HDTenEightyP/NetNews huggingface dataset:
From: pratt@Sunburn.Stanford.EDU (Vaughan R. Pratt)
Subject: Re: Report on Philosophies of Physicists
Organization: Computer Science Department,  Stanford University.
Date: Sun, 13 Sep 1992 21:12:50 GMT

In article <TORKEL.92Sep13202910@bast.sics.se> torkel@sics.se (Torkel Franzen) writes:
>In article <1992Sep13.174721.23818@CSD-NewsHost.Stanford.EDU> pratt@Sunburn.
>Stanford.EDU (Vaughan R. Pratt) writes:
>
>  >The meaning of ZFC+# as a foundation for mathematics is no
>  >different from say ZFC+V=L (all sets constructible), or any other
>  >addition to ZFC.  It just means the same mathematics you've always
>  >done, plus anything new you can get from this additional postulate.
>
>  What this seems to say is that a "foundation for mathematics" is any
>formal theory extending ZFC, possibly subject to some adequacy
>conditions which are unclear from your formulation. Why do you call
>this a "foundation for mathematics"? It seems to pertain, rather, to a highly
>formal kind of mathematics, of limited interest.

Fergie sometimes dresses highly formally, but this doesn't seem to have
prevented her from dressing very informally to suit the occasion.  It's
the same with ZFC, you can write it out highly formally, but you get
the idea better when you work with it informally (who wants to work
with a big mass of symbols?).  Likewise ZFC+V=L, or ZFC+CH, can be
written formally, but one tends to think about their respective
meanings informally.

As to interest, ZFC+P has been of enormous interest for certain P.
Whether Fergie will meet a new and interesting P is not for us mortals
to predict, even if we have our prejudices about certain P's such as #.
Those prejudices can prove wrong.

>  Why should I do that? # is an ordinary (false) arithmetical statement.

In ZFC+#, # is true.  You are identifying # with "ZFC is inconsistent",
but this is incorrect: it is a Goedel coding of the full meaning of
this statement, which is a nasty complicated thing due to its having to
depend on every last little detail of how proofs work, including such
basic things as the definitions of "finite" and "number".  You should
not put so much faith in very complicated things.

You mention that # is arithmetical.  In R this becomes only partly
true, in the following sense.  In Q the syntactic and semantic
definitions of "arithmetical" are equivalent.  But in my R they are
not.  In particular # remains syntactically arithmetical (because it
has not changed) but ceases to be semantically arithmetical, as a
result of the interpretation of "finite" being different in R (to
scratch the surface of the details involved in this shift to R).  Since
the more complicated definition is the syntactic one, this would seem
to be the correct one to give up.  At that point # ceases to be an
arithmetical statement and becomes just gibberish based on an old
misunderstanding about how mathematics works.

-- 
======================================================| God found the positive
Vaughan Pratt   pratt@cs.Stanford.EDU   415-494-2545  | integers, zero was
======================================================| there when He arrived.
Newsgroups: sci.physics
From: allenk@molest.ugcs.caltech.edu (Allen Knutson)
Subject: Supersymmetry joke
Organization: California Institute of Technology, Pasadena
Date: Mon, 14 Sep 1992 01:43:26 GMT

Ascribed to Don Finnell:

"What do you mean, no evidence for supersymmetry? They've already found
half the particles!"
From: mcirvin@husc8.harvard.edu (Mcirvin)
Newsgroups: sci.physics
Subject: Re: Wave/particle duality
Keywords: photon,particle,dual slits,interference,quantum waves
Date: 15 Sep 92 14:52:18 GMT
 <1992Sep14.201601.24668@riacs.edu> <1992Sep14.235046.5270@galois.mit.edu>

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

>namely molecules of some sort that respond to light (the word
>"rhodopsin" comes to mind but I really don't know), 

Rhodopsin is the pigment that responds to light in the rods.  It
isn't associated with color vision, but is what you see with in
low light levels.
-- 
Matt McIrvin, Cambridge, Massachusetts, USA 
Newsgroups: sci.physics
From: mls@cbnewsm.cb.att.com (mike.siemon)
Subject: Re: Question of Theory of Everything (or Grand Unified theory)
Organization: AT&T
Date: Wed, 9 Sep 1992 01:13:27 GMT
Summary: adaptive nature of intelligence

In article <88251@netnews.upenn.edu>, weemba@sagi.wistar.upenn.edu (Matthew P Wiener) writes:
> In article <1992Sep8.023027.15883@nuscc.nus.sg>, matmcinn@nuscc (Mcinnes B T (Dr)) writes:

> >Now: is it not truly astounding that the complexity of the universe
> >is so precisely calibrated to the intelligence of homo sapiens?

> I think Einstein had a famous quotation on just this point.  Something
> about the most incomprehensible thing about the universe being that it
> is comprehensible.

The "precision" is quite likely an illusion.  If our brains, and the ways
they use to tie our consicousnesses into the objects thereof, are products
of a long process of adaptation, it is hardly surprising that *for our
purposes* the adaptation provides a good makeshift of "comprehension" --
whether or not our internal models have anything much to do with reality.

Exactly how would we KNOW, for example, if our models were totally inade-
quate beyond the range of what is admitted (on whatever random grounds)
into the substratum of our model building?  The stability of physical
theories (i.e., that they seem at least to "keep on working") is certainly
encouraging -- but it is hard (as Hume noted) to draw any serious conclus-
ions from that.

-- 
Michael L. Siemon			"I know of nothing -- I suspect
					not even death -- that is so fixed
mls@usl.com				in the present tense as love."
standard disclaimer					-- Jess Anderson
Newsgroups: sci.physics,sci.math
From: torkel@sics.se (Torkel Franzen)
Subject: Re: Report on Philosophies of Physicists
Organization: Swedish Institute of Computer Science, Kista
	<1992Sep13.211250.26056@CSD-NewsHost.Stanford.EDU>
	<TORKEL.92Sep14001401@bast.sics.se>
	<1992Sep14.005448.28555@CSD-NewsHost.Stanford.EDU>
Date: Mon, 14 Sep 1992 06:49:02 GMT

In article <1992Sep14.005448.28555@CSD-NewsHost.Stanford.EDU> pratt@Sunburn.
Stanford.EDU (Vaughan R. Pratt) writes:

 >Matthew Wiener asserted earlier today that physicists could safely base their
 >mathematics on PA.  (I've omitted RH to simplify this thread.)  Is that
 >a foundation as you understand the term?  Now add enough to bring this
 >up to ZFC.  Is this extension of PA a foundation?  Now add CH.  Is that
 >a foundation?  Are these three foundations different foundations?  Now
 >add some famous undecided but natural-sounding proposition in group
 >theory to ZFC.  Is that a foundation?  Is ZFC+# a foundation?  (Just
 >checking :-)

  How should I know? That depends on what you mean by "foundation". I
myself don't use the locution "the formal theory T is a foundation",
and so have no opinion. However, judging by your first statement you
seem to have in mind something along the following lines: "T is a
foundation for the work of mathematicians X,Y,.. if their work is
formally representable within T". This makes sense applied to PA and
ZFC, since it is a non-trivial discovery that very much actual mathematical
work is so representable (although the significance of the terminology
remains to be investigated), but I don't see that it makes sense
applied to e.g.  ZFC+#. In this case, "ZFC+# is a foundation" seems to
mean, in your terminology, essentially "work on drawing conclusions
from # in ZFC is formally representable in ZFC+#". Now if this is in
fact all you mean by this term, I have no other objection than the
suggestion that this terminology is perhaps a bit misleading, since
"the foundations of mathematics" is usually assumed to have something
to do with the interpretation and justification (or interpretability
and justifiability) of mathematics.

   >Meanwhile, now my answer is much much easier than with #.  I have no
   >reason to suppose that the satisfiability of a random Diophantine
   >equation is independent of ZFC, so I'm certainly not going to waste my
   >time doing mathematics under the assumption that it is satisfiable.

  I was insufficiently explicit. I was presupposing the fact that by the
theorem of Matiyasevic et al, "ZFC is inconsistent" is equivalent in ZFC
to a statement (not too horribly complex, I believe) of the form "the
Diophantine equation ... has a solution".
From: Richard.Mathews@West.Sun.COM (Richard M. Mathews)
Newsgroups: sci.physics
Subject: Re: Rotating Bucket of Water in a Gravitation Field...Part #2
Date: 8 Sep 1992 21:55:08 GMT
Organization: Sunsoft Inc., Los Angeles, CA.
NNTP-Posting-Host: astro
Originator: richard@astro.West.Sun.COM

ric@hpspdla.spd.HP.COM (Ric Peregrino) writes:
>>"rotate the Heaven
>>of fixed stars, and see what happens to the water in the bucket".
>I think this is wrong. Say there was only one star

Others have pointed out that it really takes a universe full of stars to
see this effect.  I want to explain the reason for that.

GR predicts a rotational drag effect; if you rotate a shell of matter,
objects inside will want to begin rotating in the same direction due
to a "gravito-magnetic" effect of sorts.  This amount of dragging is
proportional to the mass in the shell and inversely proportional to the
square of the radius of the shell.  But if the density of the universe
is constant at large scales, and if we take a Euclidean approximation,
the mass in each shell goes as the square of the radius.  Thus as the
universe rotates around you, all shells contribute equally to tendency
to rotate with the universe.  Since the radius of your own galaxy is
only a tiny fraction of that of the whole universe, your own galaxy
contributes little to defining rotational inertia.  It takes the sum
of all of the galaxies of the universe to produce enough inertia to
generate the inertial mass of local objects.

     Richard M. Mathews			Lietuva laisva = Free Lithuania
					Brivu Latviju  = Free Latvia
Richard.Mathews@West.Sun.COM		Eesti vabaks   = Free Estonia
					        WE  DID  IT!!!
Newsgroups: sci.physics
From: pad@galaxy.nsc.com (Paul Denny x8349)
Subject: gravity/height
Keywords: mount everest
Organization: National Semiconductor, Santa Clara
Date: Tue, 15 Sep 1992 20:11:19 GMT

The recent thread about changes in gravity has reminded 
me of a physics problem I was given at school about age
17 where I disagreed with the teacher and just about
everyone in the class, now with the benefit of experience
I still think I'm right but am willing to be persuaded
otherwise by knowledgable folk with a sound argument.

The problem was something along the lines of how much
less do you weigh at the top of everest than at sea level?
The answer was arrived at by calculating the lower gravity
due to the inverse square law at further distances from
the centre of the earth as a recent poster has done. My
argument is that on top of everest you have the additional
mass of the mountain attracting you (or bending spacetime
I suppose) and therefore you will weigh *more* on top of
everest. This argument was rejected pretty much out of
hand but I was further convinced of my argument when
the same teacher at another time claimed that if you hold
a pendulum on the side of a mountain it will hang slightly
towards the mountain - this I believe.

So - who is right and more importantly why?
From: sichase@csa2.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Re: Why do protons outnumber antiprotons?
Date: 5 Sep 92 01:06:40 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 <12950076@hpspdla.spd.HP.COM>, ric@hpspdla.spd.HP.COM (Ric Peregrino) writes...
> 
>At higher photon energies, you'll get particle anti-particle creations
>of higher energy particles. Say you get a neutron and anti-neutron.
>Now say the neutron undergoes beta decay. For the above conservation
>to hold, then the mass of the proton plus the electron must equal the
>mass of the anti-neutron plus the anti-neutrino. I don't know if this
>is the case or not. Do you? Please advise.

It is not the case.  If it were, there would be no phase space for the decay,
i.e., after the decay, the products could not move relative to one another
(no energy left over for kinetic energy).  Decays only happen when the 
final products have combined mass less than the parent.

>Anti-bosons? What are the properties of an anti-photon?

Photons are their own antiparticles.  So there is no distinct antiphoton.

-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: paul@mtnmath.UUCP (Paul Budnik)
Newsgroups: sci.physics
Subject: Re: Hidden variable theories, was: Uncertainty Princi
Date: 11 Sep 92 14:16:36 GMT
Organization: Mountain Math Software, P. O. Box 2124, Saratoga. CA 95070

In article <1992Sep11.015614.28674@galois.mit.edu>, jbaez@riesz.mit.edu (John C. Baez) writes:
> In a down-to-earth vein, I would only say information was being
> transmitted by such a device if I could use it tell my grandma what I
> was having for dinner, or at least do so with some statistically
> significant chance (i.e., I'll accept a noisy channel as long as it's
> not 100% noise).  It would only be if someone did THIS with quantum
> trickery that I would get nervous.  But of course one can't.

You are free to redefine information in any way you choose (at least
in a posting) but what you are defining here is normally regarded as
sending a signal. Information is often transferred in ways that no
human being can control.

>...
> We will sink into idle semantics here but I would not say the
> correlation was "transmitted".  Quantum mechanics simply allows
> different sorts of correlations than classical mechanics.  That's why a
> local hidden variables theory can't account for violations of Bell's
> inequality.  I would speak of transmission only if I could use the
> device to send a message to my grandma - NOT just produce some
> correlation that we can only verify when I go visit her later.

What you can do is send an encrypted message to your grandmother. This
appears to be a totally random sequence. Later you can provide her with
another totally random sequence. When your grandmother combines the two
sequences she can decode your message. The first sequence was transmitted
instantaneously potentially over billions of light years. There is no
way the message could be determined from the second sequence alone. Thus it
seems to me that the first sequence contained information that was
transmitted instantaneously by any conventional definition of these terms.

> >It is a fact that a distant manipulation instantly produces a local affect
> >according to the instantaneous collapse postulate.
> ...
> 
> Yeah, and several more have made the opposite point.  Namely, that you
> are using the word "causality" in a certain way, which I think is the
> "wrong" way, but in any case, that there's another sensible usage of it
> such that causality is not violated.

I would appreciate some references. In everything I have read in respected
journals there is no disagreement that either causality or Lorentz invariance
is violated. There is a lot of garbage written in popular accounts
of this subject. 

Regarding the rest of your message, there is no absolute contradiction
in quantum mechanic only some very unlikely predictions.

Paul Budnik
Newsgroups: sci.physics,sci.astro
From: bhoughto@sedona.intel.com (Blair P. Houghton)
Subject: Re: My son would like to know about photons...
Keywords: photon,size
Organization: Intel Corp., Chandler, Arizona
Date: Thu, 10 Sep 1992 17:52:25 GMT

If you see this article twice, then you are (an successful)
part of a very important experiment in quantum newsmatics.
Send me your name and I'll make sure the Committee includes
it on the certificate for my Nobel Prize in Usenet...

In article <9SEP199202514450@reg.triumf.ca> asnd@reg.triumf.ca (Donald Arseneau) writes:
>If, however, you try to locate a photon precisely, or time its arrival,
>interference and other wave-like behavior disappear!

I'm going to go out on a limb here and say RTFM (Read the
Feynman, Man :-)). 

Given the standard two-slit "interference" experiment
(chesNUUUUUUts roasting on an open fiiiiiire...) you see
that, if you outfit the target wall with an array of
scintillators, you can count each particle's arrival
as a unique event in time and space; only one scintillator
detects the particle, and it detects it all at once (even
if it's capable of detecting continuous waves).  But,
over time, if you look at the spatial histogram from
your echelon of scintillators, you see that the particles
arrive at certain scintillators more than at others.
The pattern is similar, in the mathematical sense, to
that observed for interference of plane waves incident
on the same apparatus.  The difference is that the
plane waves produce the interference pattern continuously
whereas it takes a certain amount of time to produce it
using QM particles.

That is, they are particle-like in that they occupy small
regions of space and time; they are wave-like in that they
interfere.  Their waveness has nothing to do with whether
they are waves or not, since it's a waveness of their
aggregate distribution, not of individual particles.  They
interfere even though they occupy small regions of space
and time but very rarely occupy the same region of space
and time (in particular, they very rarely occupy the
slits or the detectors simultaneously).

Feynman goes on about how he's mystified by the incredible
things this implies about how quantum particles affect each
other even if they don't exist simultaneously, and if he
didn't get it, I'm not even going to try.

				--Blair
				  "In the quantum interference pattern
				   of physicists, Feynman landed right
				   on a peak; I'm more likely to hit
				   somewhere up the slope of one of
				   the lower bumps..."
Newsgroups: sci.physics,sci.astro
From: bhoughto@sedona.intel.com (Blair P. Houghton)
Subject: Re: My son would like to know about photons...
Keywords: photon,size
Organization: Intel Corp., Chandler, Arizona
Date: Thu, 10 Sep 1992 17:45:07 GMT

In article <9SEP199202514450@reg.triumf.ca> asnd@reg.triumf.ca (Donald Arseneau) writes:
>If, however, you try to locate a photon precisely, or time its arrival,
>interference and other wave-like behavior disappear!

I'm going to go out on a limb here and say RTFM (Read the
Feynman, Man :-)). 

Given the standard two-slit "interference" experiment
(chesNUUUUUUts roasting on an open fiiiiiire...) you see
that, if you outfit the target wall with an array of
scintillators, you can count each particle's arrival
as a unique event in time and space; only one scintillator
detects the particle, and it detects it all at once (even
if it's capable of detecting continuous waves).  But,
over time, if you look at the spatial histogram from
your echelon of scintillators, you see that the particles
arrive at certain scintillators more than at others.
The pattern is similar, in the mathematical sense, to
that observed for interference of plane waves incident
on the same apparatus.  The difference is that the
plane waves produce the interference pattern continuously
whereas it takes a certain amount of time to produce it
using QM particles.

That is, they are particle-like in that they occupy small
regions of space and time; they are wave-like in that they
interfere.  Their waveness has nothing to do with whether
they are waves or not, since it's a waveness of their
aggregate distribution, not of individual particles.  They
interfere even though they occupy small regions of space
and time but very rarely occupy the same region of space
and time (in particular, they very rarely occupy the
slits or the detectors simultaneously).

Feynman goes on about how he's mystified by the incredible
things this implies about how quantum particles affect each
other even if they don't exist simultaneously, and if he
didn't get it, I'm not even going to try.

				--Blair
				  "In the quantum interference pattern
				   of physicists, Feynman landed right
				   on a peak; I'm more likely to hit
				   somewhere up the slope of one of
				   the lower bumps..."
Newsgroups: sci.physics
From: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr))
Subject: Re: How old is the universe?
Organization: National University of Singapore
Date: Sat, 12 Sep 1992 01:50:06 GMT














:   cOuld any one of you check reasonableness of the following figures by

:   computer calculations:
:                            50
:   There exist about 5000*10  kg ordinary mass (positive) in the whole universe,
:                                50
:   and there exist about 6000*10  kg so-called "magic mass" (negative) in the
:   whole universe.
: 
:   From these figures it is possible to calculate the age of the universe, if
:   you use the correct model for the universe.
: 
:   The universe is oscillatory in nature, in other words there exists
:   periodically "Big-Bang" and "Big-Crunch". Masses for all base particles
:   are only due to expansion resistance of the positive mass part of the
:   universe and masses for all base particles are only due to contraction
:   resistance of the negative part of the universe. The reason why absolute
:   values of all base particles are bigger in negative mass part of the universe
:   is due the point of view that there exist enormous concentration of mass in
:                                50
:   center of the space (about 10   kg) which increases contraction resistance
:   in negative mass part of the universe.
: 
:   From these figures it is perhaps possible to calculate how much time it
:   is to the "Big-Chrunch", if you use the correct model for the universe.
: 
:   Reference for these figures is my article "Structure of Time", which was
:   not accepted to publication by Physical Review newspaper.
: 
: 
: 
:             Hannu.
: 
: 
:    "I would not buy myself at least for a while any stocks of Physical
:     Review newspaper from the stock exhange, because Somebody may be
:     very very angry. ..."
: