HDTenEightyP/NetNews huggingface dataset:
From: matt@physics2.berkeley.edu (Matt Austern)
Newsgroups: sci.physics
Subject: Re: TOP in TIME
Date: 7 Jan 93 10:57:58
Organization: Lawrence Berkeley Laboratory (Theoretical Physics Group)
Reply-To: matt@physics.berkeley.edu
NNTP-Posting-Host: physics2.berkeley.edu
In-reply-to: Walid Majid's message of Wednesday, 6 Jan 1993 21:31:36 PST

In article <93006.213136WALID@SLACVM.SLAC.STANFORD.EDU> Walid Majid <WALID@SLACVM.SLAC.STANFORD.EDU> writes:

> There is an article in this week's issue of Time, about the discovery of
> the top quark by the CDF collaboration.  It mentions two events that could
> be t -> W + b events with W -> mu + nu_mu.
> Can some kind soul (perhaps a CDF member) put more light into this signal.
> What is the expected background at this region?

There isn't much to say beyond this: CDF saw one "interesting event"
in the last run, and one in this run.  Maybe they're t-tbar events,
maybe they're not; with only two events, you can't really say for
sure.  D0 has also seen one "interesting event," but they're not
talking about it in public very much.

The background for events with a high Pt electron and a high Pt muon
is expected to be very small, which is the reason that people talk
about these events as candidate t-tbar evants.  Unfortunately, if the
top has the mass that LEP results seem to point to, the t-tbar
production cross section is also expected to be quite small.
--
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: G.Joly@cs.ucl.ac.uk (Gordon Joly)
Newsgroups: sci.physics
Subject: Re: Why are elementary particles small?
Date: 7 Jan 93 17:59:37 GMT


I thought that all wave functions were infinite (but localized)?

Gordon.
____

Gordon Joly      Phone  +44 71 387 7050 ext 3703      FAX  +44 71 387 1397
Internet: G.Joly@cs.ucl.ac.uk        UUCP: ...!{uunet,uknet}!ucl-cs!G.Joly
Computer Science, University College London, Gower Street, LONDON WC1E 6BT
Newsgroups: sci.physics
From: pratt@Sunburn.Stanford.EDU (Vaughan R. Pratt)
Subject: Re: *.research request: limit number of articles per day
Organization: Computer Science Department,  Stanford University.
Date: Sat, 9 Jan 1993 19:12:57 GMT

In article <1993Jan9.153636.12903@black.ox.ac.uk> rabson@oxford.ac.uk (David Rabson) writes:
>I should like to suggest that the moderated, research-oriented newsgroup
>should have a limit on the number of articles posted each day.  Twelve seems
>like a good number; it can be raised later if the moderators deem it
>helpful.
>
>David Rabson
>Theoretical Physics, Oxford

I agree.  But given that the moderators are proposing a rather more
generous threshold, this seems like another reason to just make
sci.physics a moderated group without further ado.  Those wanting the
still higher threshold can then decide whether they want to go to the
bother of spinning off a separate sci.physics.research.
-- 
Vaughan Pratt				There's safety in certain numbers.
From: bhoughto@sedona.intel.com (Blair P. Houghton)
Newsgroups: sci.physics
Subject: Re: TIME HAS INERTIA     (A1) EXPERIMENTALLY VERIFIED 30 TIMES/DAY
Date: 11 Jan 1993 00:21:52 GMT
Organization: Intel Corp., Chandler, Arizona
NNTP-Posting-Host: stealth.intel.com
Keywords: THE CRAVE FOR GAINING A FEELING OF SECURITY

Come on, Alexander, is Liz Taylor REALLY going
to lose the weight?

				--Blair
				  "Enquiring minds want to know!"
Newsgroups: sci.physics,alt.sci.physics.new-theories,sci.skeptic,alt.paranormal,alt.alien.visitors,alt.conspiracy
From: sarfatti@well.sf.ca.us (Jack Sarfatti)
Subject: Feynman 47: The Master shows the existence of precognition in QED
Organization: Whole Earth 'Lectronic Link
Date: Wed, 6 Jan 1993 19:07:56 GMT


Feynman 47. Elimination of photons requires future causation! part1
(from "Mathematical Formulation of the Quantum Theory of Electromagnetic
Interaction" paper 23 in Schwinger.)

Problem from Feynman 46  - what about the Lenard-Wichert potentials for a
moving charge? If the Coulomb potential for a charge at rest has frame-
invariant spacelike influence so must they.

"the Hamiltonian method ... replaced by the over-all space-time point of
view of a direct particle interaction ... the Lagrangian form of quantum
mechanics ,,, useful in this connection ....

The advantage of a Lagrangian form of quantum mechanics is that in a system
with interacting parts it permits a separation of the problem such that the
motion or any part can be analyzed or solved first, and the results of this
solution may then be used in the solution of the motion of the other parts
.... The electromagnetic field is an especially simple system and its
behavior can be analysed completely ... the net effect of the field is a
delayed interaction of the particles. It is possible to do this easily only
if it is not necessary at the same time to analyse completely the motion of
the particles. ...

2.QED in Lagrangian form:
Non-relativistic matter, plane wave expansion of electromagnetic transverse
vector potential. Field Hamiltonian is sum of harmonic oscillators etc.
Longitundinal-scalar part of field replaced by Coulomb potential. Then
Feynman writes down the Lagrangian version.

"The Lagrangian enters through the statement that the functional which
carries the system from one state to another is e^iS where

S = Integral[Ldt]    (3)

... it is possible to eliminate the transverse oscillators ... One must
specify, however, the initial and final state of all oscillators."

The necessity of "future causation" is in the phrase "One must specify,
however, the initial and final state of all oscillators."

to be continued.



The math details in part 2 will only be posted to sci.physics and alt.sci.
physics.new-theories.

What are the lessons of New Age Physics?
Mass without mass.
Charge without charge.
Force without force.
Geometry without geometry.
Cause without cause.
Physics without physics.
Reason without reason.
God without god.
Existence without existence.

The Mantra of SAR.
From: dseeman@novell.com (Daniel Seeman)
Newsgroups: sci.physics
Subject: Re: infinite universe
Date: 4 Jan 93 18:42:45 GMT
Organization: Novell Inc., San Jose, Califonia

In article <1993Jan4.184114.151@vms.huji.ac.il> tabitha@vms.huji.ac.il writes:
>Another question from a non-physicist.
>
>I frequently read that cosmologists debate whether the
>universe has infinite size.  If the Big Bang started
>at a definite time in the past, and has since expanded
>at a finite speed, how can it be infinite?  What am
>I missing?
>

On a philosophical level, what is the meaning of a Universe with a finite
size?  What is happening at the boundary between that which is the Universe and
that which is not?  And, what would happen if I stepped into that region which
was defined as the "Non-Universe?"

On this very non-rigourous (even symplistic) level, there can be no boundary to
the Universe. Any "region" found outside the Universe would automatically
become part of our Universe (which would have just expanded to include the
"region" you were interested in).  I belive this provides a qualitative descript
ion of the "Infinite Universe."

dks.
From: Richard.Mathews@West.Sun.COM (Richard M. Mathews)
Newsgroups: sci.physics
Subject: Re: range of EM force
Date: 8 Jan 93 01:53:11 GMT
Organization: Sunsoft Inc., Los Angeles, CA.
NNTP-Posting-Host: astro
Pate: astro!richard
Originator: richard@astro

nariani@utdallas.edu (Sushil Nariani) writes:

>	This must be very stupid. If the EM force is via virtual photons,
>	how does it have an infinite range, given that a virtual photon
>	of frequency 'v' has a non-zero "borrowed" energy 'hv' ? 
>	Leggett, in his book, "Problems of Physics", says this is because the
>	photon has zero rest mass and hence a zero "borrowed" energy. I 
>	find this fishy.

Here is a hand-waving argument I like for explaining this, but don't
take it too literally.

A photon with borrowed energy, h*nu, can exist for a time, 1/nu.  In this
time it can travel a distance of c/nu.  Since nu can be arbitrarily small,
there can be some virtual photons an arbitrarily large distance from the
source.

Now generalize:

A virtual particle with mass, m, and energy, E, can exist for a time,
h/E.  In this time it can travel no more than a distance of c*h/E.  But
E's minimum value is m*c^2, so no virtual photons can be at a distance
of more than about h/(m*c) from the source.

    Richard M. Mathews			 Freedom for Lithuania
Richard.Mathews@West.Sun.COM		        Laisve!
From: matt@physics20.berkeley.edu (Matt Austern)
Newsgroups: sci.physics
Subject: Re: Speed of neutrinos
Date: 11 Jan 93 22:46:29
Organization: Lawrence Berkeley Laboratory (Theoretical Physics Group)
Reply-To: matt@physics.berkeley.edu
NNTP-Posting-Host: physics20.berkeley.edu
In-reply-to: gbshaw@rigel.cs.pdx.edu's message of 12 Jan 93 04:54:20 GMT

In article <6691@pdxgate.UUCP> gbshaw@rigel.cs.pdx.edu (Bert Shaw) writes:

> Please note: This may be a foolish question, but it's not a naive one.  I 
> have years of experience in theoretical physics, though not particle physics.
> 
> Q: Is it really well-established that the propagation velocity of
> the neutrino is the speed of light?

It is well established that the speed of the neutrino is *close to*
the speed of light.  I don't know how precisely it has been measured.

I suspect that the best measurement is probably from the SN1987a
supernova: several groups detected neutrino bursts at roughly the same
time as the maximum brightness of the supernova.  At this kind of
distance, even a slight difference between the speed of neutrinos and
the speed of light would have made a big timing difference.

(It's amazing, actually, just how much that one supernova taught us
about particle physics!  It has also given us the most stringent
limits in existence for the Dirac mass of the neutrino, the magnetic
moment of the neutrino, etc.)

Similarly (and equivalently, according to special relativity) the mass
of the neutrino is known to be small, but it is not known to be zero.
In fact, many people think there is good reason to believe that
neutrinos have a small, but nonzero, mass.
--
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!
Newsgroups: sci.physics
From: clarke@acme.ucf.edu (Thomas Clarke)
Subject: Re: infinite universe
Organization: University of Central Florida
Date: Mon, 4 Jan 1993 19:54:34 GMT

In article <1993Jan4.184114.151@vms.huji.ac.il> tabitha@vms.huji.ac.il writes:
> Another question from a non-physicist.
> 
> I frequently read that cosmologists debate whether the
> universe has infinite size.  If the Big Bang started
> at a definite time in the past, and has since expanded
> at a finite speed, how can it be infinite?  What am
> I missing?

The way I understand it is the extent of the universe in time
and its extent in space are independent.  At the big-bang
the universe could be infinite or finite and it continues to be
infinite or finite.  The "radius" of the universe at a given time
thus provides a measure of "density" at a particular epoch, and
not a measure of the "size" of the universe.

Of course a finite universe with omega < 1 (critical density) 
would expand forever, becoming asympotically an infinite universe.

--
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,news.groups,sci.misc
From: ron@syacus.acus.oz.au (Ron Williams)
Subject: Re: sci.physics.research: proposed panel of moderators
Organization: ACUS Australian Centre for Unisys Software, Sydney
X-Newsreader: TIN [version 1.1 PL6]
Date: Mon, 11 Jan 1993 00:51:59 GMT

Mark Corscadden (markc@smsc.sony.com) wrote:
> In article <1993Jan8.160818.19578@galois.mit.edu> jbaez@riesz.mit.edu (John C. Baez) writes:
> >...  We will be excluding such things as: *bian's
> >endless thread, discussions of religion and politics (which threads on
> >sci.physics often turn into), endless repeats of questions that are in
> >the FAQ, re-re-rehashes of discussions ofthe interpretations of quantum
> >mechanics, etc..

> How did re-re-rehashes of the interpretations of quantum mechanics make
> it's way onto the scrap heap?  How does eliminating such discussions fit
> in with the goal of making sci.physics.research "lightly" moderated?
> (No, I did not miss the "re-re-re" in "re-re-rehashes".)

[ deletes ]
> 
> I've found the discussions of the interpretations of quantum mechanics
> to be very valuable and educational, and other discussions which would
> be of little interest to professionals.  Are people who are intensely
> interested in physics but committed to some other career path (like
> software engineering) going to find sci.physics.research to be a
> more-or-less hostile environment where their curiosity is not welcome?

Yes. I also fit into the above category. Having trained in physics, and still
having a lively interest in what's new, I am, however working in another field.
I find it annoying to wade through the garbage that makes it into sci.physics,
but really value the discussion that Mr. (Dr.?) Sarfatti provoked.

[deletes]

> 
> What about a compromise?  For certain topics like the interpretations
> of quantum mechanics the moderators could mandate a standard subject
> line, requiring that it start with "QMI" for example, to allow a simple
> killfile entry to be used by the non-interested.  Would that be enough?
> 

I second this. I was extremely interested in the QMI articles, it being eight
years since I finished my degree.

regards,

--
Ron Williams                  ACSnet : ron@syacus.acus.oz
Ph : +61 2 390-1366         Internet : ron@syacus.acus.OZ.AU
Fax: +61 2 390-1391             UUCP : uunet!munnari!syacus.acus.oz.au!ron
Standard Disclaimers Apply
Xref: sparky sci.physics:22461 sci.math:17950
From: jcf@world.std.com (Joseph C Fineman)
Newsgroups: sci.physics,sci.math
Subject: Re: Ansatz (as used in mathematical physics)
Date: 11 Jan 93 04:04:48 GMT
Organization: The World Public Access UNIX, Brookline, MA

siegman@EE.Stanford.EDU (Anthony E. Siegman) writes:

>   I've seen the term Ansatz used (in English) to describe the
>mathematical structure that is set up to analyse a physics problem or
>solve a mathematical physics problem; but none of several English
>dictionaries I've check contain this term, nor do my Deutsch-English
>dictionaries give much clue to this usage.  Can anyone quote any
>authoritative references on this particular usage?

I can't find it in any of my reference books either, but I've seen it
often enough, over the last 30 years or so.  So far as I know, it is a
synonym for "trial solution".  IMHO, it is an import that English can
well do without.  The native phrase is intelligible at first sight,
and it is only one syllable longer.  Also, a plural is occasionally
needed, and "Ansatz" presents one with the choice between the
pretentious "Ansaetze" and the horrible "Ansatzes".  (Incidentally, in
my experience it is usually not capitalized in English.)

%^)  Joe
-- 
        Joe Fineman             jcf@world.std.com
        239 Clinton Road        (617) 731-9190
        Brookline, MA 02146
From: paul@mtnmath.UUCP (Paul Budnik)
Newsgroups: sci.physics
Subject: Re: Quantum Mechanics Incomplete
Date: 9 Jan 93 15:48:12 GMT
Organization: Mountain Math Software, P. O. Box 2124, Saratoga. CA 95070

In article <1ikj50INNgc6@gaia.ucs.orst.edu>, preddy@comphy.physics.orst.edu writes:
> > [...]
> 
> >> Not in cases where you have to use the assumption that 
> >> the wave function changes instantaneously when an 
> >> observation is made. There is nothing remotely 
> >> resembling this in classical theory.
> [...] 
> As Feynman says, in "QED:  The Strange Theory of Light and
> Matter": 
> 
> "...It is to be emphasized that no matter how many arrows we
> draw, add, or multiply, our objective is to calculate a _single
> final arrow for the event_.  Mistakes are often made by physics
> students at first because they do not keep this important point
> in mind.  They work for so long analyzing events involving a
> single photon that they begin to think that the arrow is
> somehow associated with the photon.  But these are probability
> amplitudes, that give, when squared, the _probability_ of a
> complete event.  (Keeping this principle in mind should help
> the student avoid being confused by things such as the
> 'reduction of the wave packet' and similar magic)."

If you think this is a valid argument against my claim that you have
to use wave packet reduction in analyzing tests of Bell's inequality
you are mistaken. It is not possible to get the standard predictions
of quantum mechanics about the expected correlations without using
wave packet reduction as an *intermediate* step. If you think there
is a way around this I urge you to attempt it. I can assure you
that if you succeed you will have an important original result. You
will not succeed because you need some nonlocal physical law and the
reduction of the wave packet is the only one around.

What Feynman says is true of most experiments. I made this point in
the introduction to my proof. It is not true of experiments designed
to test Bell's inequality or any other experiment that predicts
*macroscopic* nonlocal effects. Feynman was brilliant
but not infallible. In analyzing these experiments you have to do
a wave packet reduction *before* you get the final result or
`complete event'.

Paul Budnik
Xref: sparky sci.physics:22481 news.groups:25337
From: goedde@math.ohio-state.edu (Chris Goedde)
Newsgroups: sci.physics,news.groups
Subject: Re: sci.physics.research: Are there important unresolved issues?
Date: 11 Jan 1993 11:46:48 -0500
Organization: Department of Mathematics, The Ohio State University
NNTP-Posting-Host: ellipse.mps.ohio-state.edu

In article <MATT.93Jan10010325@physics2.berkeley.edu> matt@physics.berkeley.edu writes:
>The purpose of this article is exactly what the subject line says: I'm
>trying to find out if there are any issues that haven't been resolved
>yet that people think are important.  (I think it's best that we do
>this before the vote, not after...)

Maybe you could repost the charter, Matt?  I can't seem to find a
copy.

In any case, I have a couple technical questions and comments.

Will crossposting to sci.physics be allowed or disallowed?
Personally, I don't see any reason for any articles to be crossposted
between these two groups---do the moderators agree?

On the other hand, I can see myself wanting to crosspost between
sci.physics.{research,moderated} and sci.math.research.  I assume that
this will be possible and the moderators will know how to deal with
it?

Regarding the name, I think that sci.physics.research is a little less
obscure to people who are new to the net, so I have a slight
preference for that name.  I don't really think that the name is very
important, though.

chris
goedde@shape.mps.ohio-state.edu
Newsgroups: sci.physics
From: dabbott@augean.eleceng.adelaide.edu.AU (Derek Abbott)
Subject: Creation of Solid-State Physics Newsgroup
Organization: Electrical and Electronic Eng., University of Adelaide
Date: Wed, 13 Jan 1993 01:29:47 GMT

Can the guy who was creating a Solid-State group towards the end of last
year please let us know how it is going? Based on the votes received, so far,
how likely is it that the creation will happen?
Xref: sparky sci.physics:22334 sci.astro:13777
From: bweiner@ruhets.rutgers.edu (Benjamin Weiner)
Newsgroups: sci.physics,sci.astro
Subject: Re: reported dark matter observation (PART 2)
Date: 8 Jan 93 21:53:24 GMT
Followup-To: sci.physics
Organization: Rutgers Univ., New Brunswick, N.J.

metzler@pablo.physics.lsa.umich.edu (Chris Metzler) writes:
>3.  Mushotzky's group measured an X-ray binding mass for this small
>group of galaxies and found a very large mass, and thus a very
>small baryonic fraction, and thus a large \Omega_o.

>This result is in direct contrast with small \Omega_o values (0.1-0.3)
>obtained by following the EXACT SAME PROCEDURE, only on rich clusters
>of galaxies rather than small groups.

>There are four ways to interpret this:

>a) This newly announced result is wrong.  I don't know much about the
>group they observed, but it's hard for me to see how they were able
>to get both a gas temperature, and a temperature slope, at large
>radii from the center of the group (~400 kpc or so). ...

Is Rosat's resolution really so great that they can get a temperature 
profile on such a small group?  Or are they engaging in Wishful
Thinking (tm)?

>b) The rich cluster observations which predict \Omega_o is low are
>wrong.  This is possible, but not very probable.  This is what
>theorists would like to be true, and accordingly theorists have
>worked very hard to show how this might be true.  ...

It seems to me that the latest wave of cluster-formation simulations
which include hydrodynamic effects are finding that even if you put
\Omega = 1 in, you will get clusters of galaxies which have a mass-to-
light ratio that would make you think \Omega = 0.2 or 0.3.  I heard
a talk by David Weinberg which said this.  (The paper was in a recent Ap
J Letters.)

>c) Neither set of observations are wrong, but this group of
>galaxies is not a representative object; it's an oddity.
>Then while the structure of this group may be interesting,
>it doesn't tell us anything about \Omega_o per se.

It seems like this is an awfully slim reed to base a determination of
\Omega on, let alone a front-page article in the New York Times (whoops,
my jealousy is showing).  Hey, dwarf galaxies are usually dark matter
dominated.  But no one believes they are a good measure of \Omega.

Maybe I feel a little extra skeptical about this, because there was a
paper a few years ago that got people antsy (Cowie Henriksen and Mushotzky,
Ap J 337, 593) by claiming that there was actually a lot *less* mass
in Coma than everyone else had got.  That paper was based on (non-spatially
resolved) old HEAO-1 data, and Rosat's a much better instrument, but that
paper drew a big conclusion based on (what I think was) a slim piece of
evidence.

>d) [both observations are correct]

Thanks for the posts, Chris.
Newsgroups: sci.physics