is spin not angular momentum?
why is QM spin a label of integer and half?
Spin should be speed instead.
Who can argue otherwise?

Mitchell Raemsch

mitchr...@gmail.com <mitchrae3323@gmail.com> wrote:

> is spin not angular momentum?

It is, as can be established by measuring
the macroscopic angular momentum
of a macroscopic number of polarised spins.

See under 'Einstein-de Haas effect'
<https://en.wikipedia.org/wiki/Einstein%E2%80%93de_Haas_effect>

Jan

On Tuesday, March 1, 2022 at 1:24:16 AM UTC-8, J. J. Lodder wrote:
> mitchr...@gmail.com <mitchr...@gmail.com> wrote:
>
> > is spin not angular momentum?
> It is, as can be established by measuring

if it is why isn't a quantity of speed instead of the integer label?
Show your speed measurements for your spin then...

Mitchell Raemsch

> the macroscopic angular momentum
> of a macroscopic number of polarised spins.
>
> See under 'Einstein-de Haas effect'
> <https://en.wikipedia.org/wiki/Einstein%E2%80%93de_Haas_effect>
>
> Jan

mitchr...@gmail.com wrote:

> ıs sdıu uoʇ ɐuƃnןɐɹ ɯoɯǝuʇnɯ?
> ʍɥʎ ıs bɯ sdıu ɐ ןɐqǝן oɟ ıuʇǝƃǝɹ ɐup ɥɐןɟ?
> sdıu sɥonןp qǝ sdǝǝp ıusʇǝɐp.
> ʍɥo ɔɐu ɐɹƃnǝ oʇɥǝɹʍısǝ?

Btw, this man is saying half of americans, driven by the mainstream media,
truly believe russia 2016 was electing drumpf as president.

Patrick Henningson https://www.bitchute.com/video/BdLFJy2eEeAm/

On 2/28/2022 11:19 PM, mitchr...@gmail.com wrote:
> is spin not angular momentum?
> why is QM spin a label of integer and half?
> Spin should be speed instead.
> Who can argue otherwise?
>
Read all about it, Smitch. https://en.wikipedia.org/wiki/Spin_(physics)

Michael Moroney wrote:

> On 2/28/2022 11:19 PM, mitchr...@gmail.com wrote:
>> is spin not angular momentum?
>> why is QM spin a label of integer and half?
>> Spin should be speed instead.
>> Who can argue otherwise?
>>
> Read all about it, Smitch. https://en.wikipedia.org/wiki/Spin_(physics)

A Reality Check on the NWO Lies About Russia vs Ukraine.
https://www.bitchute.com/video/2GmMZqZ97fD3/

On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
> is spin not angular momentum?

It is.

> why is QM spin a label of integer and half?

This is forced on us by an experimental result (the Stern-Gerlach magnet).
And then the theory of angular momentum operators in QM matches that.
The strange thing is that the half-integer spins do not correspond to
the usual "r x momentum" definition (unless one fudges the
definition of space by adding extra dimensions).

> Spin should be speed instead.

One reason spin cannot be naively thought of as a particle rotating is that,
say, calculating the speed of rotation of an electron this way yields
a value greater than the speed of light [exercise, see if I'm correct here,
which I may not be].

OTOH angular momentum is conserved in collisions IF "angular momentum"
is accounted for as the sum of the orbital angular momentum (r x momentum)
AND the spin. They are not conserved separately.

So this is a bit of a mystery there.

> Who can argue otherwise?

Anyone can argue anything :-)

--
Jan

On Tuesday, March 1, 2022 at 4:35:24 PM UTC-8, JanPB wrote:
> On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
> > is spin not angular momentum?
> It is.
> > why is QM spin a label of integer and half?
> This is forced on us by an experimental result (the Stern-Gerlach magnet).
> And then the theory of angular momentum operators in QM matches that.
> The strange thing is that the half-integer spins do not correspond to
> the usual "r x momentum" definition (unless one fudges the
> definition of space by adding extra dimensions).
> > Spin should be speed instead.
> One reason spin cannot be naively thought of as a particle rotating is that,
> say, calculating the speed of rotation of an electron this way yields
> a value greater than the speed of light [exercise, see if I'm correct here,
> which I may not be].
>
> OTOH angular momentum is conserved in collisions IF "angular momentum"
> is accounted for as the sum of the orbital angular momentum (r x momentum)
> AND the spin. They are not conserved separately.
>
> So this is a bit of a mystery there.
>
> > Who can argue otherwise?
>
> Anyone can argue anything :-)
>
> --
> Jan

So what is the speed of spin 1 or 1/2 jan?
If you have no answer you can't argue anything can you?

Mitchell Raemsch

On 2/28/22 10:19 PM, mitchr...@gmail.com wrote:
> is spin not angular momentum?

Yes and no. But given the colossal ignorance you have repeatedly
demonstrated around here, and your inability to correct such ignorance,
subtleties like this are beyond you.

> why is QM spin a label of integer and half?

Because spin is modeled using the irreducible representations of the
Lorentz group, and they are so labeled.

[BTW everything I say here about spin also applies to
angular momentum in general.]

Note that for macroscopic objects (> 1mm or so), their angular momentum
quantum numbers are so enormous that the quantization to integer values
is unobservable.

Here's the thing that will blow your mind: in NON-relativistic quantum
mechanics spin is modeled using the irreducible representations of the
Lorentz group. This is a very strong indication of how fundamental the
Lorentz group is in the world we inhabit.

[Note that the Lorentz group, and the corresponding
(local) invariance of physical laws, are the essence
of Special Relativity. People who doubt the validity of
SR simply don't understand how thoroughly woven it is in
the fabric of physics, including non-relativistic
physics; nor do they appreciate the comprehensive
experimental validation of SR.]

Tom Roberts

On Tuesday, March 1, 2022 at 6:41:38 PM UTC-7, mitchr...@gmail.com wrote:
> On Tuesday, March 1, 2022 at 4:35:24 PM UTC-8, JanPB wrote:
> > On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
> > > is spin not angular momentum?
> > It is.
> > > why is QM spin a label of integer and half?
> > This is forced on us by an experimental result (the Stern-Gerlach magnet).
> > And then the theory of angular momentum operators in QM matches that.
> > The strange thing is that the half-integer spins do not correspond to
> > the usual "r x momentum" definition (unless one fudges the
> > definition of space by adding extra dimensions).
> > > Spin should be speed instead.
> > One reason spin cannot be naively thought of as a particle rotating is that,
> > say, calculating the speed of rotation of an electron this way yields
> > a value greater than the speed of light [exercise, see if I'm correct here,
> > which I may not be].
> >
> > OTOH angular momentum is conserved in collisions IF "angular momentum"
> > is accounted for as the sum of the orbital angular momentum (r x momentum)
> > AND the spin. They are not conserved separately.
> >
> > So this is a bit of a mystery there.
> >
> > > Who can argue otherwise?
> >
> > Anyone can argue anything :-)
> >
> > --
> > Jan
> So what is the speed of spin 1 or 1/2 jan?
> If you have no answer you can't argue anything can you?
>
> Mitchell Raemsch

Angular momentum is NOT a "speed" -- it doesn't have the UNITS
of speed (m/sec). It has the units of kg-m²/sec. The quantum
spin is measured in units of h-bar = h/2π. There's nothing to
"argue" here.

On Tuesday, March 1, 2022 at 7:42:20 PM UTC-8, tjrob137 wrote:
> On 2/28/22 10:19 PM, mitchr...@gmail.com wrote:
> > is spin not angular momentum?
> Yes and no. But given the colossal ignorance you have repeatedly
> demonstrated around here, and your inability to correct such ignorance,
> subtleties like this are beyond you.
> > why is QM spin a label of integer and half?
> Because spin is modeled using the irreducible representations of the
> Lorentz group, and they are so labeled.
>
> [BTW everything I say here about spin also applies to
> angular momentum in general.]
>
> Note that for macroscopic objects (> 1mm or so), their angular momentum
> quantum numbers are so enormous that the quantization to integer values
> is unobservable.
>
> Here's the thing that will blow your mind: in NON-relativistic quantum
> mechanics spin is modeled using the irreducible representations of the
> Lorentz group. This is a very strong indication of how fundamental the
> Lorentz group is in the world we inhabit.
>
> [Note that the Lorentz group, and the corresponding
> (local) invariance of physical laws, are the essence
> of Special Relativity. People who doubt the validity of
> SR simply don't understand how thoroughly woven it is in
> the fabric of physics, including non-relativistic
> physics; nor do they appreciate the comprehensive
> experimental validation of SR.]
>
> Tom Roberts

Maybe it would help to explain the other quantities what
comprise the field occupation numbers basically in the multipole.
(Eg the quadrupole.) In various theories what happen to include
both QM and GR, and SR variously for electrons and photons,
and of course a theory of gravity in a unified field theory.

On 3/1/22 6:35 PM, JanPB wrote:
> One reason spin cannot be naively thought of as a particle rotating is that,
> say, calculating the speed of rotation of an electron this way yields
> a value greater than the speed of light

For that one uses the classical radius of the electron, which is ~
2.8E-15 meters. That calculation is based upon classical
electrodynamics, and is roughly the radius at which QED effects become
important....

More importantly, experiments show no structure down to at least 1000
times smaller than that.

Tom Roberts

On Tuesday, March 1, 2022 at 8:52:05 PM UTC-7, tjrob137 wrote:
>
> On 3/1/22 6:35 PM, JanPB wrote:
> >
> > One reason spin cannot be naively thought of as a particle rotating is that,
> > say, calculating the speed of rotation of an electron this way yields
> > a value greater than the speed of light
>
> For that one uses the classical radius of the electron, which is ~
> 2.8E-15 meters. That calculation is based upon classical
> electrodynamics, and is roughly the radius at which QED effects become
> important....
>
> More importantly, experiments show no structure down to at least 1000
> times smaller than that.
>
> Tom Roberts

And yet it has angular momentum. Classically, that would require a speed
of rotation of > 1000c! Things are really strange down there.

“If you are not completely confused by quantum mechanics,
you do not understand it.” -- John Wheeler

JanPB <filmart@gmail.com> wrote:

> On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
> > is spin not angular momentum?
>
> It is.
>
> > why is QM spin a label of integer and half?
>
> This is forced on us by an experimental result (the Stern-Gerlach magnet).
> And then the theory of angular momentum operators in QM matches that.
> The strange thing is that the half-integer spins do not correspond to
> the usual "r x momentum" definition (unless one fudges the
> definition of space by adding extra dimensions).
>
> > Spin should be speed instead.
>
> One reason spin cannot be naively thought of as a particle rotating is that,
> say, calculating the speed of rotation of an electron this way yields
> a value greater than the speed of light [exercise, see if I'm correct here,
> which I may not be].

Quite correct. Lorentz already said so,
even before the Uhlenbeck and Goudsmit paper was published.
But to reach that conclusion you need to assume
the classical electron model, with the classical electron radius.
So that model is wrong.
The electron is not a tiny billiard ball with surface charge.

It really is a point particle,
and the concept of a 'surface velocity' is meaningless,

Jan

On Wednesday, March 2, 2022 at 1:47:39 AM UTC-8, J. J. Lodder wrote:
> JanPB <fil...@gmail.com> wrote:
>
> > On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
> > > is spin not angular momentum?
> >
> > It is.
> >
> > > why is QM spin a label of integer and half?
> >
> > This is forced on us by an experimental result (the Stern-Gerlach magnet).
> > And then the theory of angular momentum operators in QM matches that.
> > The strange thing is that the half-integer spins do not correspond to
> > the usual "r x momentum" definition (unless one fudges the
> > definition of space by adding extra dimensions).
> >
> > > Spin should be speed instead.
> >
> > One reason spin cannot be naively thought of as a particle rotating is that,
> > say, calculating the speed of rotation of an electron this way yields
> > a value greater than the speed of light [exercise, see if I'm correct here,
> > which I may not be].
> Quite correct. Lorentz already said so,
> even before the Uhlenbeck and Goudsmit paper was published.
> But to reach that conclusion you need to assume
> the classical electron model, with the classical electron radius.
> So that model is wrong.
> The electron is not a tiny billiard ball with surface charge.
>
> It really is a point particle,
> and the concept of a 'surface velocity' is meaningless,
>
> Jan

"Test particle"

Ross A. Finlayson <ross.finlayson@gmail.com> wrote:
> On Wednesday, March 2, 2022 at 1:47:39 AM UTC-8, J. J. Lodder wrote:
>> JanPB <fil...@gmail.com> wrote:
>>
>>> On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
>>>> is spin not angular momentum?
>>>
>>> It is.
>>>
>>>> why is QM spin a label of integer and half?
>>>
>>> This is forced on us by an experimental result (the Stern-Gerlach magnet).
>>> And then the theory of angular momentum operators in QM matches that.
>>> The strange thing is that the half-integer spins do not correspond to
>>> the usual "r x momentum" definition (unless one fudges the
>>> definition of space by adding extra dimensions).
>>>
>>>> Spin should be speed instead.
>>>
>>> One reason spin cannot be naively thought of as a particle rotating is that,
>>> say, calculating the speed of rotation of an electron this way yields
>>> a value greater than the speed of light [exercise, see if I'm correct here,
>>> which I may not be].
>> Quite correct. Lorentz already said so,
>> even before the Uhlenbeck and Goudsmit paper was published.
>> But to reach that conclusion you need to assume
>> the classical electron model, with the classical electron radius.
>> So that model is wrong.
>> The electron is not a tiny billiard ball with surface charge.
>>
>> It really is a point particle,
>> and the concept of a 'surface velocity' is meaningless,
>>
>> Jan
>
> "Test particle"
>

“Boundary condition”

“Hypergeometric distribution”

“Quasi-modo”

--
Odd Bodkin -- maker of fine toys, tools, tables

Op 02-mrt.-2022 om 16:11 schreef Odd Bodkin:
> Ross A. Finlayson <ross.finlayson@gmail.com> wrote:
>> On Wednesday, March 2, 2022 at 1:47:39 AM UTC-8, J. J. Lodder wrote:
>>> JanPB <fil...@gmail.com> wrote:
>>>
>>>> On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
>>>>> is spin not angular momentum?
>>>>
>>>> It is.
>>>>
>>>>> why is QM spin a label of integer and half?
>>>>
>>>> This is forced on us by an experimental result (the Stern-Gerlach magnet).
>>>> And then the theory of angular momentum operators in QM matches that.
>>>> The strange thing is that the half-integer spins do not correspond to
>>>> the usual "r x momentum" definition (unless one fudges the
>>>> definition of space by adding extra dimensions).
>>>>
>>>>> Spin should be speed instead.
>>>>
>>>> One reason spin cannot be naively thought of as a particle rotating is that,
>>>> say, calculating the speed of rotation of an electron this way yields
>>>> a value greater than the speed of light [exercise, see if I'm correct here,
>>>> which I may not be].
>>> Quite correct. Lorentz already said so,
>>> even before the Uhlenbeck and Goudsmit paper was published.
>>> But to reach that conclusion you need to assume
>>> the classical electron model, with the classical electron radius.
>>> So that model is wrong.
>>> The electron is not a tiny billiard ball with surface charge.
>>>
>>> It really is a point particle,
>>> and the concept of a 'surface velocity' is meaningless,
>>>
>>> Jan
>>
>> "Test particle"
>>
>
> “Boundary condition”
>
> “Hypergeometric distribution”
>
> “Quasi-modo”
>

"Basically"

Dirk Vdm

On Tuesday, March 1, 2022 at 7:45:14 PM UTC-8, hit...@yahoo.com wrote:
> On Tuesday, March 1, 2022 at 6:41:38 PM UTC-7, mitchr...@gmail.com wrote:
> > On Tuesday, March 1, 2022 at 4:35:24 PM UTC-8, JanPB wrote:
> > > On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
> > > > is spin not angular momentum?
> > > It is.
> > > > why is QM spin a label of integer and half?
> > > This is forced on us by an experimental result (the Stern-Gerlach magnet).
> > > And then the theory of angular momentum operators in QM matches that.
> > > The strange thing is that the half-integer spins do not correspond to
> > > the usual "r x momentum" definition (unless one fudges the
> > > definition of space by adding extra dimensions).
> > > > Spin should be speed instead.
> > > One reason spin cannot be naively thought of as a particle rotating is that,
> > > say, calculating the speed of rotation of an electron this way yields
> > > a value greater than the speed of light [exercise, see if I'm correct here,
> > > which I may not be].
> > >
> > > OTOH angular momentum is conserved in collisions IF "angular momentum"
> > > is accounted for as the sum of the orbital angular momentum (r x momentum)
> > > AND the spin. They are not conserved separately.
> > >
> > > So this is a bit of a mystery there.
> > >
> > > > Who can argue otherwise?
> > >
> > > Anyone can argue anything :-)
> > >
> > > --
> > > Jan
> > So what is the speed of spin 1 or 1/2 jan?
> > If you have no answer you can't argue anything can you?
> >
> > Mitchell Raemsch
> Angular momentum is NOT a "speed" -- it doesn't have the UNITS

So Earth's rotation does not have a speed you moron?
That doesn't fly...

mitchr...@gmail.com wrote:

>> Angular momentum is NOT a "speed" -- it doesn't have the UNITS
>
> So Earth's rotation does not have a speed you moron?
> That doesn't fly...

you are right, quantum spin is not spin. It's quantum anyway, the logic of
spin is macro scale.

On 3/2/2022 1:34 PM, mitchr...@gmail.com wrote:
> On Tuesday, March 1, 2022 at 7:45:14 PM UTC-8, hit...@yahoo.com wrote:
>> On Tuesday, March 1, 2022 at 6:41:38 PM UTC-7, mitchr...@gmail.com wrote:
>>> On Tuesday, March 1, 2022 at 4:35:24 PM UTC-8, JanPB wrote:
>>>> On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
>>>>> is spin not angular momentum?
>>>> It is.
>>>>> why is QM spin a label of integer and half?
>>>> This is forced on us by an experimental result (the Stern-Gerlach magnet).
>>>> And then the theory of angular momentum operators in QM matches that.
>>>> The strange thing is that the half-integer spins do not correspond to
>>>> the usual "r x momentum" definition (unless one fudges the
>>>> definition of space by adding extra dimensions).
>>>>> Spin should be speed instead.
>>>> One reason spin cannot be naively thought of as a particle rotating is that,
>>>> say, calculating the speed of rotation of an electron this way yields
>>>> a value greater than the speed of light [exercise, see if I'm correct here,
>>>> which I may not be].
>>>>
>>>> OTOH angular momentum is conserved in collisions IF "angular momentum"
>>>> is accounted for as the sum of the orbital angular momentum (r x momentum)
>>>> AND the spin. They are not conserved separately.
>>>>
>>>> So this is a bit of a mystery there.
>>>>
>>>>> Who can argue otherwise?
>>>>
>>>> Anyone can argue anything :-)
>>>>
>>>> --
>>>> Jan
>>> So what is the speed of spin 1 or 1/2 jan?
>>> If you have no answer you can't argue anything can you?
>>>
>>> Mitchell Raemsch
>> Angular momentum is NOT a "speed" -- it doesn't have the UNITS
>
> So Earth's rotation does not have a speed you moron?
> That doesn't fly...

No, Roy, earth has a rotation rate of once per 24 hours or f=1/86400.
(actually slightly different since it's measured against the "fixed
stars", not the sun)
That's a frequency, not a speed.
If you want the speed of something due to rotation, you have to specify
where on earth you're talking about.

On Wednesday, March 2, 2022 at 10:45:20 AM UTC-8, Walton Drage wrote:
> mitchr...@gmail.com wrote:
>
> >> Angular momentum is NOT a "speed" -- it doesn't have the UNITS
> >
> > So Earth's rotation does not have a speed you moron?
> > That doesn't fly...
> you are right, quantum spin is not spin. It's quantum anyway, the logic of
> spin is macro scale.

So why would science name it wrong?

On Wednesday, March 2, 2022 at 10:50:25 AM UTC-8, Michael Moroney wrote:
> On 3/2/2022 1:34 PM, mitchr...@gmail.com wrote:
> > On Tuesday, March 1, 2022 at 7:45:14 PM UTC-8, hit...@yahoo.com wrote:
> >> On Tuesday, March 1, 2022 at 6:41:38 PM UTC-7, mitchr...@gmail.com wrote:
> >>> On Tuesday, March 1, 2022 at 4:35:24 PM UTC-8, JanPB wrote:
> >>>> On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
> >>>>> is spin not angular momentum?
> >>>> It is.
> >>>>> why is QM spin a label of integer and half?
> >>>> This is forced on us by an experimental result (the Stern-Gerlach magnet).
> >>>> And then the theory of angular momentum operators in QM matches that.
> >>>> The strange thing is that the half-integer spins do not correspond to
> >>>> the usual "r x momentum" definition (unless one fudges the
> >>>> definition of space by adding extra dimensions).
> >>>>> Spin should be speed instead.
> >>>> One reason spin cannot be naively thought of as a particle rotating is that,
> >>>> say, calculating the speed of rotation of an electron this way yields
> >>>> a value greater than the speed of light [exercise, see if I'm correct here,
> >>>> which I may not be].
> >>>>
> >>>> OTOH angular momentum is conserved in collisions IF "angular momentum"
> >>>> is accounted for as the sum of the orbital angular momentum (r x momentum)
> >>>> AND the spin. They are not conserved separately.
> >>>>
> >>>> So this is a bit of a mystery there.
> >>>>
> >>>>> Who can argue otherwise?
> >>>>
> >>>> Anyone can argue anything :-)
> >>>>
> >>>> --
> >>>> Jan
> >>> So what is the speed of spin 1 or 1/2 jan?
> >>> If you have no answer you can't argue anything can you?
> >>>
> >>> Mitchell Raemsch
> >> Angular momentum is NOT a "speed" -- it doesn't have the UNITS
> >
> > So Earth's rotation does not have a speed you moron?
> > That doesn't fly...
> No, Roy, earth has a rotation rate of once per 24 hours or f=1/8640

Yes and that has a speed.
If spin is angular momentum what does momentum represent but speed?

Mitchell Raemsch

On Wednesday, March 2, 2022 at 7:28:28 AM UTC-8, Dirk Van de moortel wrote:
> Op 02-mrt.-2022 om 16:11 schreef Odd Bodkin:
> > Ross A. Finlayson <ross.fi...@gmail.com> wrote:
> >> On Wednesday, March 2, 2022 at 1:47:39 AM UTC-8, J. J. Lodder wrote:
> >>> JanPB <fil...@gmail.com> wrote:
> >>>
> >>>> On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
> >>>>> is spin not angular momentum?
> >>>>
> >>>> It is.
> >>>>
> >>>>> why is QM spin a label of integer and half?
> >>>>
> >>>> This is forced on us by an experimental result (the Stern-Gerlach magnet).
> >>>> And then the theory of angular momentum operators in QM matches that..
> >>>> The strange thing is that the half-integer spins do not correspond to
> >>>> the usual "r x momentum" definition (unless one fudges the
> >>>> definition of space by adding extra dimensions).
> >>>>
> >>>>> Spin should be speed instead.
> >>>>
> >>>> One reason spin cannot be naively thought of as a particle rotating is that,
> >>>> say, calculating the speed of rotation of an electron this way yields
> >>>> a value greater than the speed of light [exercise, see if I'm correct here,
> >>>> which I may not be].
> >>> Quite correct. Lorentz already said so,
> >>> even before the Uhlenbeck and Goudsmit paper was published.
> >>> But to reach that conclusion you need to assume
> >>> the classical electron model, with the classical electron radius.
> >>> So that model is wrong.
> >>> The electron is not a tiny billiard ball with surface charge.
> >>>
> >>> It really is a point particle,
> >>> and the concept of a 'surface velocity' is meaningless,
> >>>
> >>> Jan
> >>
> >> "Test particle"
> >>
> >
> > “Boundary condition”
> >
> > “Hypergeometric distribution”
> >
> > “Quasi-modo”
> >
> "Basically"
>
> Dirk Vdm

Seems an Open Letter....

On Wednesday, March 2, 2022 at 1:47:39 AM UTC-8, J. J. Lodder wrote:
> JanPB <fil...@gmail.com> wrote:
>
> > On Monday, February 28, 2022 at 8:19:50 PM UTC-8, mitchr...@gmail.com wrote:
> > > is spin not angular momentum?
> >
> > It is.
> >
> > > why is QM spin a label of integer and half?
> >
> > This is forced on us by an experimental result (the Stern-Gerlach magnet).
> > And then the theory of angular momentum operators in QM matches that.
> > The strange thing is that the half-integer spins do not correspond to
> > the usual "r x momentum" definition (unless one fudges the
> > definition of space by adding extra dimensions).
> >
> > > Spin should be speed instead.
> >
> > One reason spin cannot be naively thought of as a particle rotating is that,
> > say, calculating the speed of rotation of an electron this way yields
> > a value greater than the speed of light [exercise, see if I'm correct here,
> > which I may not be].
> Quite correct. Lorentz already said so,
> even before the Uhlenbeck and Goudsmit paper was published.
> But to reach that conclusion you need to assume
> the classical electron model, with the classical electron radius.
> So that model is wrong.
> The electron is not a tiny billiard ball with surface charge.
>
> It really is a point particle,
> and the concept of a 'surface velocity' is meaningless,

Yes. That's another reason why spin is not the "r x momentum"-type thing
(unless forced by adding extra dimensions).

--
Jan

On 3/2/22 12:34 PM, mitchr...@gmail.com wrote:
> So Earth's rotation does not have a speed?

Right. Earth's ROTATION does not "have a speed", because the concepts
are incommensurate.

But a given point on the surface of the earth does have a speed relative
to the ECI frame. For points on earth's geoid (mean sea level), that
speed depends only on latitude, which is characteristic of a rigid
spheroid rotating around its principal axis.

> That doesn't fly...

Sure it does, once one realizes that precision in thought and word is
needed. You have confused two completely different concepts (which, BtW
you do quite often around here).

Tom Roberts