HDTenEightyP/NetNews huggingface dataset:
From: gilligan@bldrdoc.gov (Jonathan Gilligan 303-497-3861)
Newsgroups: sci.physics
Subject: Re: sea waves
Keywords: waves
Date: 19 Aug 92 01:43:34 GMT
Organization: National Institute of Standards and Technology

In article <25584@dog.ee.lbl.gov> sichase@csa2.lbl.gov writes:
|>In article <boudouvi.714144870@theseas>, boudouvi@ntua.gr (Andreas Boudouvis) writes...
|>> 
|>>A summer-time question:
|>>Why the crests of sea waves are white (esop. when the waves 
|>>break at the seashore?)
|>
|>Neat question.  The answer must be "turbulence."  Presumably, the turbulant 
|>water on the crest scatters light without preference  to wavelength (at least
|>in the visable), leading to white caps.  I am no expert on turbulence, but
|>I believe that it is characterized by fluctuations on many length scales,
|>which leads to the scattering of all wavelengths.  

I wouldn't think that the water on top of a wave would be that
turbulent.  There's just not anything to stir it up until after it
breaks.  If I look at a fleck of seaweed or foam on a wave (that is,
when I get to the ocean) I don't see it being stirred up by turbulence
until the wave breaks. I think it's more plausible that the scattering
is off bubbles in the water. The surf produces myriad tiny bubbles,
which then scatter isotropically at all (visible) wavelengths and look
white to the extent there are enough bubbles that the scattering
happens in a length short compared to absorption of red light by the
seawater.

---Jon
-- 

Disclaimer --- The government probably disagrees with my opinions.
Xref: sparky sci.physics:12716 sci.astro:8851 sci.philosophy.tech:2953 talk.religion.misc:13852
From: elee969@elroy.uh.edu (Brown, William J.)
Subject: FTL Microwave Signal
News-Software: VAX/VMS VNEWS 1.41    
Organization: University of Houston
Date: Thu, 20 Aug 1992 18:36:00 GMT

In the December 1991 issue of 'IEEE Microwave Guided Wave Letters', two
researchers apparently claim to have measured a pulsed microwave signal in
a waveguide that was travelling faster than light.  Has anybody heard anything
about this? The reference is,

G.C. Giakos and T.K. Ishii, "Rapid pulsed microwave propagation",
IEEE Microwave Guided Wave Lett., vol. 1, pp. 374-375, Dec. 1991.



William Brown
Applied Electromagnetics Group
Univ. of Houston
From: yvent@ntua.gr (Yiannis Ventikos)
Newsgroups: sci.physics
Subject: Re: sea waves
Keywords: waves
Date: 22 Aug 92 06:54:18 GMT
Organization: National Technical University of Athens

Waves have white crests when they break. Wave breaking is a
phenomenon that occurs when the gradient of the wave (slope)
is bigger than X deg. (X is from 16.4 to 24 deg. , opinions
of experts differ) This is caused because potential energy
by gravitation exceeds the velocity momentum.
Then we have foam which is many many little bubbles that have
a coef. of reflection, scattering et.c. different than that of
water and such that gives us the white.


 
-------

******************************************************************************
* Yiannis Ventikos                              *        DISCLAIMER          *
* Viscous Flows Group,                          * Any and all opinions that  *
* Dept. of Naval Arch. & Marine Eng.,           * I have  expressed  so far  *
* National Technical University of Athens,      * reflect  thoughts of mine  *
* P.O. Box 64070, GR-15710, Zografos, GREECE    * and  mine alone and  have  *
* Voice: (301) 7700405                          * nothing  to do  with  the  *
* Fax:   (301) 7774478                          * policy of the  Department  *
* e-mail: yvent@areti.marinentua.ariadne-t.gr   * I currently belong to.     *
******************************************************************************
Newsgroups: sci.physics,sci.math
From: barry@arnold.math.ucla.edu (Barry Merriman)
Subject: Re: the nature of exclusion
Organization: UCLA, Mathematics Department
Date: Sun, 23 Aug 92 02:39:12 GMT

In article <1992Aug22.225111.9325@galois.mit.edu> jbaez@nevanlinna.mit.edu  
(John C. Baez) writes:
> 
> Well, I feel I have an intuition for it

['statistical repulsion', do to the exculsion principle]

> imagine lots of energy levels and think about how when it's cold the
> fermions will fall into the lowest energy levels, subject to the
> restriction that there can only be one per state.  As one squeezes a
> box full of cold fermions the energy levels go up, so if one does this
> adiabatically the fermions will stay in the "same" state as its energy
> level goes up, causing the energy of the whole system to go up.  
> 
> I suppose you will say this is not the sort of intuition you want.  Sigh.

Well, perhaps it is. Really, I would like to intuitively understand
how the exlusion principle prevents a neutron star from collapsing
into a black hole, as this is where one most often hears about the effects
of 'statistical repulsion'. 

Thinking about it as you suggest is useful:
the exclusion law  implies a rise in the energy level of the fermions as the
star collapses spatially, and thus a rise in energy density even moreso. 
Since pressure = energy density, we see that the exlusion law implies
an increase in pressure in the collapsing system, and therby---via simple
fluid pressure---produces the 'statistical repulsion' needed to resist
further collapse.

I can deal with that as an intuition. I like it. The key is that 
the mystical 'statistical repulsion' is just ordinary fluid pressure. 
It exists for a weird reason (QM law of nature), but its a standard kind of  
force.

Thanks for the intuitional boost.

--
Barry Merriman
UCLA Dept. of Math
UCLA Inst. for Fusion and Plasma Research
barry@math.ucla.edu (Internet; NeXTMail is welcome)
From: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr))
Newsgroups: sci.physics
Subject: Re: The dangers in microwaved food...
Date: 21 Aug 92 01:43:11 GMT
Distribution: na
Organization: National University of Singapore

At this point Scott wants to point out that "potatos" was a deliberate
jest. But he is probably afraid that nobody will believe him. Permit me,
therefore, to do it for him.
From: snarfy@cruzio.santa-cruz.ca.us
Newsgroups: sci.physics
Subject: Photinos and Evil Twins
Keywords: Photinos,evil
Date: Sat, 22 Aug 92 12:23:13 PDT
Reply-To: snarfy@cruzio.santa-cruz.ca.us


   Two  eminent  scientists  discuss  the  existence of `photinos' and `evil
   twins' , while snarfy monitors the discussion..

>>Photinos don't sound dull to me,

  (Stuff deleted)

>They'd be great for physics, but they wouldn't do anything interesting
>other than gravitate for astronomy.

  (More Stuff deleted)

   "Photinos? Balderdash! I scoff at your science! There ,I've always
   wanted to say that...

   My twin and I are BOTH evil.. - Snarfy (Jim Ostrowski)
From: Richard.Mathews@West.Sun.COM (Richard M. Mathews)
Newsgroups: sci.physics
Subject: Re: BLACKHOLES IN THE CENTRE OF THE EARTH
Date: 19 Aug 92 23:35:46 GMT
Organization: Sunsoft Inc., Los Angeles, CA.
NNTP-Posting-Host: smaug.West.Sun.COM

anderson@fermi.phys.ualberta.ca (Warren G. Anderson) writes:
>However, a black hole of a given mass will
>have limited charge and angular momentum. Thus, the magnetic field of the
>earth would put a lower bound on the mass of the black hole. It should be
>relatively simple to determine this bound. 

A black hole with magnetic dipole moment, m, and charge, q, must have a
mass of at least
	q^2 + m^2/q^2
This, in turn, has a minimum when q is m^(1/2).  Thus the minimum mass
of a black hole with magnetic moment, m, is just 2*m (of course with
G=c=1).  Anybody have a value for the magnetic dipole moment of the
earth?

Richard M. Mathews			G eorge
Internet:   richard@locus.com		 D epression
UUCP:	    ...!uunet!lcc!richard	  B ush casts a
MIL/BITNET: richard%lcc@UUNET.UU.NET	   G loom on us all
From: dwr2560@zeus.tamu.edu (RING, DAVID WAYNE)
Newsgroups: sci.physics
Subject: Re: SU(5) GUT (was Re: Superbashing ...)
Date: 19 Aug 92 08:34:00 GMT
Article-I.D.: zeus.19AUG199203341292
Distribution: usa
Organization: Texas A&M University, Academic Computing Services
News-Software: VAX/VMS VNEWS 1.41

mcgrew@skid.ps.uci.edu (Clark McGrew) writes...
>the literature if you're really interested), the predicted lifetimes
>are around tau(Nuc->Lep K)<10^30 years.  This is ruled out by both the
>IMB-1 and Kamioka and will be further constrained by new IMB-3 data.
>There are several fixes for SUSY such as the flipped-SU(5) model which
>predict pdk limits that are not ruled out yet.

I think your data is mixed up somehow. Minimal SUSY SU(5) is ok. Flipped SU(5)
is getting pretty unlikely. In fact a lot of people in our department have
been working feverishly to patch it up.

Dave Ring
dwr2560@zeus.tamu.edu
From: yvent@ntua.gr (Yiannis Ventikos)
Newsgroups: sci.physics
Subject: DYNAMICAL SYSTEMS, CHAOS, CFD out there?
Summary: Inquiry for people interested in these subjects and for appr. news-grou
Keywords: DYNAMICAL SYSTEMS CHAOS CFD
Date: 22 Aug 92 06:45:58 GMT
Organization: National Technical University of Athens





DYNAMICAL SYSTEM, CHAOTICS, CFD FOR PEOPLE WHO WORK IN THESE FIELDS


Is  this  the  place  where  dynamical  systems,  chaos  and the related
math-phys  topics  should  appear?  If  no,  where? ,  if  nowhere   and
there are  more people interested  in it  what  action  should we  take?
Also  interested in  Computational  Fluid Dynamics, just seen an article
asking similar questions.
e-mail  (address at the end of this posting) or post here (sci.physics).
If I get e-mail answers that say something generally interesting, I will
summarize and post.

WARNING: This is for phys. - math. - eng. who are involved in dyn. systems
         seriously  or  *seriously*. It  is NOT  for users of mand.-julia-
         happy_fractals-colors   programms.  (there  are  news-groups  for
         them elsewhere)
 
-------

******************************************************************************
* Yiannis Ventikos                              *        DISCLAIMER          *
* Viscous Flows Group,                          * Any and all opinions that  *
* Dept. of Naval Arch. & Marine Eng.,           * I have  expressed  so far  *
* National Technical University of Athens,      * reflect  thoughts of mine  *
* P.O. Box 64070, GR-15710, Zografos, GREECE    * and  mine alone and  have  *
* Voice: (301) 7700405                          * nothing  to do  with  the  *
* Fax:   (301) 7774478                          * policy of the  Department  *
* e-mail: yvent@areti.marinentua.ariadne-t.gr   * I currently belong to.     *
******************************************************************************
From: steinly@opal.ucsc.edu (Steinn Sigurdsson)
Newsgroups: sci.physics
Subject: Re: "What's New" July-24-1992
Date: 13 Aug 92 21:15:24 GMT
	<1992Aug5.181137.9250@sei.cmu.edu>
	<STEINLY.92Aug6153937@topaz.ucsc.edu> <10213@sun13.scri.fsu.edu>
	<Bsxsz5.v@news.cso.uiuc.edu>
Organization: Lick Observatory/UCO
NNTP-Posting-Host: opal.ucsc.edu
In-reply-to: tjn32113@uxa.cso.uiuc.edu's message of 13 Aug 92 19:33:03 GMT

In article <Bsxsz5.v@news.cso.uiuc.edu> tjn32113@uxa.cso.uiuc.edu (Thomas J. Nugent) writes:

   jac@ds8.scri.fsu.edu (Jim Carr) writes:

   >All of which seems to ignore the one design that we actually launched! 
   >Skylab was designed, two of them built, one launched and used for 
   >quite some time.  It is presumably man-rated and that design could be 
   >built again.  Of course one might wish to update it, but Mir has shown 
   >that a simple and conservative design is the best way to get up there 
   >early and stay there for an extended period of time.  

   Perhaps.  But I would also consider what you are able to do up there besides
   sit (float?) on your hands.  Simply put, Freedom can do alot more than Mir.
   There was an excellent post recently, perhaps in sci.space, regarding the
   differences between Freedom and Mir.  Freedom has more power, more space, etc.
   etc. etc.  

As true as this is, there is an even simpler reason. Skylab was
allowed to come down, after that there is no way that Congress would
admit it was wrong and fund another one - has to be something
different (bigger and "better")!

   >Except for unfortunate delays in the shuttle program, the one that we 
   >launched could have been kept up there and still be used as the base 
   >platform for a larger system. 

   >The one thing I really do not understand in all of the discussion of the 
   >need for long-term study of human biology in orbit and the recent story 
   >about problems in zero-g adaptation is why none of this was studied back 
   >in the days of Skylab.  

   They were busy studying other things?  I imagine that there was some study
   of the effects of zero-g on the astronauts.  But two(?) missions, each less
   than 84 days, is definitely not enough to complete the book (probably not
   even the first chapter) on the effects of zero-g on humans.

Even more simple, it was the early missions like skylab and the
salyuts that demonstrated there was a problem to be studied!
You have to go out there and find out the hard way what problems there
are to solve and what interesting things the solutions may tell you,
that, ultimately, is how we learn. This is a concept that members of 
Congress and many other allegedly well educated people seem to have
enormous difficulty grasping...

|  Steinn Sigurdsson	|I saw two shooting stars last night		|
|  Lick Observatory	|I wished on them but they were only satellites	|
|steinly@helios.ucsc.edu|Is it wrong to wish on space hardware?		|
| "standard disclaimer"	|I wish, I wish, I wish you'd care - B.B. 1983	|
Newsgroups: sci.physics
From: nextc.Princeton.EDU!mdd (Mark D. Doyle)
Subject: Re: Symmetries, groups, and categories
Originator: news@nimaster
Reply-To: mdd@nextc.princeton.edu
Organization: Princeton University
Date: Fri, 14 Aug 1992 22:19:06 GMT

In article <1992Aug14.195651.22652@galois.mit.edu> jbaez@zermelo.mit.edu  
(John C. Baez) writes:
> I should make clear that there are only certain things about string
> theory that bug me, aside from the fact that people make such a big deal
> about it.  One is that traditionally it has treated strings wiggling
> around in a background spacetime with a given metric.  (So that the
> tubular Feynman diagrams are really surfaces IN, say, Minkowski space or
> some 26-dimensional analog thereof.)  This is rather unfortunate if one
> is advocating string theory as an explanation of gravity, since in
> gravity it is the dynamics of the metric one is trying to explain!
> Writing string field actions that depend on a background metric sounds
> awfully like trying to do quantum gravity perturbing around a flat
> background metric.  Maybe a string fan can say what the current state of
> the art is.

Well, not having a background independent string field theory is very  
disturbing to string theorists too. In fact, one could argue that finding  
such an animal is the holy grail of string theory. Well, at least one of  
them :^). As for the state of the art: In closed string field theory one  
writes down a non-polynomial action but this action is written using a  
particular background. However, one can show that this action is unchanged  
by certain restricted sets of background shifts. This is not ideal, but it  
is a start. As for open string field theory, Ed Witten has just put out a  
paper (last week) that purports to give a background independent  
formulation. The paper is more of a "maybe we should look in this  
direction" paper, than a detailed formalism, but Witten promises some  
concrete examples soon. (Preprint is available on hepth.)

So to sum up. I would say that lack of background independence is a  
shortcoming of our present formulation of string theory, and not  
necessarily a shortcoming of string theory itself. We just don't  
understand it well enough. Just where future understanding will come from  
is debatable. I hope that it will in the direction of topological field  
theories and the like. Or even from category theory...

Mark Doyle
mdd@nextc.princeton.edu
Newsgroups: sci.physics
From: somlo@swifty.dap.CSIRO.AU (Peter Somlo)
Subject: Re: I can travel faster than light (A riddle)
Keywords: FTL
Organization: CSIRO, Division of Applied Physics, Sydney
Date: Thu, 20 Aug 1992 23:46:31 GMT

>
>However, guys read this:
>
>
>IEEE Microwave & Guided Wave Letters Vol. 1, No. 12, Dec. 1991 pp.374-375
>                                     Vol. 2, No. 5,  May  1992 pp.199-206
>
>
>They claim it can be done!!!
>
>Any comments?

Yes: See also: IEEE M & GWL Vol. 2 No. 6, p. 255, Conclusion: IT CAN'T BE
DONE!
-- 
Dr Peter I. Somlo FIEEE | CSIRO Div. Appl.Phys. | "Every coin has three
Head RF/Microwave Proj. | Natl. Meast. Lab.     |  sides - at least"
FAX: 61-2-413-7383	| POB 218 Lindfield 2070|  (Somlo, cca. 1985)
TEL: 61-2-413-7505      | NSW AUSTRALIA         |
From: dwr2560@zeus.tamu.edu (RING, DAVID WAYNE)
Newsgroups: sci.physics
Subject: Re: sea waves
Keywords: waves
Date: 19 Aug 92 08:50:00 GMT
Article-I.D.: zeus.19AUG199203505798
Organization: Texas A&M University, Academic Computing Services
News-Software: VAX/VMS VNEWS 1.41

>>In article <boudouvi.714144870@theseas>, boudouvi@ntua.gr (Andreas Boudouvis) writes...
>>>A summer-time question:
>>>Why the crests of sea waves are white (esop. when the waves 
>>>break at the seashore?)

Bubbles. But let's not forget about Olber's paradox. :-)

Dave Ring
dwr2560@zeus.tamu.edu
Newsgroups: sci.physics
From: david@euclid.JPL.NASA.GOV (David Bernath)
Subject: Re: The dangers in microwaved food...
Organization: Jet Propulsion Laboratory, NASA/Caltech
Date: Thu, 20 Aug 1992 20:05:52 GMT


>>In article <1992Aug20.015531.7842@nuscc.nus.sg> matmcinn@nuscc.nus.sg (Mcinnes B T (Dr)) writes:
>>there are serious health risks in eating.
>
>There are serious health risks.

Health is a serious risk.
From: jtchew@csa3.lbl.gov (JOSEPH T CHEW)
Newsgroups: sci.physics.fusion
Subject: Periodic Table and Chart of the Nuclides (was Re: Press Release)
Date: 13 Aug 92 17:18:34 GMT
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
Distribution: world
Reply-To: jtchew@csa3.lbl.gov
NNTP-Posting-Host: 128.3.254.198
Summary: Mac softcopy apparently available by FTP
News-Software: VAX/VMS VNEWS 1.3-4   

Check out this bit of E-mail I received some time ago.  Happy
downloading, assuming it's still on that FTP server...

--Joe
"Just another personal opinion from the People's Republic of Berkeley"

From: bobwhite@nova.ta52.lanl.gov (James R. White)
~ A handy-dandy Macintosh Hypercard stack I downloaded the
~ other day has a combination of the chart of the nuclides as well
~ as the periodic table.
~
~ Best I recall, I got it from the file named /info-mac/card/isotopes.hqx
~ from the Mac archives at sumex-aim.stanford.edu
~
~ Do you not read the newsgroup comp.sys.mac.digest ?  It may not be as
~ fun as rec.motorcycles, but it is a heck of a lot more useful. . .
~
~ The file contains two stacks, one of the 'chart of the nuclides', another
~ containing the periodic table, and they work together.  Really nicely done.
From: blue@nscl01.nscl.msu.edu
Newsgroups: sci.physics.fusion
Subject: See Tom. See Dick. See us agree!
Date: 18 Aug 92 15:53:18 GMT
Reply-To: blue@nscl01.nscl.msu.edu
Organization: Sci.physics.fusion/Mail Gateway

Keep it up, Tom.  I don't mind being your straight man (or is it vice versa).
And now we are going to come down on the same side of the issues raised by
the latest fanfare from Brigsten, Mallove, and Rothwell.  Talk about off-
the-wall ideas!  Lest you think that Jed is being a very good sport about
apologizing to Warren Buck, you should be aware of the fact that many of
the other names dropped in that press release got there under equally
doubtful circumstances.  Clearly the press release was intended to lend
an air of credibility to the Brigsten-Mallove "theory" it does not
deserve.  Now Jed is claiming that the names of Buck and others were
included for their benefit?  

>From what I have been able to gather, several years ago Brigsten wrote
and circulated privately a paper in which he applied a nuclear cluster
model to nulcear fission.  Brigsten may have actually known something
about fission!  If the listed supporters of the Brigsten theory ever
actually saw a paper involving a nuclear cluster model, it was this
earlier work.  How about it, Jed?  Have any of the people mentioned
in the press release seen or endorsed anything written by Brigsten
that links a nuclear cluster model to cold fusion?

What is the Brigsten-Mallove theory?  From Tom Droege, the intrepid
experimenter, we hear that 3He and 4He are produced by a VERY ENERGETIC
reaction that sends them flying away at multi-GeV energies so they
can leave the scene without being detected, unless of course you
plan to conserve momentum.  As Tom points out, the recoil is going
to give a very healthy signal, and if anybody wants to look for them,
so will the escaping Helium nuclei.  I'd like to see what the CSC
folks are predicting for rates.  As was noted right from the beginning,
if the neutron rates had been as expected we would have had some
very dead experimenters in very radioactive laboratories.  Do you
think that GeV-type helium nucleii are going to sail right through
your bod without a trace?  WRONG!

So the only way this new form of magic could possibly have gone
unnoticed is if the rates a very, very low, and therein lies the
rub.  In order to put together a theory that involves low reaction
rates, you must boost the energy output per event.  Brigsten-Mallove
goes to the extreme of saying its several GeV, but then most of the
energy leaves the calorimeter without contributing to the heating.
All that remains is the recoil energy of the Pd or whatever.  If
as Tom suggests that is 100 MeV per event, the event rate is only
knocked down by a factor of 25 from the orignal estimates made
for the Pons and Fleischman experiments.  You don't have to know
much physics to know that something very much out of joint here>
Is there anyone out there ready to defend Brigsten-Mallove as
it has so far been reported?

Dick Blue
NSCL @ MSU         "Now is not that ridiculous..." Gilbert & Sullivan
From: logajan@SLEEPY.NETWORK.COM (John Logajan)
Newsgroups: sci.physics.fusion
Subject: NCM and cosmic rays?
Date: 20 Aug 92 22:32:36 GMT

So did the NCM theory predict a new explanation for cosmic rays?
From: jac@ds8.scri.fsu.edu (Jim Carr)
Newsgroups: sci.physics.fusion
Subject: Re: Press Release
Date: 12 Aug 92 15:06:19 GMT
Reply-To: jac@ds8.scri.fsu.edu (Jim Carr)
Organization: SCRI, Florida State University

In article <1992Aug12.142146.202345@uctvax.uct.ac.za> hndcol02@uctvax.uct.ac.za (Colin Henderson, Physics Dept. UCT) writes:
>
>> Mr. Brightsen has submitted a scientific paper describing the application
>> of the NCM  to the conventional fission processes to the Journal Fusion
>> Technology.
>
>Why there?  Hey, Nuclear Physics A, no less, or Phys Rev C for
>something as far reaching and as completely successful as this!

Or Zeitschrift fur Phyzik, Journal of Physics G, or Nuovo Cimento 
for that matter.  And start it off with a short paper in Modern 
Physics Letters, etc etc etc. 

>>  The paper has already been reviewed and praised by leading
>> experts in the nuclear energy field. 
>
>How about in the nuclear physics field?

Actually, I *know* one of those people listed as reviewers, and another 
is very respected in the field of nuclear engineering and radiation effects.
I shall have to find out what he says about it.

--
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)