[net.physics] White Holes?

gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (01/01/70)

> Assume that the energy of a "still" electron is ~ due to its electro- 
> static energy.  ...

Aw, I was hoping for something new.  If you're going to assign a radius
to an electron based on having pure electrostatic energy (== mass by
special relativity), then you need to explain why its parts don't repel
each other (in other words, why it is a single cohesive entity).  The
only semi-classical explanation for that seems to be that it has no
parts, which is tricky if it has nonzero radius...

This idea was dropped early in the 20th century.  That doesn't prove
that it's wrong, but people weren't happy with it.

williams@kirk.DEC (John Williams 223-3402) (08/15/85)

	I have a theory somewhat similar, which I call Historical
Relativity. This somewhat indirectly states that Matter is ejected
from black holes when black holes form inside. Time being the orthagonal
direction, it points differently inside a black hole. It would then be
possible for time to reorient itself by the same mechanism that causes
black holes inside the black holes. This would explain the cosmic jets
we have observed in the distant regions of the universe.

	My intuition tells me that the universe is a continuous function.
This would not necessitate a creator, where would a creator come from?
A mathematical function simply exists.

						John Williams

cjh@petsd.UUCP (Chris Henrich) (08/17/85)

[]
In article <3656@decwrl.UUCP> williams@kirk.DEC (John Williams 223-3402) writes:
>	My intuition tells me that the universe is a continuous function.
>This would not necessitate a creator, where would a creator come from?
>A mathematical function simply exists.

As I remember the definition of "continuous function" from
various mathematical courses and books, it is this:

In an elementary context:

	f is continuous at x0 if the limit of f(x) as x 
	approaches x0 exists, and is equal to f(x0). 
	(Perfunctory apologies for a crude approximation
	to mathematical notation.)  The function is
	continuous if it is "continuous at x0" for every
	x0 in its domain.

Another definition, roughly equivalent to the first, is this:

	The function f is continuous at x0 if, for every
	Eps > 0, there exists a Del > 0 such that

	   | x - x0 | < Del  ==>  |f(x) - f(x0)| < Eps.

Or, if one has the notion of a "distance" or "metric" on the
domain and another on the range, then

	The function f is continuous at x0 if, for every
	Eps > 0, there exists a Del > 0 such that

	dist(x, x0) < Del  ==>  dist( f(x), f(x0) ) < Eps.

The most general definition known to me is like this.

	Let X and Y be topological spaces. (I.e. they are
	sets, and for each a class of "open" subsets is
	determined somehow.)  Let f be a function whose domain
	is X and whose range is contained in Y.
	Then f is continuous if, for every open subset S of
	Y, the inverse image of S under f is an open subset 
	of X.

References are abundant.  Books on "mathematical analysis"
or "functional analysis" usually explain some or all of these
definitions.  (Good ones include _Analysis_I_ and
_Analysis_II_ by S. Lang.)  See also introductory books on
"topology."  There are good ones by Kelley and by Dugundji,
and many more.

If we try to apply these definitions to Mr. Williams's
statements, nothing much happens.  To call the universe a
continunous function seems to me to be saying remarkably
little.  What, pray tell, is the domain, and what is the
range?  These questions being settled, can you tell us
something about the values the function takes at various
elements of the range?

Or is there some completely different idea that is going by
the name "continuous function"?  If so, what is it?


Regards,
Chris

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pmk@prometheus.UUCP (Paul M Koloc) (08/17/85)

> possible for time to reorient itself by the same mechanism that causes
> black holes inside the black holes. This would explain the cosmic jets
> we have observed in the distant regions of the universe.
> 						John Williams

Interesting!

> My intuition tells me that the universe is a continuous function.

Two things tell us that the universe isn't continuous.  First, the "big bang",
and second, the constant "h bar" or even the fact that particles are not 
points. 

Time can more understandably be viewed as as "unfolding" of sequential infor-
mation arrays like the distinct frames of a moving picture.  The framing rate 
for a particle like a neutron would be ~(m*c^2)/(<h bar>) where "m" is the 
mass of a neutron, "c" the speed of light, and "h" Planck's constant.  The 
framing rate decreases with the increase in effective mass of a neutron due 
to its general and special relativity effects (its position in a dense 
gravitational field or in rapid motion "velocity space").  

If space were continuous then an infinite number of points would exist along 
a path an "inch" long.   Scanning this space with a "point" test particle 
would not discover any "spatial holes" or gaps where "points" aren't defined 
(exit).  In fact all of the information known to man (and the angels) could 
be put into a binary code and stored in such a space.  Our space is "grainy" 
and there are gaps and spaces, and nature has a special trick to make it 
"look" continuous.  Mathematically it is a "delta function" and in reality 
it is "the particle"   

The trick is also used by physicists to smooth out grainy data on a film 
strip.  It is simply to make the width of the film scanning aperture or 
"slit width" wide enough so that there is always a few grains within view.  
Making the aperture even wider reduces the fluctuations and makes the output 
even smoother and perhaps less exact.  

> My intuition tells me that the universe is a continuous function.
> This would not necessitate a creator, where would a creator come from?
> A mathematical function simply exists.
> 						John Williams

Energy is more or less proportional to the square of "grain density" or
"information density".  That means if we pack information into a smaller
space, the energy density goes up and the time  or framing rate goes down.
That also implies that as the framing rate decreases each frame has more
"persistence"

There is obviously information in our 3 space and that and the operators 
that "process" it are together what constitute entities we observe as par-
ticles.  Information could also exist in two space and 1 space, independent-
ly of whether or not three space exists.  Of course, the "physics" of those 
spaces would be different than for three space".  The idea is that informa
tion could flow from a dense higher energy density form to a lower density 
form.  Then it could flow from 1 space to two and from two to three.  In 
the latter transition it would appear to create a big bang and condense 
into the preferred form of three space, namely, matter. Also as "existence" 
(or information) perculates down from one to two dimensions, time 
activates and then in thee dimensions passes at a faster rate or "speeds up" 

Since lines can cross in two space and in three space, points exit and areas 
(surfaces)/ volumes can be delineated.  That means that a multiplicity of 
objects can exist in those two spaces.  But in one space there can only be 
one object because location is absent.  One can not cross two lines to 
produce a point, without moving out of that space.  If the grain density is 
infinite there, then existence would be infinitely persistent and time would 
not pass.  There would be only one direction. So the concept of space and 
time would be contradictory as we know it. Words like eternal and omni-
presence can also be used to describe such a state. True that physics can 
not understand the creation of the universe YET, it may well do so in the 
future.  The idea that time is quantized seen as the continuous discreet 
fading and replacement of information "frames" means that in a sense the
process of creation is still going on. This would occur for each and every 
particle in the universe.  Are we just an ensemble of information, a sort of
rapidly exchanging three dimensional arrays of matter generated by billions 
of little information processors called particle.? If thats true then we 
too are "compound" entities which display and process information.

As to where to find the CREATOR, I would vote for an infinitely dense 
and continuous independently existing one dimensional space as the place 
for the CREATOR to exist.  This is perhaps a little net.religion, net.-
cosmology, and net.metaphysics; but, what the hell.   Oh "hell" by the
way is ..  .         ..            .       maybe some other time.  :-)

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tmb@talcott.UUCP (Thomas M. Breuel) (08/18/85)

In article <166@prometheus.UUCP>, pmk@prometheus.UUCP (Paul M Koloc) writes:
> > My intuition tells me that the universe is a continuous function.
> 
> Two things tell us that the universe isn't continuous.  First, the "big bang",
> and second, the constant "h bar" or even the fact that particles are not 
> points. 
> [...]
> If space were continuous then an infinite number of points would exist along 
> a path an "inch" long.   Scanning this space with a "point" test particle 
> would not discover any "spatial holes" or gaps where "points" aren't defined 
> (exit).  In fact all of the information known to man (and the angels) could 
> be put into a binary code and stored in such a space.  Our space is "grainy" 
> and there are gaps and spaces, and nature has a special trick to make it 
> "look" continuous.  Mathematically it is a "delta function" and in reality 
> it is "the particle"   
> [...]
> True that physics can
> not understand the creation of the universe YET, it may well do so in the
> future.  The idea that time is quantized seen as the continuous discreet
> fading and replacement of information "frames" means that in a sense the
> process of creation is still going on. This would occur for each and every 

Nice that you all have intuitions and feelings about the universe.
I do too. Nevertheless, the only fact is that we don't know whether
the universe is continuous or discrete in either time or space,
whether it is finite of infinite, or whether it has discontinuities,
even if it is a continuum.

Modern physics has lots of theories about these questions, some
of them proven to higher degrees of accuracy than others. None
of them promise to be 'the final theory' of the universe.

Your remark about QM and discreteness of time strikes me as odd.
Time is, of course, treated as a real variable in QM, and you
can't just go from differential equations in time to difference
equations and still have a working QT (at least I have never seen
such a theory... it would definitely be interesting, though).

Your remark about QM and discreteness of space strikes me
as even odder. If you know of a way of representing QM on
a lattice, I would like to hear about it. What tells you, by the way,
that you can't store infite amounts of data in a limited space,
and by what means can you infer from that that space is organised
as a lattice? Unless you have a better argument than you presented
in your posting, I would be extremely careful in making such statements.

Finally, the object of physics simply cannot be to find out the
'cause' for the existence of the universe. By definition, the creation
of the universe took place outside the realm of the physical laws that
govern our universe. Therefore, physics is just not applicable to
what happened before the universe existed.

Another way of stating the above is that any physical theory must
be testable. A theory of the creation of the universe is not
testable or verifyable.

Don't misunderstand me: I love physics, and there are lots of extremely
interesting questions to be answered. Like any other natural science,
physics does not give final answers, though. Every theory, however well
established, may always turn out to be incorrect after all. Physics
can only describe the universe to better and better approximations,
and we may eventually find a theory that describes our world better than
we have means to test it. Nevertheless, it is only a theory. QM and
GR do not even meet these criteria. There are serious conflicts between the
two theories, and (at least) one of them needs a lot of fixing.

But physics is also not a religion or a philosophy. Physics cannot
tell you either *why* or *how* the universe was created, or what the
*purpose* of life or intelligence is. Physical sciences can only
tell you what probably happened right after the universe was created
and what kinds of systems may give rise to life and intelligence.
Purpose and reason, although often used euphemistically in physics
courses, have no place in the sciences. (reason here not in the sense
of logic or intelligence, of course).

						Thomas.

gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (08/18/85)

> Finally, the object of physics simply cannot be to find out the
> 'cause' for the existence of the universe. By definition, the creation
> of the universe took place outside the realm of the physical laws that
> govern our universe. Therefore, physics is just not applicable to
> what happened before the universe existed.

One possibility, though, is that physics can clarify whether the concept
of "before the universe existed" has any meaning.  In some cosmologies,
time (by any reasonable definition) runs infinitely backward and forward
so there can be no "before the universe existed".

A lot of the popularizations of "the first few seconds after the big
bang" cavalierly use everyday notions of time to discuss what most
certainly cannot be correctly described with such notions.

I don't know why so many people think the universe needs an external
cause.  Just what good would that do?

Perhaps the observation that the universe operates according to definite
rules contributes to this.  However, it is possible to make considerable
progress in understanding (a) how the rules are interrelated and (b) how
at least some of the rules could not be otherwise.  It seems perfectly
plausible to me that the fundamental laws are inherent in the nature of
existence and do not need to be ascribed to capricious whims of an
external agency.

stark@sbcs.UUCP (Eugene Stark) (08/19/85)

> Time can more understandably be viewed as as "unfolding" of sequential infor-
> mation arrays like the distinct frames of a moving picture.  The framing rate 
> for a particle like a neutron would be ~(m*c^2)/(<h bar>) where "m" is the 
> mass of a neutron, "c" the speed of light, and "h" Planck's constant.  The 
> framing rate decreases with the increase in effective mass of a neutron due 
> to its general and special relativity effects (its position in a dense 
> gravitational field or in rapid motion "velocity space").  

I have by now read several descriptions by Paul Koloc of the universe as
evolving by "unfolding of sequential information arrays," "grainy time,"
etc.  I wonder if he or some other reader could post some references to
published work in this area, so that those of us who can't follow the
description can perform the necessary "paradigm shift"?

							Gene Stark

pmk@prometheus.UUCP (Paul M Koloc) (08/20/85)

> Modern physics has lots of theories about these questions {the 
> nature of physical universe}, some of them proven to higher degrees 
> of accuracy than others. None of them promise to be 'the final 
> theory' of the universe.

That was b. k.    (before Koloc) :-)
Precise accuracy is secondary to being comprehensive and coherent.

> Your remark about QM and discrete time strikes me as odd.
> Your remark about QM and discrete space strikes me as even odder.

By the way didn't mention Quantum Mechanics.  Matter certainly isn't
continuous, consider the atomic theory, and I believe that the theory
was "invented" before it could be directly verified by electric field
microscope.  Particles aren't points.  They have a "delta function"
over a discrete distribution width in space, and if there is an 
symmetry then there is a "delta function distribution" in time as well. 
That implies framing. Of course, if the framing rate (~10**25/sec) 
is fast enough, time "looks" very nearly continuous.   Seems 1+1=2 to me, 
therefore. not so odd :-) 

> What tells you, by the way,
> that you can't store infinite amounts of data in a limited space,

Well, I tried to print the New York times on a neutron and gave up
because I wasn't able to get my pencil sharp enough.    :-) 

> and by what means can you infer from that that space is organized
> as a lattice? Unless you have a better argument than you presented
> in your posting, I would be extremely careful in making such statements.

Huh?  I didn't say and I didn't intend to imply anything related 
to a "lattice".  In fact, quite the contrary.

> Finally, the object of physics simply cannot be to find out the
> 'cause' for the existence of the universe. By definition, the creation
> of the universe took place outside the realm of the physical laws that 
> govern our universe. Therefore, physics is just not applicable to
> what happened before the universe existed.

Nonsense! Physics will go where ever the search for the nature of matter
takes it.  What more exciting place than that state it existed in before
it was released into 3 space manifold and took on the its material form.  
My guess is that some formulations of physics could be made which would
be applicable both to the matter of three space and the herein proposed 
hypo- matter of two space.  Maybe micro chunks of hypo-matter are still 
"decaying" into matter and thereby generating the phenomena we observe as 
quasars.  That's not quite as spectacular as "the big bang" but it's still 
pretty impressive. 

> Another way of stating the above is that any physical theory must
> be testable. A theory of the creation of the universe is not
> testable or verifiable.  ..  . . physics does not give final answers

Why not??  ?  I'm sure that we could get the defense department to fund
an experiment to locally decay a micro chunk of hypo-matter but if
we did it would be hazardous to our health, as according to one theory
of Sagan, it has been for thousands of previously existing intelligent
more technologically developed life in our universe.  If hypo space 
exists and if our space is grainy and point wise not continuous, then 
it should be possible to "test" the theory in the following way.  Since 
we live one the three space "side of the tracks" we can't observe 
hypo-matter.  (this stuff doesn't have volume).  However, if our matter 
was previously hypo-matter then we might be able to cause a chunk of
"matter" to be put back into the "hypo matter" state.  

Now that would be a test, because we could demonstrate that the effected
matter would "vanish".  Of course, that's a no no.  How can this be done?
Glad you asked! Accelerate the matter to the speed of light.  But, the 
theory says that before that happens the matter will become contracted 
so much that it will "slip between the grains" and our transitioned
matter can't interact with it.  It would essentially become so "thin" 
that it would "jump" to two space.  (A quantum jump, of course!)

Now if space is point wise continuous then it can't "fall through the
fingers" and transitioned matter would not disappear.   BUT for all you 
sci-fi fans, if it DOES jump then we have a  little problem ..  . the
problem  ..  . . is   that    hypo-space   might "tear"  and dump some 
hypo-matter on us, which as it generates a "white hole" and transforms 
into matter, transforming us into a supernova fragment. 

> But physics is also not a religion or a philosophy. 
> Physics can not tell you .. . *how* the universe was created.. .

Physics is a natural philosophy (and occasionally is catachismic).  What
are they teaching you up there at Harvard??  The Bible says God made 
the world and with a little help and a lot of work physics will tell 
us how.   Gosh, you mean we're NOT the center of the universe!

                             Aw Shucks! 

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pmk@prometheus.UUCP (Paul M Koloc) (08/20/85)

Doug Gwyn writes: 
> that physics can clarify whether the concept
> of "before the universe existed" has any meaning.  In some cosmologies,
> time (by any reasonable definition) runs infinitely backward and forward
> so there can be no "before the universe existed".

I agree! 
Without matter time runs at an "infinite rate" and no information is altered.
So reality is empty.  However, with the injection of existence, which then
takes on material forms in our three space, time is clamped "slowed greatly".
So it does make sense to look at that moment when 3space became "non empty".
Further assume the material state represents the "debris" of a decay of a 
two space "hypo-matter".  Then time had meaning, even "before" our (three 
dimensional) portion of the universe became non-empty, because time had 
already existed for hypomatter.

> A lot of the popularizations of "the first few seconds after the big
> bang" cavalierly use everyday notions of time to discuss what most
> certainly cannot be correctly described with such notions.

Maybe not in a precisely measurable physics sense, but in terms of 
time being sequential framing of "information arrays" it still makes sense
to contemplate it.  That means that we may be able to reason to 
the maximum peak densities and minimum framing rates and that could
give us some understanding of what the state of hypo-matter is.  

> I don't know why so many people think the universe needs an external
> cause.  Just what good would that do?

Energy can't be created nor destroyed so it must have transformed from a
non-three dimentsional manifold.  Two space is the nearest adjacent 
manifold that satisfies the need for a hyper compressed and ultra high 
energy density state sufficient to power a "big-bang" 3d injection.
It then transforms to the much fluffier (almost cotton candy-like state, 
by comparison) material state. This scenario conserves energy for the 
multi-manifold universe for one thing.  Of course, the next step is to 
deal with the existence state of one dimensional space.  If that state 
is infinitely dense then we are sort of 1/4 th of the way between 
absolute void and God,  between an infinitely persistent time frame 
and an infinitely high framing rate.  What good did it do to find out 
that the cosmos didn't have the earth as its center?  For one it was
humbling. More intelligent creatures then we?  I have little doubt.

> Perhaps the observation that the universe operates according to definite
> rules contributes to this.  However, it is possible to make considerable
> progress in understanding (a) how the rules are interrelated and (b) how
> at least some of the rules could not be otherwise.  It seems perfectly
> plausible to me that the fundamental laws are inherent in the nature of
> existence and do not need to be ascribed to capricious whims of an
> external agency.

Yes, half of particle duality is that they function as "logic operators".
Let's face it we write software that becomes the filter to transform
information, why can't the physical universe be the software read-out
of some two space net wizards (accomplished programmers - angels?) 

sra@oddjob.UUCP (Scott R. Anderson) (08/23/85)

In article <166@prometheus.UUCP>, pmk@prometheus.UUCP (Paul M Koloc) writes:

>> Two things tell us that the universe isn't continuous.  First, the "big bang",
>> and second, the constant "h bar" or even the fact that particles are not 
>> points. 

And in another article,

>> Particles aren't points.  They have a "delta function"
>> over a discrete distribution width in space, and if there is an 
>> symmetry then there is a "delta function distribution" in time as well.

So far as we know, the "fundamental" particles (quarks, leptons, etc.) ARE
points.  Experiments have yet to determine any finite extent for these
particles.  I believe that the current upper limit on the radius of the
electron is 10^(-18) meters or 0.001 fermi.

Such particles are described by wave functions, which under appropriate
conditions (i.e. the particle is at point x) are delta functions.  A
delta function has no width, as it is non-zero only at x.  This is how
one describes a point particle quantum-mechanically.

In article <490@talcott.UUCP> tmb@talcott.UUCP (Thomas M. Breuel) writes:
>
>Time is, of course, treated as a real variable in QM, and you
>can't just go from differential equations in time to difference
>equations and still have a working QT (at least I have never seen
>such a theory... it would definitely be interesting, though).
>....
>Your remark about QM and discreteness of space strikes me
>as even odder. If you know of a way of representing QM on
>a lattice, I would like to hear about it.

This is done on a regular basis in field theories, although only as
a calculation technique.  The procedure uses the path integral
formulation of QM and discretizes space-time onto a lattice with
some lattice spacing 'a'.  After everything is all said and done, 
the limit a -> 0 is taken.

Lurking nearby, however, is the question of the distinguishability of
small a (e.g. Planck Length) from a = 0.  At this point, we can't tell
the difference because the energies required are so enormous.  If space
were discretized, though, there would be some probability of "Umklapp"
processes occurring, in which a particle could change it's momentum for
no apparent reason.

				Scott Anderson
				ihnp4!oddjob!kaos!sra

pmk@prometheus.UUCP (Paul M Koloc) (08/25/85)

> > Time can more understandably be viewed as as "unfolding" of sequential 
> > information arrays like the distinct frames of a moving picture.  The 
> > framing rate for a particle like a neutron would be ~(m*c^2)/(<h bar>)
> > ....  . .

> I have by now read several descriptions by Paul Koloc of the universe as
> evolving by "unfolding of sequential information arrays," "grainy time,"
> etc.  I wonder if he or some other reader could post some references to
> published work in this area, so that those of us who can't follow the
> description can perform the necessary "paradigm shift"?
> 							Gene Stark
Eugene,
My view of the universe comes from notions gathered from Lucretius,
Feynmann, Einstein,  . and Wheeler. The concept is a sort of generalized 
"information theory", which includes considering the dynamics of
operator and array aspects "particles" to be the basis for what the 
physical universe is all about. The question is "If nature is unified 
and we discover the element of unification, then what word would best 
describe that entity?".   It seems to me that "information" would
be an excellent candidate.  The difference between existence and
non-existence is the presence of "grains".  

What's interesting is that most physicsl laws seem to apply, and some
new stuff seems to be falling out.  For example, it allows the existence
of "antimatter of charge 1"  but prohibits antimatter particles from
being "stable" with charge two or more.  (Sorry folks no "antimatter
galaxy" floating around some place.)  It also generates a basis
for the description of gravity, electric fields, magnetic fields in
a way which clearly unifies them in terms of a grainy information. 
As a result, the generation of magnetic fields by massive spinning
and precessing objects is allowed and is a calculable artifact of 
a "time distortion" due to the mass induced distortion of the 
"local metric". 

Current efforts are directed in a completely different area of 
research, namely, controlled thermnuclear fusion.  However, in about
three to four years, that project should be successful enough (or
will be shown not to be feasible), that I can devote time to working 
out a more concise and comprehensive description of the theory.  I'm 
sure that the "mind set" of billard ball elementary particle theory 
is about to crumble, and a more operator/array duality along the lines 
of information theory will emerge whether or not I'm successful. 
~
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pmk@prometheus.UUCP (Paul M Koloc) (08/25/85)

> In articles <166@prometheus.UUCP>, pmk@prometheus.UUCP (Paul M Koloc) writes:
>>> Two things tell us that the universe isn't continuous.  First, "big bang",
>>> Particles aren't points.  They have a "delta function"
> 
> Scott Anderson  (ihnp4!oddjob!kaos!sra)  <3656@decwrl.UUCP> answers:
> So far as we know, the "fundamental" particles (quarks, leptons, etc.) ARE
> points.  Experiments have yet to determine any finite extent for these
> particles.  I believe that the current upper limit on the radius of the
> electron is 10^(-18) meters or 0.001 fermi.

If you had said kilometers.  Actually, electron radius is ~ e^2/(m*c^2)
which comes to about 3 * 10^(-15) meters.  Still infinitely larger than
a point radius. --"e" is charge; "m" is electron mass; and "c" is light 
speed. They are represented as points, for convenience. 

> Such particles are described by wave functions, which under appropriate
> conditions (i.e. the particle is at point x) are delta functions.  A
> delta function has no width, as it is non-zero ONLY AT x.  This is how
> one describes a point particle quantum-mechanically.

I think "point" in quantum mechanics means "smudge".  And certainly, you
are right provided your mesh isn't too fine.  Now reads:
                    "only at (smudge) 'x'".

> In article <490@talcott.UUCP> tmb@talcott.UUCP (Thomas M. Breuel) writes:
> >. ..Your (Koloc) remark about QM and discreteness of space strikes me
> >as even odder. If you know of a way of representing QM on
> >a lattice, I would like to hear about it.
> 
> This is done on a regular basis in field theories, although only as
> a calculation technique.  The procedure uses the path integral... . 
> formulation of QM and discretizes space-time onto a lattice with
> some lattice spacing 'a'.  After everything is all said and done, 
> the limit a -> 0 is taken.  

Thanks for the help.  Consequently, a --> 0 approximates a --> "smudge x"
It usually is considered to be the other way around!

> Lurking nearby, however, is the question of the distinguishability of
> small a (e.g. Planck Length) from a = 0.  At this point, we can't tell
> the difference because the energies required are so enormous.  If space
> were discretized, though, there would be some probability of "Umklapp"
> processes occurring, in which a particle could change it's momentum for
> no apparent reason.

It does "change" and the reason is its lack of infinite "information 
density"; so it "jiggles" a little in "momentum space".  Wish I could 
claim that as an excuse to get out of paying off a speeding ticket.

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gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (08/26/85)

> Actually, electron radius is ~ e^2/(m*c^2)

Oh, really?  How did you determine this?

pmk@prometheus.UUCP (Paul M Koloc) (08/26/85)

In an earlier article I corrected an estimate of electron radius:
> > Actually, electron radius is ~ e^2/(m*c^2) ~ 3*10^15 meters

In article <966@brl-tgr.ARPA> (Doug Gwyn gwyn@brl-tgr.ARPA
Organization: Ballistic Research Lab challenges:
> Oh, really?  

Yep! An electron is neato because its the ground state of "THE" 
elementary half particle.  A pure information annihilator.  
Enough for the commercials.

> How did you determine this?

Assume that the energy of a "still" electron is ~ due to its electro- 
static energy.  If that's a reasonable approximation then, its energy 
can be measured by its still mass.  So Energy(mass) = Energy(electric 
field).  Then m*c^2 = e^2/r;   e is proportional to charge, m is mass 
and c is light speed.    Then r (its smallest smudge radius) is as 
above!       Happy?    :-)

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sra@oddjob.UUCP (Scott R. Anderson) (08/28/85)

>> So far as we know, the "fundamental" particles (quarks, leptons, etc.) ARE
>> points.  Experiments have yet to determine any finite extent for these
>> particles.  I believe that the current upper limit on the radius of the
>> electron is 10^(-18) meters or 0.001 fermi.

In article <171@prometheus.UUCP> pmk@prometheus.UUCP (Paul M Koloc) writes:
>If you had said kilometers.  Actually, electron radius is ~ e^2/(m*c^2)
>which comes to about 3 * 10^(-15) meters.  Still infinitely larger than
>a point radius. --"e" is charge; "m" is electron mass; and "c" is light 
>speed. They are represented as points, for convenience. 

This is what is known as the classical electron radius; it can be derived
in several ways based on classical electrodynamics (ref. Jackson, Classical
Electrodynamics).  However, an electron is a quantum mechanical object, and
as one might expect the above expression is only valid in certain regimes
(e.g. when the experimental probe has a wavelength much greater than the
c.e.r.).  Current experimental results make clear that the c.e.r. has
nothing to do with the true electron radius, assuming it has one.  Note
that I am not saying that the electron doesn't have a finite radius,
just that experiments have set a limit on what it can be.  And ascribing
a finite size to electrons (or muons or quarks) is an unnecessary
complication for most field theories (recall Occum's Razor!).

>I think "point" in quantum mechanics means "smudge".

If you choose to know nothing at all about a particle's momentum, "point"
means "point" in the mathematical sense.  This is the delta function.

				Scott Anderson
				ihnp4!oddjob!kaos!sra