Bizarre Pattern among anti-SR "Dissidents"

On Mar 3, 3:35*pm, PD wrote:
On Mar 3, 2:27*pm, mluttgens wrote:

....

And btw, how do you demonstrate that the electron has zero volume?

One measures its size.

And one operationalizes that concept how?

I googled around a little bit, and discovered that at least one skein
of contemporary thought is that the electron lacks a commonly accepted
meaningful definition of "size". You disagree?

For example, in http://wiki.answers.com/Q/What_is_th...of_an_electron

"Curiously, this most common of atomic parts has only a fuzzy estimate
of size.
Linus Pauling says "The radius of the electron has not been determined
exactly, but it is known to be less than 1 X 10-13 cm".
So roughly the electron is 1/1000 the size of a proton. Maybe. But a
cooler answer is-- physicists are annoyed by the question. A good case
can be made for other sizes, even huge sizes....because the properties
of the electron OTHER than it's size are the ONLY important ones. In
fact the size of atomic pieces smaller than the nucleus usually does
not matter at all....and may in fact have no meaning. After all, how
do you propose to measure these guys?"

But then the same author turns around and says:

"The electron is known to be a point particle down to a limit of
10^-18m. It, as far as we know does not have a classical 'size'."

Which implies some operational definition. There is some kind of
problem here.

On Mar 3, 12:44*pm, (Daryl McCullough)
wrote:
Koobee Wublee says...



On Mar 3, 4:22 am, Daryl McCullough wrote:
Koobee Wublee says...

Yes, I know that you anti-relativity people claim that the nonsensical
version is the version that Einstein actually meant.

Who cares about what Einstein the nitwit, the plagiarist, and the liar
meant?

I would say that you certainly do. You are invested in the claim
that Einstein was a "nitwit, plagiarist and liar". If you didn't
care about Einstein, then you wouldn't bring him up in the discussion.

Einstein is your obsession. He's your John Lennon and you're his
Mark Chapman.

Fortunately, Einstein is pre-deceased.

On Mar 4, 11:53*am, Edward Green wrote:
On Mar 3, 3:35*pm, PD wrote:

On Mar 3, 2:27*pm, mluttgens wrote:

...

And btw, how do you demonstrate that the electron has zero volume?

One measures its size.

And one operationalizes that concept how?

I googled around a little bit, and discovered that at least one skein
of contemporary thought is that the electron lacks a commonly accepted
meaningful definition of "size". You disagree?

For example, inhttp://wiki.answers.com/Q/What_is_the_size_of_an_electron

"Curiously, this most common of atomic parts has only a fuzzy estimate
of size.
Linus Pauling says "The radius of the electron has not been determined
exactly, but it is known to be less than 1 X 10-13 cm".
So roughly the electron is 1/1000 the size of a proton. Maybe. But a
cooler answer is-- physicists are annoyed by the question. A good case
can be made for other sizes, even huge sizes....because the properties
of the electron OTHER than it's size are the ONLY important ones. In
fact the size of atomic pieces smaller than the nucleus usually does
not matter at all....and may in fact have no meaning. After all, how
do you propose to measure these guys?"

But then the same author turns around and says:

"The electron is known to be a point particle down to a limit of
10^-18m. It, as far as we know does not have a classical 'size'."

Which implies some operational definition. There is some kind of
problem here.

There is certainly a problem.

The first problem is that classical size implies some kind of clear
boundary, a surface between inside and outside. But you quickly run
into the fact that some things do not have that kind of boundary.
Clouds, for example. Or the footprints of mountains. Or atoms. One can
define some kind of *convention* like "there is a 95% probability of
finding the constituents of this body inside this boundary" where
you've by further convention chosen surfaces of iso-something. But
this doesn't really do the job. Electrons are also the same way.

Another way to think about size is whether there is any discernible
structure to the object. That is, is there any property of the object
that can be mapped according to some spatial distribution, such as the
charge distribution in a hadron, or the location of scattering centers
inside a nucleon? Electrons in this sense have NO discernible
structure down to the level of 1E-18 m.

On 4 mar, 12:58, PD wrote:
On Mar 4, 9:23*am, mluttgens wrote:





On 4 mar, 10:35, PD wrote:

On Mar 3, 7:58*pm, mluttgens wrote:

On 3 mar, 19:53, PD wrote:

On Mar 3, 3:33*pm, mluttgens wrote:

On 3 mar, 16:35, PD wrote:

On Mar 3, 2:27*pm, mluttgens wrote:

On 3 mar, 15:42, PD wrote:

On Mar 3, 1:19*pm, mluttgens wrote:

On 3 mar, 13:49, (Daryl McCullough) wrote:

Koobee Wublee says...

Said that from a person who does not even know how the Lorentz
transform actually mean.

I use the Lorentz transforms in a consistent manner that agrees
with experiment (within the limitations of applicability; the
region of spacetime must be small enough that spacetime curvature
can be neglected). You cannot use them consistently.

The proof of understanding of a theory is the ability to use
it consistently. You don't have that. Not about SR, not about
GR, not about the Doppler shifts, not about any topic of physics.

You are basically an idiot. A rude, pretentious, arrogant self-important,
anti-semitic idiot.

--
Daryl McCullough
Ithaca, NY

Daryl, how do you physically explain the GR BH'singulartity?

Iow, how can a dimensionless point have mass or other physical
properties?

I'm not sure I understand the problem, Marcel.
Forget the black hole. The electron, as far as we can tell, does not
have finite volume. This does not prohibit it from having physical
properties including mass.

I'm curious why you think that the properties of mass and volume (or
charge and volume, or angular momentum and volume) are *necessarily*
tied together.

As this is impossible, GR is almost right, meaning it is wrong.

Marcel Luttgens

Paul,

You want to forget the BH because of its unphysical singularity!

Not so. And it doesn't appear to be unphysical. I chose the electron
as something else to look at, because I doubt that you would claim
that any theory that involves electrons must be wrong.

Thus, according to you, infinites are physical.

What infinities?
The mass is nonzero and finite, and the volume is zero and of course
finite.

Generally speaking, we do not have *measurable* quantities that are
infinite, but there doesn't seem to be anything measurable in either
case that would be infinite.

What about density, i.e. mass/volume? When the volume is zero,
the density is of course infinite, unless the mass is also zero.
Hence, the density of a massive point electron is infinite, which is
physically
nonsensical.

Density is not a *measurable* property of either an electron or a
black hole.
Secondly, density is a property that is not something that is
attributable to EVERYTHING physical, and in fact it is a property that
ONLY applies to composite structures. One can talk about the density
of a salt crystal, because a salt is composed of ions. One can talk
about the density of an atom (roughly, since an atom strictly speaking
has no clear boundary and therefore no unambiguous volume) because an
atom is composed of protons, neutrons, and electrons. And once you
catalog things for which you do attribute density to and see that this
is the case, then it becomes clear as to why. Volume itself is a
property of only material composites. That volume is determined not so
much by the size of the constituents but by the *interactions* between
the constituents. In a salt crystal, the lattice spacing is determined
by the electromagnetic energy minimum in the interaction between
positive and negative ions, not by the size of the ions themselves. In
an atom, the radius of the atom is determined not by the size of the
nucleus or the electrons, but by the electromagnetic energy minimum in
the interaction between protons and electrons. In a nucleon, the
radius of the proton (say) is determined not by the size of the
constituent quarks but by the QCD interaction among them. This tells
you something -- something which LACKS constituents will not then have
interactions among those constituents and therefore there will be
nothing that is driving volume. Therefore there is no need to PRESUME
volume as a property of a noncomposite object.

And btw, how do you demonstrate that the electron has zero volume?

One measures its size. So far, there is no indication of any finite,
nonzero size.

And so far, there is no indication that the electron is dimensionless.

This doesn't mean that its size has been *proven* to be zero. But that
wasn't my question to you. The question to you is why you assume that
anything that has mass must also have volume?

The question is, how could a dimensionless point be massive?

Because volume and mass are independent properties. One does not
demand the other.
But also to your statement, an electron is not to be equated with a
mathematical point. A mathematical point does not have the property of
electric charge, for example. A electron (as far as we know) and a
mathematical point share the property of having no volume but this
does not equate one with the other, any more than a zebra is equated
with a tiger because they both have stripes.

An electron, as far as we know, exhibits mass, charge, spin, lepton
number, parity, and a few other properties, but it does not exhibit
nonzero volume.

I agree.

Nor does any of the properties that it does have
DEMAND that it have volume.

If it had no volume, its density would be infinite.

Density is not a measurable property of an electron.

Your mathematical modelling is no more than a tentative interpretation
of the physical world.

The mathematical model, however, is successful, where success is based
on observation.

Not in the case of BH, where the model leads to infinite values..

Of what measurable property?

Its density. But of course, an infinite density is not measurable,
and makes no sense.

Density of a black hole is not a *measurable* property, period.

It is a calculable property.

There is no nonphysicalness to a *calculable* property being infinite.

Does "no nonphysicalness" means physicalness?


Consider the calculable property "potentialness", which is the ratio
of potential to kinetic energy. That is infinite for your coffee cup.

And if I move my cup, its potentialness is finite...


In physics, we have the expectation that only MEASURABLE properties
should be finite.



Btw, Shuba wrote
"Newtonian gravity leads to infinite values at r=0, and is another
successful model."
I reply
"r=0 is only possible for mathematical points."

As, according to you, an electron (or a positron) has no volume,
the Newtonian force of gravity between electron and positron would
be infinite (r=0).

If they were touching, yes.
But they don't touch in positronium, because the volume of positronium
is governed by the energy minimum of the electromagnetic interaction
between them.

And, according to you, the positronium is made of two point particles.
But this is today's paradigm, see for instance
http://www.scienceagogo.com/news/renormalization.shtml

"Physicist Johan Prins, from the University of Pretoria, South
Africa,
says that both prior to, and after, the introduction of quantum
mechanics,
a fundamental problem has persisted. “Classical electrodynamics
required
that the electron should be modeled as a point-particle, but when they
tried
to model the electron as a particle with a radius, inconsistencies
arose,”
explains Prins. Niggling problems with electrons are nothing new, and
Feynman
himself acknowledged this in The Feynman Lectures on Physics II. One
of
the biggest problems, says Prins, is that: “today’s electron-electron
scattering
experiments indicate that the electron’s radius could be
infinitesimally small,
which causes the energy of the electric field around the electron to
be
infinitely large.” So in order to avoid completely nonsensical
answers,
a mathematical procedure called renormalization was introduced to
remove
infinity from equations, so that scientists could find a workable
answer
to their calculations rather than what amounted to gibberish. Prins
states
that this: “procedure has become such an inherent part of all quantum
field
theories, that at present the ‘renormalizability of a theory’ is
accepted
as proof that the theory is realistic.”

"Prins believes that renormalization provides a distorted view of
reality,
which is worrying, as physicists have relied on renormalization to
inform
much of their research, including attempts to reconcile the quantum
and
classical worlds in order to arrive at the coveted Theory of
Everything (TOE).

Marcel Luttgens


Another indication that such particles must have some volume.

Marcel Luttgens

The question is put to you how it is your assertion that nonzero mass
necessarily implies nonzero volume is supported by any scientific
measure of success.

How can a nonzero volume implies a nonzero mass?

It doesn't. An empty box is an example of a nonzero volume with zero
mass.
A crystal is an example of a nonzero volume with nonzero mass.

Sorry, I meant a zero volume with a nonzero mass.

An electron is an example, as far as we know, of a zero volume with a
nonzero mass.

An infinite density has no physical meaning.

Marcel Luttgens

On Mar 4, 2:41*pm, mluttgens wrote:
[...]

Shouldn't you be learning the theories you criticize so your
criticisms don't sound so amateur?

Or, even better, try to explain why a theory that predicts things you
think are so wrong manages to be right every time we try to measure it.

On Mar 4, 4:41*pm, mluttgens wrote:
On 4 mar, 12:58, PD wrote:

On Mar 4, 9:23*am, mluttgens wrote:

On 4 mar, 10:35, PD wrote:

On Mar 3, 7:58*pm, mluttgens wrote:

On 3 mar, 19:53, PD wrote:

On Mar 3, 3:33*pm, mluttgens wrote:

On 3 mar, 16:35, PD wrote:

On Mar 3, 2:27*pm, mluttgens wrote:

On 3 mar, 15:42, PD wrote:

On Mar 3, 1:19*pm, mluttgens wrote:

On 3 mar, 13:49, (Daryl McCullough) wrote:

Koobee Wublee says...

Said that from a person who does not even know how the Lorentz
transform actually mean.

I use the Lorentz transforms in a consistent manner that agrees
with experiment (within the limitations of applicability; the
region of spacetime must be small enough that spacetime curvature
can be neglected). You cannot use them consistently..

The proof of understanding of a theory is the ability to use
it consistently. You don't have that. Not about SR, not about
GR, not about the Doppler shifts, not about any topic of physics.

You are basically an idiot. A rude, pretentious, arrogant self-important,
anti-semitic idiot.

--
Daryl McCullough
Ithaca, NY

Daryl, how do you physically explain the GR BH'singulartity?

Iow, how can a dimensionless point have mass or other physical
properties?

I'm not sure I understand the problem, Marcel.
Forget the black hole. The electron, as far as we can tell, does not
have finite volume. This does not prohibit it from having physical
properties including mass.

I'm curious why you think that the properties of mass and volume (or
charge and volume, or angular momentum and volume) are *necessarily*
tied together.

As this is impossible, GR is almost right, meaning it is wrong.

Marcel Luttgens

Paul,

You want to forget the BH because of its unphysical singularity!

Not so. And it doesn't appear to be unphysical. I chose the electron
as something else to look at, because I doubt that you would claim
that any theory that involves electrons must be wrong.

Thus, according to you, infinites are physical.

What infinities?
The mass is nonzero and finite, and the volume is zero and of course
finite.

Generally speaking, we do not have *measurable* quantities that are
infinite, but there doesn't seem to be anything measurable in either
case that would be infinite.

What about density, i.e. mass/volume? When the volume is zero,
the density is of course infinite, unless the mass is also zero.
Hence, the density of a massive point electron is infinite, which is
physically
nonsensical.

Density is not a *measurable* property of either an electron or a
black hole.
Secondly, density is a property that is not something that is
attributable to EVERYTHING physical, and in fact it is a property that
ONLY applies to composite structures. One can talk about the density
of a salt crystal, because a salt is composed of ions. One can talk
about the density of an atom (roughly, since an atom strictly speaking
has no clear boundary and therefore no unambiguous volume) because an
atom is composed of protons, neutrons, and electrons. And once you
catalog things for which you do attribute density to and see that this
is the case, then it becomes clear as to why. Volume itself is a
property of only material composites. That volume is determined not so
much by the size of the constituents but by the *interactions* between
the constituents. In a salt crystal, the lattice spacing is determined
by the electromagnetic energy minimum in the interaction between
positive and negative ions, not by the size of the ions themselves. In
an atom, the radius of the atom is determined not by the size of the
nucleus or the electrons, but by the electromagnetic energy minimum in
the interaction between protons and electrons. In a nucleon, the
radius of the proton (say) is determined not by the size of the
constituent quarks but by the QCD interaction among them. This tells
you something -- something which LACKS constituents will not then have
interactions among those constituents and therefore there will be
nothing that is driving volume. Therefore there is no need to PRESUME
volume as a property of a noncomposite object.

And btw, how do you demonstrate that the electron has zero volume?

One measures its size. So far, there is no indication of any finite,
nonzero size.

And so far, there is no indication that the electron is dimensionless.

This doesn't mean that its size has been *proven* to be zero. But that
wasn't my question to you. The question to you is why you assume that
anything that has mass must also have volume?

The question is, how could a dimensionless point be massive?

Because volume and mass are independent properties. One does not
demand the other.
But also to your statement, an electron is not to be equated with a
mathematical point. A mathematical point does not have the property of
electric charge, for example. A electron (as far as we know) and a
mathematical point share the property of having no volume but this
does not equate one with the other, any more than a zebra is equated
with a tiger because they both have stripes.

An electron, as far as we know, exhibits mass, charge, spin, lepton
number, parity, and a few other properties, but it does not exhibit
nonzero volume.

I agree.

Nor does any of the properties that it does have
DEMAND that it have volume.

If it had no volume, its density would be infinite.

Density is not a measurable property of an electron.

Your mathematical modelling is no more than a tentative interpretation
of the physical world.

The mathematical model, however, is successful, where success is based
on observation.

Not in the case of BH, where the model leads to infinite values.

Of what measurable property?

Its density. But of course, an infinite density is not measurable,
and makes no sense.

Density of a black hole is not a *measurable* property, period.

It is a calculable property.

There is no nonphysicalness to a *calculable* property being infinite.

Does "no nonphysicalness" means physicalness?



Consider the calculable property "potentialness", which is the ratio
of potential to kinetic energy. That is infinite for your coffee cup.

And if I move my cup, its potentialness is finite...

Yes, of course. But notice that the physical description of the cup
doesn't blow up and become nonsense before you move it.




In physics, we have the expectation that only MEASURABLE properties
should be finite.

Btw, Shuba wrote
"Newtonian gravity leads to infinite values at r=0, and is another
successful model."
I reply
"r=0 is only possible for mathematical points."

As, according to you, an electron (or a positron) has no volume,
the Newtonian force of gravity between electron and positron would
be infinite (r=0).

If they were touching, yes.
But they don't touch in positronium, because the volume of positronium
is governed by the energy minimum of the electromagnetic interaction
between them.

And, according to you, the positronium is made of two point particles.

As far as we know, yes.

But this is today's paradigm, see for instancehttp://www.scienceagogo.com/news/renormalization.shtml

"Physicist Johan Prins, from the University of Pretoria, South
Africa,
says that both prior to, and after, the introduction of quantum
mechanics,
a fundamental problem has persisted. “Classical electrodynamics
required
that the electron should be modeled as a point-particle, but when they
tried
to model the electron as a particle with a radius, inconsistencies
arose,”
explains Prins. Niggling problems with electrons are nothing new, and
Feynman
himself acknowledged this in The Feynman Lectures on Physics II. One
of
the biggest problems, says Prins, is that: “today’s electron-electron
scattering
experiments indicate that the electron’s radius could be
infinitesimally small,
which causes the energy of the electric field around the electron to
be
infinitely large.” So in order to avoid completely nonsensical
answers,
a mathematical procedure called renormalization was introduced to
remove
infinity from equations, so that scientists could find a workable
answer
to their calculations rather than what amounted to gibberish. Prins
states
that this: “procedure has become such an inherent part of all quantum
field
theories, that at present the ‘renormalizability of a theory’ is
accepted
as proof that the theory is realistic.”

"Prins believes that renormalization provides a distorted view of
reality,
which is worrying, as physicists have relied on renormalization to
inform
much of their research, including attempts to reconcile the quantum
and
classical worlds in order to arrive at the coveted Theory of
Everything (TOE).

Marcel Luttgens

And that is Prine's worry. Some people do worry about it. Others say
that a perturbative expansion is a calculational method and there is
no guarantee that you can make those methods work in every physical
situation. The fact that you make it work in an unusual way for a real
situation indicates more about the inappropriateness of the
calculational method than it does about the physics of the situation.
And in fact, that is the driver for the lattice gauge calculation
approach, which involves no perturbative expansion at all and no
renormalization, to calculate the same physics.

The essence of the point to you is that it is not OBVIOUSLY an issue,
as you casually toss it off to be. It's in fact quite a subtle one, if
one at all. For you to say that objects with physical properties
SIMPLY CANNOT have zero volume, is to greatly overgeneralize to the
point of making a gross error.

Another indication that such particles must have some volume.

Marcel Luttgens

The question is put to you how it is your assertion that nonzero mass
necessarily implies nonzero volume is supported by any scientific
measure of success.

How can a nonzero volume implies a nonzero mass?

It doesn't. An empty box is an example of a nonzero volume with zero
mass.
A crystal is an example of a nonzero volume with nonzero mass.

Sorry, I meant a zero volume with a nonzero mass.

An electron is an example, as far as we know, of a zero volume with a
nonzero mass.

An infinite density has no physical meaning.

Marcel Luttgens

On Mar 4, 4:05*pm, PD wrote:
On Mar 4, 11:53*am, Edward Green wrote:



On Mar 3, 3:35*pm, PD wrote:

On Mar 3, 2:27*pm, mluttgens wrote:

...

And btw, how do you demonstrate that the electron has zero volume?

One measures its size.

And one operationalizes that concept how?

I googled around a little bit, and discovered that at least one skein
of contemporary thought is that the electron lacks a commonly accepted
meaningful definition of "size". You disagree?

For example, inhttp://wiki.answers.com/Q/What_is_the_size_of_an_electron

"Curiously, this most common of atomic parts has only a fuzzy estimate
of size.
Linus Pauling says "The radius of the electron has not been determined
exactly, but it is known to be less than 1 X 10-13 cm".
So roughly the electron is 1/1000 the size of a proton. Maybe. But a
cooler answer is-- physicists are annoyed by the question. A good case
can be made for other sizes, even huge sizes....because the properties
of the electron OTHER than it's size are the ONLY important ones. In
fact the size of atomic pieces smaller than the nucleus usually does
not matter at all....and may in fact have no meaning. After all, how
do you propose to measure these guys?"

But then the same author turns around and says:

"The electron is known to be a point particle down to a limit of
10^-18m. It, as far as we know does not have a classical 'size'."

Which implies some operational definition. There is some kind of
problem here.

There is certainly a problem.

The first problem is that classical size implies some kind of clear
boundary, a surface between inside and outside. But you quickly run
into the fact that some things do not have that kind of boundary.
Clouds, for example. Or the footprints of mountains. Or atoms. One can
define some kind of *convention* like "there is a 95% probability of
finding the constituents of this body inside this boundary" where
you've by further convention chosen surfaces of iso-something. But
this doesn't really do the job. Electrons are also the same way.

Another way to think about size is whether there is any discernible
structure to the object. That is, is there any property of the object
that can be mapped according to some spatial distribution, such as the
charge distribution in a hadron, or the location of scattering centers
inside a nucleon? Electrons in this sense have NO discernible
structure down to the level of 1E-18 m.

Which is demonstrated how? Or does this exceed the limits of a typical
Usenet reply?

On Mar 4, 6:27*pm, Edward Green wrote:
On Mar 4, 4:05*pm, PD wrote:



On Mar 4, 11:53*am, Edward Green wrote:

On Mar 3, 3:35*pm, PD wrote:

On Mar 3, 2:27*pm, mluttgens wrote:

...

And btw, how do you demonstrate that the electron has zero volume?

One measures its size.

And one operationalizes that concept how?

I googled around a little bit, and discovered that at least one skein
of contemporary thought is that the electron lacks a commonly accepted
meaningful definition of "size". You disagree?

For example, inhttp://wiki.answers.com/Q/What_is_the_size_of_an_electron

"Curiously, this most common of atomic parts has only a fuzzy estimate
of size.
Linus Pauling says "The radius of the electron has not been determined
exactly, but it is known to be less than 1 X 10-13 cm".
So roughly the electron is 1/1000 the size of a proton. Maybe. But a
cooler answer is-- physicists are annoyed by the question. A good case
can be made for other sizes, even huge sizes....because the properties
of the electron OTHER than it's size are the ONLY important ones. In
fact the size of atomic pieces smaller than the nucleus usually does
not matter at all....and may in fact have no meaning. After all, how
do you propose to measure these guys?"

But then the same author turns around and says:

"The electron is known to be a point particle down to a limit of
10^-18m. It, as far as we know does not have a classical 'size'."

Which implies some operational definition. There is some kind of
problem here.

There is certainly a problem.

The first problem is that classical size implies some kind of clear
boundary, a surface between inside and outside. But you quickly run
into the fact that some things do not have that kind of boundary.
Clouds, for example. Or the footprints of mountains. Or atoms. One can
define some kind of *convention* like "there is a 95% probability of
finding the constituents of this body inside this boundary" where
you've by further convention chosen surfaces of iso-something. But
this doesn't really do the job. Electrons are also the same way.

Another way to think about size is whether there is any discernible
structure to the object. That is, is there any property of the object
that can be mapped according to some spatial distribution, such as the
charge distribution in a hadron, or the location of scattering centers
inside a nucleon? Electrons in this sense have NO discernible
structure down to the level of 1E-18 m.

Which is demonstrated how? Or does this exceed the limits of a typical
Usenet reply?

Scattering.

You can bounce objects off each other to determine its' scattering
cross section and thus its' physical size. Unfortunately for the 'an
electron MUST be a little physical object' crowd, the behavior is
consistent to many places right of zero.

I've always liked to think the electron is a topological defect in
space, but I can't reconcile that theory with the proton which is an
actual assemblage of parts which has the opposite charge.

On Mar 4, 8:27*pm, Edward Green wrote:
On Mar 4, 4:05*pm, PD wrote:



On Mar 4, 11:53*am, Edward Green wrote:

On Mar 3, 3:35*pm, PD wrote:

On Mar 3, 2:27*pm, mluttgens wrote:

...

And btw, how do you demonstrate that the electron has zero volume?

One measures its size.

And one operationalizes that concept how?

I googled around a little bit, and discovered that at least one skein
of contemporary thought is that the electron lacks a commonly accepted
meaningful definition of "size". You disagree?

For example, inhttp://wiki.answers.com/Q/What_is_the_size_of_an_electron

"Curiously, this most common of atomic parts has only a fuzzy estimate
of size.
Linus Pauling says "The radius of the electron has not been determined
exactly, but it is known to be less than 1 X 10-13 cm".
So roughly the electron is 1/1000 the size of a proton. Maybe. But a
cooler answer is-- physicists are annoyed by the question. A good case
can be made for other sizes, even huge sizes....because the properties
of the electron OTHER than it's size are the ONLY important ones. In
fact the size of atomic pieces smaller than the nucleus usually does
not matter at all....and may in fact have no meaning. After all, how
do you propose to measure these guys?"

But then the same author turns around and says:

"The electron is known to be a point particle down to a limit of
10^-18m. It, as far as we know does not have a classical 'size'."

Which implies some operational definition. There is some kind of
problem here.

There is certainly a problem.

The first problem is that classical size implies some kind of clear
boundary, a surface between inside and outside. But you quickly run
into the fact that some things do not have that kind of boundary.
Clouds, for example. Or the footprints of mountains. Or atoms. One can
define some kind of *convention* like "there is a 95% probability of
finding the constituents of this body inside this boundary" where
you've by further convention chosen surfaces of iso-something. But
this doesn't really do the job. Electrons are also the same way.

Another way to think about size is whether there is any discernible
structure to the object. That is, is there any property of the object
that can be mapped according to some spatial distribution, such as the
charge distribution in a hadron, or the location of scattering centers
inside a nucleon? Electrons in this sense have NO discernible
structure down to the level of 1E-18 m.

Which is demonstrated how? Or does this exceed the limits of a typical
Usenet reply?

An attempt to do deep-inelastic scattering, comparable to what was
done for the proton in the late 1960s at the 1E-15m scale.

In article
,
PD wrote:

snip

There is no nonphysicalness to a *calculable* property being infinite.

Consider the calculable property "potentialness", which is the ratio
of potential to kinetic energy. That is infinite for your coffee cup.

Or the slope of a vertical plane, for an example of a property that's
encountered more often.

In physics, we have the expectation that only MEASURABLE properties
should be finite.

Continuing the example, one might measure the angle to be 90° +/-
epsilon, and thus infer the slope to be greater than some large number
(more ar less the reciprocal of epsilon in radians). In the limit of
perfect precision this number would become infinite.

--
Odysseus