HDTenEightyP/NetNews huggingface dataset:
From: whit@milton.u.washington.edu (John Whitmore)
Newsgroups: sci.physics,sci.environment,misc.consumers
Subject: Re: Radioactivity and Superstition; was: Re: Are Your Light Bulbs Radioactive?
Date: 3 Sep 92 02:50:04 GMT
Article-I.D.: u.1992Sep3.025004.20771
Organization: University of Washington, Seattle

In article <1992Sep2.172549.29172@ornl.gov> de5@ORNL.GOV (Dave Sill) writes:
>In article <1992Aug29.000626.16080@u.washington.edu>, whit@milton.u.washington.edu (John Whitmore) writes:
>>In article <l9ns6oINNmol@utkcs2.cs.utk.edu> de5@ORNL.GOV (Dave Sill) writes:
>>
	<talking about the things kids might eat>
>>>Few of which are radioactive, since most folks don't have concentrated sources
>>>laying around their house...unless they have smoke detectors or compact
>>>flourescents. ... Radioactivity *is* a different kind of threat than most
>>>parents are used to dealing with. 

>>	This is not true; ALL organic foods are radioactive (carbon-14,
>>remember?), and potassium contains 0.01% of K-40... so an eight-year-old
>>child (just about hammer-wielding age) has a 'safe and adequate'
>>recommended dietary intake of circa 1 gram of potassium per day...
>>which comes to about two microcuries.

>Which of my statements is not true?  Do you consider organic foods
>concentrated sources of radioactivity?
	Basically, you can't call a compact fluorescent lamp's
initiator a 'concentrated radioactive source'.  The initiator is
no more radioactive than a bite of banana.

	I know of quite a few household items that have natural
radioactivity which is large compared to that of compact fluorescent
bulbs.  International standard 'radiation warning' symbols are
not present on those bulbs, because they are NOT HAZARDOUS
radiation sources.  There is no hazard here to be discussed.
The radiation is comparable to (or less than) natural sources.

	What, exactly, is the reason for that label?  I'm mystified.
The reason for the radioactive materials is to initiate the arc
in the discharge lamp; if you leave the source out, the bulb
requires a 'starter' circuit (expensive and/or unreliable).

	John Whitmore
From: muttiah@stable.ecn.purdue.edu (Ranjan S Muttiah)
Newsgroups: sci.physics
Subject: Re: Report on Philosophies of Physicists
Date: 30 Aug 92 20:46:44 GMT
Organization: Purdue University Engineering Computer Network

In article <mcirvin.715196487@husc8> mcirvin@husc8.harvard.edu (Mcirvin) writes:
>>The folks in the 17th and 18th century
>>seem to have gotten along with Newtonian physics much easier
>>than have the moderns.  Short of Leibniz's characterization of
>>gravity as an "occult force", by and large, they were happy
>>to accept and work with it in practice.  Not that it made it
>>right of course :=).
>I'm not quite so sure about this.  Newton himself was troubled by
>the idea of action at a distance with no intermediary.  Many others
>were as well.  Philosophers like Berkeley were distressed at what they
>saw as sloppy reasoning in the math Newton had used to back up his
>statements.  There was some support for Descartes' cosmology in which
>planetary motion was determined by vortices in a swirling ether, and
>for Goethe's optics, in which white light had no colored components.
>
>There was easily as much jumping to theological and philosophical
>conclusions from Newtonian physics as there has been from 20th-
>century physics, at least if you scale for the respective size of
>the media apparati.  Newton got into the act; he was an alchemist
>and heretical religious thinker himself, and used the ideas of absolute
>space and time and mechanical determinism to further his theological
>views.

Something I forgot to follow up on earlier.  I don't think there was
as much a finality to the work of Newton as when compared to what was
found in relativity and QM.  As Einstein showed, it was possible to predict 
Newtonian physics using a different set of assumptions.  To find any new reality, 
one would have to walk through the castle doors laid by relativity and QM: 
relativity sets an upper limit on speed of communication, QM a lower limit 
on measurement. Period.  To speak of anything beyond that would be nonsensical 
according to these theories.  There is a sense of arbitrariness here that may
bother some.  Luckily, my job doesn't depend on it.
Newsgroups: sci.physics
From: sarfatti@well.sf.ca.us (Jack Sarfatti)
Subject: Status of FTL QM Communication
Organization: Whole Earth 'Lectronic Link
Date: Mon, 24 Aug 1992 02:08:59 GMT


Status Report on Quantum Connection Communication
by Jack Sarfatti

If we make the seemingly natural assumption that the phase shift (between
reflected and transmitted beams) in the transmitter interferometer beam
recombiner for incident pair-correlated light is the same as it is for
uncorrelated light, then, it is generally true, barring tapping of energy
from vacuum fluctuations, that there is no mean quantum connection signal
at the receiver. This is true even in presence of absorption. While
absorption shifts the phase away from 90 degrees, there is a compensating
effect at the receiver such that the difference in receiver count rates is
zero in the mean.

Conservation of energy implies that the phase shift is cosb = -
|a|^2/2|r||t| where a, r and t are the absorption, reflection and
transmission amplitudes. The nonlocal effect of absorption in the
transmitter beam recombiner at the receiver precisely cancels the parity
violating signal in the sense of statistical average values.

On the other hand, if we do not assume that the phase shift for
uncorrelated light input to the recombiner carries over to the correlated
input, then any value of cosb is compatible with energy conservation. Also
it appears that one can microengineer any cosb one wishes by putting in an
optical inhomogeneity in the internally reflected return path inside the
glass plate. This would seemingly permit parity-violating quantum
connection communication in the mean (i.e., controllable shifts of average
value of difference in receiver count rates). The problem then is how to
interpret cosb not equal to zero for uncorrelated light where it appears to
imply non-conservation of energy or perturbing or the vacuum or some sort
of screening effect at the surfaces of the plate modifying the boundary
conditions for Fresnel's equations.

There is also the possibility of locally decoding quantum connection
messages inside the window of opportunity of the cosb quantum fluctuations
about the mean. If the quantum fluctuations of cosb are correlated on a
time scale T then modulation times of phi much smaller than T might be
detectable. This requires investigation. It will involve the question of
possible fractal order in quantum fluctuation time series. Is it white
noise, brown noise, pink noise etc. The problem becomes a lot more complex
in that case. This is the direction that I think Brian Josephson is taking
when he says an extension of quantum mechanics is needed to account for the
hypothesis that living matter does utilize quantum connection
communication.
From: smorris@tweedledum.ucsb.edu (Stephen Morris)
Newsgroups: sci.physics
Subject: Re: Radioactivity and Superstition; was: Re: Are Your Light Bulbs Radioactive?
Date: 3 Sep 92 05:05:42 GMT
Reply-To: smorris@tweedledum.ucsb.edu (Stephen Morris)
Distribution: na

In article <1992Aug26.195524.25813@athena.cs.uga.edu>  
mcovingt@athena.cs.uga.edu (Michael A. Covington) writes:
++ All this talk about children ingesting smoke detectors points up one thing:
++ Much of the otherwise educated populace views radioactivity in a
++ superstitious way, with numinous awe, as if it were witchcraft.
++ 

This is the topic of an excellent book called "Nuclear Fear" by Spencer Weart.  
It is a resonable and balanced account of the history and phsychology of  
radioactivity, nuclear power, the bomb etc.

Physicists who go off on "Oh people are so stupid ..." tirades about this 
stuff are urged to read this book: it helps to bridge the gap and illuminate
the historical causes of radioactivophobia.

| S > < M | 
Newsgroups: sci.physics
From: bhoughto@sedona.intel.com (Blair P. Houghton)
Subject: Re: Progress Report FTL QM Communication
Organization: Intel Corp., Chandler, Arizona
Date: Tue, 1 Sep 1992 21:21:01 GMT

Hey, Jack, how about, if'n youse so smart, posting
a postscript picture of the setup.

				--Blair
				  "Stimpy-Ren Etalon."
Newsgroups: sci.physics
From: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr))
Newsgroups: sci.physics
Subject: Re: Report on Philosophies of Physicists
Date: 29 Aug 92 01:23:02 GMT
Organization: National University of Singapore

barry@arnold.math.ucla.edu (Barry Merriman) writes:












: 
: But, I'd think that if you learned anything from the survey, it
: would have been that this mushy, warm fuzzy philosphy is not the
: way to understand nature. You should be distressed by the way 
: philosophical tracts such as the Tao of Physics and Dancing Wu-Li 
: Masters have warped physics to fulfil some philosphical need, and
: sucked you into their fantasy. I can't believe you want to follow
: in their footsteps.
: 
: Why not become a _real_ scientist, instead of an intellectual gadfly.
: I take it you're at U of Washington? Take my advice (I went there 
: 10 years ago, BS Math, BS Phys): run on over to the physics dept, 
: and stay away from the philosphy dept. The more you learn, the more you will be  
: glad you did.
: 
: (I took plenty of philosophy courses---easy way to fulfil humanities
: requirements...:-)
: 
Come on, it is outrageous to refer to Capra et al as philosophers. You
are right, their stuff is trash, but there are philosophers with
worthwhile things to say about physics. You will get a deeper
understanding of eg General Relativity from Friedman's "Foundations of
Spacetime theories" than from the grotesquely over-praised MTW.
: --
: Barry Merriman
: UCLA Dept. of Math
: UCLA Inst. for Fusion and Plasma Research
: barry@math.ucla.edu (Internet; NeXTMail is welcome)
: 
: 
Newsgroups: sci.physics,sci.astro,sci.math,sci.philosophy.tech
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: Misner et al.
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Mon, 31 Aug 92 22:22:01 GMT

In article <mcirvin.715055017@husc8> mcirvin@husc8.harvard.edu (Mcirvin) writes:

>I still can't decide how I feel about MTW.  It gets referred to a lot
>on this group, but that has a lot to do with the fact that it devotes
>a lot of time to weird things involving black holes, and explains
>that particular subject in fair detail with lots of examples and nice
>pictures.  There are, however, a lot of problems with the book.  I
>despise the portions in which it lapses into bad free-verse poetry or
>clipped stereo-manual language without articles. 

As Segal has said of the University of Chicago, "It's not very good -
it's only the best there is."  This may no longer be true of MTW; I like
Wald quite a bit.  But when it came out I think it was true.
From: ted@physics.Berkeley.EDU (Emory F. Bunn)
Newsgroups: sci.physics
Subject: Re: Liquid mirrors (was Re: Rotating Bucket of Water ...)
Date: 4 Sep 1992 21:02:02 GMT
Organization: /etc/organization
Distribution: world
NNTP-Posting-Host: physics.berkeley.edu

I just found the specs on Borra's rotating liquid mirror:  It's F/2,
with a 1.5 mirror diameter, and he does indeed claim it's diffraction limited.
(Ap. J. 346:L41)

I think Berg is the other person who's publishing things about such mirrors,
but I haven't read anything of his.

-Ted

Newsgroups: sci.physics
From: kim@Lise.Unit.NO (Kim Gunnar St|vring \yhus)
Subject: Re: ELECTRON HELIX : ITS POWER AND POSSIBLITIES
Organization: Norwegian Institute of Technology
Date: Wed, 2 Sep 92 15:40:49 GMT

In article <12950073@hpspdla.spd.HP.COM>, ric@hpspdla.spd.HP.COM (Ric Peregrino) writes:
 > 
 > Regarding the electron helix.
 > 
 > This won't work.
 > 
 > You can't make a helix with magnetic fields which produces a bigger 
 > magnetic field than the sources. 

What about 4 electron beams passing close to each other, like this:
    A
    |     |       The magnetic field in this crossing could
  --+-----+-->    be stronger than the fields in the
    |     |       accelerators.
    |     |
 <--+-----+---
    |     |
          V
 > You can't accelerate with a magnetic field; F = Q V x B.
 > 
 > Q is a scalar, F and V are vectors, B is a pseudo vector and x denotes
 > the vector cross product. So an ion at rest will feel no force in a
 > magnetic field (V = 0), and an ion in motion is only deflected and 
 > the magnitude of V remains constant.
 > 
 > But don't stop thinking and studying,

What about static coloumb fields?
F.ex. the tip of a cone. Theoretically the field is infinite there.

  Kim 0
From: sichase@csa3.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Re: Why do protons outnumber antiprotons?
Date: 2 Sep 92 19:31:37 GMT
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
Distribution: na
Reply-To: sichase@csa3.lbl.gov
NNTP-Posting-Host: 128.3.254.198
Summary: Baryogenesis at the Electroweak Phase Transition
News-Software: VAX/VMS VNEWS 1.3-4   

In article <1992Sep2.023824.18450@cco.caltech.edu>, brahm@cco.caltech.edu (David E. Brahm) writes...
>sichase@csa1.lbl.gov writes:
>> [Sakharov's 3 conditions for generating a baryon asymmetry:
>>   1) Baryon violation   2) CP violation   3) Thermodynamic Nonequilibrium]
>> There is no baryon-number (B) violation in the Standard Model by itself.
>> Only in the framework of grand unified theories (GUTs) ... does B
>> violation become a part of the extended SM.
> 
>Not true.  Though the Standard Model conserves B classically (no terms in
>the Lagrangian violate B), quantum effects allow the universe to tunnel
>between vacua with different values of B.  This tunneling is _very_
>suppressed at energies/temperatures below 10 TeV (the "sphaleron mass"),
>_may_ occur at e.g. SSC energies (controversial), and _certainly_ occurs at
>higher temperatures.

Sorry about that.  I took a statement in Kolb and Turner somwhat out
of context.  They wrote that " in the context of GUTs and an expanding universe"
all three conditions were at hand.  I mistakenly rewrote that to say that
without GUTs there is no mechanism for B violation.  This is clearly false,
though the mechanism is quite different. 

The worst part is that I thought to myself "I should probably let this one
slide because Dave Brahm or some other expert will know more."  I didn't
listen to myself (nobody does...) and put my foot squarely in my mouth.
When will I ever learn?

-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: nicho@VNET.IBM.COM
Newsgroups: sci.physics
Subject: Re: Impure Mathematics
Date: 1 Sep 92 11:07:12 GMT
Reply-To: nicho@vnet.ibm.com

In <10511@sun13.scri.fsu.edu> Jim Carr writes:
>This joke would not be so popular if Paul Lynomial had been the
>victim of homosexual rape at the hands of a burly Curly Pi, for
>example.
  <sigh> why oh why oh why do those with critical conceptual deficiencies
always project those same deficiencies on others. The story is amusing
in it's clever use of language, in the same way as Finnegan's Wake is
a delightful read. The actual topic is (to the story) irrelevant. I
would have found it equally amusing under the conditions you describe,
as, no doubt, would all the other 'neanderthal' males who have commited
the heinous crime of having a slightly warped sense of humour.
  As a test, I have circulated this among some of the female staff here.
Most (being maths impaired) looked blank. Some thought it amusing, a
few winced at the puns, and then shook their heads sadly. None reacted
as we have seen here. Lets not judge the average reaction to something
like this from the few yahoos who get worked up enough to complain.
 -----------------------------------------------------------------
               ** Of course I don't speak for IBM **
Greg Nicholls ... nicho@vnet.ibm.com or nicho@cix.compulink.co.uk
                  voice/fax: 44-794-516038
Newsgroups: sci.physics
From: Y3111DAA@vm.univie.ac.at
Subject: This is a test; please ignore.
Organization: University of Vienna
Date: Fri, 28 Aug 1992 11:45:15 GMT

This was a test; please ignore.
From: mcirvin@husc8.harvard.edu (Mcirvin)
Newsgroups: sci.physics
Subject: Re: Satellite spying
Date: 25 Aug 92 23:50:05 GMT
Article-I.D.: husc8.mcirvin.714786605

ted@physics3 (Emory F. Bunn) writes:

[Calculation deriving 0.07 arc-second resolution for a spy satellite]

>Even taking into
>account the fact that this is a very rough calculation, that seems
>hard to believe.  It's significantly better than the best ground-based 
>telescopes, which get about 0.5 arc-second resolution on a good day.  
>Naively, one would expect those two resolutions to be comparable,
>since they're both limited by "seeing" (atmospheric turbulence).

This may not be such a significant discrepancy.  The atmospheric
limit, if I remember correctly, comes from fluctuations in the
atmosphere that have a characteristic size.  If you're at an
altitude of 3x10^5 m looking down, these have a smaller angular
size than if you're on the ground looking up, since they'll be
at an altitude on the order of 10^4 m.

The diffraction limit certainly seems more serious.

-- 
Matt McIrvin, Cambridge, Massachusetts, USA 
Newsgroups: sci.physics
From: wdb3926@zeus.tamu.edu (BRUTON, WILLIAM DANIEL)
Subject: Rotating Bucket of Water in a Gravitation Field...Part #2
News-Software: VAX/VMS VNEWS 1.41    
Organization: Texas A&M University, Academic Computing Services
Date: Fri, 4 Sep 1992 06:52:00 GMT

>Anyone ever proved that the surface of water in a bucket rotating
>in a gravitational field is a paraboloid? 
>
>Dan

Thanks for the replies reminding me how to work this problem.  It was 
not a homework problem from a class.  I was just trying to determine 
how fast one needs to rotate a cylinder of molten glass to make telescope
mirrors of a particular focal length.  Thanks.

I found the problem today in Halliday and Resnic Part 1, Chapter 17,
Problem 18.  The result in cylindrical coordinates is 
	z = w^2 r^2 / (2 g) , where w = angular velocity of the bucket.


I have a new question....

Suppose there is a closed cylinder filled with a liquid in empty space
(i.e. far away from any objects) and that one can somehow measure the 
pressure along the radial direction remotely.  If the cylindar is
rotating along the axis there will be a pressure variation along
the radius of the cylindar, right?    

Doesn't this say that there is some absolute inertia frame that
the rotation is to be measured from?  This reeks of "ether" so it
must be incorrect.  Were is my error?

I suppose this is some kind of apparent paradox in relativity.  I have
seen someone give a talk about the "rotating bucket paradox".  But
the speaker did not seem to clear up the paradox. 		 

Thanks again,
Dan

Newsgroups: sci.physics
From: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr))
Subject: Re: Misner et al.
Organization: National University of Singapore
Date: Mon, 31 Aug 1992 04:04:23 GMT

mcirvin@husc8.harvard.edu (Mcirvin) writes:
: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr)) writes:
: 
: > You will get a deeper
: >understanding of eg General Relativity from Friedman's "Foundations of
: >Spacetime theories" than from the grotesquely over-praised MTW.
: 
: I'll have to look that up.
: 
: I still can't decide how I feel about MTW.  It gets referred to a lot
: on this group, but that has a lot to do with the fact that it devotes
: a lot of time to weird things involving black holes, and explains
: that particular subject in fair detail with lots of examples and nice
: pictures.  There are, however, a lot of problems with the book.  I
: despise the portions in which it lapses into bad free-verse poetry or
: clipped stereo-manual language without articles.  The latter seems to
: happen, furthermore, when complicated calculations are being described.
: Also, the machinery it builds up to explain cotangent spaces and 
: differential forms is far too baroque for what is being explained, and
: I suspect it mostly confuses people.
: 
: Its major virtues are that it is fairly encyclopedic, at least concerning
: developments up to 1973, and that it has a lot of very good diagrams 
: where most books have none. 
: 
: Personally, from what I've read, I like Wald's book.  It was written
: a decade after MTW and Weinberg and consequently has some newer stuff
: in it.
:  
: -- 
I recommend Friedman for the discussion of the fundamental principles,
not for the technicalities. For that, Wald is good. Plus a good solid
differential geometry book. MTW is essential reading because it has been
so influential. By the way, Weinberg's book is notorious for the claim
that you don't really need geometry to understand GR. But somebody once
told me that Weinberg retracted this bizarre claim. Can anyone verify?

: Matt McIrvin, Cambridge, Massachusetts, USA
From: gilligan@bldrdoc.gov (Jonathan Gilligan 303-497-3861)
Newsgroups: sci.physics
Subject: Re: My son would like to know about photons...
Date: 27 Aug 92 00:02:26 GMT
Distribution: na
Organization: National Institute of Standards and Technology

In article <25778@dog.ee.lbl.gov> sichase@csa3.lbl.gov writes:
|>In article <1992Aug26.142916.533@csc.canterbury.ac.nz>, phys169@csc.canterbury.ac.nz writes...
|>>I have a question on behalf of my 9-year old son...
|>> 
|>>If you can split atoms, can you split photons?
|>
|>The simple answer (not completely satisfactory from an adult point of view)
|>would be "No."  "Splitting an atom" refers to breaking up its nucleus, which
|>is a composite object composed of neutrons and protons.  But a photon
|>is fundamental.  It has no constituents and therefore cannot be split
|>anymore than an electron or quark (so far as we know) can be split.

There is a device called an optical parametric oscillator that will
split a photon into two photons of lower energy. However, this is
somewhat pedantic and Scott's answer is probably closer to the spirit
in which your son asked his question.

---Jon
-- 

Disclaimer --- The government probably disagrees with my opinions.
From: bweiner@ruhets.rutgers.edu (Benjamin Weiner)
Newsgroups: sci.physics
Subject: Re: Length scales in physics 4 - the Planck length
Date: 26 Aug 92 21:31:38 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

matmcinn@nuscc.nus.sg writes:
>In short, I am not convinced that eg the Planck length has any
>particular meaning or significance. People can waffle on about "buckets
>of dust" until they spacetime foam at the mouth...but where does it get
>you? We hear that superstrings are of "length" 10^-33 cm, at which
>length spacetime is replaced by something else, so depriving words like
>"length" and "string" of their meaning....

Well, I'm with you there; I have no idea of what the Planck length
"means."  Neither, I imagine, do most of us.  If you draw examples
from the exotica of theoretical physics, it is easier to deflate
dimensional analysis than if, for example, you are just trying to
do a magnetostatics problem or something more useful like that.  After
all, there are a lot of things that don't make any sense "at the
Planck length," including me.
Newsgroups: sci.physics
From: staffelb@acd.acd.ucar.edu (Thomas Staffelbach 497-1499 room 382)
Subject: Re:electron mass in body
Organization: Ntl Center for Atmospheric Research, Atmospheric Chemistry
Date: Wed, 26 Aug 1992 13:49:25 GMT

Somebody asked about the percentage of the electron mass
in the human body.
The electron mass is 9e-31 kg.
The proton and neutron mass are about equal, 1.6e-27 kg.
There are about as many neutrons as protons as electrons, which leads
to a ratio of 9e-31/2/1.6e-27=3-e4=0.03 %

Newsgroups: sci.physics