HDTenEightyP/NetNews huggingface dataset:
From: kmc@netcom.com (Kevin McCarty)
Subject: Re: QM non-causal?
Try-To-Followup-To: A Clean Well Lighted Place
Summary: let's get our priorities straight.
Keywords: think before speak, know before say
Organization: Self
Date: Thu, 24 Dec 1992 06:30:41 GMT

In article <448@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:
>In article <1992Dec21.191210.4740@galois.mit.edu>, jbaez@riesz.mit.edu (John C. Baez) writes:
>> In article <440@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:
>> 

[elisions]

>> >I suspect that
>> >Everett only succeeds in obscuring the problem with some pointless
>> >mathematics. 
>> 
>> Please read his work before critiquing it, huh?

[elisions]

>Reading Everett
>is a low priority on my long list of things I would like to do.
>
>Paul Budnik

Now, if only posting about things low on the priority list of things
to find out about were equally low on the priority list. <sigh>.
-- 
Kevin McCarty (kmc@netcom.com)
Newsgroups: sci.physics
From: Leigh Palmer <palmer@sfu.ca>
Subject: Re: bubble in container
X-Xxmessage-Id: <A7663029AE011C19@rs12-annex3.sfu.ca>
X-Xxdate: Tue, 29 Dec 92 00:41:13 GMT
Organization: Simon Fraser University
X-Useragent: Nuntius v1.1.1d16
Date: Wed, 30 Dec 1992 00:39:58 GMT

In article <29DEC199215373722@venus.tamu.edu> RING,
dwr2560@venus.tamu.edu writes:
>Let's see if we can make the paradox a little clearer. Start with the
>sealed jar of incompressible fluid. Our gremlin builds a small sphere
>near the bottom of the container which naturally will contain a bit of
>fluid. Then through a tube he drains the sphere and fills it with
>air at the local fluid pressure. He then breaks the sphere and lets the
>bubble rise to the top, increasing the pressure everywhere. When the
>bubble reaches the top he reverses the procedure, surrounding it with
>a sphere, filling it with fluid, and breaking the sphere.
>
>The final state has the same fluid in the same volume but different
>pressure. In fact one can repeat the procedure ad infinitum to get
>as high a pressure as one likes.

'cept as soon as he pumps one femtoliter of air into the bubble the
pressure becomes infinite. :-))

Leigh
From: sichase@csa3.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Re: Richard P. Feynman
Date: 23 Dec 1992 12:22 PST
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
Distribution: world
NNTP-Posting-Host: 128.3.254.198
News-Software: VAX/VMS VNEWS 1.41    

In article <Dec.13.18.15.03.1992.6526@ruhets.rutgers.edu>, bweiner@ruhets.rutgers.edu (Benjamin Weiner) writes...
> 
>Sorry Dale, couldn't resist.  To stay close to drifting from the subject,
>I was wondering why physicists often feel compelled to put down engineers,
>and I thought of a few reasons:
> 
>2.  Physics grad students hate TA'ing the "physics for engineers" course.

Personally, I hate teaching "physics for people who don't give a damn
about physics."  This usually does not include engineers.  At MIT, most
of the engineering students were as interested as I was in our required
physics classes.  

As a grad student I TA'ed a class at UCB which is essentially "physics
for pre-meds."  Though many students just didn't give a damn, there were
enough that did to keep me busy and interested.  

-Scott
--------------------
Scott I. Chase			"It is not a simple life to be a single cell,
SICHASE@CSA2.LBL.GOV		 although I have no right to say so, having
				 been a single cell so long ago myself that I 
				 have no memory at all of that stage of my 
				 life." - Lewis Thomas
Newsgroups: sci.physics
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: TIME HAS INERTIA
Keywords: ATTENTION  Mr.  Benjamin WEINER
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Sat, 19 Dec 92 21:38:26 GMT

In article <1992Dec17.184403.26492@ugle.unit.no> kim@Lise.Unit.NO (Kim Gunnar St|vring \yhus) writes:

>I am tired of seing ABIAN treating all the nice people here on sci.physics the
>way he does. What can be done to make this SADIST disappear? 

Support a moderated version of the newsgroup sci.physics, and then read that.


Newsgroups: sci.physics
From: crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass)
Subject: Re: can sound waves boil water?
Keywords: ultrasound fetus heat
Organization: University of Virginia
Date: Sun, 27 Dec 1992 19:51:10 GMT

In article <1992Dec27.180159.20483@magnus.acs.ohio-state.edu> acampane@magnus.acs.ohio-state.edu (Angelo Campanella) writes:
>Hear! Hear!
>
>More needs to be discussed here about fetus exposure to ultrasound.
>
>My family is in a hiatus at this point.
>My children are grown, but my grandchildren have yet to be.
>
>And I fear about this wanton use of ultrasound for 'baby's first pucture',
>or what I interpret to be the behavior of our medical community to that end.

      Ultrasound is not used to take 'baby's first picture', and there
      *is* certainly discussion in the medical community of the medical
      effects of exposure to ultrasound.  However, I hasten to tell you
      that a friend's wife, a radiologist, gave herself nearly daily
      ultrasounds during a pregnancy with no apparent deleterious effect.

>What has occurred to date to speak against damage is only that no visible
>or calcualtable effects have been found TO DATE for fetal exposure to
>ultrasound.

      And considering the very useful knowledge gained by use of ultrasound
      vs. the 'risk' of something not yet noticed, I suggest continued
      use is much more prudent.

>But, considering that highly accelerated chemical formations are taking place
>in the fetus during the nine month period, I do shudder to propose that some
>affectation by ultrasound on these chemical proccesses is NOT occurring.
>
>I would not stake my professional reputation on it.

      However, that is not the question.  The question is whether deleterious
      medical effects occur in the fetus.  I think the medical
      evidence is overwhelming.

>I think that all women in childbearing should shun exposure to ultrasound.

      To their disadvantage.  Childbearing is a rather large medical risk
      for a woman.  Anything that lowers the risk saves lives.

      Do you honestly wish to increase women's mortality on a whim?

                            dale bass
-- 
C. R. Bass                                          crb7q@virginia.edu        
Department of Mechanical, 
     Aerospace and Nuclear Engineering
University of Virginia                              (804) 924-7926
Newsgroups: sci.physics
From: sarfatti@well.sf.ca.us (Jack Sarfatti)
Subject: re:Pagels Phenomenon - Kepley
Organization: Whole Earth 'Lectronic Link
Date: Thu, 31 Dec 1992 04:02:42 GMT


Apology accepted Kep.
Newsgroups: sci.physics
From: cliftonr@netcom.com (Pope Clifton)
Subject: Re: Why is the sky blue? in bed
Organization: t.b, t.p.d, & a.d
X-Newsreader: Tin 1.1 PL5
Date: Thu, 24 Dec 1992 05:40:26 GMT

James Kibo Parry (kibo@world.std.com) wrote:
: [sci.physics]
: In article <11571@sun13.scri.fsu.edu> jac@ds8.scri.fsu.edu (Jim Carr) writes:
: >And some people would be happy with the answer the Kibo created the 
: >universe, complete with your question and various answers, just a 
: >few nanoseconds ago, because...
: 
: ...because if you're not happy with it I'll destroy the Universe in a
: few more nanoseconds.
: 					-- K.

Do it.  I double-dare you.  You chicken or what?
  -- Clifton

--
cliftonr@netcom.com     Home: +1 808 521 9073  Work: +1 808 625 3234
Clifton Royston, Pope of the Church of the Subgenius in Paradise
"Have a revelation, the first one's free/Soon to be addicted to eternity" - HMR
Newsgroups: sci.physics
From: rsf1@Ra.MsState.Edu (Robert S. Fritzius)
Subject: Re: Nuclear Waste Disposal
Keywords: Accelerator Transmutation of Waste
Organization: Mississippi State University
Date: Mon, 28 Dec 1992 01:37:39 GMT

In (rsf1.723799992@Ra.MsState.Edu) I asked:
 
>Should there not be some way to bombard radioactive nuclear waste with
>sufficient quantities of high energy electrons, nuclei, or gamma rays so
>as to ignite a controllable exothermic "fission-fire" which reduces the
>waste material to mostly non-radioactive lighter elements while
>simultaneously supplying a thermal source for electrical power generation?
 
 [stuff deleted]
 
One e-mail responder, who may prefer to remain anonymous, wrote:
 
 [This is slightly changed from the original response.]
 
>There are indeed some people thinking about that - there was an article
>in Nuclear Instruments and Methods some time ago, but I don't have
>the reference handy .
 
>They call it ATW - Accelerator driven Transmutation of nuclear Waste .
 
 [stuff deleted]
 
>You have to build a high-current proton accelerator , fire at a target to
>produce a high current of neutrons and put the nuclear waste in the neutron
>stream.  If the neutron flux is high enough, you can convert all long-lived
>isotopes (Plutoninun,... ) to short-lived ones, and if you add a lot of
>chemistry and a power-plant, you can get the energy to drive the
>accelerator from the fission-process and still have some energy left.
 
>Advanteges:
 
>1) Small amount of fuel (subcritical i.e. can't explode) - Can't get out
>   of control: In case of a problem, just shut down the accelerator.
>2) You can use a lot of isotopes as fuel, much more than in an
>   nuclear reactor.
 
>Problems (just a few , there are more ... ) :
 
>1) You need a really high beam current ( some Amp's )
>2) You have to build a target that can stand the beam power
>3) You have to build a large chemical plant to remove the 'burned' Isotopes
>   and fill in new ones ( the fuel is circulated in molten salt ... )
>..... much more ....
 
This responder stressed the idea of a high neutron flux density as being a
central feature in the process.
 
Another responder, on this news group, intimated that the energy extraction
process would *not* be able to power the whole setup.
 
Any further comments on these two issues?
 
The impetus behind my original posting (although not stated in the post) was
the idea of somehow producing a gamma-rich environment to tickle neutrons
to death and let what follows follow.  The proton beam, if that's what
we use, would be the "igniter" for this process.
 
How about some insights or speculations on the gamma-induced neutron-decay
issue and especially on whether it is possible for that process to ever go
critical.  Don't want to burn up the world, but then that *would* solve the
nuclear waste problem.
 
My apology for that "textbook" and "endothermic" raciblesse(*).
 
 
Robert S.Fritzius  rsf1@ra.msstate.edu
 
(*) That's a new word for bull dung.
From: wellison@kuhub.cc.ukans.edu
Newsgroups: sci.physics
Subject: HeNe lasers for sale...
Date: 31 Dec 92 10:36:27 CST
Organization: University of Kansas Academic Computing Services


These are .8mW to 1.2mW red (632.8Nm) HeNe modules with power supply.
They run off of +12VDC at 600mA. They also have the capability of TTL control
(I.E. true when low, +5vdc off). They are new surplus from the bar code
industry. They measure 6.5"L x 2.25"H x 1.25" W. I am selling them for $45
plus $5 shipping (overseas shipping cost more :-( I noticed that the same
module is being sold by dealers like Meredith Instruments for $75 plus $10
shipping. They are rated as a Class II laser device (except for the >1mW which
is Class IIIa). If you ever wanted to play with a laser but the bucks were to
high, this is the way to go.....

-=-= Wes =-=-

(each module has a 30 day warrenty...)
From: bhoughto@sedona.intel.com (Blair P. Houghton)
Newsgroups: sci.physics
Subject: Re: Scientific Truth Is Not Found in Threats
Date: 30 Dec 1992 21:06:58 GMT
Organization: Intel Corp., Chandler, Arizona
NNTP-Posting-Host: stealth.intel.com

In article <1992Dec29.235031.1574@cs.unca.edu> kepley@cs.unca.edu (Brad Kepley) writes:
>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.

Feh.

Jack couldn't find his asshole with both elbows, much
less a lawyer.

><cooling down now>

Neat.

A flaming lurker with diags.

				--Blair
				  "Parse it any way you like."
From: gross@maxwell.ucsc.edu (Mike Gross)
Newsgroups: sci.physics
Subject: Re: Searching gravity info:
Date: 21 Dec 1992 17:26:26 GMT
Organization: University of California, Santa Cruz
NNTP-Posting-Host: maxwell.ucsc.edu

In <swarner.02ur@bbs1984.chi.il.us> swarner@bbs1984.chi.il.us (Steve Warner) writes:

>         Good morning all...
>    Some friends and I have a running interest in matter physics, and 
>we are in the process of gathering information on current gravity 
>theory. We are intrigued by the notion of "Dark Matter" and the role 
>it plays in both Cosmology and Physics. 
>    In a recent article written by Corey S. Powell, entitled, "Machos 
>or Wimps; Astronomers stalk the invisible cosmic majority" (Scientific 
>American, January 1993, pg 27)....John A Bahcall of the Institute for 
>Advanced Study in Princeton, writes; "the dark matter problem may be a 
>sign that some fundamental aspect of physics, such as the theory of 
>gravity, demands revision." 
>    A statement such as this, tends to heighten ones interest and 
>thirst for follow-up information....which of course, I'm hoping someone 
>"out there" can supply reference to. Has anyone seen published information on 
> current trends in gravity theory, from books, periodicals, journals or 
>letters? Any help would be greatly appreciated.
>Thanks in advance....
> 
>Steve Warner    Swarner.@bbs1984.chi.il.us
>------------------------------------------
>Get your facts ft, and then you can distort 
>them as much as you please.       -Mark Twain-  

Dark matter is now a very hot field, so you're not likely to find any correct
books out there. The COBE measurement announced last year sent all the
theorists back to the drawing board. The latest theory people are playing
with is a mixture of cold, hot and baryonic dark matter, with contributions
of around 60%, 30%, and 10%, respectively. Much of the research is still
underway, so it won't be published for several months. Watch for Ma &
Bertschinger, and Klypin, Holzmann, Primack, & Regos, both in the
Astrophysical Journal (KHPR is further along now).

The competing theory is called "Tilted CDM," and it comes from mucking around
with the inflation potential. The COBE group likes this one (though I'm not
sure offhand if Smoot et al talks about this).

You might wish to get started by looking for a review article in Annual
Reviews of Astronomy and Astrophysics. That should give you background, and
then you can attack the Citation Index. Good places to look for other
references are Monthly Notices of the Royal Astronomical Society and Physical
Review D. Be *very* careful to take statements about why CDM is better than
HDM with a grain of salt. You can find the original minimal CDM theory in
books -- my favorites are Kolb & Turner and Linde -- but be wary of old
information.

There was a lot of talk on this topic in the Texas/PASCOS meeting in Berkeley
last week, so the meeting proceedings might be useful. However, it takes lots
of months for these things to get published.

Good luck.

Mike Gross
Physics Board
Univ of California                    GO SLUGS!!!!!!
Santa Cruz, CA 95064
gross@lick.ucsc.edu
From: marty@amaterasu.physics.uiuc.edu (Marty Gelfand)
Newsgroups: sci.physics
Subject: Re: Link invariants and gauge theory
Date: 23 Dec 92 00:42:25 GMT
Organization: Department of Physics, University of Illinois at Urbana-Champaign

In article <Dec.22.18.34.29.1992.25749@ruhets.rutgers.edu> bweiner@ruhets.rutgers.edu (Benjamin Weiner) writes:
>marty@amaterasu.physics.uiuc.edu (Marty Gelfand) writes:
>[defending conformal field theory as useful in condensed matter]
>
>>  Conformal field
>>theory provides a classification scheme for 2D critical points
>>(due to Belavin, Polyakov, and Z.m.l.chikov):  ...
>
>Zamolodchikov (there are two, Alexander and Alyosha; both are here
>(Rutgers) right now.)  Zamolodchikov(s) is (are) usually thought of as 
>string theorist(s) but this stuff is having an impact on condensed matter -
>I tease the theory grad students that all the talks they give are 
>about conformal field theory, whether in particle physics OR condensed
>matter.  I don't understand it, though, so I can't give references -
>sorry!
  And a sorry from me as well...I've been informed via e-mail that
the classification scheme is more properly attributed to Friedan, Qui, and
Shenker (BPZ and FQS are often cited together, which accounts for
my confusion).  I'll try to do better next time...
--Marty Gelfand  marty@amaterasu.physics.uiuc.edu
From: doug@retzlaff.llnl.gov (Douglas S. Miller)
Newsgroups: sci.physics
Subject: Re: APS Award for Outstanding Doctoral Thesis Research
Date: 30 Dec 92 21:59:51 GMT
Organization: UC Davis Dept of Applied Science at LLNL

In article <1992Dec22.054323.22949@udel.edu> berryh@huey.udel.edu (John Berryhill, Ph.D.) writes:
>
>Wow, a whole $1000, a certificate suitable for framing, and a resume' line.

At the APS Division of Plasma Physics meeting this November which my
wife attended, the APS DPP Award for Outstanding Doctoral Thesis
was awarded.  The recipient went up to the lectern, accepted the award
and said something like "I thank my advisor for making me do all the
work that got me this fine award...but I would rather have gotten out a 
year earlier."
From: rsf1@Ra.MsState.Edu (Robert S. Fritzius)
Newsgroups: sci.physics
Subject: General Relativity Tests
Keywords: Perihelion advancement
Date: 28 Dec 92 15:34:14 GMT
Organization: Mississippi State University

In the Authorized Translation of  Einstein's book "Relativity, The Special
and General Theory,"  Crown Publishers, Inc., New York (1961), Appendix III
is titled, "The Experimental Confirmation of the General Theory of
Relativity."  Section (a) of this appendix deals with the motion of the
perihelion of Mercury.  (Keep in mind that this translation is aimed at
friendly high school graduates.)
 
In the book, the (simplified?) GR equation that Einstein used to compute
the angular advancement between perihelion passages for a planet is shown
on page 125.
 
		  24 * pi^3 * a^2
	  +  ------------------------
	       T^2 * c^2 * (1 - e^2)
 
where  a = semi-major axis of planetary ellipse
       T = period of revolution
       c = speed of light
       e = eccentricity of planetary ellipse
 
 
The factor  pi^3 standing alone looks intimidatingly mathematically
elegant, and that other stuff is nice, but
 
		  pi^2 * a^2        v^2
to first order   ------------  =  -------- ,
		  T^2 * c^2         c^2
 
where v is the average speed of the planet in orbit.
 
 
		24 * pi         v^2
This gives    -----------  *  --------  = 43 arc secs, for Mercury.
	       (1 - e^2)        c^2
 
It's my understanding that the  c^2 factor relates to Einstein's view that
gravitational effects (static and dynamic) travel at the speed of light and
that 'c' in this case represents *the* gravitational propagation speed.
 
(If the so-called static speed of gravity was, say  200,000 times the speed
of light, or greater, then Einstein's equation would predict an undetectable
advancement for Mercury and we wouldn't be having all this fun.)
 
The quantities   v^2 / c^2   and  (1 - e^2)  seem like reasonable elements,
and reasonably placed, in such an (approximate) equation.
 
Can somebody provide a *rigorous* general relativity rationale for the
remaining  24 * pi  factor?  (If this is the wrong question, please
answer the question that should have been asked.)
 
Robert S. Fritzius  rsf1@ra.msstate.edu
 
 
Newsgroups: sci.physics,sci.math
From: tim@iss.nus.sg (Tim Poston)
Subject: Re: Can space-time intersect itself?
Organization: Institute of Systems Science, NUS, Singapore
X-Newsreader: Tin 1.1 PL4
Date: Wed, 23 Dec 1992 09:29:59 GMT

jbaez@riesz.mit.edu (John C. Baez) writes:

: An embedding is a 1-1 immersion, or loosely one with no
: self-intersections.  
Not quite.
The immersion of the real line into the torus
that winds around with an irrational slope is 1-1,
but _not_ an embedding because the image
has a topology different from the real line.
(A sequence of points in R can go to infinity
while their images in the torus tend to a limit.)

For compact manifolds, true,

   embedding = 1-1 immersion ;
   
but compact is as boring as a positive definite metric.

tim

______________________________________________________________
	      My lucky number irrational.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Newsgroups: sci.physics
From: bhoughto@sedona.intel.com (Blair P. Houghton)
Newsgroups: sci.physics
Subject: Re: bubble in container
Date: 30 Dec 1992 21:02:33 GMT
Organization: Intel Corp., Chandler, Arizona
Distribution: world
NNTP-Posting-Host: stealth.intel.com

In article <29DEC199215373722@venus.tamu.edu> dwr2560@venus.tamu.edu (RING, DAVID WAYNE) writes:
>Let's see if we can make the paradox a little clearer. Start with the
>sealed jar of incompressible fluid. Our gremlin builds a small sphere
>near the bottom of the container which naturally will contain a bit of
>fluid. Then through a tube he drains the sphere and fills it with
>air at the local fluid pressure. He then breaks the sphere and lets the
>bubble rise to the top, increasing the pressure everywhere. When the
>bubble reaches the top he reverses the procedure, surrounding it with
>a sphere, filling it with fluid, and breaking the sphere.
>
>The final state has the same fluid in the same volume but different
>pressure. In fact one can repeat the procedure ad infinitum to get
>as high a pressure as one likes.
>
>:-)

Keep smiling.

There's no paradox, only a misapprehension.

The pressure in the bubble can not change unless the number
of atoms of gas change, the temperature of the bubble
changes, or the volume of the bubble changes.

(BTW, Since the fluid is incompressible, it is also inextensible,
since it couldn't have been compressed enough to extend any).

In this situation, in fact, the bubble will rise only
because the fluid will fall so as to reduce the
gravitational potential energy of the system (this assumes
that the density of the fluid is greater than that of the
gas; and I do not expect this assumption to hold in all
cases of incompressible fluids and ideal gases).

However, if you let the vessel in which this experiment is
conducted be an expandable one...

				--Blair
				  "Flotsam vs. jetsam:
				   the eternal struggle."
From: rev@enh.nist.gov
Newsgroups: sci.physics
Subject: RE: Why does sticky tape glow?
Date: 22 Dec 92 01:51:21 GMT
Organization: NIST

In a previous article, b259phl@utarlg.uta.edu (PHILIP LIPPEL) wrote:
>This phenomenon was widely discussed back when I was processing my own B&W film
>in highschool. I wish I knew the answer, but since I don't, I'll just pass on a
>related piece of folklore. A similar effect can be seen if you break a 
>wintergreen Lifesaver in a dark room.

For more drama with the life saver, chew it.  The sparks fly from tooth to 
tooth.  It's really a pretty cool effect to see, but as to why...well, I 
didn't know in college, and I still don't.  =(  But I'd like to know...


-Rob Vest
 rev@enh.nist.gov
Newsgroups: sci.physics