HDTenEightyP/NetNews huggingface dataset:
From: prim!dave@germany.eu.net (Dave Griffiths)
Subject: Transactional interpretation of QM
Organization: Primitive Software Ltd.
Date: Sat, 26 Sep 1992 21:50:15 GMT

Having seen a lot of debate here recently about the collapse of the wave
function and the Copenhagen interpretation, I wondered what people thought
of the "transactional interpretation" of QM? I came across this paper by
John Cramer (Rev Mod Phys July 1986) where he describes his interpretation.

I've only skimmed through it, but it sounds like a fun idea. Basically an
emitter sends out an "offer wave" in both time directions, and an absorber
responds by sending back a "confirmation wave" in the reverse time direction.
This process "continues to completion with satisfaction of quantum boundary
conditions at emitter and absorber loci, in analogy with a standing wave
between terminating walls". Furthermore "In the transactional interpretation
the collapse, i.e., the development of the transaction, is atemporal and thus
avoids the contradictions and inconsistencies implicit in any time-localized
SV collapse".

Personally, I don't buy it because of the requirement for things to go
backwards in time. This approach to physics seems to beg an awful lot of
questions!

Dave Griffiths
From: johnh@prism.CS.ORST.EDU (John Holeman)
Newsgroups: sci.physics
Subject: Re: Make time stop?
Date: 30 Sep 92 06:16:40 GMT
Article-I.D.: CS.1992Sep30.061640.4023
Organization: Oregon State University, Computer Science Dept.

In article <1992Sep30.000423.15940@spss.com> markrose@spss.com (Mark Rosenfelder) writes:
>In article <1992Sep29.171040.26549@hellgate.utah.edu> tolman%mindblow.cs.utah.edu@cs.utah.edu (Kenneth Tolman) writes:
>>  A frame of reference moving very very fast has a time dilation, correct?
>>(That is, if we are still and looking at someone moving they are "slow")
>>When we look out into the universe- all galaxies are moving away from us,
>>and the very far away galaxies are moving near the speed of light.
>
>So far so good.  When you look into the night sky, you're looking into 
>the past-- a few years ago for the nearby stars, a few billion years ago
>for distant galaxies.
>
>>Therefore, THEIR TIME HAS BARELY BEGUN.  Their civilization's have not 
>>started, and they live in a "young" universe.  
>
>Whoops, no.  It's true that we see Andromeda as it was two million years 
>ago.  But it's not that Andromeda is stuck in the past.  It continues to
>exist, in the present; it's just that our news from there is two million 
>years out of date.
>
>>Thus, if we could travel
>>faster than light, we could jump backwards and live this whole universe
>>through once again.  
>
>No; even if you could travel instantaneously, you could only arrive in
>the Andromeda of today (whose light won't reach us back on Earth for two
>million years), not the Andromeda we see (that of two million years ago).

Noticable time dialation occurs only between two frames of reference 
are moving at reletivistic speeds to each other.  If we were travelling
toward Andromeda near the speed of light, any motion detected within the
Andromeda frame of reference will appear to us to slow down, as per 
special reletivity.  Likewise if an Andromedan were to watch us approach,
all motion occuring with in our frame of reference will appear to slow
down.  However, once we reach Andromeda and begin moving at non-
reletivistic speed, that is, to join thier frame of reference, things
will return to "normalcy".
From: seh@neutron.physics.arizona.edu (Steven E. Hoell)
Newsgroups: sci.physics
Subject: Rishon
Date: 29 Sep 92 17:30:39 GMT
Distribution: na
Organization: University of Arizona, Tucson AZ

Does anyone know what a "rishon" is? Someone asked me about this a while
ago and I couldn't find it in the "Particle Data Handbook." Sounds pretty
exotic, though...

Thanks,
Steve Hoell		seh@neutron.physics.arizona.edu
Newsgroups: sci.physics,rec.pets.cats
From: schroede@bnlux1.bnl.gov (gary l. schroeder)
Subject: Re: Radioactive Cat: How Dangerous is She? <LONGISH>
Organization: Brookhaven National Laboratory, Upton, NY 11973
Date: Fri, 25 Sep 1992 18:24:29 GMT

In article <1992Sep9.225426.20316@hsv3.lsil.com> mvp@hsv3.lsil.com (Mike Van Pelt) writes:

>An old high-school friend of mine went to work at a nuclear plant after
>he got out of the Navy, and he had a story or two to tell about I131
>treatments.  Like the time they had to cordon off the Port-A-Pottie
>with radiation hazard signs and guards because someone had their
>thyroid done, came to the site, and used their john.  And how they
>trace the plume of I131 downstream from the sewage treatment plant
>whenever anyone in the city gets a thyroid treatment.

Radionuclides used in patient therapy such as iodine-131, are 
non-regulated in that the material that leaves the patient via excreta
is non-regulted.  In other words, the hospital simply is not required to
track the material as it leaves the patient.  When I was going to school
(which was directly accross the street from both a Burger King and a
major hospital) one of my profs said that if you _really_ want to get
your daily radiation dose, just go to the Burger King for lunch.  You
can track the iodine all over the place (mostly on door handles).  It
comes right out as sweat and sticks to whatever the patient touches
after they leave the hospital.  (Many out patients go to the Burger King
after their treatment. )

As far as traces in sewers go, it's really easy to find.  We do the same
thing where I work.  When we get a spike on the monitor, ten to one it's
someone peeing after getting an injection of iodine.
 

-- 
------------------------------------------------------------------------
Gary L. Schroeder  		|  
schroede@bnlux1.bnl.gov         |             Boo. 
Brookhaven National Laboratory  | 
Newsgroups: sci.physics
From: steinly@topaz.ucsc.edu (Steinn Sigurdsson)
Newsgroups: sci.physics
Subject: Re: Spin
Date: 29 Sep 92 10:52:05
Organization: Lick Observatory/UCO
	<1992Sep29.065640.18839@CSD-NewsHost.Stanford.EDU>
NNTP-Posting-Host: topaz.ucsc.edu
In-reply-to: pratt@Sunburn.Stanford.EDU's message of Tue, 29 Sep 1992 06:56:40 GMT

In article <1992Sep29.065640.18839@CSD-NewsHost.Stanford.EDU> pratt@Sunburn.Stanford.EDU (Vaughan R. Pratt) writes:

   If we had chosen our parents more carefully so as to be born in a solar
   system with a binary star, we might find it easier to determine the
   velocity of gravity experimentally than with good old Sol.  In a binary
   system the gravity from each component should arrive at the other
   component delayed by several seconds, whence it should appear to be
   coming not from the center of the "transmitting" star, but where that
   center was a few seconds earlier.  While this isn't much of a
   displacement, it might be just enough to be measurable with enough
   technology, care, and time.

Figured I might as well interject at this point.
Tom? You lurking there waiting to pounce??? ;-)
The "gravity" from each component in a binary star does
not arrive delayed, see for example LPPT 12.4 and MTW 18.4 and 39.9,
especially eqn 39.64

Essentially, in GR, bodies moving geodesically act as if the
classical force is coming from a body at the geodesically projected
position of the body - to the first 2.5 orders at least, the higher
order effect shows up as gravitational radiation. What happens
if one of the bodies is moved by a "external force" is not clear,
as the boundary conditions of the problem have never been well
defined as applications of "force" require some rearrangement
of the local mass-energy distribution...

*  Steinn Sigurdsson   			Lick Observatory      	*
*  steinly@lick.ucsc.edu		"standard disclaimer"  	*
*  The laws of gravity are very,very strict			*
*  And you're just bending them for your own benefit - B.B. 1988*


Xref: sparky sci.physics:15516 soc.culture.china:26523
From: joe@astro.as.utexas.edu (Joe Wang)
Newsgroups: sci.physics,soc.culture.china
Subject: Re: Eastern Philosophy
Date: 27 Sep 92 23:19:21 GMT
Followup-To: sci.physics,soc.culture.china
Organization: McDonald Observatory, University of Texas @ Austin

In article <1992Sep23.190947.1244@galois.mit.edu> jbaez@riesz.mit.edu (John C. Baez) writes:
>I realise that this has little to do with physics by now, but if
>you are going to try to turn physicists on to Eastern philosophy
>you might as well give some precise information, rather than vague
>remarks like the above, which will probably only strengthen their
>opinion that it's all a bunch of mush.  It's not, it's very interesting,
>and it might even help one be a better scientist to know some.

I think it's very misleading to classify modes of thought as Eastern
versus Western.  One curious thing that happens when people talk about
"Eastern mysticism" as opposed to "Western rationalism" is that they 
seem to forget about Eastern schools of thought which are rationalistic
and Western schools of thought which are mystic.

One curious example of this is the fact that almost every book on
"Eastern mystic philosophies" leaves out Confucianism.  If you were to
read the "Tao of Physics" or the "Dancing Wu-li Masters," you wouldn't
know at all that Confucianism exists, much less that it was one of the
most influential if not the most influential philosophy in China for
over two thousand years.  The reason for this is that the Confucianism
tends to look down at mysticism and hence doesn't fit at all into the
idea that "Eastern" philosophy is more mystical than "Western"
philosophy.  Hence most writers who talk about "Eastern mysticism" try
to ignore it (as they ignore "Legalism", "Mohism", and "Maoism").

On thing that's important to note is that the attempt to mix science
and Eastern philosophy seems mainly to be a Western effort which has
little impact on scientists from the East.  Every scientist that I
know from China practices science in exactly the same way as their
Western counterparts.  Indeed, I suspect that public attitudes toward
science in China are much more positive than public attitudes toward
it in the United States.

I know of one Buddhist who is also a scientist, and he seems to
reconcile his beliefs exactly the same way a devout Catholic scientist
would reconcile science and Catholicism.  In other words, he doesn't
mix the two.


Xref: sparky sci.physics:15663 sci.astro:10247 sci.math:12454 sci.philosophy.tech:3478
From: phfrom@nyx.uni-konstanz.de (Hartmut Frommert)
Newsgroups: sci.physics
Subject: Re: What is the Speed of Gravity - A Call for a Volunteer
Date: 1 Oct 92 13:19:29 GMT
Organization: Dept. of Physics, University of Constance

matmcinn@nuscc.nus.sg (Mcinnes B T (Dr)) writes:

>I hope that the eventual entry will discuss what happens when the
>gravitational waves are propagating in a background which is not
>approximately flat. Does "gravity" propagate at the speed of light near
>a black hole?

To my knowledge, Einsteinian gravity waves always propagate at the same
velocity as "classical" light, i.e. mass- and structureless point particles
[which do not exist] along null geodesics.


 Hartmut Frommert                 <phfrom@nyx.uni-konstanz.de>
 Dept of Physics, Univ of Constance, P.O.Box 55 60, D-W-7750 Konstanz, Germany
                                           -- Eat whale killers, not whales --
Newsgroups: sci.physics
From: sarfatti@well.sf.ca.us (Jack Sarfatti)
Subject: PARAPHYSICS
Organization: Whole Earth 'Lectronic Link
Date: Sun, 4 Oct 1992 02:12:35 GMT


Professor I. J. Good worked with Alan Turing breaking the Nazi war code in
MK ULTRA. On April 24, 1980 Good gave a paper in Detroit at the American
Culture Association called "Is there any scientific basis for
parapsychology?". In that paper he wrote: "On many planets life will be
ahead of us in development, and, where it is, it will usually be hundreds
of millions of years ahead, for humans have only recently evolved. Such
life will often be ultra-intelligent, or it might have been supplanted by
ultr-intelligent machines or biomachines or disembodied fields of some
kind. Such entities will have had plenty of time to take over the galaxy
but the society of ultr-intelligent entities might have a serious
communication problem because the diameter of the galaxy is some 80,000
light years. The entities will haveperfected telepathy if telepathy is
possible at all, and, if telepathic signals can be propagated with infinite
speed, the whole society of ultra-intelligent entities can be in continual
instantaneous communication and so the individuals can act as the cells of
a vast brain, or integrated immortal consciousness..... I call this...
Godd."

Some time earlier Martin Gardner in "Magic and Paraphysics" (MIT Technology
Review, June 1976 - reprinted in SCIENCE,GOOD,BAD AND BOGUS) wrote: "Our
consciousness, according to Sarfatti and others, can instantly perceive and
influence any part of the universe. It can leave the body and roam, faster
than a photon, through endless reaches of space and time. If a
superintelligence in some distant galaxy wishes to communicate with Uri
Geller and give him the power to bend a spoon, there is no reason why it
can't."

The Esalen Institute in Big Sur housed Jenny O Conner and "THE NINE" which
was allegedly (according to the Esalen catalog) a Godd-like entity that
appears to ahave influenced the Esalen-Soviet exchange program that evolved
into the present-day Gorbachev Foundation headed by Jim Garrison a former
director of Esalen. I was the first director of the Esalen Paraphysics
program as reported in introduction to Gary Zukav;s best seller THE DANCING
WU LI MASTERS.
Newsgroups: sci.physics,sci.math
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: How do you draw a straight line?
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Tue, 6 Oct 92 03:02:13 GMT

In article <1992Oct5.154211.21663@ecrc.de> micha@ecrc.de writes:
>In article 24242@access.usask.ca, choy@skorpio.usask.ca (I am a terminator.) writes:
>>How do you know that the line you draw is really straight? What
>>defines straightness?
>
>This is something I've been wondering about since a long time. Although we can
>make a circle as precise as we want, I think we cannot make a really
>precise straight line - every straight line is made from another one or from a tool
>that has been made using some older straight lines - so it all comes down to
>copying a line that has been made thousands years ago. Although we have precise
>instruments and tools, we can only make better and better lines (so that eventually
>the error is less than an atom, and we are there), but IMHO there is no
>process to create a straight line directly. Or is it?

The compass is nice because it works straight from the definition of a
circle, while a ruler, as you note, is not so nice since it does not
work from the definition of a straight line as the shortest path between
two points.  However, there is a machine that has been built which draws
straight lines "by definition."  Alas, I forget how it works.  Maybe
someone can remind us or reinvent it.  Of course this is not to say it
really is better than a good ruler but it is philosophically satisfying.
I seem to remember that it was built, not for practical reasons, but
just to show it could be done.  Back in the age of mechanical (as
opposed to electronic) ingenuity they did this sort of thing.  Some of
you may know how to built a device which will measure the area of a
shape if you trace the outline of the shape.  Others may enjoy figuring
it out.  Nothing electronic allowed!  Big clue: Green's theorem.
Disclaimer: I would have to figure out the details myself so don't ask....





Newsgroups: sci.physics
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: black holes & baryon number
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Tue, 6 Oct 92 04:10:17 GMT

In article <718283204.2@mailbox.bison.mb> Paul.Ciszek@mailbox.bison.mb.ca (Paul Ciszek) writes:
>Organization: University of Denver, Dept. of Math & Comp. Sci.
>
>Could someone please clear up the following for me?
>
>Suppose we start with a cloud of hydrogen, with a total baryon number
>equal to the number of hydrogen atoms present.  As this cloud goes from
>protosun -> star -> supernovae -> neutron star, baryon number is conserved.
>Fine and dandy.  Now the neutron star collapses into a black hole.  I guess
>I ought to assume the black hole still "remembers" the baryon number somehow.
>Now, according to Hawking, the black hole evaporates into "radiation".
>Does it "evaporate" into light?  Or did he mean "particle radiation"?
>Is baryon number conserved in this last stage?

We have just been discussing this, so perhaps some kind soul will email
you some of what we wrote.  The short answer is "no-one knows."  The
not-so-short answer is that current theories seem to predict baryon
number nonconservation due to the process you describe, although many
people dislike this and are writing papers to wiggle out of it somehow.
Much worse than the baryon number nonconservation, at least in my
opinion, is the loss of unitarity.  

The black hole should emit particles of all kinds, not just light, but
nobody sees any reason why a black hole into which lots of baryons fell
should emit more baryons than antibaryons.


Newsgroups: sci.physics
From: bhv@areaplg2.corp.mot.com (Bronis Vidugiris)
Subject: Re: Defining local, causal etc., was: Hidden variable theories
Organization: Motorola, CCR&D, CORP, Schaumburg, IL
Date: Thu, 1 Oct 1992 22:40:27 GMT

In article <1992Sep29.170356.13002@newshost.lanl.gov> jlg@cochiti.lanl.gov (Jim Giles) writes:
)In article <1992Sep28.202508.17001@lmpsbbs.comm.mot.com>, bhv@areaplg2.corp.mot.com (Bronis Vidugiris) writes:
)|> [...]
)|> But it is possible to distinguish between theories where wavefunctions
)|> are hypothetical entities that collapse 'at the speed of light' (aka 'in a
)|> lorentz invariant manner), and wavefunctions are hypothetical entities that
)|> collapse 'instantaneously' - or some of the other equivalent alternatives
)|> that may not involve collapse.
)
)It is not possible to distinguish between wavefunctions that are
)hypothetical entities and  wavefunctions which are real objects.
)Not empirically.  Therefore, their introduction violates Occam's
)razor.

I worded my post the way I did to <try to> sidestep this very issue!

) A wavefunction is easily determined to be a mathematical
)abstraction which computes probability distributions.  I'm happy
)that they remain only that.   `Collapse' cannot be determined to 
)happen at all!  Since the wavefunction computes *distributions*, 
)it applies to large numbers of events, not to individual ones.

However, there is a undesirable (IMO) feature of QM with the current
formalism, a problem that can be avoided if the formalism is modified
only very slightly (i.e. the formalism is modified so that the hypothetical
wavefunction collapses in a different manner).

This feature is the 'non-locality' of QM.

However, a more important question is whether reality exhibits these
non-local effects.  This hasn't been totally answered, but no prediction
of QM has been proven wrong - yet.  However, QM hasn't been totally proven
right, and the modification to it is very small.

Anyway, if you set up an experiment with a pair of photons in the 'singlet'
state (i.e. opposite spins) and measure the spin of  both photons along
an arbitrary axis with an angle from the vertical of theta1 (for detector1)
and theta2 (for detector2)

detector 1     <======     source           =======>    detector 2


you get the following result from QM

p(theta1,theta2) = p1(delta) = cos^2(theta2-theta1)

However, Bell has shown that any local realistic theory must follow
the relationship.

1-p2(2*delta) <= 1 - 2*p2(delta)

There are some similar inequalities with a formal proof in 'Bell's Therom:
Theoretical Tests and Implications' by Clauser and Shimony, which has (alas)
disappeared from my files.  There's a really simple proof of the inequality
in Quantum Reality by Nick Herbert which is much less formal.

Anyway, there *is* a way to distinguish between the two condtions I
was describing.  Local Realistic theories predict that you will have a
constraint on p1(delta).  A simple 'speed-of-light-collapse' theory predicts
that p1(delta) *will* change its value when the spins are measured in a
'timelike' manner (i.e within a lightcone) vs a 'spacelike' manner.
Newsgroups: sci.physics
From: hporopudas@tnclus.tele.nokia.fi
Subject: Re: Make time stop?
Organization: Nokia Telecommunications.
Date: Wed, 30 Sep 1992 12:55:40 GMT


In article <1992Sep29.171040.26549@hellgate.utah.edu>,
tolman%mindblow.cs.utah.edu@cs.utah.edu (Kenneth Tolman) writes:
>   A frame of reference moving very very fast has a time dilation, correct?
> (That is, if we are still and looking at someone moving they are "slow")
> When we look out into the universe- all galaxies are moving away from us,
> and the very far away galaxies are moving near the speed of light.
>
   ...deleted stuff...
>

  One interesting question arised from the Subject of Kenneth's article:

    What would we see 'for a while', when we look out into the universe,
  about red-shifts of near stars and red-shifts of distant galaxies, if our
  universe would suddenly stop it expansion.?
    This is called a point when there exist 'no time' or a point when
  'time has stopped'.

    This is quite strange and catastropic point, because all mass and
  hence hundreds of thousands of radiation peripheries, which form the
  'time-dimension' would start to disappear at this 'moment'. And
  'for a while' 'all times' would then exist 'together'.

          Hannu.


Newsgroups: sci.physics
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: Can Information Have Physical Units?
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Tue, 6 Oct 92 17:05:13 GMT

In article <12950089@hpspdla.spd.HP.COM> ric@hpspdla.spd.HP.COM (Ric Peregrino) writes:
>
>Shooting from the hip I'd say information has the same units as entropy,
>which I thought was unitless. But what about Gibbs free energy:
>
>dG = dH + TdS
>
>S then has units of energy/temperture? Maybe I'm just being dense?

You'll have to check your specific gravity yourself.  The usual
definition of entropy a la stat mech is S = k ln Omega, where Omega is
the number of microstates in the given macrostate, a dimensionless
quantity.  I believe this formula appears on Boltzmann's grave, by the
way.  k here is his constant, which appears in the formula for the
probability that a state of energy E will be occupied at temperature T, 

exp(-E/kT)

(suitably normalized).  So since things in exponentials have to be
dimensionless, k has units of energy/temperature, so yes, you're right,
S has units of energy/temperature.  Information however is dimensionless
(as are "bits"); in Boltzmann's formula the information required to say
which microstate the macrostate is really in is ln Omega.  (If we use
base 2 log here the way computer scientists do, we get the number of
"bits".  If we use natural log, as Boltzmann did, this number is the
number of "nits".  Wasting energy arguing over small pieces of
information is therefore known as "nitpicking."
From: ah335@cleveland.Freenet.Edu (Richard Banks)
Newsgroups: sci.physics
Subject: density and hardness
Date: 30 Sep 1992 20:20:56 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: ah335@cleveland.Freenet.Edu (Richard Banks)
NNTP-Posting-Host: slc4.ins.cwru.edu



What are the difference between the two properties of density and hardness?
And what is their relationship with each other and elasticity if any?

I was thinking about a theorectical model of a 3-d matrix of hard rocks
unmoveably suspened in air.  And a 3-d matrix of clay balls with the
same density configuration at the rocks.

Richard Banks