HDTenEightyP/NetNews huggingface dataset:
From: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr))
Subject: Re: BAEZZIAN physics and astronomy [was: Space-time IS a semi-Riemannian manifold (?)
Organization: National University of Singapore
Date: Tue, 6 Oct 1992 04:40:07 GMT

firth@sei.cmu.edu (Robert Firth) writes:
: In article <1992Oct5.091234.29484@nuscc.nus.sg> matmcinn@nuscc.nus.sg (Mcinnes B T (Dr)) writes:
: 
: >So naturally what I meant was that CLASSICAL spacetime IS a
: >semi-riemannian manifold.
: 
: ... and later ...
: 
: >Spacetime is the set of all events.
: 
: Now I'm *really* confused!  Which of the above mutually contradictory
: views do you in fact hold?

No contradiction. The assertion is that the set of all events is a
manifold. We often picture manifolds as consisting of structureless
points, but that is not necessary. For example, the frame bundle over a
manifold is itself a manifold, though its elements are by no means
"points" in the sense of Euclid. A typical element of the set
"spacetime" would be "George Bush groans"...ie an "event".
Maybe this is what will happen in quantum gravity: [CAUTION: baseless
speculation follows] maybe we will no longer be allowed to ignore the
structure of the events in spacetime: maybe the nature of the "points"
themselves will have to be taken into account.                      ?
Newsgroups: sci.physics
From: bhv@areaplg2.corp.mot.com (Bronis Vidugiris)
Subject: Re:  Simple observation about Quantum Kitty Cats
Organization: Motorola, CCR&D, CORP, Schaumburg, IL
Date: Fri, 2 Oct 1992 16:40:32 GMT

In article <1OCT199211415927@csa3.lbl.gov> sichase@csa3.lbl.gov (SCOTT I CHASE) writes:
)
)Why would you say that?  Neutron interferometry experiments have been done 
)which in fact show that gravity does affect interference of a split neutron
)beam which is recombined after the beams travel through a gravitational
)potential difference.

Interesting.  My impression of the original post was that the concern was
with interaction with gravity constituted a 'measurement' which would destroy
the interference fringes.  Since I was fairly sure that actual interference
experiments with particles have been done, and I was pretty sure they were
not done in zero G, I concluded the mere presence of a gravity field was not
enough to disturb the measurement sufficiently to prevent fringes from
forming.

It's logical that changing the momentum of the neutron would affect it's
wave function and hence the measured interference fringes, and interesting
that the energies were low enough to observe the effect experimentally.
(I suppose that's logical too - you want to make the wavelength as long
as possible and that implies low momentum, I believe).

Newsgroups: sci.physics,sci.astro
From: mmm@qedqcd.rye.ny.us (Mike Miskulin)
Subject: Re: hanna-maria1.gif (01/03)
Organization: High Energy Concepts
Date: Mon, 28 Sep 1992 01:20:34 GMT

In article <1992Sep21.164326.4275@ichips.intel.com> bhoughto@sedona.intel.com (Blair P. Houghton) writes:
>
>First of all, we, and especially I, requested that these be
>posted to these groups.  

Groups were specifically created for the postings of GIF's.  Ask *your*
system admin. for access to those groups.

>If you're having bandwidth or disk
>problems then you're in the 17th century, newswise[*], and
>I advise that you turn your efforts to upgrading your
>hardware, rather than wasting more bandwidth whining about
>your weaknesses.  (Popular and somewhat specious estimates
>would show that you could buy a month on a T1 line for what
>the net spent passing your flame around).

Really?  Perhaps you have forgotten that not every site in Usenet
has a T1 line?  Have you heard of UUCP connections?  There are many
of these still out there.  And probably many other slower means
of getting news.  Don't presume that everybody and every site can
afford what yours can.  Usenet was *not* created for you only.

>
>Secondly, you're free to get your newsadmin to expire the articles.

Again, just as *you* are free to ask your newsadmin for access to
the appropriate groups.

>				--Blair
>				  "Shorting like mad..."


-- 
--------------------------------------------------------------------------------Mike Miskulin		mmm@qedqcd.rye.ny.us	70053,551@compuserve.com
--------------------------------------------------------------------------------
From: jac@ds8.scri.fsu.edu (Jim Carr)
Newsgroups: sci.physics
Subject: Re: Nuclear equations
Date: 6 Oct 92 20:11:14 GMT
Reply-To: jac@ds8.scri.fsu.edu (Jim Carr)
Organization: SCRI, Florida State University

In article <1992Oct2.230447.25257@access.usask.ca> choy@skorpio.usask.ca (I am a terminator.) writes:
>What do we know for closed form equations describing or modelling
>the activity experienced by subatomic particles? How about recursive

Unclear if you are asking about nuclear physics (i.e. the behavior 
of quarks and gluons when they are mainly color singlets in the 
form of protons and neutrons effectively exchanging mesons) or 
particle physics (i.e. the behavior of what used to be called 
"elementary" particles). 

>equations or series? Do we tend to talk about collections of
>particles or can we talk about each individual particle as it
>interacts with other particles? Can we predict what happens at
>a particular point in space as time passes? I'm wondering about the
>extent of any generalization that has been done from experimental
>results. Is there a handbook of formulas available? in the works?
>Anyone interested in compiling one?

There is a "standard model" for particle physics described in all 
recent particle physics text books.  Which one you like is a 
matter of taste.  A working knowledge of quantum field theory is 
needed to appreciate this model. Its predictive power is outstanding 
as long as the energy of the interactions is high enough that one 
can calculate an answer.  It has yet to be able to calculate the 
mass of a proton; the low energy sector is really untested.  

Nuclear physics is basically the low energy sector of QCD, with 
the complication of having lots of particles interacting with 
one another.  The most complete description of the field is 
probably a pair of massive (and expensive) tomes: deShalit and 
Feshbach (Theoretical Nuclear Physics Vol. I, Nuclear Structure) 
and a new book by Feshback (basically vol. II on reactions, but 
I do not think it is called volume 2).  This material requires a 
good working knowledge of quantum mechanics with more of an 
emphasis on many-body theory than field theory altho the latter 
is helpful at times.  It is an intense book. 

--
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: prim!dave@germany.eu.net (Dave Griffiths)
Subject: Re: Understand...!!!!
Organization: Primitive Software Ltd.
Date: Sat, 26 Sep 1992 20:43:45 GMT

In article <25SEP199209055315@utahep.uta.edu> sawyer@utahep.uta.edu (Lee Sawyer) writes:
>In article <92Sep24.232130.15043@acs.ucalgary.ca>, shteinbo@acs.ucalgary.ca (Boris Shteinbock) writes...
>> 
>>Strange thing. We talk about physics using all this different words
>>and phrases like mass, energy, time, particle, wave ,field, etc.
>>but this words don't make any sense if you'll look more carefully
>> 
>> 
>>What is Energy ?
>> 
>>What is time ?
>> 
>>What is field ?
>> 
>>What is ... ?
>> 
>
> Posts like this really piss me off. Take a couple of physics
>courses, then ask "What is energy ?"
>

That's better than studying the subject for a few years and believing you
now _know_ what these words mean. I hate to go metaphysical on you, but
aside from the mathematical definition of time as a variable in your
calculations, what _is_ time? Given that most physics is time reversible,
how do you know that you're going forward in time?

Do you believe that fields really _exist_, or are they just a mathematical
device? If the former, how do you imagine something that is infinite?

Just curious.

Dave Griffiths
From: ric@hpspdla.spd.HP.COM (Ric Peregrino)
Date: Mon, 5 Oct 1992 18:46:27 GMT
Subject: Re: How do you draw a straight line?
Organization: HP Stanford Park - Palo Alto, CA
Newsgroups: sci.physics


How about a taught string?

--------------------------------------------------------------------
Ric Peregrino   c/o Hewlett Packard Co.    I represent only myself
ric@spd.hp.com  1501 Page Mill Rd Bldg 5M  I may be wrong, maybe not
415-857-7526    Palo Alto, CA 94304        Do DC photons exist?
--------------------------------------------------------------------
Newsgroups: sci.physics
From: gilligan@camelot.bradley.edu (Edward Henigin)
Subject: a test for white noise?
Keywords: white noise
Organization: Bradley University
Distribution: na
Date:  7 Oct 92 03:52:08 GMT

Hi y'all . . . . 
If you had a set of data points (a 2d array: position versus time for ex.)
what set of criteria does it have to meet to be classified as
'white noise' or 'brownian motion' or whatnot?  How could you tell
if it was purely random? Is there a degree of randomness, ie, a
scale of 0 to 100 where 0 is totally un-random and 100 is totally
random?  And, is my head up my wazoo for thinking that brownian motion,
white noise, and pure randomness are essentially the same thing?

Either direct info or references to books or articles would be 
greatly appreciated.

ed
gilligan@camelot.bradley.edu
From: 00jcbenson@bsu-ucs.uucp
Newsgroups: sci.physics
Subject: black holes & thermodynamics
Date: 5 Oct 92 00:50:35 GMT

First let me qualify my statement by saying that I am an archaeology major, and
not too knowledgable about physics.  But, I have a question which I would like
some kind person to correct me on.

It seems to me that a Black Hole is an object which orders the universe.  It 
brings matter together into a point.  Now the Law of Thermodynamics concerning
Chaos seems to suggest that the universe tends to bring down rather than to
order itself.  So, my question is, why can a Black Hole exist if it continually
orders the universe instead of breaking down?  

I hope that was intelligable enough for someone to understand my question.

A kind reply in the simplest language would be greatly appreciated.

Thank you,
Joe Benson
Ball State University
Newsgroups: sci.physics
From: yjj@neptune.ctr.columbia.edu (Yuan Jiang)
Subject: Bessel Function J0(x) roots
Organization: Columbia University Center for Telecommunications Research
Distribution: usa
Date: Sat, 3 Oct 1992 03:56:19 GMT
X-Posted-From: neptune.ctr.columbia.edu
NNTP-Posting-Host: sol.ctr.columbia.edu

Does any one have the roots of Bessel function J0(x) handy.  If
you do, I'd like to have the first 5-10 roots sent to me by
email.  I know I can write up a program to calculate the roots.
But I have to write a decent root finding program.

thanks.
From: choy@skorpio.usask.ca (I am a terminator.)
Subject: Do physicists wax metaphysical?
Organization: University of Saskatchewan, Saskatoon, Canada
Date: Tue, 6 Oct 1992 01:22:21 GMT

Our world seems made to order for life and happiness. Things get better,
some of the chaos in the universe is turned into order with due credit
to knowledge of physics. We have always wondered if some divine
guidance or ends is in the works. What (wild) speculations do physicists
have on our future as the Milky Way jams across the void? I can think
of a few things. I'll bet most are pipe dreams.

  + We come to understand and control nature as metaphysics and
    observations mesh to clue us into what makes everything tick and
    why.
  + We fizzle out, party's over.
  + It's an endless joyride.
  + The universe is a large computing device bound and run by God knows
    what (but God knows I'm going to find out). We're here as something
    is being computed (or the machinery is idle).
  + Deterministic. Things just happen as they happen and get out
    of way.
  + Matter is gathering itself into one large bowl of chocolate fudge.

Henry Choy
Newsgroups: sci.physics
From: COWAN@ssrl01.slac.stanford.edu (Paul L. Cowan)
Subject: Top 10 List (was Re: Another Cute Math Joke)
Organization: CALIFORNIANS ON THE ORIENT EXPRESS
Date: Sat, 3 Oct 1992 16:53:09 GMT
X-News-Reader: VMS NEWS 1.24

In <1992Oct2.123755.22685@ulrik.uio.no> jarleb@athena.uio.no writes:

:        TOP TEN EXCUSES FOR NOT DOING THE MATH HOMEWORK
:
: 1.      I accidentally divided by zero and my paper burst into flames.
: 2.      Isaac Newton's birthday.
: 3.      I could only get arbitrarily close to my textbook.  I couldn't
:         actually reach it.
: 4.      I have the proof, but there isn't room to write it in this margin.
: 5.      I was watching the World Series and got tied up trying to prove
:         that it converged.
: 6.      I have a solar powered calculator and it was cloudy.
: 7.      I locked the paper in my trunk but a four-dimensional dog got in
:         and ate it.
: 8.      I couldn't figure out whether i am the square of negative one or
:         i is the square root of negative one.
: 9.      I took time out to snack a doughnut and a cup of coffee.  I spent
:         the rest of the night trying to figure which one to dunk.
: 10.     I could have sworn I put the homework inside a Klein bottle, but
:         this morning I couldn't find it.
:
:						Jarle.

These are great! Does there exist a similar list for physics? 
After all this is sci.physics. If there is one (in the FAQ?) please excuse
this modest attempt: 

        TOP TEN EXCUSES FOR NOT DOING THE *PHYSICS* HOMEWORK

10.     My homework paper fell into a wormhole and was transported through
        time into next week.
 9.     A freak statistical fluctuation caused all the molecules in the paper
        head south simultaneously.
 8.     I have the wavefunction, but I misplaced its complex conjugate.
 7.     I was comparing my homework to my roommates, but unfortunately 
        his paper was made of anti-matter and they annihilated.
 6.     I couldn't spell "Podalski".
 5.     I rolled it into a ball and dropped it off the Tower of Pisa.
 4.     I was sitting under a tree working on it when an apple hit me
        on the head, and they just released me from the hospital.
 3.     I was riding on a train going near the speed of light when 
        lighting struck both ends *SIMULTANEOUSLY* and the paper was 
        burned in the ensuing fire.
 2.     I was measuring the height of a tall building with a barometer,
        and the wind on the roof blew my paper away as I was timing
        how long it took the barometer to fall.

And the number one reason for not handing in ones Physics homework...





















 1. Schroedinger's cat ate it.



---------------------------------------------------------------------------
P. L. Cowan     Please send replies, comments etc. (no flames thank you) to 
COWAN@ANL.GOV  (I'm posting from my own account, but not the preferred one)
        "Gentlemen, you can't fight in here! This is a War Room!"
from _Dr._Strangelove_or:_How_I_Learned_to_Stop_Worrying_and_Love_the_Bomb_
---------------------------------------------------------------------------
Newsgroups: sci.physics
From: ledwards@leland.Stanford.EDU (Laurence James Edwards)
Subject: Re: STRUCTURE OF TIME
Organization: DSG, Stanford University, CA 94305, USA
Date: Tue, 29 Sep 92 23:23:49 GMT

In article <1992Sep29.212630.1@tnclus.tele.nokia.fi>, hporopudas@tnclus.tele.nokia.fi writes:
|> 
|>  my aphorism:
|> >  >
|> >  >   "Mads so. peoples without self-disipline, become entangled only in
|> >  >    pleasant's trap when they only choose pleasant instead of good, and they
|> >  >    get lost so. they do not ever reach the goal to become happy."
|> 
|> >
|> > This is not what was discussed. Keep to the subject!
|> > Or do you confuse science and atheism with pleasure-seeking and undiscipline?
|> > If that's the case, you are mistaken. Learn what the words mean before using
|> > them.
|> >
|> > Kim0
|> 
|>   Yes it was.

um, no it wasn't ... the discussion centered on whether atheistic scientists
were responsible for the "suffering" of "ordinary" people.

|>   One lesson to 'undeveloped peoples':
|>   Man chooses between good and pleasant (not between good and evil):
|> 
|>  "Good is one, pleasant is an another matter. These two lead man to very
|>   different goals. Who chooses good, will become happy. Who keeps pleasant
|>   better, will loose his goal. Wises let never pleasant delude themself.
|>   They choose good. Mads become entangled only in pleasant's toils and they
|>   get lost.

One lesson for Hannu:

If someone chooses not to believe in a god it is not because it is a "pleasant"
thing to do. Rather, they believe it is the truth, and they believe it is
"good" to accept the truth.

small language hint:

"Mads so," "Mads," and "Wises" are not english words or phrases.

Larry Edwards
From: ethan@ut-emx.uucp (Ethan Tecumseh Vishniac)
Newsgroups: sci.physics
Subject: Re: Are redshifts discrete?
Summary: Rotation curves
Date: 29 Sep 92 15:49:19 GMT
Organization: The University of Texas at Austin; Austin, Texas


It might be worth remembering, when considering Tifft's claim, that
a number of different kinds of redshifts are obviously not quantized
in units of 72 km/sec.  For example, redshifts within our galaxy
are not.  Redshifts of nearby galaxies are not.  Redshifts of
gas inside other galaxies are not, since rotation curves are
masured by looking at 21cm emission.  This effect, if real, only
shows up when considering the average redshifts of distant galaxies.

I would bet, if I were a betting man, that this is some sort of
statistical problem with the data reduction, a topic on which I'm
largely ignorant.  If it keeps cropping up in various studies then 
I'll have to pay more attention to it.

-- 
"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
Newsgroups: sci.physics
From: prim!dave@germany.eu.net (Dave Griffiths)
Subject: Re: Understand...!!!!
Organization: Primitive Software Ltd.
Date: Tue, 29 Sep 1992 17:15:45 GMT

In article <1992Sep28.210054.17335@lmpsbbs.comm.mot.com> bhv@areaplg2.corp.mot.com (Bronis Vidugiris) writes:
>
>I've got a great answer for the question of 'what is time'.  I don't recall
>where it came from, but it's really simple:
>
>Time is what you measure with a clock.
>
>Philosophically, this is the viewpoint that once you have something defined,
>(such as a way to measure it, for example) it has *some sort* of reality.
>

The wierdest thing about time is the fact that you can sit there and
observe it flowing at a certain "rate". If you imagine our four dimensional
universe as being like a reel of film, why does a character in any one
frame have the impression that he is travelling in a particular direction
with a particular speed through the film? To be aware of time flowing
almost seems to require one to be outside it.

Dave Griffiths
Newsgroups: sci.physics
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: Quantum Zeno Effect, Part 1.
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Tue, 6 Oct 92 17:21:42 GMT

In article <1992Oct6.120707.14830@sei.cmu.edu> firth@sei.cmu.edu (Robert Firth) writes:
>In article <1992Oct6.024752.20086@galois.mit.edu> jbaez@riesz.mit.edu (John C. Baez) writes:
>
>>Oh-oh, not this again.  The point, as I have argued earlier, is that no
>>physically reasonable process can give EXACTLY exponential decay; very
>>general arguments show that there is a short "plateau" before the curve
>>approximates an exponential.
>
>Yes, there are several models of the decay process that predict a plateau.
>However, last time I checked, all of them predict that the length of time
>spent on this plateau is smaller than hbar/delta-E, which means the
>plateau is unobservable.  If that's not so, I'd appreciate a correction.

Hmm, that's a new twist.  We would have to know how we were going to
"observe the plateau" before we could figure this out.
From: mcirvin@husc8.harvard.edu (Mcirvin)
Newsgroups: sci.physics
Subject: Re: Quantum Zeno Effect, Part 1.
Date: 5 Oct 92 14:47:25 GMT
Article-I.D.: husc8.mcirvin.718296445

firth@sei.cmu.edu (Robert Firth) writes:

>However, as I said, that's a minor point.  Your major point is that the
>act of observing a system, and finding it seemingly unchanged from a
>previous observation, can indeed affect the subsequent behaviour of the
>system.  In other words, a "null observation" has an effect on the
>thing observed.

I was under the impression that, if the fields used to do the null
observations are included in the model, the Zeno effect shows up without
the need to postulate any sort of extra collapse event.  Does anybody know
specifics?
-- 
Matt McIrvin, posting nonsense again
From: joe@astro.as.utexas.edu (Joe Wang)
Newsgroups: sci.physics
Subject: Re: Local expansion
Keywords: expansion, Hubble, gravity
Date: 27 Sep 92 01:40:08 GMT
Organization: McDonald Observatory, University of Texas @ Austin

In article <1992Sep23.143830.25927@cid.aes.doe.CA> ynecgan@cid.aes.doe.CA (Greg Neill) writes:
>I have repeatedly come across
>statements similar to: "...the general expansion of the universe does
>not affect galaxy structure or clusters, since they are held together
>too firmly by gravitational forces."  Now, what the heck does this mean?
>Is space not expanding uniformly at all scales?  

Nope.

The calculations that demonstrate that the universe should expand a
uniform rate ASSUME that you have a universe whose density is uniform.
Now at large scales, this is a pretty good assmuption.  If you look
at the universe as a whole, it looks and acts a lot like a uniform
fluid, just like a air looks and acts a lot like a uniform fluid if
you don't look closely enough to see atoms.

At small scales, however, the universe is not uniform, and so you have
to throw any calculations assume that it is out the window.  

Newsgroups: sci.physics
From: J103680@LMSC5.IS.LMSC.LOCKHEED.COM
Subject: X-ray map of Northern California
Organization: Lockheed Missiles & Space Company, Inc.
Date: Mon, 5 Oct 92 21:14:49 GMT

I am searching for an X-ray map of N. CA to reveal caves and
caverns underground.  Do you know of any sources?
Newsgroups: sci.physics
From: mazzucch@ghost.dsi.unimi.it (massimo mazzucchi)
Subject: microvawe
Keywords: Microvawe
Organization: Computer Science Dep. - Milan University
Date: Thu, 1 Oct 1992 16:34:37 GMT



Ciao io sono Max studente di informatica di Milano
non direttamente ma per un mio amico, riguardo le microonde,  
lui lavoro nel settore spazio e precisamente nella 
costruzione di satelliti

vorrei informazioni circa la 
caratterizzazione in corrente continua

DI FET HEMT



Sono grato a chi mi sapra' dare una risposta al seguente indirizzo
di email:

mazzucch@ghost.sm.dsi.unimi.it



ciao e grazie.




hi

I am Max, student of computer science of Milan

my friend, that work to build of satellit, would know information about 
MICROVAWE

and especially for

caracterizaction in direct current 

di FET HEMT

If you want\can help me send to me mail at the address

mazzucch@ghost.sm.unimi.it

Thanks and bye!!