgeous" science....
From: jac@ds8.scri.fsu.edu (Jim Carr)
Newsgroups: sci.physics
Subject: Re: How to write integrals (was Re: The confusion of tongues (was ...))
Date: 23 Jan 93 21:32:13 GMT
Reply-To: jac@ds8.scri.fsu.edu (Jim Carr)
Distribution: usa
Organization: SCRI, Florida State University

In article <COLUMBUS.93Jan21101415@strident.think.com> columbus@strident.think.com (Michael Weiss) writes:
>
>On the topic of mathematicians' vs. physicists' notation, does anyone know
>why most mathematicians will write an integral as shown below on the left
>(unless they omit the dummy variable x entirely), whereas physicists prefer
>the form on the right?
>
>         /                       /
>         |  f(x) dx              | dx f(x)
>         /                       /

Well, I got my BS in math and my PhD in physics, so no wonder I feel 
schizophrenic when I work with integrals.

If all I had was a simple case such as above, I would use the first form, 
probably a result of my original training.  Where the distinction really 
matters is in *real* equations (where there might be 3 integrals, some 
nested, and it requires a full page to write the thing down).  In that 
case I choose on the following basis: 

In cases where the limits on integration are simple things like 0 to 
infinity but I have nested integrals, I will keep the dx at the end as 
a place keeper, in place of a set of parentheses (which I think look ugly 
around an integrand, especially when the integrand fits on one line), 
to denote what is covered by the integral.  

If there is any possibility that I will be changing variables or making 
some other transformation, I like keeping the info on the range of 
integration and the integration variable together, for the reasons 
Emory notes below.  

In article <1jn1jv$k1c@agate.berkeley.edu> ted@physics1 (Emory F. Bunn) writes:
>
>              ....                                the reason I put the
>dx next to the integral sign in multiple integrals is that it makes it
>instantly clear which integral sign (and hence which limits of integration)
>go with which variable.  

This reduces errors when making such manipulations.  It also puts the 
differential in a place that reminds me to put in the Jacobian. 

Not that any of this matters much from a fundamental standpoint: just 
do whatever makes it possible to get correct answers efficiently.  For 
example, I tend to cluster the integral signs together only if that is 
how I will program the nested loops.  Structuring the algebra similar 
to how I will code it up helps eliminate transcription errors.

--
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: smlg1015@uxa.cso.uiuc.edu (Stuart M Lichtenthal)
Subject: Books Forsale
Organization: University of Illinois at Urbana
Distribution: usa
Date: Thu, 21 Jan 1993 13:08:08 GMT

I have the following books forsale:

Many-Particle Physics, Gerald D. Mahan.  Hardcover, 1003 pages,
	1986 edition.  $50

Semiconductor Physics, K. Seeger.  Softcover, 514 pages,
	$15

Ordinary Differential Equations 3rd ed. Garrett Birkhoff
	Gian-Carlo Rota, Hardcover, 342 pages,
	$15
From: matt@physics3.berkeley.edu (Matt Austern)
Newsgroups: sci.physics
Subject: Re: Trouble understanding bra-ket notation
Date: 23 Jan 93 23:52:04
Organization: Lawrence Berkeley Laboratory (Theoretical Physics Group)
Distribution: usa
	<DAVIS.93Jan24012415@pacific.mps.ohio-state.edu>
Reply-To: matt@physics.berkeley.edu
NNTP-Posting-Host: physics3.berkeley.edu
In-reply-to: davis@pacific.mps.ohio-state.edu's message of Sun, 24 Jan 1993 06:24:15 GMT

In article <DAVIS.93Jan24012415@pacific.mps.ohio-state.edu> davis@pacific.mps.ohio-state.edu ("John E. Davis") writes:

> Feynman presents a nice discussion of Dirac Notation in Volume III of his
> famous lectures.  I do not recommend this for learning QM though.  Also,
> Baym's book introduces Dirac notation in a nice way but at a somewhat higher
> level.

Actually, I think that the best place to learn about Dirac notation is
Dirac!  Specifically: _The Principles of Quantum Mechanics_, 4th
edition.  This is a truly wonderful book: a succinct exposition of the
theoretical and mathematical structure of quantum mechanics.  It's a
little bit abstract, so you probably shouldn't read it as your first
QM book, but if you already understand a little bit about the
experimental aspects of quantum mechanics, and the physical motivation
for this type of theory, Dirac's book is the ideal place to see how
things really fit together.

--
Matthew Austern                   Just keep yelling until you attract a
(510) 644-2618                    crowd, then a constituency, a movement, a
austern@lbl.bitnet                faction, an army!  If you don't have any
matt@physics.berkeley.edu         solutions, become a part of the problem!
From: brahm@cco.caltech.edu (David E. Brahm)
Newsgroups: sci.physics
Subject: Re: Black hole insights
Date: 24 Jan 1993 07:06:04 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: punisher.caltech.edu
Summary: Coordinate time to reach the horizon depends on coordinates

bbowen@megatest.com (Bruce Bowen) writes re: an uncharged, non-rotating
black hole,
> The coordinate time for an infalling infinitesimal testpoint to reach
> the horizon is infinite.  The proper time is finite.

I've been trying to get this straight too, so someone let me know if I'm
mistaken, but I think your first statement is only true in some coordinate
systems (e.g. Schwarzschild coordinates), not in others (e.g. ingoing
Eddington-Finkelstein coordinates).  See MTW pp. 828-829, 872-875.

What I want to know is, when people calculate how much "time" it takes for
a black hole to evaporate (proportional to M^3 they say), what coordinate
are they talking about?  I'm still confused by the fact that a test
particle takes infinite Schwartzschild "t" to pass the horizon, but the
hole evaporates in finite "t", and I'm not convinced that the "bulging"
effect people have mentioned is the answer.  Perhaps I'm just being
irresponsible using Schwarzschild coordinates when M is changing.

--
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.
Newsgroups: sci.physics
From: dennis@medusa.dseg.ti.com (dennis womack)
Subject: Re: VOTE YES for sci.physics.research
Reply-To: dennis@medusa.dseg.ti.com
Organization: Texas Instruments, Inc.
Date: Tue, 26 Jan 1993 18:30:41 GMT

I also vote yes

... Dennis Womack
     Texas Instruments
From: dseeman@novell.com (Daniel Seeman)
Newsgroups: sci.physics
Subject: Re: photon 'detectors' - how reliable?
Date: 21 Jan 93 16:20:25 GMT
Organization: Novell Inc., San Jose, Califonia

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.
From: aephraim@physics3 (Aephraim M. Steinberg)
Newsgroups: sci.physics
Subject: Re: photon 'detectors' - how reliable?
Date: 25 Jan 1993 21:56:48 GMT
Organization: /etc/organization
NNTP-Posting-Host: physics3.berkeley.edu

In article <1993Jan23.224608.16959@lynx.dac.northeastern.edu> mkagalen@lynx.dac.northeastern.edu (michael kagalenko) writes:
>In article <1jms14$ibn@agate.berkeley.edu> aephraim@physics3 (Aephraim M. Steinberg) writes:
>>In article <wwadge.727584610@csr> wwadge@csr.UVic.CA (Bill  Wadge) writes:
>>>I was browsing through one of the many 'pop' physics books,
>>>
>>> .. 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 ...
>>
>>Does seem unlikely, doesn't it?  But it will happen one day (just about).
>>
>No, it won't. It's general property of QM that if you have inelastic
>scattering (photon-detector interaction is inelastic, of  course), there
>always exists non-zero elastic part in the cross-section (see Landau's
>QM I, chapter about non-elastic scattering). 

Thank you for the correction.  I haven't looked up the reference yet,
but I can believe the result; by adding "(just about)" I mean to acknowledge
that no process is 100% efficient, but that one could get arbitrarily
close in principle.

Nonetheless, I am curious about a particular inelastic process which seems
to me to be 100% efficient (in principle, of course), and I wonder whether
(i) Some idealization I assume is not even possible in principle, OR
(ii) Your statement holds not for cross-sections but rather for scattering
amplitudes, implying that interference effects could be arranged to make
the total elastic cross-section go to zero.

The instance I have in mind is a superconducting micromaser cavity.  If
an atom in an excited state, whose excitation is resonant with the cavity,
is sent through the maser, it has some chance of decaying.  As the atom  
propagates through the cavity, it undergoes Rabi oscillations, emitting
a photon, reabsorbing it, and so on.  Walther's group in Munich has
shown that by correctly selecting the atom's velocity, it is possible to
cause it to decay most of the time.  Now, if the cavity is lossless,
it seems to me that there exist incident k-vectors for which the probability
is exactly 100%.  True, in a real experiment, there is a superposition of
different velocities, and the cavity isn't ENTIRELY lossless, but are these
issues of fundamental importance, or is it perhaps unfair to neglect edge 
effects when the atom enters or exits the cavity, or is my picture correct IN
PRINCIPLE, and the theorem somehow evaded in this case?


-- 
Aephraim M. Steinberg                    | "WHY must I treat the measuring
UCB Physics                              | device classically??  What will
aephraim@physics.berkeley.edu            | happen to me if I don't??"
                                         |       -- Eugene Wigner
Newsgroups: sci.physics
From: myellam@eng.clemson.edu (y. murali krishna)
Subject: Boundary to the Universe
Reply-To: myellam@eng.clemson.edu
Organization: College of Engineering, Clemson Univ.
Distribution: usa
Date: Thu, 28 Jan 1993 16:55:03 GMT



Hi: 

	I have been following articles on this newsgroup for sometime now.
I have always had this query, perhaps somebody would care to respond to it.
Does our Universe have an end or is the limit defined as infinity (something
similar to the mathematical infinity).

thanks 



murali


From: ric@hpspdla.spd.HP.COM (Ric Peregrino)
Date: Sat, 23 Jan 1993 00:43:54 GMT
Subject: Re: Luminous Intensity
Organization: HP Stanford Park - Palo Alto, CA
Newsgroups: sci.physics


It wasn't stated that the frequencies were equal!
Xref: sparky sci.physics:23517 sci.skeptic:22885 alt.paranormal:2840 alt.sci.physics.new-theories:2843 rec.arts.startrek.tech:7766
From: ethan@emx.cc.utexas.edu (Ethan T. Vishniac)
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 1993 13:25:00 -0600
Organization: The University of Texas at Austin, Austin, Texas
NNTP-Posting-Host: emx.cc.utexas.edu
Summary: New acronym for the net


In cases like this the request for appropriate references
is doomed to failure, but making the request makes a point
so....

How about CARP?  

Cite Appropriate References Please
-- 
"Quis tamen tale studium, quo ad primam omnium rerum causam evehimur,
tamquam inutile aut contemnendum detractare ac deprimere ausit?"-Bridel
Ethan T. Vishniac, Dept. of Astronomy, The University of Texas at Austin
Austin, Texas, 78712                   ethan@astro.as.utexas.edu
Xref: sparky sci.physics:23577 sci.skeptic:22937 alt.paranormal:2864 alt.sci.physics.new-theories:2870 rec.arts.startrek.tech:7807
From: jcf@world.std.com (Joseph C Fineman)
Subject: Re: Origin of Limerick?
Organization: The World Public Access UNIX, Brookline, MA
Date: Fri, 22 Jan 1993 04:19:33 GMT

"Vincent J. Matsko" <vm0h+@andrew.cmu.edu> writes:

>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?

This has been around for a long time, and I doubt if its author is
known.  At any rate, it appears, as "Anon.", in _A Little Treasury of
Modern Poetry_ (Oscar Williams, Ed., rev. ed., Scribner's, 1952) in
the form

	There was a young lady named Bright,
	Who travelled much faster than light.
		She started one day
		In the relative way,
	And returned on the previous night.

-- which scans a little better than your advisor's version.

It is only reasonable that there should also be a limerick about the
spatial component of the Lorentz transformation:

	There was once a young fellow named Fisk,
	At fucking exceedingly brisk.
		So rapid his action,
		Fitzgerald contraction
	Shrunk his dingdong darn down to a disk.

Heard at Caltech in the summer of 1956.
-- 
        Joe Fineman             jcf@world.std.com
        239 Clinton Road        (617) 731-9190
        Brookline, MA 02146
Newsgroups: sci.physics,sci.skeptic,alt.paranormal,alt.sci.physics.new-theories,rec.arts.startrek.tech
From: petitc@nuge105.its.rpi.edu (Christopher Jon Petit)
Subject: Re: New Physics, Healing, Paranormal
Date: Tue, 26 Jan 1993 16:07:04 GMT

det@sw.stratus.com (David Toland) writes:

>More's the pity that this is "no joke".  I'm afraid that there *is* a decline
>in the quality of education in at least American universities, but it would
>be far worse if they were to teach classes in New Age pseudoscience, unless
>it were in debunking it with critical analysis.  What we need is a more
>solid grounding in foundation subjects, beginning in primary and secondary
>schools, with higher graduating standards in oral and written communication,
>literature, critical analysis, the physical sciences, and mathematics.

 Well, I do agree that the quality of education has declined, but saying that
'New Age' ideas are all worthless is total crap.  While some of the ideas are
ridiculous, there is supposedly (or so I've heard) scientific proof that some
forms of ESP do in fact exist.  I think the head of Stanford's Engineering
dept. did some studies which showed that, by trying to influence certain
statistically valid actions (e.g. 100,000 flips of a coin, in one second, by a
computer), the subjects did have a small but measurable influence.

 Now, I want to see those tests done myself, but I don't have the resources.
Has anyone else heard of these experiments?


-- 
"Protect endangered species!  Contribute to the Exxon Supporter's Fund!"
"Pay no attention to that little man behind the keyboard."
"If you want to look for fish, best not to look in desert."
"The greatest beauty in the world is beauty that is private."
Newsgroups: sci.physics
From: Leigh Palmer <palmer@sfu.ca>
Subject: Re: ATOMS & ELECTRONS
X-Xxmessage-Id: <A7882D3142021C03@rs1-annex3.sfu.ca>
X-Xxdate: Sun, 24 Jan 93 19:25:37 GMT
Organization: Simon Fraser University
X-Useragent: Nuntius v1.1.1d16
Date: Sun, 24 Jan 1993 19:25:33 GMT

In article <1993Jan23.220138.15459@lynx.dac.northeastern.edu> michael
kagalenko, mkagalen@lynx.dac.northeastern.edu writes:

>You don't think that renormalization is an  answer to UVcatastrophy,
Leigh?

It is my fond hope that the Canadian Deplorers of Reification will become 
as infamous (and successful) as the Spanish Inquisition. You're on our
list,
Michael.

Quasipalmer
Newsgroups: sci.physics.fusion