HDTenEightyP/NetNews huggingface dataset:
From: hall@vice.ICO.TEK.COM (Hal Lillywhite)
Newsgroups: sci.physics
Subject: Re: A Modest Proposal
Date: 24 Jul 92 16:03:35 GMT
Organization: Tektronix Inc., Beaverton, Or.

In article <24830@dog.ee.lbl.gov> sichase@csa2.lbl.gov writes:

>I propose that we attempt to initiate a series of periodic News postings,
>generated by volunteers at various institutions, say monthly - and scattered
>throughout the month, so that we can get the latest "News from Fermilab,"
>"News from Bell Labs," "News from the Center for Particle Astrophysics,"
...

I'm not in a positon to contribute much to this but it sounds like a
great idea.  As one of those stuck in a company which does very
little research I would very much appreciate having something like
this available.
Newsgroups: sci.physics
From: carl@aoa.aoa.utc.com (Carl Witthoft)
Subject: Re: Lightning
Organization: Adaptive Optics Associates
Date: Wed, 22 Jul 1992 12:10:20 GMT

In article <1085@kepler1.rentec.com> andrew@rentec.com (Andrew Mullhaupt) writes:
>You hear lightning on AM radio so it isn't just DC, right? It's pretty broad
>band, since you can get it all over the spectrum. So it's perhaps true that
>initially the spark crosses the gap in some directional sense, there's a lot
>of AC in a lightning strike.
x
I guess a redirect to the subject "Fourier Analysis" would be 
a good idea here. :=)
Any short pulse or collection of short pulses have frequency content
all over the spectrum (so to speak).  Any radio receiver has finite
out-of-band frequency rejection.
And, of course, any finite event can't be pure DC.


-- 
Bobby Newmark, aka  Carl Witthoft @ Adaptive Optics Associates
aoa!carl@bbn.com  carl@aoa.utc.com
54 CambridgePark Drive, Cambridge,MA 02140 617-864-0201
**Just say NO to HMOs**
Newsgroups: sci.physics,sci.astro,sci.philosophy.tech
From: phillies@wpi.WPI.EDU (George D. Phillies)
Newsgroups: sci.physics
Subject: Ecoterrorism
Date: 26 Jul 92 19:22:01 GMT
Article-I.D.: wpi.1992Jul26.192201.18981
Distribution: na
Organization: Worcester Polytechnic Institute

In <1992Jul24.141352.17358@scott.skidmore.edu>, 
datkatz@scott.skidmore.edu (david atkatz) quotes dean@vexcel.com (dean 
alaska) and carl@SOL1.GPS.CALTECH.EDU (Carl J Lydick) on the general 
subject of terrorism, noting that previous posters had argued

[long section deleted here}

>>In each of these examples, ecoterrorists misrepresent things in order
>>to scare the uninformed, in order to force their policies through.

and arguing

>"pointing to," "grossly overstating," and "confusing,"
>are being equated to, e.g., bombing civilian
>airliners, machine gunning passengers at airports, beating 
>airline passengers to death, shooting crippled cruise
>ship passengers, etc.

>Make much sense to you?  I think there is a little 
>problem of scale here.

There is a problem of scale here, but it is more a problem of 
economics.  The ecoterrorist Luddites in question here have acted to 
drive up the cost of resources, and to divert resources that might 
have been spent elsewise.  Those resources might have been spent on 
making rail grade crossings safer, on paying workers better (thereby
dropping stress-related heart attacks), on installing better highway 
guard rails, on innoculating children against potentially fatal 
diseases, and on dozens of unromantic but cost-effective approaches to 
improving our society, in its quality of life and its culture.

The people who died because resources were incrementally not available 
for other uses are just as dead as people who were machine gunned at 
airports (in my case, airport deaths include the 10 year old friend of 
the 12 year old daughter of a close friend), had the airplanes blown 
up in midair, etc. etc.  Their causes of death are less photogenic, 
less likely to be seen on the six o'clock  'if it bleeds it leads' TV 
headline news, but the people are just as dead as if an ecoterrorist 
had laid into them with a chain saw.  Thus, I maintain, the 
antinuclear and other ecoextremists, however ghandiesque their 
posings, however untraceable the detailed consequences, by escalating 
the cost of nuclear electricity by tends of billions of dollars, have 
in fact caused the deaths of people by the hundreds and thousands, 
potentially in numbers far larger than the number of people killed by 
the airline bombers.  

George Phillies
phillies@wpi.wpi.edu
Newsgroups: sci.physics
From: leyfre@McRCIM.McGill.EDU (Frederic Leymarie)
Subject: Re: WANTED: Concise text on Fourier Transforms
Originator: leyfre@monet.mcrcim.mcgill.edu
Organization: McGill Research Center for Intelligent Machines, Montreal, Canada
Date: Thu, 30 Jul 92 14:53:46 GMT


In article <4g1xrwp@rpi.edu>, pierct@rpi.edu (Tom Pierce) writes:
|> I'm trying to find a text on Fourier Transforms aimed at the intelligent
|> Physics student that is interested in applying them practically.  I'd
|> like a fair bit of examples, and clear, concise text.  Most of the books
|> I've read either pass them over with a "You should know this already"
|> attitude or go into deep mathematical theory.  I'm not partically
|> interested in their history, or what great aesthetic significance they
|> may have to ivory tower theorists.  I want to learn how to use them to
|> actually simulate (optical) processes.

You may want to have a look at the following book:

@Book{Weaver83Applic,
  author = 	{H. J. Weaver},
  title = 	{Applications of Discrete and Continuous {F}ourier
		 Analysis},
  publisher = 	JWS,
  year = 	1983,
  address = 	NY,
  note = 	{375 pages.}}


A more detailed one is:

@Book{Bracewell86Fourier,
  author =	{R. N. Bracewell},
  title =	{The {F}ourier Transform and its Applications},
  year =	1986,
  publisher =	McGH,
  address =	NY,
  edition =	{$2^{nd}$, rev.},
  note = 	{474 pages.}}

Enjoy !
-- 
Frederic Leymarie -- leyfre@mcrcim.mcgill.edu
McGill University, Electrical Eng. Dept., McRCIM,    |	Tel.: (514) 398-8204
3480 University St., Montreal, QC, CANADA, H3A 2A7.  |	FAX:  (514) 398-7348
From: mcirvin@husc10.harvard.edu (Mcirvin)
Newsgroups: sci.physics
Subject: Re: Defining Photons
Keywords: Relating photons E=MC^2 criticism
Date: 28 Jul 92 14:55:42 GMT
 <9976@sun13.scri.fsu.edu> <26JUL199218561022@zeus.tamu.edu> <24926@dog.ee.lbl.gov> <27JUL199219012221@zeus.tamu.edu>
Distribution: na

dwr2560@zeus.tamu.edu (RING, DAVID WAYNE) writes:

>So now I think the thing which makes the photon classically 'different' from
>other particles is that it's a neutral boson. Like helium. Hmmm... 

Or hydrogen, for that matter.  A professor in my department   
has discussed the possibility of doing "optics" with atoms.  I
don't know how close it is to being feasible.

-- 
Matt McIrvin  mcirvin@husc.harvard.edu 
Newsgroups: sci.physics
From: leon@unixg.ubc.ca (Leon ter Beek)
Subject: Re: Gyromagnetic ratio of the proton
Organization: University of British Columbia, Vancouver, B.C., Canada
Date: Tue, 28 Jul 1992 20:04:56 GMT

>In article <1992Jul27.191552.13679@unixg.ubc.ca> I@unixg.ubc.ca wrote:
>>
>>Can someone indicate where I can find an accurate number for the
>>gyromagnetic ratio of the proton in SI-units [1/s*T].   
>

Thanks to all who responded. The gyromagnetic moment of the proton is
determined up to 7 significant figures to this date:

gamma_p = 2.67522128(81) 1/(s T) )

Leon
Newsgroups: sci.physics
From: geoff@math.ucla.edu (Geoffrey Mess)
Subject: Re: Noah's formation: The rainbow
Organization: UCLA, Mathematics Department
Date: Thu, 23 Jul 92 00:15:59 GMT

In article <2A6DEF17.1804@ics.uci.edu> bvickers@valentine.ics.uci.edu  
(Brett J. Vickers) writes:
> peterk@public.sub.org (Peter Kittel) writes:
> >Is it only me or does the sky beneath a rainbow also appear lighter
> >to others than the sky above a rainbow (or wait, was it the other way
> >around?)?
 
> Optical illusion?  Two fields of the same color, separated by a line
> of a brighter or darker color, give the optical illusion that one half
> is lighter than the other.  The trick is to cover the line and see that
> they are the same.  I've never tried this with a rainbow.

Not an optical illusion. Above the primary bow of the rainbow is  
Alexander's dark band, first 
described by a philosopher Alexander [not the Great] in Hellenistic times.
There's a  Scientific American reprint volume on atmospheric optics which
explains this and other features of the rainbow (I don't have the  
reference handy.) There's also a Dover book "The nature of light and 
colour in the open air" (approx. title); I've never seen it but it's  
probably a good place to look for information on atmospheric optics.  

--
Geoffrey Mess
Department of Mathematics, UCLA
Los Angeles, CA.
geoff@math.ucla.edu
NeXTmail welcome.
Newsgroups: sci.physics
From: tjn32113@uxa.cso.uiuc.edu (Thomas J. Nugent)
Subject: Re: "What's New" July-24-1992
Organization: University of Illinois at Urbana
Date: Mon, 27 Jul 1992 23:27:33 GMT

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

>In article <JMC.92Jul25123947@SAIL.Stanford.EDU> jmc@cs.Stanford.EDU writes:

>likely kill off unmanned exploration of the planets.  Some biologists 
>are concerned that it will be classified as life science research and 
>hurt their projects.  Physicists have mainly worked just to make it 
>clear that they find the proposed design worthless for the material 
>science research that has been alleged to be a reason to build it. 

>>The reason for the space station is only marginally science and
>>even more marginally prestige.  The space station is a start on
>>human expansion into the solar system.  That is what generates
>>the public support for it.  It may not be the best design, but
>>it's the only design we have, and the scientist opposition has
>>made matters worse, not better.

>I wish NASA was as forthright as you are, since then the design could 
>be judged on that specific question.  My concern is that the plan 
>will not meet that goal either, since it seems to get worse with 
>time rather than better -- and that NASA originally said that they 
>could build a space station for an amount that is less than they 
>have spent on design studies so far.

From this and other postings, I get the impression that some people think
that absolutely _NO_ science will come from SSF.  This just isn't true.
Freedom should not be touted simply as a scientific project, but it also
should not be touted simply as a first step in human exploration of the 
solar system.  As I've said in other replies to the What's New, we will
learn about the long-term effects of weightlessness on the human body.
They also will achieve microgravity on SSF, contrary to what some people
have said.  This will allow some great research to go on.  They might not
(probably won't?) find a cure for cancer, but some experiments which will
definitely further cancer research will be performed.  Same for AIDS.  
They haven't crystallized the AIDS virus here on Earth yet, so expecting
them to be able to do it in orbit (which they tried on a recent shuttle
flight) anytime soon is unreasonable.  But they will contribute in the
fights against these medical problems.  Similarly, if they grow a nice
big crystal of gallium arsenide more pure than what has been done so far,
they could sell it for big$$$$.  They won't (probably), but scientists
on Earth may be able to use it for research. Etc. etc.

"We shall not cease from exploring//And the end of all our exploring//
 Will be to arrive where we started//And know the place for the first time."
			- T.S. Eliot
-- 
"To be average scares the hell out of me." -- Anonymous
Tom Nugent		e-mail: tjn32113@uxa.cso.uiuc.edu
Newsgroups: sci.physics,alt.fan.dale-bass
From: gsh7w@fermi.clas.Virginia.EDU (Greg Hennessy)
Subject: Re: "What's New" July-24-1992
Followup-To: alt.fan.dale-bass
Organization: University of Virginia
Date: Wed, 29 Jul 1992 01:26:28 GMT

In article <1992Jul29.010055.3863@murdoch.acc.Virginia.EDU>
crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass) writes: 
#    NIH is being forced to fund study into chiropractry(?) along with the
#    other 'alternative medicine' approaches. 

"Forced"? I would consider such studies to be good. Surgeons don't
have a monopoly in how to help people get better. Alternative methods,
which are probably less expensive than "mainstream" medicine are good
things if they are effective. 

#    As far as astrology goes, I'd think that such widespread antiscientific
#    beliefs would be of great interest to those in the APS apparently
#    interested in scientific purity.  

Yea, those astrologers might be after our vital bodily fluids. Come on
Dale, this is farther then even you normally stretch a point. I have
seen letters from the APS to newspapers asking them to put disclaimers
on horoscopes. 

#    Also, I'm sure such base things as dollars never come into consideration
#    of certain members of the APS when things like the integrity of science
#    come into play.  After all, we have been told many times that the APS
#    is not against SSF because of the competition for money, just because
#    'it is not science'. 

Well the only person who says that dollars never come into
consideration is you, so you get little credit from knocking down your
own strawman. 

As for the space station not being science, read todays Post and
you'll see that Goldin's article has the first 4 non-introductory
paragraphs being the scientific return of SSF. If Goldin is going to
make "scientific" return the number 1 thing he talks about, it is
quite fair to point out it ain't much science to be done, and the
budget is better spent in other programs. 



--
-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      gsh7w@virginia.edu  
 UUCP:		...!uunet!virginia!gsh7w
From: jac@ds8.scri.fsu.edu (Jim Carr)
Newsgroups: sci.physics
Subject: Re: Blue Sky
Date: 22 Jul 92 21:29:28 GMT
Reply-To: jac@ds8.scri.fsu.edu (Jim Carr)
Organization: SCRI, Florida State University

In article <1992Jul22.180659.13623@watson.ibm.com> platt@watson.ibm.com (Daniel E. Platt) writes:
>In article <1992Jul22.154233.21594@linus.mitre.org>, m14494@mwvm.mitre.org (Mike White) writes:
>|> Andrew Mullhaupt writes:
>|> > Why is the sky blue?
>|> 
>|> You'll get lots and lots of answers, and I'll bet my tenure that not one 
>|> of them will address the question "Why?"; they'll all address the question 
>|> "How?".     .....
>
>Let's see... 
>
  [4 good comments deleted]

Also, there is the question of why our eyes are sensitive to this 
particular range of E-M wave frequencies (discussed earlier this 
year in this forum). 

  <philosophical mode on>

>You don't want to get stuck in the position of the little child who asks
>'why' in response to every explanation...  Ultimately, it has to reduce to
>some basis of common experience (agreed standards...).

Right.  The ultimate reason is that "blue" is the name we give to the 
color of the sky in the english language we happen to use to communicate 
this concept.  No one has any idea if what I perceive as "blue" is the 
same as what anyone else perceives as "blue", just that we both agree 
that that thing we perceive is to be called "blue".  

  <philosophical mode off>

--
J. A. Carr                                    |  "The New Frontier of which I  
jac@gw.scri.fsu.edu                           |  speak is not a set of promises
Florida State University  B-186               |  -- it is a set of challenges."
Supercomputer Computations Research Institute |   John F. Kennedy (15 July 60)
Newsgroups: sci.physics
From: jmc@SAIL.Stanford.EDU (John McCarthy)
Subject: Re: twin paradox
Reply-To: jmc@cs.Stanford.EDU
Organization: Computer Science Department, Stanford University
Date: 26 Jul 92 13:51:52

There is no twin paradox in special relativity, as I suppose most
of the posters have said.  Here's an approach to understanding
the phenomenon and explaining it to students.

Suppose on twin travels to Alpha Centauri, 4 light years away
at half the speed of light and immediately returns at the same
speed.  Consider the event of his arriving At Alpha Centauri.

What event on earth is simultaneous with it?  According to
special relativity, this depends on the co-ordinate system.
There are three relevant co-ordinate systems, that of the
stay-at-home twin, one moving at half the speed of light
from earth in the direction of Alpha Centauri, and one moving
at half the speed of light in the opposite direction.

1. In the stay-at-home system, the traveler's arrival at Alpha Centauri is
eight years after his departure from earth.

2. In the going-out system, the arrival is  4 sqrt(3) years have
elapsed, because in that system, Alpha Centauri wasn't 4 light years
from earth but only 2 sqrt(3) light years.  The stay-at-home twin
has aged only that amount of time in that co-ordinate system.

3. In the coming-back system, the clock at home reads 16 - 4 sqrt(3)
years when the traveller turns around at Alpha Centauri.

In this approximation we imagine the traveller to turn around
instantaneously, i.e. to switch from going at half light speed
towards alpha centauri to going at half light speed back towards
Earth.  Taking into account a finite acceleration would make the
problem somewhat more complicated but change the numbers only
a small amount if the acceleration was high enough.  If you don't
like high accelerations, consider a longer journey in which the
time for reversal of direction would be smaller in comparison
with the time spent going at constant speed.

To get the aging of the traveller, not that he spent 4 sqrt(3)
years going out by his own watch and the same time coming back,
so he is 8 sqrt(3) years older when he arrrives at Earth.  His
twin is 16 years older.

The apparent symmetry between the twins, which has misled many people
into believing there is a paradox, is broken by the fact that
the travelling twin is involved with two co-ordinate systems,
which differ in what Earth event is simultaneous with the
turn-around at Alpha Centauri.
--
John McCarthy, Computer Science Department, Stanford, CA 94305
*
He who refuses to do arithmetic is doomed to talk nonsense.
From: sichase@csa2.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Re: Converting the masses
Date: 23 Jul 92 19:37:48 GMT
Reply-To: sichase@csa2.lbl.gov
Distribution: na
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
NNTP-Posting-Host: 128.3.254.197
News-Software: VAX/VMS VNEWS 1.3-4

In article <mcirvin.711904014@husc8>, mcirvin@husc8.harvard.edu (Mcirvin) writes...
> 
>Actually, neither definition of mass would be temperature-independent,
>if you define it for the whole lump of coal.  When you raise the
>temperature, the energy in the rest frame increases!  The sum of
>the masses of all the particles is perhaps temperature-independent,
>but as you complained before, that's not the mass of the lump.

But inertial mass *can* be termperature dependent.  Consider experiments
now being done to "weigh" molecules in Penning traps and other such devices.
They are getting (soon) to the precision where you can actually "weigh" the 
molecular bond between two atoms (i.e., detect the difference between the
mass of two protons + two electrons vs. a hydrogen molecule which is the
result of the binding energy).  If you had a sufficiently hot sample
of hydrogen, in which some molecules were in excited molecular orbitals,
and you weigh some of these molecules, you will find that the inertial
mass is different for molecules in different orbital configurations - 
the mass of a hydrogen atom depends on the temperature of the gas.

-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
From: tvaughan@buphyk.bu.edu (Timothy Vaughan)
Newsgroups: sci.physics
Subject: Re: Noah's formation: The rainbow
Date: 21 Jul 92 18:24:55 GMT
Organization: Boston University, Physics Department

It turns out that the third and fourth arcs are not only fainter, but
also projected back in the direction of the sun, where the sky is
obviously brighter.  The fifth arc, which is away from the sun again,
is pretty darn faint! :-)

Tim
Newsgroups: sci.physics
From: tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman)
Subject: Earthquake's amplified?
Date: 24 Jul 92 17:32:20 MDT
Organization: University of Utah, CompSci Dept


  I am wondering if there is some autocatalytic element in earth-quakes. 
That is- does the beginning of a slippage induce further slippage by
reducing friction or through some other mechanism?  Is the quake self
amplifying- and is that why they occur with tremendous energy rather than
as a series of small imperceptible quakes?

  Is there any sort of amplification process in this deal?  (The implication
being that earthquakes may indeed be truly unpredictable)
Newsgroups: sci.physics
From: Bruce.Scott@bbs.oit.unc.edu (Bruce Scott)
Subject: Re: Blue Sky
Organization: Extended Bulletin Board Service
Date: Fri, 31 Jul 1992 14:07:21 GMT

In article <1992Jul28.024259.1692@qedqcd.rye.ny.us> mmm@qedqcd.rye.ny.us (Mike Miskulin) writes:

>I can remember reading somewhere that we are in fact most sensitive to
>yellow, at approximately the same wavelenght as light from our sun?

How could it be otherwise? Quite clearly, we were evolved over 4 Gyr in
this environment. I expect that, the evolutionary timescale being
shorter than the *stellar* evolutionary timescale for a G2 star, "eye"
response has been closely correlated with the sun's spectrum since the
inception of life in earth.

Gruss,
Dr Bruce Scott                             The deadliest bullshit is
Max-Planck-Institut fuer Plasmaphysik       odorless and transparent
bds at spl6n1.aug.ipp-garching.mpg.de                 -- W Gibson

--
   The opinions expressed are not necessarily those of the University of
     North Carolina at Chapel Hill, the Campus Office for Information
        Technology, or the Experimental Bulletin Board Service.
           internet:  bbs.oit.unc.edu or 152.2.22.80
Newsgroups: sci.physics
From: gl8f@fermi.clas.Virginia.EDU (Greg Lindahl)
Subject: Re: ZERO Nuclear impact (was: Is car pooling for real? etc)
Organization: Department of Astronomy, University of Virginia
Date: Sat, 25 Jul 1992 19:40:03 GMT

In article <1992Jul25.192603.5892@murdoch.acc.Virginia.EDU> crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass) writes:

> Usually, I'll just stick to making and rebutting arguments presented.

Please rebut all the Scientific American articles that people have
been refering to.
From: clarke@acme.ucf.edu (Thomas Clarke)
Newsgroups: sci.physics
Subject: Re: Twins Paradox Resolved
Date: 27 Jul 92 13:20:00 GMT
Organization: University of Central Florida

In article <Bs0L9u.LwK@well.sf.ca.us> metares@well.sf.ca.us (Tom Van Flandern)  
writes:
>      As for logical problems, one must give up totally on the concept of
> distant simultaneity; and one must accept that *apparent* aging depends upon
> direction of travel, approach or receding.  There is a way to avoid both of
> these considerable logical compromises.  But I do not argue that they cannot
> be possible, only that one must make a sacrifice (unnecessarily, it turns
> out) of "common sense" to accept this interpretation of the experimental
> data.  -|Tom|-
> 
I can only quote from _Through the Looking Glass_:

  "I can't believe that!" said Alice.
  "Can't you?" the Queen said in a pitying tone.
  "Try again: draw a long breath, and shut your eyes." Alice laughed.  
"There's no use trying," she said: "one can't believe impossible things."
  "I daresay you haven't had much practice," said the Queen.  "When I was 
your age, I always did it for half-an-hour a day.  Why, sometimes I've 
believed as many as six impossible things before breakfast..."
--
Thomas Clarke
Institute for Simulation and Training, University of Central FL
12424 Research Parkway, Suite 300, Orlando, FL 32826
(407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu
Newsgroups: sci.physics