HDTenEightyP/NetNews huggingface dataset:
From: mtj@babar.asd.sgi.com (Michael Jones)
Newsgroups: sci.physics
Subject: Re: TIME HAS INERTIA - ABIAN replies to Beatty
Date: 31 Dec 1992 02:02:18 GMT
Organization: Silicon Graphics, Inc.
Distribution: world
NNTP-Posting-Host: babar.asd.sgi.com

In article <...>, polowin@chem.queensu.ca (Joel Polowin) writes:

|> Abian's a mathematician (of sorts), not a physicist.  He's bucking for
|> the Nobel prize, but he ain't gonna get it in physics, that's for sure.
|> Perhaps we could nominate him to receive the 1993 Nobel for mathematics?
|> :-)

No, for Typography. He's presented ample evidence that THE EXCLAIMATION 
POINT IS NOT NEEDED and is, therefore, REDUNDANT. ;-)

-- 

Be seeing you,      mtj@sgi.com  415.390.1455  M/S 7L-590
Michael Jones       Silicon Graphics, Advanced Graphics Division
                    2011 N. Shoreline Blvd., Mtn. View, CA 94039-7311
Newsgroups: sci.physics
From: dseeman@novell.com (Daniel Seeman)
Subject: Re: bubble in container
Organization: Novell Inc., San Jose, Califonia
Date: Tue, 29 Dec 1992 16:50:04 GMT

In article <1992Dec29.011215.11278@novell.com> dseeman@novell.com (Daniel Seeman) writes:
>In article <1992Dec29.002632.22407@sfu.ca> Leigh Palmer <palmer@sfu.ca> writes:
>>In article <1992Dec28.214917.27561@CSD-NewsHost.Stanford.EDU> Vaughan R. 
>>Pratt, pratt@Sunburn.Stanford.EDU asks several questions about this 
>>fascinating problem, for which I thank him:
>>
>
>Hi,
>
>Let us (for fun of course) add on this extra twist.  Make a glass bubble whose
>inner cavity is filled with air (at say 1 atm).  Then, drop that "bubble" in a
>container of liquid (water would be fine) and close the top.  Assume there is an
>air gap at the top of the container that separates the water surface from the
>top lid of the container. Now, increase the pressure in the container until the
>"bubble" sinks.  As soon as the "bubble" hits the bottom, it breaks (as-
>sume there are a bunch of VERY SHARP pins on the bottom and they rupture the 
>"bubble" on contact).  What then happens to the air that was originally contain-
>ed in the glass "bubble?"  What happens to the overall pressure in the container?
>
>Just thought I would add a bit to the puzzle...
>
As I left yesterday evening I realized this is problem description is not very
clear.  And I got some mail saying that too, so let me try to clear it up...

The container is very shallow, so that when the top of the bubble is pushed to
surface level, the bottom of the bubble is hitting the nails and will burst.
Also, the enclosed gas must be compressible.

But the sinking part is really not central to the problem.  One could just
anchor the bubble to the bottom of the container, fill the container with water,
and close it.  With the help of a friendly gremlin (that lives inside the con-
tainer, of course ;-) the bubble would get bursted.   After the system returns
to equilibrium, what are the differences between the initial and final pressures
in the container?

dks.

ps.  Sorry for the poor description.  My amature status has a way of showing up
(like a glowing beacon in the dark)!
>dks.
From: mcirvin@husc8.harvard.edu (Matt McIrvin)
Newsgroups: sci.physics
Subject: Re: hidden variables
Date: 31 Dec 92 23:26:56 GMT

terry@asl.dl.nec.com writes:

>In article <31DEC199211004292@author.gsfc.nasa.gov>
>rkoehler@author.gsfc.nasa.gov (Bob Koehler) writes:

>> Would someone be so kind as to summarize the argument that hidden variable
>> theories violate causality?

>They don't.  Hidden variable theories simply say that the values controlling
>two "readings" of what was originally a single quantum event (e.g., release
>of two oppositely polarized photons) were fully determined when the event
>happened.  They are very mundane, actually, requiring only that each "piece"
>emanating out of such a quantum event should carry all the information ever
>needed to make accurate statistical predictions about it.

>As John Bell showed, such theories are mathematically incompatible with the
>predictions of ordinary quantum mechanics, which requires "spooky action at
>a distance" to make its predictions. 

[argument that QM doesn't really violate causality deleted]

You're referring to *local* hidden-variable theories of the EPR variety.
Those don't violate causality; but many of them, at least, are excluded
by Aspect's results.  I think he may be referring to the fact that one can
construct hidden-variable theories like Bohm's pilot wave theory that are
not so excluded, but which do violate causality in the sense that real
messages are being transmitted around faster than light on the level
underlying quantum mechanics.  

Of course, such theories remove the original rationale for hidden-variable
theories, which was precisely to get rid of spooky action at a distance.

-- 
Matt McIrvin         I read Usenet just for the	tab damage!
==== =======         = ==== ====== ==== === === === ======= 
Newsgroups: sci.physics
From: sarfatti@well.sf.ca.us (Jack Sarfatti)
Subject: Quantum noise
Organization: Whole Earth 'Lectronic Link
Date: Thu, 31 Dec 1992 09:01:27 GMT


 My questions seem to have drowned in Sarfatti noise. Scott, you had
        said a good quantum no. for a system is that whose operator
        commutes with the Hamiltonian for that system. But you left open the
        question whether the position operator can ever commute with a
        Hamiltonian and if it does, how one can interpret the delta function
        eigenstate of the position operator. This was in context of Liboff's
        statement that the measurement of a varible leaves the system in an
        eigenstate of that system. My other question about transition
        lifetime from the first excited state in a 1-D infinite well has
also
        gone unanswered. I do wish Sarfatti would rather answer such
questions
        than adding all that noise.

        Sushil
One man's noise is another man's signal.
Newsgroups: sci.physics
From: schiffd@tigger.cs.Colorado.EDU (David M. Schiff)
Newsgroups: sci.physics
Subject: Are there plans to perform a quantum eraser type experiment?
Date: 27 Dec 92 01:05:05 GMT
Organization: University of Colorado, Boulder

I was just wondering if anyone has heard of any plans to perform an
experiment that will test the "quantum eraser" effect.  The last thing I
read about this said it was still just a thought experiment but implied
that it might be within experimentalists capabilities in the near future.
Newsgroups: sci.physics
From: bhv@areaplg2.corp.mot.com (Bronis Vidugiris)
Subject: Re: Special relativity is SOOO irritating!
Organization: Motorola, CCR&D, CORP, Schaumburg, IL
Distribution: sci
Date: Tue, 22 Dec 1992 14:27:40 GMT

In article <92Dec18.124837edt.547@neuron.ai.toronto.edu> radford@cs.toronto.edu (Radford Neal) writes:

)Yes and no. Your original assumption that the staff is stopped by the
)wall without being deformed is not just unlikely, but quite
)impossible, according to special relativity. You have two choices -
)either the staff is stopped by the wall, but is deformed, in a very
)real sense, or it is stopped by some other process that leaves it
)undeformed, and just happens to come to rest in front of the wall. The

Anyone for 'The staff and the wall are both blasted into glowing vapor'?  At
somewhere around 3000 meters/second artillery shells made out of even very
hard substances tend to have severe problems with fragmentation of the shell.
(Velocities this high are special experimental designs  even for
artilery, BTW - see Ogorkiewicz  "Design and Development of Fighting
Vehicles' for example, where he talks about Canadians firing a 1 lb
sub-caliber projectile (presumably discarding sabot) at this velocity from a
modified 76.2mm (3") smoothbore gun with an extra barrel attached to the end.

'Deformation' is a very mild word for what happens when an artillery shell
strikes its target.  (Esp elastic deformation).  And we are talking about
velocities on the order of 10^5 times higher and energies 10^10 times higher
here.  Meteor impacts are low speed by comparison, at a mere 25,000 m/s or
so velocity.  Unless you can make the staff and the wall out of something
like neutronium - (how do you keep it from collapsing into a sphere?) -
scenarios of elastic deformation seem rather unrealistic.

)answers in the two cases are different. In the first cases, the rod
)does rebound and hit the hatch, but this rebound is not in any sense
)"virtual" - it is just as real as the rebound of any other compressed,
)elastic object. In the second case, there is no rebound, and you can't
)even close the hatch to start with.
From: wolf@doppel.first.gmd.de (Wolfgang Koehler)
Newsgroups: sci.physics,news.groups
Subject: Re: Atropos needed (was: Reluctant call for moderation of sci.physics)
Date: 23 Dec 92 21:27:17 GMT
	<1992Dec16.075642.19770@murdoch.acc.Virginia.EDU>
	<COLUMBUS.92Dec16103152@strident.think.com>
	<1992Dec20.202022.26659@galois.mit.edu>
Reply-To: wolf@first.gmd.de
Followup-To: sci.physics
Organization: GMD-FIRST, Berlin
In-reply-to: jbaez@riesz.mit.edu's message of 20 Dec 92 20:20:22 GMT


Since the clouds over sci.physics are growing I thought about jumping into
this discussion.
I always felt that the traffic in this newsgroup is too large and the amount
of garbage one has to shuffle to find out something interesting is constantly
growing (garbage = Abian, Hanna-Maria, Number of religious physicists...)
So, I would appreciate some moderation.
However, on the other hand this group lives from the broad spectrum of
many *very different* ideas and controvers discussion (also flames included)
and this makes me loving it (mostly as a reader).
The worst thing that could happen with some rigorous moderator it
would turn out as an electronic preprint reviewer.
If I read the cited post correctly these fears are not groundless.
(I should add that I appreciate J.Baez postings.)

In article <1992Dec20.202022.26659@galois.mit.edu> jbaez@riesz.mit.edu (John C. Baez) writes:
  
[partially deleted]

   I guess I would feel comfortable having several moderators with
   good taste and considerable freedom to run things, who would be loose enough to
   keep the newsgroup FUN and strict enough to kick off *most* postings
   with low physics content and all postings with blatant misinformation, flames,
   and stuff that smells too strongly of crackpottery.

   For example: 
   1) No Abian, ever.
Total agreement.

   2) Sarfatti only if cleans up his act.
Also my general opinion.

   3) Discrete physics only if there are very concrete proposals.
At this point I would be cautious.

   4) Interpretation of QM only if there is something NEW to say (e.g. the
   stuff Weiss mentions below).
No.

   5) Data about the SSC, but no policy disputes.
Yes.

   6) Nothing about religion, pro or con, at all.
Ok.

I hope some other readers like me will join this discussion.

wolf

Merry Christmas to all physicists !


--
-------------------------------------------------------------------------
    ... always look on the bright side of life ... (Monty Python)
-------------------------------------------------------------------------
Wolfgang Koehler                               wolf@first.gmd.de
GMD-FIRST an der TU Berlin              German National Research Centre 
Tel. (Berlin 030/049) 6704-2650              for Computer Science



Xref: sparky sci.physics:21697 news.groups:24886
From: sichase@csa3.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics,news.groups
Subject: Re: Reluctant call for moderation of sci.physics
Date: 23 Dec 1992 13:31 PST
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
Distribution: world
NNTP-Posting-Host: 128.3.254.198
News-Software: VAX/VMS VNEWS 1.41    

In article <MATT.92Dec15152210@physics.berkeley.edu>, matt@physics.berkeley.edu writes...

>Incidentally, I might not have stressed this enough in my original
>posting: we can't have a moderated newsgroup without a moderator.  It
>is important that we get some volunteers for that position if we want
>anything to happen.

This seems to be the crux of the matter.  Personally, I will vote for or 
against the new group depending mostly on who has volunteered to moderate
it.  So I want to know this *first*, before we have a great deal more
discussion of the details.  The first time this idea was (informally)
proposed, some of the volunteers for moderators were the people who generate
most of the material that I would want to exclude in the first place.  

So let's here some public commitments.  Who's going to run this show?

-Scott
--------------------
Scott I. Chase			"It is not a simple life to be a single cell,
SICHASE@CSA2.LBL.GOV		 although I have no right to say so, having
				 been a single cell so long ago myself that I 
				 have no memory at all of that stage of my 
				 life." - Lewis Thomas
Newsgroups: sci.physics,sci.math
From: jmc@SAIL.Stanford.EDU (John McCarthy)
Subject: Re: Why no Nobel Prize in Math?
Reply-To: jmc@cs.Stanford.EDU
Organization: Computer Science Department, Stanford University
Date: 30 Dec 92 22:27:41

In article <C03zDG.JM2@knot.ccs.queensu.ca> hausner@qucis.queensu.ca (Alejo Hausner) writes:

   Xref: CSD-NewsHost.Stanford.EDU sci.physics:44672 sci.math:38098
   Newsgroups: sci.physics,sci.math
Path: CSD-NewsHost.Stanford.EDU!stanford.edu!agate!spool.mu.edu!uunet!cs.utexas.edu!torn!news.ccs.queensu.ca!hausner
   From: hausner@qucis.queensu.ca (Alejo Hausner)
   Sender: news@knot.ccs.queensu.ca (Netnews control)
   Organization: M.Sc, C.S, Queen's, Kingston, Canada.
   Date: Thu, 31 Dec 1992 05:32:04 GMT
   Lines: 13

   One of my mathematics professors once told me that the reason
   there are Nobel prizes in mathematics, even though there are
   prizes in physics, chemistry, etc, is that a mathematician had a
   love affair with Alfred Nobel's wife.  He swore the story was
   true.  It seemed unlikely to me at the time that a mathematician
   would have a love life, much less an adulterous one, but I've
   since realized they're human too.

   My question is, what was the mathematician's name?  I vaguely
   remember it being a multiple name.

   Alejo Hausner (hausner@qucis.queensu.ca)

It was supposed to have been Gustav Mittag-Leffler.  However, the
_Britannica_ article on Nobel says "He never married".
--
John McCarthy, Computer Science Department, Stanford, CA 94305
*
He who refuses to do arithmetic is doomed to talk nonsense.

Newsgroups: sci.physics
From: palmer@sfu.ca (Leigh Palmer)
Subject: Re: Christmas problem
Organization: Simon Fraser University
Date: Wed, 23 Dec 1992 20:41:06 GMT

In article <8456@charon.cwi.nl> vanloon@cwi.nl (Maarten van Loon) writes:

>1. A glass of water is standing on a balance.
>   At a certain moment someone puts a thermometer in the glass,
>   without touching the glass and still holding the thermometer
>   in his (or her) hand. Question: does the balance show a
>   heigher or lower weight or does it indicate the same weight?

The weight measured by the balance will include the (transmitted) reaction
to the bouyant force on the thermometer, equal to the weight of the volume
of water displaced.

>2. An astronout takes a bottle filled half with whine with him
>   in space. What does he see when he looks to the bottle in
>   space?

I don't know what a half-filled bottle of wine would look like in space,
but if one drops a bottle it looks "sloshed" while in free fall. It's my
guess that "sloshed" is as good an answer as you will get. If the bottle
were to remain absolutely unperturbed the minimum energy condition would 
be determined by surface tension, and the minimum surface condition 
corresponds pretty much to the shape the liquid takes in a more mundane
environment. That is, ultimately an undisturbed half-full bottle of wine 
would have the wine at one end or the other and a flat air-wine interface.

MX&aHNY,

Leigh
From: swarner@bbs1984.chi.il.us (Steve Warner)
Newsgroups: sci.physics
Subject: Searching gravity info:
Date: 20 Dec 92 12:00:56 CST
Organization: Not an Organization

         Good morning all...
    Some friends and I have a running interest in matter physics, and 
we are in the process of gathering information on current gravity 
theory. We are intrigued by the notion of "Dark Matter" and the role 
it plays in both Cosmology and Physics. 
    In a recent article written by Corey S. Powell, entitled, "Machos 
or Wimps; Astronomers stalk the invisible cosmic majority" (Scientific 
American, January 1993, pg 27)....John A Bahcall of the Institute for 
Advanced Study in Princeton, writes; "the dark matter problem may be a 
sign that some fundamental aspect of physics, such as the theory of 
gravity, demands revision." 
    A statement such as this, tends to heighten ones interest and 
thirst for follow-up information....which of course, I'm hoping someone 
"out there" can supply reference to. Has anyone seen published information on 
 current trends in gravity theory, from books, periodicals, journals or 
letters? Any help would be greatly appreciated.
Thanks in advance....
 
Steve Warner    Swarner.@bbs1984.chi.il.us
------------------------------------------
Get your facts ft, and then you can distort 
them as much as you please.       -Mark Twain-  
Newsgroups: sci.physics,sci.electronics
From: smjeff@lerc05.lerc.nasa.gov (Jeff Miller)
Subject: Re: Lasers/collimated light in RGB? (full repost)
Organization: NASA Lewis Research Center, Cleveland Ohio
Date: Wed, 30 Dec 1992 18:07:13 GMT

In article <1992Dec30.161427.19053@radian.uucp> jlange@radian.uucp (John Lange) writes:
>My first posting was truncated.  Here's how it should have read.
>
>In nightclubs I have recently seen light effects which apparently
>use bright red, green, and blue lasers which are modulated with 
>mirrors (I think) to do interesting things like project color 
>images on a wall.  The red could be a simple He-Ne laser, but what 
>about the green and the blue?  I know these light sources can be 
>made with expensive and sophisticated lasers, but how could this 
>be done as simply and inexpensively as possible?  Is it possible 
>that these really weren't "lasers" and were instead some sort of 
>collimated and color filtered bright light sources? 
[stuff deleted]

Aren't you describing a projection TV?

>


-- 
Jeffrey H. Miller     smjeff@lerc05.lerc.nasa.gov
Sverdrup Technology, NASA Lewis Research Center Group, Cleveland, Ohio

favorite book title: Attack of the Deranged Mutant Killer Monster Snow Goons
Newsgroups: sci.physics
Subject: Re: Tapping a pop can
From: wglad@nexus6.uu.holonet.net
Date: Wed, 23 Dec 92 07:06:25 -0600 (CST)
X-Mailer: rnMac Buggy, I mean Beta, Test Version


>From article <BzKMK1.G7p@usenet.ucs.indiana.edu>, by 
mkohlhaa@silver.ucs.indiana.edu (mike):
>> Hello.  A friend and I were recently discussing the often-performed practice
>> of tapping the lid of a pop/beer can after it has been dropped, which 
>> thereby relieves the pressure within and your beverage doesn't explode.
>> 
>> Anyhow, I was pondering this and with my *limited* knowledge of physics this
>> made no sense to me.  Does anyone know if this really works, and if so, 
>> can give a physics explanation for it?



Whenver I drop an open pepsi, I notice that all the fizz is gone when I pick
it up. This might support the tapping the can technique (??). I am suprised
noone else mentioned this. Of course I might be the only one here who drops
his soft drinks on a regular basis <drooling>       :)


												Bill

____________________________________
William Gladnick (504)522-6607
wglad@nexus6.uu.holonet.net
Newsgroups: sci.physics
From: paul@mtnmath.UUCP (Paul Budnik)
Newsgroups: sci.physics
Subject: Re: QM non-causal?
Date: 22 Dec 92 17:23:06 GMT
Organization: Mountain Math Software, P. O. Box 2124, Saratoga. CA 95070

In article <1992Dec21.134142.3455@oracorp.com>, daryl@oracorp.com (Daryl McCullough) writes:
> [...] 
> I'm not sure what you mean by "an objective measure". The statistics
> is definitely *not* objective, in that different observers might use
> different weights on the possibilities.

I mean it is based on objective evidence. It is not different from QM in
this respect. The difference is in what the statistics refer to. In classical
mechanics they measure our ignorance and knowledge about a single objective
physical state.

> [...] 
> Why does it preclude it? Why isn't it possible to assume that we are
> in some definite world, and the wave function measures our lack of
> knowledge of which world we are in? Of course, the wave function does
> not represent our lack of knowledge in the form of a probability, but
> in the form of a probability amplitude.

I happen to think that this is the case. However this assumption is in
direct conflict with the assumption that QM is a complete theory. I think
there is an objective physical state of a different nature than anything
in either or classical or quantum mechanics and that the wave function
provides a limited measure of our knowledge of that state. 

>[...]
> I don't know why you think the physical existence of many different
> worlds is any more necessary in the quantum case than in the classical
> case of statistical mechanics.

I only think it is if you assume the probabilities of QM are irreducible,
i. e. not the measure of our state of ignorance of a more complete
objective reality, but as a *complete* description of objective reality
within the domain that QM applys to. If you are in disagreement with
this dogma of QM there is no difference between classical statistical
mechanics and quantum mechanics in this respect. If you do not disagree
with this then I think you do have a problem. You do not need many worlds
to resolve it but you need something and I have no idea what that
something could be.

> [...] 
> I disagree that Everett was doing "pointless mathematics". What the
> mathematics shows is the coherence of quantum theory. [...]

I may be forced to read Everett yet. I did not mean to imply that he was only
doing pointless mathematics. I suspect that he did not address the problem
of relating theory to experimental observations but only obscured
*this problem* with pointless mathematics. You may be correct that aspects of
his work are valuable contributions. You apparently agree that he has
not adequately addressed the interpretation problem in QM:

> I don't agree that Everett's work has closed the book on
> interpretations of quantum mechanics by any means, but I
> believe that it is an important contribution.
> [...] 
> I'll have to postpone a rebuttal to [Bell's criticism of Everett]
> until I reread his essay.

I look forward to your comments on this.

Paul Budnik
Newsgroups: sci.physics,rec.arts.startrek.tech
From: ewright@convex.com (Edward V. Wright)
Subject: Re: Accellerating Spaceship (yet another bird in a plane)
Date: Wed, 23 Dec 1992 20:31:29 GMT
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <1992Dec21.92013.53@stephsf.com> wengland@stephsf.com (Bill England) writes:

>  Antimatter is about as weird and funky as you can get. AM has 
>  been predicted to have negative mass (impies negative inertia and
>  repulsion from normal gravity wells).  

No, antimatter has perfectly normal, positive mass.  What you're
thinking of is "negative matter," described in a speculative
article by Robert Forward. Because it has negative mass, negative
matter would repel all other matter (including negative matter).
(There is no evidence, however, that negative matter exists.