HDTenEightyP/NetNews huggingface dataset:
From: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr))
Subject: Re: Understand...!!!!
Organization: National University of Singapore
Date: Wed, 30 Sep 1992 02:52:14 GMT

: 
: Time has puzzled people for a long time.  We are so used to being within
: spacetime that when we imagine ourselves outside it, watching peoples
: wormlines as if they were carved in a block of glass, we feel the 
: need to imagine a "hypertime" to keep track of the rate at which the 
: "now" slides along these worldlines like a glowing spot.  This is NOT
: the right way to think of it.  Instead, ponder that block of glass
: and the worldlines of all the people in it, the worldlines of the 
: photons going from the Sun to their eyes (let's leave QM out for now!!),
: the worldlines of the electrons moving in their brains, etc., until
: you see how "from within" that spacetime could seem just like our world.  
: 
: It's only when you spend hours doing this that you really understand
: the concept of spacetime at a gut level.  At least that was the case
: for me.

The usually CAUTIOUS JB has OPENED a can of WORMS here. Is he professing
a belief in strict DETERMINISM? Is he claiming that our apparent
perception of the passage of time is naught but a delusion? .
Xref: sparky sci.physics:15654 sci.optics:1017
From: agae@elder.lle.rochester.edu (Andres C. Gaeris)
Newsgroups: sci.physics,sci.optics,sci.eng
Subject: Spectral data analysis references anyone?
Keywords: Spectral analysis, Gaussian fitting
Date: 29 Sep 92 21:07:52 GMT
Reply-To: agae@elder.lle.rochester.edu (Andres C. Gaeris)
Organization: UofR Laboratory for Laser Energetics

I am analyzing a pair of hundred of digitized photographs with
spectra characterized for around half a dozen of Gaussian-like
peaks in them, some clearly isolated and some embedded in fatter
peaks or as shoulders. My questions are the following:

1- Does anyone have some references about spectral data analysis?
As a plasma theoretician that went experimental I am a complete ignoramus
on how to read spectra, including criteria for normalization, differentiating
Gaussians from Lorentzians and the physical meaning of spectral filters
and tranforms.

2- What about non-linear fitting software? I have seen the ad for a
program that fits multiple Gaussians from data taken of a multipeaked
spectrum. Anyone can recomend some UNIX or PC-DOS software that can do
this kind of fitting? Any comments about the reliability of these programs?


Andres C. Gaeris
agae@lle.rochester.edu
From: paul@mtnmath.UUCP (Paul Budnik)
Newsgroups: sci.physics
Subject: Re: Simple observation about Quantum Kitty Cats
Date: 3 Oct 92 16:06:12 GMT
Organization: Mountain Math Software, P. O. Box 2124, Saratoga. CA 95070

In article <1992Oct2.202249.21453@galois.mit.edu>, jbaez@riesz.mit.edu (John C. Baez) writes:
> >But my formalism makes the same predictions of quantum mechanics with
> >the exception of tests of Bell's inequality. 
> 
> Let's see your formalism - where are the equations?  What precisely does
> it predict in situations where QM violates Bell's inequality?  Not
> words, numbers.  Show how to do some QFT-type calculations using this
> formalism (since QFT combines relativity and QM) - say electron-electron
> scattering.  

If I could do that I would not be wasting my time posting this stuff. I
would be publishing it and patiently waiting for the Nobel committee to call.

I should not have said `my formalism'. The alternative to the existing theory
I am proposing is to add locality as an additional constraint to that
theory.  This implys that we do not know how the wave function changes
before and after an observation. The multiparticle wave function cannot,
in general, change in a local fashion when an observation is made, but that
is not the issue. It must change in such a way that there are no nonlocal
macroscopic effects. No one knows how it does change. I think it is a
chaotic-like process that cannot be modeled by an equation. The underlying
laws can be modeled and the whole process could in theory be simulated on
a computer. But one cannot give a simple equation that models this behavior,
Just as one cannot give a simple equation that models the atmosphere in
enough detail to predict the weather. That can only be done to
a limited degree by large scale simulations.

This means there are holes in the existing theory at the point an
observation is made. We shold acknowledge their existence. We do not
know what is happening at these points. Testing Bell's inequality will
give us some clues.

A few months ago you gave an argument why quantum mechanics may not be
completely valid at very small distances. You do not have an alternative
theory worked out. You would like to develop such a theory that combines
gravity with QFT but you know it will be hard problem and take a long time.
I do not think you expect to be able to do it by yourself.

My point is that questions about locality should be treated in the same way.
It would be foolish to insist that quantum mechanics is completely correct
at all distance scales. It is equally foolish to assume it violates locality.
There does not exist a shred of evidence for nonlocal affects.
The main difference between these two cases is the ability to validate
a theory with experiments. Effects at the distant scale you have in mind are
completely inaccessible by any foreseeable experimental techniques. It is
almost impossible to build correct theories under these circumstances. Tests
of locality can be done using existing technology. Perhaps you should
consider changing your area of research. :-)

Paul Budnik
From: crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass)
Newsgroups: sci.physics
Subject: Re: Spin
Date: 29 Sep 92 04:21:19 GMT
Organization: University of Virginia

In article <1992Sep28.221735.35@sjsumcs.sjsu.edu> b5249-23@mathcs.sjsu.edu (Kurt Stocklmeir) writes:
>Robert Firth
> His article
>
>Some other people have confused you.  Look at Gravitation
>Misner, Thorne, Wheeler P.177.  There are also some other parts
>of the book that include the area of gravity having an infinite
>velocity.

     Here.  Me tell you what page says in more simple way:

     Infinite velocity (very fast) = newtonian gravitation (old stuff)

     It say nothing on new stuff.

     Me suggest reading help.  Seem to lose words.

                            dale bass
-- 
C. R. Bass                                           crb7q@virginia.edu
Department of Mechanical and Aerospace Engineering
University of Virginia
Charlottesville, Virginia                            (804) 924-7926
Newsgroups: sci.physics
From: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr))
Subject: Re: Make time stop?
Organization: National University of Singapore
Date: Wed, 30 Sep 1992 02:45:08 GMT

tolman%mindblow.cs.utah.edu@cs.utah.edu (Kenneth Tolman) writes:
:   A frame of reference moving very very fast has a time dilation, correct?
: (That is, if we are still and looking at someone moving they are "slow")
: When we look out into the universe- all galaxies are moving away from us,
: and the very far away galaxies are moving near the speed of light.
: 
: Therefore, THEIR TIME HAS BARELY BEGUN.  Their civilization's have not 
: started, and they live in a "young" universe.  Thus, if we could travel
: faster than light, we could jump backwards and live this whole universe
: through once again.  Of course, the converse is true just as well from
: their perspective.  Is this analysis somewhat correct?
: 
				No.
:
From: sichase@csa1.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: What is the Speed of Gravity - A Call for a Volunteer
Date: 30 Sep 1992 11:00 PST
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
Distribution: world
NNTP-Posting-Host: 128.3.254.196
News-Software: VAX/VMS VNEWS 1.41    

OK.  I think it's time that this question appear in the FAQ.  But I'm 
not the right man to do the job.  Would one of the experts please volunteer?
Send E-mail if you're interested (or even just willing).  Don't make me
write this one myself.  You'll be sorry.

-Scott
--------------------
Scott I. Chase			"The question seems to be of such a character
SICHASE@CSA2.LBL.GOV		that if I should come to life after my death
				and some mathematician were to tell me that it
				had been definitely settled, I think I would
				immediately drop dead again."      - Vandiver
Newsgroups: sci.physics
From: bhv@areaplg2.corp.mot.com (Bronis Vidugiris)
Subject: Re: Measuring Q
Organization: Motorola, CCR&D, CORP, Schaumburg, IL
Date: Mon, 28 Sep 1992 20:30:08 GMT
Keywords: FTL Communications Experiment

In article <4350@cruzio.santa-cruz.ca.us> snarfy@cruzio.santa-cruz.ca.us writes:

)   Ah! You must be an engineer.  In  your  case  you  measure  instantaneous
)   changes in Q by paying a technician to do it.
)
)   I'm available.

Instantaneous?  That's one *damn* fast technician :-) :-) :-)

I'd be satisfied if I could get a mere 10 billion measurements per day - 
instantaneity has always seemed out of the question.
Newsgroups: sci.physics
From: hagerman@ece.cmu.edu (John Hagerman)
Subject: Re: How do you draw a straight line?
Organization: Carnegie Mellon University
Date: Mon, 5 Oct 1992 21:19:57 GMT

In article <1992Oct5.154211.21663@ecrc.de> micha@ecrc.de (Micha Meier) writes:
> 
> This is something I've been wondering about since a long time.
> Although we can make a circle as precise as we want, I think we
> cannot make a really precise straight line - every straight line is
> made from another one or from a tool that has been made using some
> older straight lines - so it all comes down to copying a line that
> has been made thousands years ago. Although we have precise
> instruments and tools, we can only make better and better lines (so
> that eventually the error is less than an atom, and we are there),
> but IMHO there is no process to create a straight line directly. Or
> is it?

How about laser milling?

(Then you *really* get a straight line :-).

- John
--
hagerman@ece.cmu.edu
From: jbaez@riesz.mit.edu (John C. Baez)
Newsgroups: sci.physics
Subject: Re: Understand...!!!!
Date: 29 Sep 92 19:36:09 GMT
Organization: MIT Department of Mathematics, Cambridge, MA

In article <1992Sep29.171545.806@prim> prim!dave@germany.eu.net (Dave Griffiths) writes:

>The wierdest thing about time is the fact that you can sit there and
>observe it flowing at a certain "rate". 

Really?  How?  

Imagine doing this and measuring this rate precisely.  How would you do
it?  What would you get - one second per second?

>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.

Time has puzzled people for a long time.  We are so used to being within
spacetime that when we imagine ourselves outside it, watching peoples
wormlines as if they were carved in a block of glass, we feel the 
need to imagine a "hypertime" to keep track of the rate at which the 
"now" slides along these worldlines like a glowing spot.  This is NOT
the right way to think of it.  Instead, ponder that block of glass
and the worldlines of all the people in it, the worldlines of the 
photons going from the Sun to their eyes (let's leave QM out for now!!),
the worldlines of the electrons moving in their brains, etc., until
you see how "from within" that spacetime could seem just like our world.  

It's only when you spend hours doing this that you really understand
the concept of spacetime at a gut level.  At least that was the case
for me.
Newsgroups: sci.physics
Newsgroups: sci.physics
Subject: Re: Understand...!!!!
From: mcirvin@husc8.harvard.edu (Mcirvin)
Date: 26 Sep 92 16:25:19 GMT

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
>> 

> Posts like this really piss me off. Take a couple of physics
>courses, then ask "What is energy ?"

I think he's asked a valid question, but it applies equally well to
everything.  What is toast?  What is democracy?  What is quality?  Chase
definitions through the dictionary, and they'll start getting circular
after two or three steps.  So, of course, these kinds of questions
are unanswerable, except in a kind of operational way.  And in that
respect physics is on ground as solid as anything.

-- 
Matt McIrvin, posting nonsense again 
Newsgroups: sci.physics
From: firth@sei.cmu.edu (Robert Firth)
Subject: Re: BAEZZIAN physics and astronomy [was: Space-time IS a semi-Riemannian manifold (?)
Organization: Software Engineering Institute
Date: Mon, 5 Oct 1992 12:58:35 GMT

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?
From: exuptr@exu.ericsson.se (Patrick Taylor)
Newsgroups: sci.physics
Subject: Re: Understand...!!!!
Date: 28 Sep 92 02:50:22 GMT
Organization: Ericsson Network Systems, Inc.
X-Disclaimer: This article was posted by a user at Ericsson in North America.
              The opinions expressed are strictly those of the user and
              not necessarily those of Ericsson.

In article <1992Sep26.204345.1200@prim> prim!dave@germany.eu.net (Dave Griffiths) writes:

>aside from the mathematical definition of time as a variable in your
>calculations, what _is_ time? 

Time is an illusion.  Lunchtime doubly so.

>Given that most physics is time reversible,
>how do you know that you're going forward in time?

Because it's closer to lunchtime.

 ----------------------------------------------------------------------------
    "This must be Thursday.  I never could get the hang of Thursdays"
                                                       - Douglas Adams
  - Patrick Taylor                                       (Arthur Dent)
    Ericsson Network Systems
    exuptr@exu.ericsson.se                       "Don't let the .se fool you"
    or exuptr@ZGNews.Lonestar.Org, exu.exuptr@memo.ericsson.se
From: ric@hpspdla.spd.HP.COM (Ric Peregrino)
Newsgroups: sci.physics
Subject: Re: Can Information Have Physical Units?
Date: 6 Oct 92 00:10:46 GMT
Organization: HP Stanford Park - Palo Alto, CA


Shooting from the hip I'd say information has the same units as entropy,
which I thought was unitless. But what about Gibbs free energy:

dG = dH + TdS

S then has units of energy/temperture? Maybe I'm just being dense?

--------------------------------------------------------------------
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        Are DC photons detectable?
--------------------------------------------------------------------
From: ted@physics.Berkeley.EDU (Emory F. Bunn)
Newsgroups: sci.physics
Subject: Re: Quantum Nights 1
Date: 2 Oct 1992 20:21:37 GMT
Organization: Physics Department, U.C. Berkeley.
NNTP-Posting-Host: physics.berkeley.edu

In article <1992Oct1.233347.16497@ichips.intel.com> bhoughto@sedona.intel.com (Blair P. Houghton) writes:
>In article <BvFCpL.Atx@well.sf.ca.us> sarfatti@well.sf.ca.us (Jack Sarfatti) writes:
>>Night Thoughts of a Quantum Mechanic in the style of Ludwig Wittgenstein. 1
>>
>>An electric charge is freely falling. A photon detector is freely falling.
>
>Okayyyy...
>
>>The freely falling detector will not detect real photons from the freely
>>falling charge.
>
>Sez who?

It's true.  The heuristic argument for why it should be true is just
the Principle of Equivalence.  "Being in free fall" is equivalent to
"being in an inertial reference frame", and if the charge and observer
are both in inertial reference frames, no radiation is seen.

But if that doesn't satisfy you, you can do the GR calculation rigorously.
Somebody wrote a nice paper on it a few years ago (Am. J. Phys., I think,
but I could be wrong).  He calculated the Poynting vector and hence
the energy flux from a charge in four cases: 

(i) Falling charge, falling observer,
(ii) Falling charge, supported observer,
(iii) Falling observer, supported charge,
(iv) Supported observer, supported charge.

(The background spacetime is Schwarzschild, far outside the horizon.
Here "falling" means "in free fall", and "supported" means at rest with respect
to the usual Schwarzschild coordinate frame.)

As one might expect, radiation is seen in cases (ii) and (iii) only.

When I first read this, I thought it made perfect sense from the classical
point of view, but I was bothered when I tried to look at it in the 
"photon picture".  After all, either the charge IS emitting photons
or it ISN'T, right?  Wrong.  I eventually learned enough physics to 
decide that everything was OK in the photon picture too, but if I
tried to explain why, I'd screw it up.  I'll leave that job to
someone else.

By the way, if you want the reference to the paper I described, send
me some mail.  I have the paper somewhere, and it shouldn't be too
hard to dig it up.

-Ted
From: mcirvin@husc8.harvard.edu (Mcirvin)
Newsgroups: sci.physics
Subject: Re: The H-Bomb secret is out
Date: 2 Oct 92 23:12:38 GMT

matt@physics.berkeley.edu (Matt Austern) writes:

>Now that the government is finally revealing some information about
>H-bomb construction, I'm curious: Does anyone out there happen to know
>how close what _Progressive_ said is to what the government is now
>saying?

A couple of years ago I took a class on the strategic arms race
at William and Mary that used a textbook which, I think, drew
heavily on the _Progressive_ article.  The book's description was
somewhat different from the one just quoted-- lithium was described
as being the source of tritium; the lithium deuteride was in
a cylindrical shape with the fission trigger at one end, and was
compressed axially by an ablator (which the book said was probably
styrofoam), with a jacket of "high-Z material" like U-238 on the 
outside.  Removing the jacket was purported to yield a neutron bomb,
with a smaller detonation but huge emission of neutrons.
-- 
Matt McIrvin, posting nonsense again 
Newsgroups: sci.physics
From: pete@cs.curtin.edu.au (Pete Staples)
Subject: Maxwell's equations.
Organization: Curtin University of Technology
Date: Wed, 30 Sep 1992 01:51:37 GMT

I am after a basic introduction and explanation of Maxwell's equations,
with particular reference to alternating current induced (or injected) 
into metal surfaces exhibiting the "classical skin effect". 
I have some good references but I thought I'd post this to see how others 
interpret them.

Please mail any input to pete@cs.curtin.edu.au

thanks in advance 

peter.
From: paul@mtnmath.UUCP (Paul Budnik)
Newsgroups: sci.physics
Subject: Re: Simple observation about Quantum Kitty Cats
Date: 3 Oct 92 16:29:47 GMT
Organization: Mountain Math Software, P. O. Box 2124, Saratoga. CA 95070

In article <1992Oct3.012308.21645@unixg.ubc.ca>, ramsay@unixg.ubc.ca (Keith Ramsay) writes:
> In article <303@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:
> >In QM there is a disconnect between the theory, which talks only about
> >probabilities, and experimental observations. It is this disconnect
> >that is the source of the problems of interpretation. One literally
> >does not know what one is talking about when one starts discussing
> >inherently random processes, as opposed to statistical models that result
> >from incomplete knowledge or an incomplete model.
> 
> I'm afraid that all I can get out of these comments (and the ones
> which followed) is that you, seemingly, agree with Einstein that "God
> does not play dice with the universe". 

There is no such thing in mathematics as a random process. This is why
interpretations of the QM are needed.  One has to establish a connection
between a model that predicts only probabilities and experimental
observations. No one knows how to do this because there is no mathematical
framework in which to do it.

> But what if the universe just *has* randomly behaving components,
> anyway, in spite of your wanting a theory which is deterministically
> linked to observations?

Physics has gone beyond what can be formalized. Maybe this
is necessary, but at the least it should be reason for concern and doubt.
I regard the assertion that no more complete theory is possible as
antiscientific. I see no difference between it and religious claims that
certain things are God's will and we cannot understand them. Either
assertion may be true, but the success of science depends on assuming they
are false and trying to figure things out.

> What if it there simply is no correct
> deterministic theory? Then asking for a probabilistic theory to be
> "formalized" so as to take the form of a deterministic theory is
> not necessary.

I am not asking that it be formalized to take the form of a deterministic
theory. I am saying only deterministic theories can be formalized with
existing mathematics. Physicists have a theory that cannot be formalized.
Maybe there exist physical effects that are beyond mathematical formalization.
Maybe there will be some new addition to set theory that allow
nondeterministic models to be formalized. I doubt it, but I certainly cannot
prove that either is impossible. I am only saying the existing state of
affairs is a red flag that a problem exists.

Paul Budnik
From: jgk@osc.COM (Joe Keane)
Newsgroups: sci.physics
Subject: Re: Are redshifts discrete?
Summary: There could be frequency peaks.
Keywords: autocorrelation
Date: 30 Sep 92 04:54:18 GMT
Reply-To: Joe Keane <jgk@osc.com>
Organization: Versant Object Technology, Menlo Park, CA
Weather: sunny, high 81, low 55
Moon-Phase: waxing crescent (18% of full)

In article <1992Sep16.213740.25001@galois.mit.edu>
jbaez@riesz.mit.edu (John C. Baez) writes:
>Redshifts only appear quantized when you are standing at or near the center
>of the concentric shells of galaxies which cause this quantization effect.
>At any other point this effect would not occur in an isotropic manner.

In article <Sep.23.19.48.07.1992.9310@ruhets.rutgers.edu>
bweiner@ruhets.rutgers.edu (Benjamin Weiner) writes:
>But, if we see redshifts as quantized, an observer someplace else won't.
>Diagram:
>
>                  A *
>                    |\
>                    | \
>                    |  \
>                  B *---* C

Well, it seems that everyone took the opportunity to show how you can't have
all the redshifts be perfectly quantized for all observers.  But that's not
what was being claimed!  What they said is that there are peaks in the power
spectrum.

You can do this so that the effect appears to all observers.  The simplest
example is to put all the galaxies at the points of a lattice.  Then everyone
will see frequency peaks.  I don't even need the fact that observers are
likely to be near the lattice points, which increases the effect a bit.  What
Benjamin Weiner's argument shows is that if your lattice has spacing 1/f, you
will also get frequency peaks at f/sqrt(2) and so on.

Clearly having galaxies at lattice points is incredible.  A better model is
the following.  Take some sand with a reasonably uniform grain size, and dump
it into a bucket.  Measure the distances between grains, and then run the
power spectrum.  You will still get frequency peaks.

Having said that, i think the claimed peaks probably don't exist.

--
Joe Keane, amateur physicist
jgk@osc.com (uunet!amdcad!osc!jgk)
Newsgroups: sci.physics