HDTenEightyP/NetNews huggingface dataset:
From: sichase@csa2.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics,rec.pets.cats
Subject: Re: Radioactive Cat: How Dangerous is She?
Date: 9 Sep 92 20:03:47 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 <8SEP199217560269@rover.uchicago.edu>, frank@rover.uchicago.edu (Frank - Hardware Hacker - Borger) writes...
> 
>	I have an old radioactive dial watch that I can use to Pin a geiger
>	counter on it's most sensitive scale. I would wear it on my wrist
>	without hesitation. Geiger counters are VERY sensitive detectors.
>	(As an aside, if I invert the watch, and put the back instead of the
>	glass dial against the tube, nothing happens.)

That's funny.  I had a radium dial watch about 12 years ago.  One day I was
goofing around with a Geiger counter in a friend's lab, killing time while
she was processing some electrophoresis gels, or one of those other things that
molecular biologists do all the time.  I discovered that my watch sent the 
counter off-scale (at the lowest setting, probably.)  Within a week I had
a new watch.  Why take any risk?  There certainly was a lead backing, so
I wasn't radiating my wrist, but my hands hang near waist level...

-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: G.Joly@cs.ucl.ac.uk (Gordon Joly)
Newsgroups: sci.physics
Subject: Re: Black hole + anti-Black hole = ?
Date: 9 Sep 92 10:52:31 GMT

Richard M. Mathews writes:
 > barry@arnold.math.ucla.edu (Barry Merriman) writes:
 > >What happens if you dump some antimatter into a black 
 > >hole that formed from normal matter? Does it 'cancel out' part of it?
 > 
 > >Or, if I take two black holes, one made from ordinary matter
 > >and the other made from anti-matter, and merge them, what happens?
 > >Do I get a bigger black hole, or are they somehow annihilated?
 > 
 > The "classical" theory of General Relativity predicts that black holes
 > are described only by 3 numbers: mass, spin, and electric charge.  Black
 > holes do not have a lepton number or a baryon number.  A black hole
 > created from ordinary matter is indistinguishable from a black hole
 > created from anti-matter.  Thus black_hole + anti_black_hole is the
 > same as black_hole + black_hole; the quantity
 > 	(M + sqrt(M^2 - Q^2 - S^2/M^2))^2 + S^2/M^2
 > summed over all black holes is guaranteed to be non-decreasing.
 > 
 > Now, it bothers me that Hawking evaporation does not conserve lepton and
 > baryon number.  Something related to gravity just shouldn't be fooling
 > with such things.  Personally, I think that a TOE will get rid of the
 > singularity at the center of a black hole (assuming it doesn't get rid
 > of black holes completely), and it will replace the singularity with
 > something which does conserve lepton and baryon number.  That would
 > mean that black holes would have lepton and baryon numbers, though you
 > might not be able to directly measure those until the hole evaporates
 > away.
 > 
 >      Richard M. Mathews			Lietuva laisva = Free Lithuania
 > 					Brivu Latviju  = Free Latvia
 > Richard.Mathews@West.Sun.COM		Eesti vabaks   = Free Estonia
 > 					        WE  DID  IT!"!

``White Holes'', as I recall, was a book by John Gribben.

____

Gordon Joly      Phone  +44 71 387 7050 ext 3703      FAX  +44 71 387 1397
Internet: G.Joly@cs.ucl.ac.uk        UUCP: ...!{uunet,uknet}!ucl-cs!G.Joly
Computer Science, University College London, Gower Street, LONDON WC1E 6BT
Newsgroups: sci.physics
From: bhoughto@sedona.intel.com (Blair P. Houghton)
Subject: Re: Elevator mayhem
Organization: Intel Corp., Chandler, Arizona
Date: Tue, 15 Sep 1992 20:35:57 GMT

In article <mcirvin.716585471@husc8> mcirvin@husc8.harvard.edu (Mcirvin) writes:
>There is a fundamental flaw... Think about what happens when you come
>back down at the end of your jump.  Remember, you've jumped off of a
>floor that is traveling downward at high speed, and you land on a floor
>that has stopped moving!  All you've done is delay the injury a fraction
>of a second. 

Not quite.  Say at 10' off the ground, the elevator is moving
at -50mph and ejects you at 50mph wrt itself.  Then, instead
of being 10ft from the ground moving 50mph, you're 10ft from
the ground moving 0mph.  All you have to do now is keep from
landing on the cat.

It's not perfect, though.  The trouble is, how fast does the
elevator accelerate you from 0mph wrt itself to 50mph wrt itself?
If it does it as fast as the ground will, then you might as well
just press all the buttons and laugh, 'cuz yer hamburger.  If,
however, the ejector is more gradual than a simple impact, then
you're probably going to be okay.

In general, pain is related to the third derivative of position,
i.e., the jerk.  (This straight-line donated to the public
domain, 9/15/92, by Blair P. Houghton).

				--Blair
				  "Is the cat alive or dead?
				   How far apart are the slits
				   in its eyes?  Is it wearing
				   heavy boots?  Are mice more
				   like particles or waves?"
Newsgroups: sci.physics
From: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr))
Subject: Re: Question of Theory of Everything (or Grand Unified theory)
Organization: National University of Singapore
Distribution: na
Date: Thu, 10 Sep 1992 01:42:15 GMT

It seems that the general consensus is that when the true TOE comes
along, it will eventually be assimilated and come to seem comprehensible
to many people. Suppose, on the other hand, that in reality the true TOE
is as far beyond human capabilities as, say, quantum field theory is
beyond a chimpanzee. Then how should we recognise such a state of
affairs? Would it be indicated, for example, by a widespread belief that
the true TOE is just around the corner?
From: hporopudas@tnclus.tele.nokia.fi
Subject: Re: Black hole + anti-Black hole = ?
Organization: Nokia Telecommunications.
Date: Wed, 9 Sep 1992 14:32:38 GMT


In article <18jgmmINNm4g@smaug.West.Sun.COM>,
Richard.Mathews@West.Sun.COM (Richard M. Mathews) writes:
> barry@arnold.math.ucla.edu (Barry Merriman) writes:
>>What happens if you dump some antimatter into a black
>>hole that formed from normal matter? Does it 'cancel out' part of it?
>
>>Or, if I take two black holes, one made from ordinary matter
>>and the other made from anti-matter, and merge them, what happens?
>>Do I get a bigger black hole, or are they somehow annihilated?
>
> The "classical" theory of General Relativity predicts that black holes
> are described only by 3 numbers: mass, spin, and electric charge.  Black
> holes do not have a lepton number or a baryon number.  A black hole
> created from ordinary matter is indistinguishable from a black hole
> created from anti-matter.  Thus black_hole + anti_black_hole is the
> same as black_hole + black_hole; the quantity
> 	(M + sqrt(M^2 - Q^2 - S^2/M^2))^2 + S^2/M^2
> summed over all black holes is guaranteed to be non-decreasing.
>
> Now, it bothers me that Hawking evaporation does not conserve lepton and
> baryon number.  Something related to gravity just shouldn't be fooling
> with such things.  Personally, I think that a TOE will get rid of the
> singularity at the center of a black hole (assuming it doesn't get rid
> of black holes completely), and it will replace the singularity with
> something which does conserve lepton and baryon number.  That would
> mean that black holes would have lepton and baryon numbers, though you
> might not be able to directly measure those until the hole evaporates
> away.
>
>      Richard M. Mathews			Lietuva laisva = Free Lithuania
> 					Brivu Latviju  = Free Latvia
> Richard.Mathews@West.Sun.COM		Eesti vabaks   = Free Estonia
> 					        WE  DID  IT!!!

 What if we combine two black holes such that one is from contracting
 universe and one from expanding universe. ?
 These two have different signs of masses. First mass is negative and second
 mass is positive.

             Hannu.



Newsgroups: sci.physics
From: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr))
Subject: Re: What We Don't Know (YET!) 
Organization: National University of Singapore
Date: Fri, 11 Sep 1992 01:57:44 GMT

I agree that John's list is good; but I hope that this festival of
ignorance will not have the effect of inhibiting discussion of items on
the list. It would be very nice if our list could be supplemented to
some extent by lists of suggested answers to the questions raised. To
start the ball rolling, I have posted a couple of questions of the form:
what is known about X and what are the proposed answers?
Newsgroups: sci.physics
Subject: Re: Did electric/magnetic symmetry "break"?
From: mcirvin@husc8.harvard.edu (Mcirvin)
Date: 5 Sep 92 18:47:40 GMT

mcirvin@husc8.harvard.edu (Mcirvin) writes:

>In what units?  I don't think this is the case if hbar=c=1.

Aieee!  I take this back.  Mr. Bollinger is more or less right: in
Gaussian units with hbar=c=1, the ration of the Dirac magnetic
monopole's charge to the electronic charge is 137.036/2, or
about 68.5.  What's really fixed, independently of the size of
the electronic charge, is the *product* of the two quantities,
which is 1/2 in these units.

The relation is fixed by quantum-mechanical considerations, according
to the reasoning of Dirac.  Both Sakurai's black book and Jackson
cover this well.
 
-- 
Matt McIrvin, Cambridge, Massachusetts, USA 
Newsgroups: sci.physics
From: torin.walker@rose.com (torin walker)
Subject: IGH SPEED PULSE TECH
Organization: Rose Media Inc, Toronto, Ontario.
Date: Sun, 6 Sep 1992 22:45:15 GMT
X-Gated-By: Usenet <==> RoseMail Gateway (v1.70)


Date Entered: 09-06-92 17:23
Hello there,

I am desparate to find and purchase the 4 volume set entitled:
HIGH SPEED PULSE TECHNOLOGY. Here are the particulars:


 Author:         Frungel, Frank B. A.

 Title:          High speed pulse technology, Frank B.A. Frungel. --

 Published:      New York : Academic Press, 1965-80.
 Description:    4 v. : illus. ; 24 cm.

 Other titles:   Impulstechnik. English

 Notes:          Translation of Impulstechnik.
                 Includes bibliographies.

 Contents note:  Capacitor discharges. Magnetohydrodynamics. X-rays.
                   Ultrasonics. -- v. 2 Optical pulses. Lasers. Measuring
                   techniques. -- v. 3. Capacitor discharge engineering. --
                   v. 4. Sparks and laser pulses.

 ISBN:           0122690036 (v. 3)


If you have a set or know where could I find one, please leave a message.

Please respond to: 'torin@torinet.com'  or  'uunet!torinet!torin' if possible.

---
   RR 1.60 R002389: It's hard to be humble when you're perfect.
   RM 2.00 : RoseNet<=>Usenet Gateway : Rose Media 416-733-2285
Newsgroups: sci.physics
From: pratt@Sunburn.Stanford.EDU (Vaughan R. Pratt)
Subject: Re: third try
Organization: Computer Science Department,  Stanford University.
Date: Thu, 10 Sep 1992 02:41:25 GMT

In article <22217@galaxy.ucr.edu> baez@ucrmath.ucr.edu (john baez) writes:
>In article <1992Sep1.041710.11504@asl.dl.nec.com> terry@aslws01.asl.dl.nec.com (Terry Bollinger) writes:
>>Ah well... I'll give it one more try:
>>...
>Well, here is where I think you're wrong.  One really never measures the
>angular momentum VECTOR in quantum mechanics, since the components don't
>commute.  This may in fact be exactly what you are referring to.  But I 
>think it's better to say that one can pick any axis and measure angular
>momentum around that axis.

Yes!  This last sentence is what I said (or tried to say) on Monday,
under the subject of quantization of angular momentum (rereading my
message I see it could have been worded a lot more clearly).  It seemed
that everyone was treating angular momentum as though it behaved like
momentum, in particular that it was invariant under translation.  My
basic objection amounted to the observation that, unlike momentum,
angular momentum is not translation invariant, it depends on where you
put the origin.

Or axis as John suggests.  The difference is that choosing an axis is
appropriate for measuring the component of angular momentum along that
axis, a scalar quantity.  If you choose just a point rather than an
axis then this defines the *whole* angular momentum, as a vector,
around that point, namely the vector r x p with r referenced to that
point.

With regard to Scott's objection to my
>>Angular momentum is not a good quantum number for a plane wave,
> I don't agree

my disagreement had nothing to do with what the wave looked like (as I
said at the time) but rather with how angular momentum was defined.
The point is, as John observes, you have to specify a reference, either
an axis for an AM component or a point for the whole AM vector, before
any statement about angular momentum makes sense.  No one was doing
that, and this is what I was objecting to.

-- 
======================================================| God found the positive
Vaughan Pratt   pratt@cs.Stanford.EDU   415-494-2545  | integers, zero was
======================================================| there when He arrived.
Newsgroups: sci.physics
From: terry@aslws01.asl.dl.nec.com (Terry Bollinger)
Subject: Re: Wave/particle duality
Keywords: photon,particle,dual slits,interference,quantum waves
Organization: NEC America, Inc. Irving, Texas
Date: Tue, 15 Sep 1992 01:38:47 GMT

In article <1992Sep14.201601.24668@riacs.edu>
danforth@riacs.edu (Douglas G. Danforth) writes:

> Are the photons point-like or is it our eyes that have point-like regions
> of activation? ... Consider a gentle wave rolling up a beach on which
> reside preset mouse traps.  Some will fire (trigger) and some won't.
> Is the wave discrete or is it the mouse traps?

I like it!

One, um, *slight* difference of course.  Your gentle wave could have been
a mile long and could as easily have set off a million mouse traps as one.

But when that wee gentle little photon wave hits a million atomic mouse
traps, not only is it guaranteed that only ONE mousetrap will trigger --
it's also guaranteed that all 999,999 of the other ones will absolutely
swear from that day onward that they never even SAW the supposed wave!

				Cheers,
				Terry Bollinger
				(working late again, sigh...)

 "Gaping in astonishment, Terry says 'You mean that Daniel E. Platt and I
  REALLY DID just say more or less the same thing??...  Wowzers!!'"
From: Richard.Mathews@West.Sun.COM (Richard M. Mathews)
Newsgroups: sci.physics
Subject: Re: Black hole + anti-Black hole = ?
Date: 9 Sep 1992 00:32:22 GMT
Organization: Sunsoft Inc., Los Angeles, CA.
NNTP-Posting-Host: astro
Originator: richard@astro.West.Sun.COM

barry@arnold.math.ucla.edu (Barry Merriman) writes:
>What happens if you dump some antimatter into a black 
>hole that formed from normal matter? Does it 'cancel out' part of it?

>Or, if I take two black holes, one made from ordinary matter
>and the other made from anti-matter, and merge them, what happens?
>Do I get a bigger black hole, or are they somehow annihilated?

The "classical" theory of General Relativity predicts that black holes
are described only by 3 numbers: mass, spin, and electric charge.  Black
holes do not have a lepton number or a baryon number.  A black hole
created from ordinary matter is indistinguishable from a black hole
created from anti-matter.  Thus black_hole + anti_black_hole is the
same as black_hole + black_hole; the quantity
	(M + sqrt(M^2 - Q^2 - S^2/M^2))^2 + S^2/M^2
summed over all black holes is guaranteed to be non-decreasing.

Now, it bothers me that Hawking evaporation does not conserve lepton and
baryon number.  Something related to gravity just shouldn't be fooling
with such things.  Personally, I think that a TOE will get rid of the
singularity at the center of a black hole (assuming it doesn't get rid
of black holes completely), and it will replace the singularity with
something which does conserve lepton and baryon number.  That would
mean that black holes would have lepton and baryon numbers, though you
might not be able to directly measure those until the hole evaporates
away.

     Richard M. Mathews			Lietuva laisva = Free Lithuania
					Brivu Latviju  = Free Latvia
Richard.Mathews@West.Sun.COM		Eesti vabaks   = Free Estonia
					        WE  DID  IT!!!
From: DOCTORJ@SLACVM.SLAC.STANFORD.EDU (Jon J Thaler)
Newsgroups: sci.physics
Subject: Re: How old is the universe?
Date: 11 Sep 92 17:49:48 GMT
Organization: Stanford Linear Accelerator Center

tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman) says:

> How old is the universe in seconds?
> How much time is left before it crunches back together?

We do not know the answer to either of these questions.

If by "age of the universe" you mean the time since the initial singularity
(or some state near, but not at, the singularity), the answer depends
on the expansion properties of the very early universe.  These
are not known.  We *DO* know the time since, for example, recombination.
This is the era one observes when one looks at the 3-degree black body
radiation.  It occurred 10-15 billion years ago (3-5 * 10**16 sec).

The answer to the second question is not known for a simpler reason - we don't
know if there is enough matter in the universe to cause it ever to crunch
back together.  This is the famous "dark matter" problem.
Newsgroups: sci.physics
From: bhv@areaplg2.corp.mot.com (Bronis Vidugiris)
Subject: Re: Hidden variable theories, was: Uncertainty Princi
Organization: Motorola, CCR&D, CORP, Schaumburg, IL
Date: Fri, 11 Sep 1992 00:11:25 GMT

In article <269@mtnmath.UUCP> paul@mtnmath.UUCP (Paul Budnik) writes:
)
)Any real experiment will always have some additional loopholes. Aspect
)was certainly aware that detector efficiency was an issue. I do not
)completely follow your argument about efficiency. If you are saying that
)only those detections that confirmed violations of Bell's inequality were
)detected because of some unknown physical process, I agree that this is 
)possible. I am sure the experimenters were aware of this and classified
)it is another improbable but still possible loophole. 
)
)Paul Budnik

The experminters covered this with an 'auxillary assumption'.  The previous
poster was just pointing out (IMO) that right now you need more than the 
experimental results, you also need the 'auxillary assumption' as well.
This 'aux assumption' is testable with more $$$$$, so it's not fundamental -
it's seen as a very low priority item for testing, though.  (I forget the
reference here, Clauser and Horne perhaps?  It's pretty old.)

I think the question about correlation not being causation also deserves
a more full response.  I think the poster who pointed out that only a
correlation has been found and not a cause-effect relationship is technically
right.  One could construct a model that involved the universe being
a computer simulation to explain the results of Bell's experiments, for
example.  In this model, the Master Programmer of the universe decided to use
_one_ random number to represent the results of the experiment at both A and
B.  This random number is not generated until a measurement is made at 'A',
however - a lot like the 'state' of a potion in the game of 'hack' which
isn't known until one opens it.  The non-local part of this theory is that
this random number is immediately available at point 'B' even though it is
physically separated from point A.  A subtle point, but it relates to the
difference between A causing B, and A being correlated to B by a 'common'
cause (said Universally Accessible Random Number generator).

Newsgroups: sci.physics
From: taylors@hubcap.clemson.edu (C. Taylor Sutherland III)
Subject: Re: How old is the universe?
Organization: Clemson University
Date: Sat, 12 Sep 1992 05:25:38 GMT

tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman) writes:

>How old is the universe is seconds?  

Convert 1.5 E 9 yrs. into seconds.

>How much time is left before it crunches back together?

First of all, we're not really sure if it's expanding in the first place, and
if it is we certainly don't have enough data (total mass (including unobserved
stars and "dark matter"), total kinetic energy, where the center is so we could
get a velocity of expansion relative to some "fixed" point, etc... etc...) to
calculate when it would come back together.  If we knew that, so many questions
in physics would have been answered by now.

>Where might I find these figures in reference texts?

Try the Hitchhikers Guide to the Galaxy


Have a nice day  :)

-- 
	I've heard a good .sig can let you meet people....
	Anybody got any good ideas for one?
The Fly Boy  <| E-MAIL:  taylors@hubcap.clemson.edu |>
+--<| My life is a math question with one equation and 42 unknowns. |>--+
From: voros@vaxc.cc.monash.edu.au (Joe Voros)
Newsgroups: sci.physics
Subject: Re: Black hole + anti-Black hole = ?
Date: 10 Sep 92 10:35:35 +1000
Organization: Physics Department, Monash University, Australia.

jbaez@riesz.mit.edu (John C. Baez) writes:
> barry@arnold.math.ucla.edu (Barry Merriman) writes:
> 
>>What happens if you dump some antimatter into a black 
>>hole that formed from normal matter? Does it 'cancel out' part of it?
>>Or, if I take two black holes, one made from ordinary matter
>>and the other made from anti-matter, and merge them, what happens?
>>Do I get a bigger black hole, or are they somehow annihilated?
> 
> Nobody has ever done these experiments so we don't know.
> 
> There - see? - I can act like a wet-blanket experimentalist just as well
> as the next guy!  It *is* worth noting, though, that we're talking about
> some heavy-duty extrapolations beyond what has been seen, and there are
> some very fishy points lurking in this issue.

This comment reminds me of one of my favourite quotes which I like to
spring on the Relativity Group here.  They are all mathematicians; I am
the token physicist.  But I digress :)

``First you have speculation.  Then you have *wild* speculation.  Then
you have cosmology.''

Source unknown.

-- 
Joe Voros
Department of Physics, Monash University, Clayton, VIC, 3168, Australia.

Quantum Mechanics is God's way of telling you to mind your P_i's and Q_j's.
Newsgroups: sci.physics
From: foxd@silver.ucs.indiana.edu (daniel fox)
Subject: Re: Hidden variable theories, was: Uncertainty Princi
Organization: Indiana University
Date: Thu, 10 Sep 1992 17:53:53 GMT



While reading these discussions I can't help wondering if there is some sort of
connection between causality and thermodynamics.  Both seem to define an arrow
to time.  Might it be that causality is only meaningful for sufficently large
collections of particles?

                                      Daniel B. Fox
                                      KF9ET
.standard disclaimer
From: schne@daimi.aau.dk (Thomas Schneider)
Newsgroups: sci.physics
Subject: A Temperature Measuring Problem
Summary: Problem of measuring the temperature on the inside of breaking blocks in action
Date: 12 Sep 92 16:41:39 GMT
Organization: DAIMI: Computer Science Department, Aarhus University, Denmark

A few friends of mine has the following problem:

In a windmill there is a break installed. The problem is that they would
like to some how measure the temperature on the inside surface of the 
breaking blocks, when they are breaking. It has been calculatet to 
approx. 600 degrees Celsius, however a closer result is would be greatly 
appreciatet.

Any surgestions or ideas as to how we can get a better measurement,
can be mailed to me, or posted. Thank you. 

             - Thomas Schneider.



+---------------------------------------+
Thomas Schneider <schne@daimi.aau.dk>
Knudriisgade 31.3, 8000 Aarhus C, Denmark