Electron radius?
Timothy Hamlin
professor is showing us why classical E&M isn't completely correct.
She claims that even QED hasn't solved the problem with the electron's
radius - infinities showing up all over due to terms with r in the
denominator.
Evidently, there is no evidence that the electron has a radius?
(This was news to me, I always assumed it had a radius but it was just so
small that we could treat it as point like, even at sub-atomic scales.)
Anybody know what the current though on this issue is?
Thanks,
Tim
Ben Bullock
> Evidently, there is no evidence that the electron has a radius?
Yes.
> (This was news to me, I always assumed it had a radius but it was just so
> small that we could treat it as point like, even at sub-atomic scales.)
> Anybody know what the current though on this issue is?
The current experimental limits are that there is no radius to the
electron. "radius" implies some kind of structure, and as far as any
experiment can see there is no "structure" to the electron, it is a
pure point-like particle.
(Anyone who disagrees with this is a crackpot, please ignore them)
--
Ben Bullock @ KEK (national lab. for high energy physics, Tsukuba, Japan)
e-mail: b...@theory.kek.jp www: http://theory.kek.jp:80/~ben/
1-1 Oho, Tsukuba, Ibaraki 305, Japan. tel: 0298 64 5403, fax: 0298 64 7831
ale2
mci...@fas.harvard.edu (Matt McIrvin) writes:
> In article <49j4ti$54...@musca.unm.edu>, Timothy Hamlin <qu...@unm.edu> wrote:
> >I'm just finishing up an undergraduate E&M course and to wrap it up the
> >professor is showing us why classical E&M isn't completely correct.
> >
> >She claims that even QED hasn't solved the problem with the electron's
> >radius - infinities showing up all over due to terms with r in the
> >denominator.
>
> Well, actually, in relativistic QED they sort of turn into *logs* of
> r, which you might call progress of a sort. And we know how to
> extract physical quantities so that they don't have divergences in
> them.
>
> Electrons have no detected components, nor do we imagine them as made
> of any sort of continuous "stuff."
^^^^^^^^^^^^^^^^^
Obviously not speaking for some of us crackpots!)
Matt McIrvin
>I'm just finishing up an undergraduate E&M course and to wrap it up the
>professor is showing us why classical E&M isn't completely correct.
>
>She claims that even QED hasn't solved the problem with the electron's
>radius - infinities showing up all over due to terms with r in the
>denominator.
Well, actually, in relativistic QED they sort of turn into *logs* of
r, which you might call progress of a sort. And we know how to
extract physical quantities so that they don't have divergences in
them.
Electrons have no detected components, nor do we imagine them as made
of any sort of continuous "stuff." As for whether you count the rich
variety of fields, and therefore virtual particles, surrounding them
at short distances as "substructure" is a huge semantic quagmire that
we have been through before in this group, and I have no desire to
step back in.
But they don't have a radius in the sense that protons have a radius;
at known distance scales, you do *not* at some point drop out of the
range of effectiveness of theories with electrons into that of
theories that have only component things.
QED *does* cease to hold at small scales, but the theory that replaces
it still has both electrons and pesky infinities. Sometimes we hope
that some radically different theory of physics will cut off those
divergences at very small scales, but for the time being we console
ourselves with removing them from measurable quantities.
--
Matt 01234567 <-- Indent-o-Meter
McIrvin ^ Indentation will soon be too cheap to meter!
keith stein
> The current experimental limits are that there is no radius to the
> electron. "radius" implies some kind of structure, and as far as any
> experiment can see there is no "structure" to the electron, it is a
> pure point-like particle.
>
> (Anyone who disagrees with this is a crackpot, please ignore them)
> Ben Bullock @ KEK (national lab. for high energy physics, Tsukuba, Japan)
dear Ben,
I AM NOT A CRACKPOT
i'm just an old fashioned classical physicist,
and I DISAGREE
There are the following possiblities:-
Either 1. The inverse square law for electrostatic forces
breaks down at small distances.
If so - that's your radius for the electron.
Or 2. The inverse square law holds up and then:-
' Minimium Radius of Electron = 1.9 * 10-15 Meters'
(Simply from the work done in charging sphere)
Or 3. Einstein's E = m c^2 is wrong !
Or 4. Energy Consevation is wrong .
Or 5. I is wrong
--
keith stein
Hauke Reddmann
: Anybody know what the current though on this issue is?
I vaguely recall the electron is pointlike down to 1E-18m
(maybe P.Esch will have the newest scattering-experiment
values). Anyway, if an electron is not pointlike, what
keeps it from flying apart? So assume it has a structure.
If the parts are not pointlike, what keeps _them_ from
flying apart? And if you land,at the end,at a truely
pointlike particle,that's even worse,because its
self-energy is infinite...(...beep...please wait for
QM/GR unification...beep...please wait...)
--
Hauke Reddmann fc3...@math.uni-hamburg.de
<:-EX8
bla...@freenet.edmonton.ab.ca
--
Reply by e-mail ONLY, please.
===================== ====================================
BLAINE GORDON MANYLUK email: bla...@freenet.edmonton.ab.ca
EDMONTON, AB
Erik Max Francis
> So electrons are naked singularities, as I suspected.
Quantum effects come into effect so strongly with an electron that
this characterization is not only not valid, but probably isn't even
close.
Erik Max Francis, &tSftDotIotE && uuwest!alcyone!max, m...@alcyone.darkside.com
San Jose, California, U.S.A. && 37 20 07 N 121 53 38 W && the 4th R is respect
H.3`S,3,P,3$S,#$Q,C`Q,3,P,3$S,#$Q,3`Q,3,P,C$Q,#(Q.#`-"C`- && 1love && folasade
_Omnia quia sunt, lumina sunt._ && GIGO Omega Psi && http://www.spies.com/max/
"The Creator Raven looked at Man and was . . . surprised to find that this
strange new being was so much like himself." -- Eskimo creation myth
Erik Max Francis
> I AM NOT A CRACKPOT
Anyone who types this claim in all uppercase is undeniably a crank.
Roger Miller
: Number 2: The electron has a density that diminishes as the *fourth* power
: of the distance from the center.
Is this supposed to be mass density or charge density or both?
: The electron has no radius as the density continually diminishes to
: virtually zero at the extremety. It has no surface -- so it has no
: radius.
: BUT, we can give it an "essential" radius -- one that will manifest in
: interactions with other particles.
"derivation" deleted
: or 1.2 x 10^ cm ("radius")
: I think this is compatible with experiment -- but am not quite sure.
Sorry about that, but it isn't compatible with experiment. All experiments
so far show the electron acts as a point particle. I believe the precision
is down to about 10^-15 cm. If the charge density does not have a finite
or infinitesimal boundary, then Coulomb's 1/r^2 law fails. Again, this
failure is not observed.
Roger Miller
is wrong as well as your radius.
: V.V.
Vertner Vergon
: I'm just finishing up an undergraduate E&M course and to wrap it up the
: professor is showing us why classical E&M isn't completely correct.
:
: She claims that even QED hasn't solved the problem with the electron's
: radius - infinities showing up all over due to terms with r in the
: denominator.
: Evidently, there is no evidence that the electron has a radius?
: (This was news to me, I always assumed it had a radius but it was just so
: Thanks,
: Tim
Number 1, I recommend you read my post, ELECTRON.
Number 2: The electron has a density that diminishes as the *fourth* power
of the distance from the center.
The electron has no radius as the density continually diminishes to
virtually zero at the extremety. It has no surface -- so it has no
radius.
BUT, we can give it an "essential" radius -- one that will manifest in
interactions with other particles.
According to my theory (model) this would be one light second (LY)
divided by the number of quanta in an electron (equal to the frequency)
LY 3 x 10^10 cm
Thus, ------- = ------------- = 2.4 x 10^-10 cm (diameter)
n 1.2 x 10^20
or 1.2 x 10^ cm ("radius")
I think this is compatible with experiment -- but am not quite sure.
V.V.
john baez
Ted Corcovilos
>> >I'm just finishing up an undergraduate E&M course and to wrap it up the
>> >professor is showing us why classical E&M isn't completely correct.
>> >
>> >She claims that even QED hasn't solved the problem with the electron's
>> >radius - infinities showing up all over due to terms with r in the
>> >denominator.
The radius of the electron can't be determined because it isn't a
point-particle, but a wave packet. After all the details of the wave
calculations, you get back to the uncertainty principle. The
inaccuracy in the measurement of the momentum (from the DeBroglie
wave-length) of the electron and the size of the wave packet (radius)
multiply to give hbar/2.
Ted Corcovilos (corc...@utk.edu)
Erik Max Francis
> According to my theory (model) this would be one light second (LY)
> divided by the number of quanta in an electron (equal to the frequency)
Oh, dear, he's back to thinking that the light-second is fundamental.
Roger Miller
: In article <gX2oFD...@alcyone.darkside.com>, m...@alcyone.darkside.com (Erik Max Francis) writes:
: |>ver...@cinenet.net (Vertner Vergon) writes:
: |>
: |>> According to my theory (model) this would be one light second (LY)
: |>> divided by the number of quanta in an electron (equal to the frequency)
: |>
: |>Oh, dear, he's back to thinking that the light-second is fundamental.
: Hold on a sec, Erik. His quanta is defined in terms of seconds, so it looks
: like the seconds cancel each other out.
He tried to argue the point, but his arithmetic had its usual gross errors.
He claims his "quanta" has a frequency of 1 Hz. That's where he places the
second as a fundamental unit of time. If he claimed the quanta had a
frequency of a milisecond, his "mass" expression would also change by a
factor of10^-3 and the units of a second would still cancel out.
Roger Miller
keith stein
>
> keith stein <ke...@sthbrum.demon.co.uk> writes:
>
> > I AM NOT A CRACKPOT
"john baez" writes
> OH YES YOU ARE
>
keith stein writes: OH NO I AM NOT
i repeat, i am just a classical physicist, and many years ago
i was taught that the radius of the electron could not be less than
2 e^2 / 3 m c^2 or 1.9 * 10^-13 cm
Now if the modern view is that the electron is 'pointlike' as several
of the previous contributors maintain, including one gentleman who was
able to assure the world that 'only a crackpot would disagree (with the
author)', then please explain why the above value is wrong.
--
keith stein
Emory F. Bunn
keith stein <ke...@sthbrum.demon.co.uk> wrote:
>i repeat, i am just a classical physicist, and many years ago
>i was taught that the radius of the electron could not be less than
> 2 e^2 / 3 m c^2 or 1.9 * 10^-13 cm
>Now if the modern view is that the electron is 'pointlike' as several
>of the previous contributors maintain, including one gentleman who was
>able to assure the world that 'only a crackpot would disagree (with the
>author)', then please explain why the above value is wrong.
It's wrong for the only reason that things are ever wrong in science:
it disagrees with experiment. The electron behaves like a point
particle, in the sense that it satisfies Coulomb's law for a point
particle (with appropriate weak-interaction corrections). This law
has been tested down to some minimum radius. The place to look for
this sort of thing is the "Review of Particle Properties" at
or for those who unaccountably prefer paper, Phys. Rev. D, 50, 1173
(1994). If I'm not mistaken, the limit they give is something like
10^{-17} cm.
This number is somewhat lower than I expected. Perhaps someone can
correct me if I'm wrong. I'm looking at the section on compositeness
of leptons (p. 1227 in particular). The limits indicate that leptons
have no substructure up to energy scales of about 1 TeV. An energy
scale E corresponds to a length scale hbar c/E. Remembering that hbar
c is about 200 MeV fm, the limit on the size of the electron is
something like (200 MeV fm / 10^6 MeV) = 2 x 10^{-4} fm, or something
like 10^{-17} cm.
So that's the answer. If the electron were an extended particle with
the radius you suggest, searches for substructure within it would have
succeeded. They didn't, so it isn't.
-Ted
john baez
>In article <4a5ecn$p...@guitar.ucr.edu> ba...@guitar.ucr.edu "john baez" writes:
>> keith stein <ke...@sthbrum.demon.co.uk> writes:
>> > I AM NOT A CRACKPOT
>"john baez" writes
>> OH YES YOU ARE
>keith stein writes: OH NO I AM NOT
>i repeat, i am just a classical physicist, and many years ago
>i was taught that the radius of the electron could not be less than
> 2 e^2 / 3 m c^2 or 1.9 * 10^-13 cm.
My comment had nothing to do with that. I just couldn't resist replying
in kind to your capitalized proclamation. There's more to life than
classical physics, by the way.... renormalization!
Christopher R. Volpe
|>ver...@cinenet.net (Vertner Vergon) writes:
|>
|>> According to my theory (model) this would be one light second (LY)
|>> divided by the number of quanta in an electron (equal to the frequency)
|>
|>Oh, dear, he's back to thinking that the light-second is fundamental.
Hold on a sec, Erik. His quanta is defined in terms of seconds, so it looks
like the seconds cancel each other out.
--
Chris Volpe Phone: (518) 387-7766 (Dial Comm 8*833
GE Corporate R&D Fax: (518) 387-6560
PO Box 8, Schenectady, NY 12301 Email: vol...@crd.ge.com
me...@cars3.uchicago.edu
>In article <4a5ecn$p...@guitar.ucr.edu> ba...@guitar.ucr.edu "john baez" writes:
>
>>
>> keith stein <ke...@sthbrum.demon.co.uk> writes:
>>
>> > I AM NOT A CRACKPOT
>"john baez" writes
>> OH YES YOU ARE
>>
>keith stein writes: OH NO I AM NOT
>
>i repeat, i am just a classical physicist, and many years ago
>i was taught that the radius of the electron could not be less than
>Now if the modern view is that the electron is 'pointlike' as several
>of the previous contributors maintain, including one gentleman who was
>able to assure the world that 'only a crackpot would disagree (with the
>author)', then please explain why the above value is wrong.
Two reasons:
1) The above value is deduced assuming that the only form of energy
involved is electromagnmatic.
2) More important, experimental evidence contradicts this value. So,
no matter how much you may be attached to it, it has to go.
Mati Meron | "When you argue with a fool,
me...@cars3.uchicago.edu | chances are he is doing just the same"
Vertner Vergon
: >> In article <49j4ti$54...@musca.unm.edu>, Timothy Hamlin <qu...@unm.edu> wrote:
: >> >I'm just finishing up an undergraduate E&M course and to wrap it up the
: >> >professor is showing us why classical E&M isn't completely correct.
: >> >
: >> >She claims that even QED hasn't solved the problem with the electron's
: >> >radius - infinities showing up all over due to terms with r in the
: >> >denominator.
:
: The radius of the electron can't be determined because it isn't a
: point-particle, but a wave packet.
From ON THE QUANTUM AS A PHYSICAL ENTITY:
(describing the electron) The concentric oscillating quanta are analogous
to an oscillating electromagnetic cavity the resonance radius (a) of
which is customarily given as
2.41 c
a = --------
omega
(Where omega is angular frequency
2 pi nu.
Following are two results for calculating the radius of the electron.
The first (r) is by the present theory, and the second (a) is by
utilizing the cavity expression above.
LS
r = ------ = 1.213 x 10^-10 cm
2 n
a = 9.306 x 10^-11 cm
(The same comparative relationship holds for the proton.)
: After all the details of the wave
: calculations, you get back to the uncertainty principle. The
: inaccuracy in the measurement of the momentum (from the DeBroglie
: wave-length) of the electron and the size of the wave packet (radius)
: multiply to give hbar/2.
:
: Ted Corcovilos (corc...@utk.edu)
:
V.V.
Erik Max Francis
> In article <gX2oFD...@alcyone.darkside.com>, m...@alcyone.darkside.com (Eri
> |>ver...@cinenet.net (Vertner Vergon) writes:
> |>
> |>> According to my theory (model) this would be one light second (LY)
> |>> divided by the number of quanta in an electron (equal to the frequency)
> |>
> |>Oh, dear, he's back to thinking that the light-second is fundamental.
>
> Hold on a sec, Erik. His quanta is defined in terms of seconds, so it looks
> like the seconds cancel each other out.
That's fine, but why does the figure 1 ls come up? Why not 10? 100?
33 523 525.667 322 322?
He's giving some special (and farcical) significance to the light-
second; it's not that the units won't cancel, it's that he's using the
value 1 ls out of nowhere.
keith stein
> >i repeat, i am just a classical physicist, and many years ago
> >i was taught that the radius of the electron could not be less than
> > 2 e^2 / 3 m c^2 or 1.9 * 10^-13 cm
Ted writes:-
> .... 10^{-17} cm.
> .. that's the answer. If the electron were an extended particle with
> the radius you suggest, searches for substructure within it would have
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >
Thanks for the reponse Ted, but it doesn't really answer my question.
The formulae for the classical radius of the electron is obtained by
assuming that all of the electron's mass energy (mc^2) is derived from
the electron's electric potential energy ( 2/3 e^2/R cgs units).
Since this formula for the PE is derived just from the inverse
square law; their would not seem to be any reason to doubt its applicability
down the relatively large value of 1.9 * 10^-13 cm which this approach yeilds.
SURELY m c^2 >= Electric Potential Energy
IN WHICH CASE R > 1.9 * 10-13 cm
now i ask again WHAT IS WRONG WITH THAT ?
--
keith stein
Matt McIrvin
keith stein <ke...@sthbrum.demon.co.uk> wrote:
>Thanks for the reponse Ted, but it doesn't really answer my question.
>The formulae for the classical radius of the electron is obtained by
>assuming that all of the electron's mass energy (mc^2) is derived from
>the electron's electric potential energy ( 2/3 e^2/R cgs units).
> Since this formula for the PE is derived just from the inverse
>square law; their would not seem to be any reason to doubt its applicability
>down the relatively large value of 1.9 * 10^-13 cm which this approach yeilds.
>SURELY m c^2 >= Electric Potential Energy
>IN WHICH CASE R > 1.9 * 10-13 cm
>now i ask again WHAT IS WRONG WITH THAT ?
To treat the electron as made of stationary "stuff" and apply the
inverse-square law is actually not correct! Once you get within the
electron's Compton wavelength (which basically the "classical radius"
times 137 times 2*pi, unless I got a 2*pi wrong somewhere), you either
have to treat the electron's position as uncertain, or take into
account that it has a significant probability of moving around at a
highly relativistic momentum, which modifies its electromagnetic
interactions. You must treat the electromagnetic field as quantized
rather than classical. You must also take into account the effects of
virtual electron-positron pairs within the electron's field.
All these effects, which become important on a scale somewhere around
10^-10 cm, change things. One interesting effect of all this is to
soften somewhat the divergence of the extra energy with decreasing
radius, so that it only goes as the logarithm. That effectively
shrinks the equivalent of the "classical electron radius" down to a
much, much smaller size. In fact, according to Sakurai's _Advanced
Quantum Mechanics_ (p. 271), it's on the order of 10^-111 cm. That's
so small that nobody believes *any* established physical theory on
that scale, let alone QED. (When we say that "in QED the electron
is a point particle," after all, all we mean is that it doesn't have
any substructure [besides what we expect from pair production]
*within the domain of application* of QED. Who knows what happens
at 10^-111 cm? Is there even *such a distance* as 10^-111 cm?!!
As Sakurai points out, a particle with that wavelength would have
more energy than the mass in the known universe!)
If you read a treatise on QED renormalization, especially an older
one, you will see a lot of hand-wringing about how unsavory it is to
cancel out infinite self-energies and other quantities with infinite
"counterterms" (which, in this case, would be a negative, infinite
"bare mass"), regardless of the fact that the infinite things never
actually show up in predictions of measurable quantities.
But it is important to realize, IMHO, that the divergent things are
not even necessarily infinite, provided we remember that we don't
expect *any* quantum field theory to apply down to infinitesimal
distances-- they are not even necessarily *large*, because in some
cases, such as this one, most of the diverging is done in the region
where nobody trusts the theory anyway! Seen in this light,
renormalization becomes much less unsavory; indeed, it is an amazing
and fortunate fact that we can divorce the actual predictions of
things like QED from the messy details of what goes on at *really*
high energies and short distances.
Emory F. Bunn
keith stein <ke...@sthbrum.demon.co.uk> wrote:
>Thanks for the reponse Ted, but it doesn't really answer my question.
Then I think you're asking the wrong question.
>The formulae for the classical radius of the electron is obtained by
>assuming that all of the electron's mass energy (mc^2) is derived from
>the electron's electric potential energy ( 2/3 e^2/R cgs units).
Since that assumption leads to a conclusion that disagrees with
experiment, it must be incorrect.
-Ted
Christopher R. Volpe
|>vo...@bart.crd.ge.com (Christopher R. Volpe) writes:
|>
|>> In article <gX2oFD...@alcyone.darkside.com>, m...@alcyone.darkside.com (Eri
|>> |>ver...@cinenet.net (Vertner Vergon) writes:
|>> |>
|>> |>> According to my theory (model) this would be one light second (LY)
|>> |>> divided by the number of quanta in an electron (equal to the frequency)
|>> |>
|>> |>Oh, dear, he's back to thinking that the light-second is fundamental.
|>>
|>> Hold on a sec, Erik. His quanta is defined in terms of seconds, so it looks
|>> like the seconds cancel each other out.
|>
|>That's fine, but why does the figure 1 ls come up? Why not 10? 100?
|>33 523 525.667 322 322?
|>
|>He's giving some special (and farcical) significance to the light-
|>second; it's not that the units won't cancel, it's that he's using the
|>value 1 ls out of nowhere.
I'm not sure. Perhaps he is just defining his "quanta" in terms of a
light-second, because that is merely a convenient unit. Although the term
"quanta" itself has fundamental connotations, I haven't seen any "fundamental"
claims about it (like it can only occur in integral quantities).
Vertner Vergon
: |>vo...@bart.crd.ge.com (Christopher R. Volpe) writes:
: |>
: |>> In article <gX2oFD...@alcyone.darkside.com>, m...@alcyone.darkside.com (Eri
: |>> |>ver...@cinenet.net (Vertner Vergon) writes:
: |>> |>
: |>> |>> divided by the number of quanta in an electron (equal to the
: |>> |>
: |>> |>Oh, dear, he's back to thinking that the light-second is fundamental.
: |>>
: |>> Hold on a sec, Erik. His quanta is defined in terms of seconds, so it
looks
: |>> like the seconds cancel each other out.
: |>
: |>That's fine, but why does the figure 1 ls come up? Why not 10? 100?
: |>33 523 525.667 322 322?
: |>
: |>He's giving some special (and farcical) significance to the light-
: |>second; it's not that the units won't cancel, it's that he's using the
: |>value 1 ls out of nowhere.
If you girls got off your lazy duffs and read my work you would
then know what you're talking about.
However, my theory yields 1.2 x 10^-10 cm. What does *your* theory yield?
It's always the empty barrel that makes the most noise. Nicht whar?
: I'm not sure. Perhaps he is just defining his "quanta" in terms of a
: light-second, because that is merely a convenient unit. Although the term
: "quanta" itself has fundamental connotations, I haven't seen any "fundamental"
: claims about it (like it can only occur in integral quantities).
How amyone with such a dim wittedness could make it through undergrad is
beyond me. Doesn't speak well of our school system.
V.V.
: --
:
Christopher R. Volpe
|>: I'm not sure. Perhaps he is just defining his "quanta" in terms of a
|>: light-second, because that is merely a convenient unit. Although the term
|>: "quanta" itself has fundamental connotations, I haven't seen any "fundamental"
|>: claims about it (like it can only occur in integral quantities).
|>
Well, if he allowed a fractional quanta greater than one, he'd have
to allow them less than one also, if we are to be able to speak of
energy differences.
|>quite explicit in claiming that this quanta of the energy (mass in his
|>terminology) calculated from nu = 1 Hz
|>is what everything else is made of, whether light or matter,
|>and that it cannot be divided into a smaller mass. This would seem to
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Oh, well then that's certainly fundamental, and therefore certainly wrong.
There's no reason why the frequency of a fundamental "quanta" should be
one cycle per second, and not one cycle per nano-year, or one cycle per
gigayear.
|>rule out anything but all energies/masses are quantized. Interesting
|>consequences would be that velocities must be quantized which would
|>imply space and/or time must also be quantized. I wonder if he can figure
|>out why?
Me too.
keith stein
> >The formulae for the classical radius of the electron is obtained by
> >assuming that all of the electron's mass energy (mc^2) is derived from
> >the electron's electric potential energy ( 2/3 e^2/R cgs units).
>
> Since that assumption leads to a conclusion that disagrees with
> experiment, it must be incorrect.
>
> -Ted
>
radius of electron > 1.9 * 10^-15 meters
Assuming Heisenberg's Uncertainty Principal leads to the conclusion that
it would never be possible to check this out,(ie the uncertainty in the
electrons position must be a lot more than this).
So i am very curious Ted, just what is this experimental evidence
which proves that the electron radius is < 1.9 * 10^-15 meters, and
does this really mean that HEISENBERG WAS WRONG ?
--
keith stein
Christopher R. Volpe
|>
|>: I'm not sure. Perhaps he is just defining his "quanta" in terms of a
|>: light-second, because that is merely a convenient unit. Although the term
|>: "quanta" itself has fundamental connotations, I haven't seen any "fundamental"
|>: claims about it (like it can only occur in integral quantities).
|>
|>beyond me. Doesn't speak well of our school system.
|>
Thanks a bunch. Perhaps you'd like to indicate what was dim-witted about the
above remark. (And in case it wasn't obvious, I was defending you.)
Vertner Vergon
: |>
: |>: I'm not sure. Perhaps he is just defining his "quanta" in terms of a
: |>: light-second, because that is merely a convenient unit. Although the term
: |>: "quanta" itself has fundamental connotations, I haven't seen any "fundamental"
: |>: claims about it (like it can only occur in integral quantities).
: |>
: |>How amyone with such a dim wittedness could make it through undergrad is
: |>beyond me. Doesn't speak well of our school system.
: |>
:
: Thanks a bunch. Perhaps you'd like to indicate what was dim-witted about the
: above remark. (And in case it wasn't obvious, I was defending you.)
We have a vast -- and unfortunate -- miscommunication here.
These posts get a little perplexing as to is saying what to *whom*.
I was adressing my caustic remark to (I think) Erik Max Francis cyclone
from the darkside who dogs me constantly with some nonsense about
my use of the second.
Unfortunately, I wasn't explicit as to whom I was referring.
I offer my abject apology, Christopher.
I also apologize for the statement itself. Even though I was exasperated
at the continual dogging, that kind of response is not called for.
So I offer (a small) apology to Erik. :-) (or whomever)
. . . . . . .
I don't know where we are now regarding the radius of the electron.
Earlier someone said that experiment showed it to pointlike. But
considering how gravity acts as though all the mass were at the center,
is it not possible that (certain) experiments would show the electron
in the same manner?
Inasmuch as my theory has the electron as a concentric set of
matter-waves expanding and contracting at velocity c, the similarity
to the resonance cavity was striking. I was particularly pleased when
the radius, a , came out to be virtually the same as my radius for
the electron (and proton).
Any thoughts?
: --
:
Emory F. Bunn
keith stein <ke...@sthbrum.demon.co.uk> wrote:
>You suggest that the radius of an electron can be determined to
>be less than 10-17 cm. Presumable therefore therefore the uncertainty
>in the electron's position < 10-17 cm.
>
>Therefore Uncertainty in the electrons momentum > h/(4 pi * 10-19)
>Therefore Relativistic Factor (sqr(1-(v/c)^2) > h/(4 pi *10^-19 *m0 c)
> = 2 * 10^6
> Note this is the factor by which the radius will be reduced
> due to the relativistic contraction of length !
>
>Thus even if i allow that your relativistic electrons have a radius
>which is less than 10^-19 meters, this would not apply to non relativistic
>electrons, would it?
Yes, it would. I'm afraid I don't have much more to say about this
than I've already said. You can calculate how electrons will
scatter off of each other when you slam them into each other. You
can perform this calculation under the assumption that the electron
is a point particle, and under the assumption that it's an extended
object with a particular radius. Then you can do the experiment.
When you do, you find that the results agree with the point-particle
theory and are inconsistent with the predictions based on assuming
that the electron is an extended object.
The predictions are made with relativity taken into account, so
there's no problem there.
-Ted
keith stein
> >That assuption leads to the conclusion that:-
> > radius of electron > 1.9 * 10^-15 meters
> >Assuming Heisenberg's Uncertainty Principal leads to the conclusion that
> >it would never be possible to check this out,(ie the uncertainty in the
> >electrons position must be a lot more than this).
> Poppycock. You can make the uncertainty in the position as small as
> you want by making the uncertainty in the momentum larger.
You suggest that the radius of an electron can be determined to
be less than 10-17 cm. Presumable therefore therefore the uncertainty
in the electron's position < 10-17 cm.
Therefore Uncertainty in the electrons momentum > h/(4 pi * 10-19)
Therefore Relativistic Factor (sqr(1-(v/c)^2) > h/(4 pi *10^-19 *m0 c)
= 2 * 10^6
Note this is the factor by which the radius will be reduced
due to the relativistic contraction of length !
Thus even if i allow that your relativistic electrons have a radius
which is less than 10^-19 meters, this would not apply to non relativistic
electrons, would it?
--
keith stein
Christopher R. Volpe
|>Christopher R. Volpe (vo...@bart.crd.ge.com) wrote:
|>:
|>: above remark. (And in case it wasn't obvious, I was defending you.)
|>
|>We have a vast -- and unfortunate -- miscommunication here.
|>These posts get a little perplexing as to is saying what to *whom*.
|>
|>I was adressing my caustic remark to (I think) Erik Max Francis cyclone
|>from the darkside who dogs me constantly with some nonsense about
|>my use of the second.
But Vertner, Erik raises an important point, which should not be neglected.
It *appears*, though I haven't been able to tell with absolute certainty,
that you *might* be assigning some kind of fundamental significance to the
second, which is a totally arbitrary man-made unit of time. I was trying to
give you the benefit of the doubt, but I still recognize Erik's objection
as something that should be addressed.
|>
|>Unfortunately, I wasn't explicit as to whom I was referring.
|>
|>I offer my abject apology, Christopher.
No problem. And feel free to call me "Chris". No need to be formal :).
Now, would you be so kind as to briefly (i.e without pointing to the entirety
of your paper, "On the Quantum...") address the issue of the significance of
the second? Are you claiming that a photon of frequency "one cycle per second"
is in any way a fundamental frequency, in that the energy (or "relativistic
mass", or "non-ponderable mass", or whatever the term du jour is) of that
photon is a fundamental indivisible amount of energy, and that all larger
amounts of energy and mass (or whatever) are integral multiples of quanta?
I hope this is not what you are claiming, otherwise it would seem an awful
coincidence that the people who decided on a (even if nominal) value of a
second however many hundreds of years ago just happened to hit upon a
fundamental unit of time.
--
Douglas A. Singleton
>>So i am very curious Ted, just what is this experimental evidence
>>which proves that the electron radius is < 1.9 * 10^-15 meters, and
>>does this really mean that HEISENBERG WAS WRONG ?
>
>predict how point particles should bounce off of each other using
>Coulomb's inverse-square law. You can also predict how they should
>bounce off under the assumption that the electron is extended, i.e.,
>that it's not a point particle. The experiments confirm that it is a
>point particle down to a length scale much lower than your proposed
>radius.
>
>No, this does not mean that Heisenberg was wrong.
>
>-Ted
Ted is right about the electron being point-like down to 10^{-17} m
or whatever the current limit is now, but I'm not so sure it's correct
to say the electron generates a simple 1/r Coulomb potential down
to this scale. If it did then the electron should be much heavier
than is observed due to the 1/2 E^2 energy in it's electric field.
What happens is that quantum coorections start modifying the electrons
potential from the simple Coulomb form long before 10^{-17} m (the
actual point where quantum corrections start becoming important is
something like 137 x [classical electron radius] --its probably
best to check Sakuraii's Advanced QM though). The point is that
in the quantum theory with the electron assumed to be a point
particle, one doesn't see any deviation from the expected results
down to 10^{-17} m, with all the quantum coorections up to a certain
order taken into account.
Doug
.
Vertner Vergon
: In article <818857...@sthbrum.demon.co.uk>,
: keith stein <ke...@sthbrum.demon.co.uk> wrote:
: >You suggest that the radius of an electron can be determined to
: >be less than 10-17 cm. Presumable therefore therefore the uncertainty
: >in the electron's position < 10-17 cm.
: >
: >Therefore Uncertainty in the electrons momentum > h/(4 pi * 10-19)
: >Therefore Relativistic Factor (sqr(1-(v/c)^2) > h/(4 pi *10^-19 *m0 c)
: > = 2 * 10^6
: > Note this is the factor by which the radius will be reduced
: > due to the relativistic contraction of length !
: >
: >Thus even if i allow that your relativistic electrons have a radius
: >which is less than 10^-19 meters, this would not apply to non relativistic
: >electrons, would it?
: Yes, it would. I'm afraid I don't have much more to say about this
: than I've already said. You can calculate how electrons will
: scatter off of each other when you slam them into each other. You
: is a point particle, and under the assumption that it's an extended
: object with a particular radius. Then you can do the experiment.
: When you do, you find that the results agree with the point-particle
: theory and are inconsistent with the predictions based on assuming
: that the electron is an extended object.
:
: The predictions are made with relativity taken into account, so
: there's no problem there.
:
: -Ted
Did you ever stop to think that there is no radius to the electron
because it has no surface?
Commencing at the outer extremety (where it is extremely rare) the
density increases continuously as the fourth power of the distance
toward the center.
No suface, no radius.
What we have to do is establish an *effective* radius that
will *more or less* apply in interactions.
That radius is 1.2 x 10^-10 cm.
VERTNER VERGON -
Who indisputably re-established the existence of radiant mass.
Who indisputably corrected two errors in the special theory of relativity.
Who produced the indisputable final solution to the twins paradox.