HDTenEightyP/NetNews huggingface dataset:
From: brandt@cco.caltech.edu (William N. Brandt)
Newsgroups: sci.physics
Subject: Schrodinger hydrogen atom partition function divergence
Date: 1 Jan 1993 15:41:50 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: sandman.caltech.edu
Summary: Schrodinger hydrogen atom partition function divergence

I have a question about the partition function of the Schrodingert
hydrogen atom. The energy eigenvalues for such an atom go like
13.6 ev * (1/n^2) so if we compute Z, the partition function,

        Z = Sum[g_n * exp(-E_n/(k*T))]

(g_n is the degeneracy of the nth state, k is Boltzman's constant,
and T is tempertature) we notice that E_n tends to zero so the
exponential tends to 1 so we get an explosively diverging series
since the g_n's tend to increase.

Since Z is not a QM observable this looks at first sight not to be a
problem. However, since the population of a given level goes as
1/Z (and this is an observable) this would seem to indicate that
the Schrodinger hydrogen atom cannot contain an electron.

I know astronomers resolve this problem by lopping off the partition
function sum when the bohr radius of the nth state is approximately
the mean atomic spacing, since EM effects would prohibit higher
states. However, is there a fundamental resolution to this
apparent problem? Or is it not really a problem and why? I notice
that the rigid rotator and harmonic oscillator partition functions
nicely converge - are there other examples of systems with divergent
partition functions (I assume most atoms will have similar problems,
for example).

Does the Dirac equation perhaps remedy this situation, since
eventually 'tickling' of high n states by QM vacuum fluctuations
will make very high n states impossible? Or is this not the case
and why?

I would be grateful if you could send email as well as posting.

Thank you, Niel Brandt

P.S. Any references to this potential problem would also be appreciated.
P.P.S. Thank to all for answering my previous Feynman graph question.

Newsgroups: sci.physics
From: scip1061@nuscc.nus.sg (Marc Paul Jozef)
Subject: Re: Boswell ...
Organization: National University of Singapore
X-Newsreader: Tin 1.1 PL4
Date: Wed, 30 Dec 1992 07:34:32 GMT

sarfatti@well.sf.ca.us (Jack Sarfatti) writes:
: 
: ...  but one these days
: "Pow! a psychic whammy - a telepathic pop! Beware the Wrath of SAR!
: Sweet Dreams, Dave! Who do the quantum voodoo? Control of
: action-at-a-distance is quite practical in may cultures, African,...
                                ^^^^^^^^^

             HAHAHA
Xref: sparky sci.physics:21889 sci.math:17512
From: columbus@strident.think.com (Michael Weiss)
Newsgroups: sci.physics,sci.math
Subject: Re: The accelerating charge meets the EPR paradox.
Date: 30 Dec 92 13:13:58
Organization: Thinking Machines Corporation, Cambridge MA, USA
	<1992Dec21.084200.456@galois.mit.edu>
NNTP-Posting-Host: strident.think.com
In-reply-to: jbaez@riesz.mit.edu's message of Mon, 21 Dec 92 08:42:00 GMT

In article <1992Dec21.084200.456@galois.mit.edu> jbaez@riesz.mit.edu (John
C. Baez) writes: 

   The business about "inversion of statistics" for the blackbody radiation
   seen by an accelerating observer in 2+1 dimensions seems utterly bizarre
   to me and my first instinct would be to attempt to show that the
   calculation was done incorrectly... but being too lazy, I will simply
   shrug and add it to my list of things to hope I eventually figure out.

Glad to hear it seems bizarre to you too!  Takagi writes: "This result has
been confirmed by Unruh [24], and also found independently by Stephens
[18]."

As for the connection with Huygens' principle, he writes: "With some
technical preparation, such as the KMS condition and the
fluctuation-dissipation relation, one can show that this circumstance is
closely related to the present problem of the apparent inversion of
statistics [14,21]."

The references, in case anyone feels intrigued enough to chase them down:

[14] Ooguri, H. "Spectrum of Hawking Radiation and the Huygens Principle."
     Phys. Rev. D, 33 (1986):3573-3580
[18] Stephens, C.R. Private communication
[21] Takagi, S. "Vacuum Noise and Stress Induced by Uniform Acceleration."
     Prog. Theor. Phys. Suppl 88 (1986):1-142
[24] Unruh, W.G. "Accelerated Monopole Detector in Odd Spacetime
     Dimensions" Phys. Rev. D 34 (1986):1222-1223
Xref: sparky sci.physics:22006 sci.math:17581
From: mwmv@athena.cas.vanderbilt.edu (Michael Mogensen-Vermillion)
Newsgroups: sci.physics,sci.math
Subject: Re: Why no Nobel Prize in Math?
Date: 1 Jan 93 20:18:15 GMT
Organization: Vanderbilt University Mathematics Department

In article <1i1qs8INNrfi@mtha.usc.edu> bruck@mtha.usc.edu (Ronald Bruck) writes:

(much discussion of urban legends about why Nobel snubbed mathematics
deleted)

>The astronomer went on to say that the real reason for the exclusion
>of astronomy was that in those days it was considered a branch of physics,
>which Nobel had already provided for.  Similarly, I have read that the
>real reason for the exclusion of mathematics is that it was not considered
>a practical science; that Nobel excluded _theoretical_ sciences.

*Economics* is a _pratical_ science ?!?!!  Now I'm insulted.

Mike
Newsgroups: sci.physics,alt.sci.physics.new-theories,alt.paranormal,sci.skeptic
From: sarfatti@well.sf.ca.us (Jack Sarfatti)
Subject: re:Baez's comment on Budnik's QM
Organization: Whole Earth 'Lectronic Link
Date: Wed, 23 Dec 1992 06:16:56 GMT


From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: QM non-causal?
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Mon, 21 Dec 92 19:12:10 GMT

In article <440@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:

>I'm happy to hear you are not convinced yet. It only sounds confusing to
>me. The problem in quantum mechanics has always been how do we connect the
>mathematics of the theory to the observations in experiments. I do not
>think anyone has a resaonable answer to this question. I suspect that
>Everett only succeeds in obscuring the problem with some pointless
>mathematics.

Please read his work before critiquing it, huh?
I agree with Baez's remark directly above - and ask Budnik once again
to explain how he would measure "delays" in his critiquie of experiments
testing Bell's inequality.
Newsgroups: sci.physics,sci.math
From: jcf@world.std.com (Joseph C Fineman)
Subject: Re: Why no Nobel Prize in Math?
Organization: The World Public Access UNIX, Brookline, MA
Distribution: na
Date: Sat, 2 Jan 1993 04:12:03 GMT

dbriggs@zia.aoc.nrao.edu (Daniel Briggs) writes:

>In article <1992Dec31.145732.19319@cbnewsl.cb.att.com>
>  wjh@cbnewsl.cb.att.com (william.j.hery) writes:
>  Among other things, COYOTE
>kept summary statistics of the sales activities of all their members, as
>ammunition for their lobbying battles.  There was always a big correlation
>between sales and a major convention in San Francisco.  Until the AMS had
>a major meeting there, that is.  COYOTE had its worst weekly sales ever!

About 25 years ago, when I was at one of the big meetings of the
American Physical Society, a friend heard one bellboy say to another
in the hotel: "Those physicists must be a bunch of queers.  Not one of
them has asked me to get him a woman."  In fact, at that time, gay
physicists were (to my knowledge) rather scarce.  But I am willing to
believe that a disproportionate number of them were faithful to their
wives.

*Biologists*, on the other hand.... %^)
-- 
        Joe Fineman             jcf@world.std.com
        239 Clinton Road        (617) 731-9190
        Brookline, MA 02146
Newsgroups: sci.physics,sci.math
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: The accelerating charge meets the EPR paradox.
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Mon, 21 Dec 92 08:42:00 GMT

The business about "inversion of statistics" for the blackbody radiation
seen by an accelerating observer in 2+1 dimensions seems utterly bizarre
to me and my first instinct would be to attempt to show that the
calculation was done incorrectly... but being too lazy, I will simply
shrug and add it to my list of things to hope I eventually figure out.

As for the following (Michael writes:)

"It is well known that Huygens' principle is valid only in even-dimensional
spacetimes."  Huygens' principle (in case anyone who doesn't know has
tagged along this far) tells us that if we make a sharp pulse disturbance
to a field (a flash of light, a hand-clap) the pulse remains sharp as it
spreads out--- so we see a flash and not a gradual increase/decrease in
illumination.  Contrast this with dropping a stone in a pond.  (There is,
incidentally, a nice intuitive argument that *because* Huygens' principle
holds in 3+1 dimensions, it will fail in 2+1.  I don't know a simple
intuitive reason though why it should hold in 3+1 dimensions.)



Well, the simplest reason way to check that Huyghen's principle holds in
3+1 dimensions is to show that the distribution delta(t^2 - r^2)
satisfies the wave equation in this case.  Here r^2 = x^2 + y^2 + z^2 as
usual, and I leave it as a challenge to work it out: show that the
second time derivative of this distribution is the same as its Laplacian
(best done in spherical coordinates).  (The trick with this exercise is
to figure out how to take derivatives of such a beast.  Carefully!)
This distribution is supported on the lightcone, and if one brutally
multiplies it by theta(t) (which is zero for t < 0 and one for t > 0)
one gets the elementary retarded solution of the wave equation.  The
fact that this lives on the lightcone is Huyghen's principle.  

Since it's the holiday season I will be nicer than usual; to do the
above one needs to know what something like delta(f(x)) really means,
and they don't usually teach this well enough.  Say f(0) = 0 and
f'(0) > 0.  What's the difference (near x = 0) between delta(f(x)) and
the good old Dirac delta(x)?  Well, delta(f(x)) only makes sense
integrated against a smooth test function, and if one does the integral
by a change of variables one sees that delta(f(x)) = delta(x)/f'(x).
Makes sense: the faster f(x) changes with x, the skinnier the delta
function delta(f(x)) is, so one must divide by f'(x).  :-)  (Yes, friends,
this CAN be made rigorous.  Read Gelfand's book Generalized Functions.)
So one can show  

delta(t^2 - r^2) = delta(t - r)/2r + delta(t + r)/2r

Now there is a much more highbrow and slick approach due to Lax...
From: atems@igor.physics.wayne.edu (Dale Atems)
Subject: Re: Budnik's proposed experiment (was Re: temporally undecided states)
Organization: Wayne State University, Detroit, MI
Date: Mon, 4 Jan 1993 00:09:08 GMT

In article <466@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:
>
>Bell's inequality is *only* predicted to hold if the relevant events
>are space-like separated. The relevant events are the correlated detections
>and the experimental manipulations that alter the probability of joint
>detections. It is easy to generate results that violate
>the mathematical relationship of Bell's inequality using local processes.
>Measuring the delays is crucial. Without such a measurement you cannot
>claim Bell's inequality is violated.

Okay, the unfamiliar element to me here is the changing of the
polarizer angles while the wave function is passing through, thereby
changing the quantum state after the photons have been emitted. As I
said, I've lost touch with this field. Any references you can give to
help me out?

>Well QM does not predict these delays it puts constraints on them.
>Thus it still predicts that locality is violated. If these delays turn
>out to be consistent with locality, as I expect they will be, then QM is
>not just incomplete, it is false. 

To comment intelligently on this I would have to know exactly how you
are defining locality operationally -- this seems to be hidden inside
the details of the statistical analysis you are performing to estimate
the time at which the probability of joint detections changes.

Still if QM does set the constraints you say, then the experiment is
worth doing. My question would be: why do you expect that locality, as
you define it, will be upheld?

>However, it is only one aspect of QM
>that is tested by measuring these delays: the assumption that the wave
>function changes instantaneously when a measurement is made.

What do "quantum eraser" experiments tell us about this assumption? I
was under the impression from someone's recent post that some
experimental work on this had already been done.

>This assumption is almost never used to solve practical problems in QM.
>Thus the experiments will not call into question anything of practical
>significance in physics.

I was exaggerating my case to make a rhetorical point. A theory that
is incomplete in the "strong" sense (i.e. is incapable of predicting
the results of an actual experiment) is still not satisfactory.
Clearly we agree on this.

>On the other hand, if these delays are consistent with
>locality these experiments will open a window on an entirely new class
>of physical phenomena. If the wave function does not change instantaneously
>then it undergoes some nonlinear structural change that is completely
>outside of any existing theory. Understanding the structure of these
>changes could be as important as QM itself. Bell's inequality may open
>an experimental window on a new class of physical phenomena.

At the moment, of course, this is pure speculation.

------
Dale Atems
Wayne State University, Detroit, MI
Department of Physics and Astronomy
atems@igor.physics.wayne.edu
Newsgroups: sci.physics
From: schumach@convex.com (Richard A. Schumacher)
Subject: Re: TIME HAS INERTIA - NewScientist Article
Organization: CONVEX Computer Corporation, Richardson, Tx., USA
Date: Mon, 21 Dec 1992 23:03:54 GMT
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 <93e1VB1w165w@dorsai.com> shire@dorsai.com (Kenneth Shire) writes:

>Sad indeed!  Though I am not by profession a physical scientist, it seems 
>that the it was not simply that the observational evidence didn't jibe 
>with Wegener's theory that did it in.

...

>  My point is that I believe it 
>was the *apparent* impossiblity of continental land masses moving *at 
>all* that did in Wegener's theory.  That, coupled fatally with his lack 
>of academic credentials in geology, of course.  In other words, it was an 
>inability to "see" coupled to a very unscientific prejudice that 
>called for not any-old but a specific university degree for a man's 
>theory to be taken seriously when it seemed to fly so thoroughly in the 
>face of both common sense and the common "wisdom" of the academics who 
>control what is "true" at any one time within essentially academic 
>communities of thought.  


But when evidence of sea-floor spreading starting appearing,
continental drift caught on pretty quickly. Wegener's ideas were
rejected at first because he had no evidence for a mechanism, not
because he didn't have the right credentials. If he had been able
to present direct measurements of spreading rates, or data on the
symmetry and age of magnetic reversals on either sides of spreading
centers his ideas would have been accepted quickly. Indeed, such data
are so compelling that the idea is an obvious conclusion.

Recall that Einstein was 
working as a patent clerk when he published special relativity, 
a far more revolutionary idea than continental drift which
nevertheless quickly won wide acceptance. What of all those
academics controlling what was thought true at the time in physics? 
Maybe they exist only in geology.



Newsgroups: sci.physics,sci.math
From: levine@symcom.math.uiuc.edu (Lenore Levine)
Subject: Re: Why no Nobel Prize in Math?
Organization: University of Illinois at Urbana
Distribution: na
Date: Fri, 1 Jan 1993 19:45:22 GMT

dbriggs@zia.aoc.nrao.edu (Daniel Briggs) writes:

>In article <1992Dec31.145732.19319@cbnewsl.cb.att.com>
>  wjh@cbnewsl.cb.att.com (william.j.hery) writes:
>>hausner@qucis.queensu.ca (Alejo Hausner) writes:
>>>       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.
>>
>>?????? Is that because you think that all mahtematicians are 1) asexual,
>>2) homosexual, 3) perfect moral speicmens according to some moral
>>code that you recognize, 4) prudes, or 5) just don't have the time
>>because they spend so much time doing mathematics?????

>Well, I can add a mildly amusing bit of annecdotal evidence which suggests
>that there might be a grain of truth to the above.  (Take the implications
>with a few smileys, but the story *is* true, albeit more than a decade
>old.)

>A friend of the household, before I moved in, was active with COYOTE in the
>SF Bay Area.  I can't remember the acronym expansion, but it is (was?) an
>organization to promote legalized prostitution.  Among other things, COYOTE
>kept summary statistics of the sales activities of all their members, as
>ammunition for their lobbying battles.  There was always a big correlation
>between sales and a major convention in San Francisco.  Until the AMS had
>a major meeting there, that is.  COYOTE had its worst weekly sales ever!

Does that really mean that male mathematicians are less sexual? Or
merely less interested in women who have no sincere romantic interest in
them?
From: doi@tartarus.uwa.edu.au (Daniel Kuan Li Oi)
Newsgroups: sci.physics
Subject: Re: can sound waves boil water?
Date: 23 Dec 1992 13:27:02 GMT
Organization: The University of Western Australia
NNTP-Posting-Host: tartarus.uwa.edu.au

eng10370@nusunix1.nus.sg (CHEW JOO SIANG) writes:

>I was thinking of this the other day - we all know that a microwave oven
>works by resonating the water molecules at its natural frequency - this
>causes a rise in its temperature. The question is, can we do the same
>with sound waves - using it to resonate the water molecules. I know that
>you need incredibly high frequecies to achieve it but is the concept
>sound theoretically?

>Kumaresan a/l Kanagasabai
>eng10370@nusunix1.nus.sg 

	Probably not in the same way as with microwave ovens.  The
problem might be getting adequate efficiency both in producing the sound
and in the absorbtion.  

	Although bulk heating may not be feasible, it has been measured
that hot spots in a liquid being exposed to high intensity ultrasound
can reach thousands of degrees centigrade.  This was due to bubbles
forming and collapsing rapidly so to compress the gas inside by enormous
amounts.

	Hope it isn't too inaccurate.

				Daniel Oi
				University of Western Australia


Disclaimer: I'm only a first year. What's your excuse.

Newsgroups: sci.physics
From: kepley@cs.unca.edu (Brad Kepley)
Subject: Re: Scientific Truth Is Not Found in Threats
Organization: University of North Carolina at Asheville
Date: Tue, 29 Dec 1992 23:50:31 GMT

Bravo!  Sarfatti's threats were the most incredible thing I have ever seen.
I thought it was a joke!  You have a Nazi mentality Mr. Sarfatti.  Add me
to the list of those you intend to sue I guess!  If anyone requires legal
aid to protect themselves against legal action from anyone on the Net, I
hope we can all pitch in to help them.  I think we need to start a news 
group concerned with providing aid to anyone sued by one of these fascists.
<cooling down now>
From: columbus@strident.think.com (Michael Weiss)
Newsgroups: sci.physics
Subject: Charter for sci.physics.moderated?
Date: 23 Dec 92 12:48:09
Organization: Thinking Machines Corporation, Cambridge MA, USA
NNTP-Posting-Host: strident.think.com


As someone who is *not* a professional physicist, but enjoys reading and
occasionally posting to sci.physics, I wonder just what people think
belongs on sci.physics.moderated?  Or more precisely, what doesn't belong?

Names are important.  Are we talking about sci.physics.moderated, or
sci.physics.research?  Are discussions at an elementary level (high school
mechanics, even) welcome?  Lighter side stuff?  Gripes, groans, and raves
over textbooks?  Folklore, history, anecdotes?  I greatly enjoyed reading
the posts a while back of people who had worked with the early bubble
chambers.  I liked the "GR without Einstein?" thread, precisely because it
didn't go on too long.

I would look forward to reading a sci.physics.moderated with the sole
charter of eliminating:

1.  Threads that have gone stale, whatever the topic.  (I don't simply mean
    "Re: ...", which kill files can take care of, but any rehash.)
2.  Posts that wouldn't happen if the poster read the FAQ (kudos to Scott,
    by the way.)  (I don't mean posts that add to a topic already in the
    FAQ, or that take exception to something stated in the FAQ.)

There may *also* be a need for a sci.physics.research with a much more
restricted charter.

And Dale, I *know* sci.physics.moderated is not meant to replace
sci.physics.  The question is, what would make a good new newsgroup?
From: mcirvin@husc8.harvard.edu (Matt McIrvin)
Newsgroups: sci.physics
Subject: Re: Are there plans to perform a quantum eraser type experiment?
Keywords: quantum,measurement
Date: 1 Jan 93 04:34:56 GMT

markc@smsc.sony.com (Mark Corscadden) writes:

>(and that mystery question is ...)

>"Why do people who are so interested in this subject fail to obtain even
> an elementary understanding of a major alternative like MWI before
> rejecting it out-of-hand?"

The answer to the mystery question is:  Because the popular literature is
so unequivocal in its presentation of wrong descriptions of the
interpretation.  I've seen one lucidly miswritten account, in Paul Davies' 
book _Other Worlds_, that actually trots out the Flatland analogy to 
describe the extra spatial dimensions in which the "other universes" 
are supposed to reside.  Our universe is described as being embedded in
a superspace with an infinite number of spatial dimensions, presumably a 
garbled reference to Hilbert space.  I'd forgive someone who read such  
a thing and assumed that the Everett interpretation involved some kind
of bizarre cosmological rending in twain in place of collapse, even in
the absence of further research.

-- 
Matt McIrvin         I read Usenet just for the	tab damage!
==== =======         = ==== ====== ==== === === === ======= 
Newsgroups: sci.physics
From: menon@ftp.phy.uab.edu (penrose)
Subject: relativistic QM
Organization: University of Alabama at Birmingham
Date: Sun, 3 Jan 1993 23:08:05 GMT

I am looking for a good text book in Relativistic QM which uses mordern
techniques and also discusses fundamental issues and the formulation in
great detail. Preferably the book is mathematically self contained.
Please respond by mail.
Thx in advance,
Govind

Newsgroups: sci.physics
From: rkoehler@author.gsfc.nasa.gov (Bob Koehler)
Subject: hidden variables
News-Software: VAX/VMS VNEWS 1.4-b1  
Organization: CSC System Sciences Division
Date: Thu, 31 Dec 1992 16:00:00 GMT

 Would someone be so kind as to summaries the argument that hidden variable
theories violate causility?  It's been a long time since grad school, and this
has been scratching at the front of my mind recently, while I know the answer
lies burried deep in the back.  I just haven't had the time to wade through my
books.

Thanks in adavance.

------------------------------------------------------------------------------
Bob Koehler                     |   Any illusion to these opinions being other
rkoehler@author.gsfc.nasa.gov   |   than just mine alone is just that.

 " Life is life, and fun is fun, but it's all so quiet when the goldfish die. "
                         - Blixie

Newsgroups: sci.physics