Re: Simple question about right-hand rule

[Jos Bergervoet]

On 5/12/2013 4:40 PM, yon...@yahoo.com wrote:
> In one physics book, the magnetic field goes into the page. An electron moves in a circle whose plane is perpendicular to the field. The movement is in clockwise direction. Should it be counter-clockwise instead, because it's negative?

Just use : F = q v x B

Then you'll know it!

--
Jos

[Salmon Egg]

In article <518fd4a3$0$15950$e4fe...@news2.news.xs4all.nl>,

Two questions:

1. Is the electron creating the field or is the field already present
deflecting an introduced electron?

2. Are you aware of and using the knowledge that the right hand rule is
based upon conventional current and not "electron" current?

--

Sam

Conservatives are against Darwinism but for natural selection.
Liberals are for Darwinism but totally against any selection.

[benj]

On Mon, 13 May 2013 03:33:51 -0700, Salmon Egg wrote:

> In article <518fd4a3$0$15950$e4fe...@news2.news.xs4all.nl>,
> Jos Bergervoet <jos.ber...@xs4all.nl> wrote:
>
>> On 5/12/2013 4:40 PM, yon...@yahoo.com wrote:
>> > In one physics book, the magnetic field goes into the page. An
>> > electron moves in a circle whose plane is perpendicular to the field.
>> > The movement is in clockwise direction. Should it be
>> > counter-clockwise instead, because it's negative?
>>
>> Just use : F = q v x B
>>
>> Then you'll know it!
>
> Two questions:
>
> 1. Is the electron creating the field or is the field already present
> deflecting an introduced electron?

I want you to think about this one: Can any single charged particle
create a magnetic field by moving that will deflect itself?

> 2. Are you aware of and using the knowledge that the right hand rule is
> based upon conventional current and not "electron" current?

Egg, nobody else is as smart as you are... But thanks anyway, for
checking for us to see if Jos is dumb.

[Poutnik]

benj posted Mon, 13 May 2013 22:14:11 GMT

> >
> > 1. Is the electron creating the field or is the field already present
> > deflecting an introduced electron?
>
> I want you to think about this one: Can any single charged particle
> create a magnetic field by moving that will deflect itself?

Quantum electrodynamics addresses AFAIK
interaction of electron with itself.

--
Poutnik

[benj]

Not the question Poutnik. The question is in classical Maxwellian theory
can the motion of a charged particle create a magnetic field that can
deflect it as Egg alleges?

[Poutnik]

benj posted Tue, 14 May 2013 03:51:11 GMT

Than 2 auxiliary questions :

1) To what direction ?

As without external field,
space is symmetrical and all directions are equal.

2) What about action-reaction Newton law ?

--
Poutnik

[benj]

1. Without an external field nothing moves the charged particle does it?

> 2) What about action-reaction Newton law ?

2. Excellent question. Does it apply to electromagnetic fields?

[Poutnik]

benj posted Tue, 14 May 2013 06:23:49 GMT

>
> On Tue, 14 May 2013 07:35:32 +0200, Poutnik wrote:
>
> > benj posted Tue, 14 May 2013 03:51:11 GMT
> >
> >
> >
> >> On Tue, 14 May 2013 02:01:15 +0200, Poutnik wrote:
> >>
> >> > benj posted Mon, 13 May 2013 22:14:11 GMT
>
> >> >> > 1. Is the electron creating the field or is the field already
> >> >> > present deflecting an introduced electron?
> >> >>
> >> >> I want you to think about this one: Can any single charged particle
> >> >> create a magnetic field by moving that will deflect itself?
> >> >
> >> > Quantum electrodynamics addresses AFAIK interaction of electron with
> >> > itself.
> >>
> >> Not the question Poutnik. The question is in classical Maxwellian
> >> theory can the motion of a charged particle create a magnetic field
> >> that can deflect it as Egg alleges?
> >
> > Than 2 auxiliary questions :
> >
> > 1) To what direction ?
> >
> > As without external field,
> > space is symmetrical and all directions are equal.
>
> 1. Without an external field nothing moves the charged particle does it?

A particle does not need a field to move, while moving. 1st Newton law.

And in classical sense even to start moving,
like electrons from beta decay.

At least, I understood your setting as you avoided external field,
deflection electron by usual way "vec F = q . vec v x vec B"

>
> > 2) What about action-reaction Newton law ?
>
> 2. Excellent question. Does it apply to electromagnetic fields?

As I understand classical fields, via field to the other objects
that are causing the field.

At least, I understood your setting as you avoided external field,
or am I wrong ?


--
Poutnik

[benj]

On Tue, 14 May 2013 08:33:19 +0200, Poutnik wrote:


>> 1. Without an external field nothing moves the charged particle does
>> it?
>
> A particle does not need a field to move, while moving. 1st Newton law.

Sure, once moving they can coast, but what gets them going?

> And in classical sense even to start moving,
> like electrons from beta decay.

You say it's not a field that gets them going? I'm not so sure. Even if
you pull a charged balloon with a string, down at the charge level it
seems likely that it is electric field (qE) doing the acceleration. Is
there some way "charge" can be mechanically attached to the balloon
without electric fields? Maybe, but I doubt it.

> At least, I understood your setting as you avoided external field,
> deflection electron by usual way "vec F = q . vec v x vec B"

Well that was the original proposition. The deflection of a moving charge
due to it's own magnetic field not an external one. If a charge is moving
in a given direction it represents a current. That current creates a
magnetic field. What is the value of the magnetic field along the line of
motion the charge is taking?

>> > 2) What about action-reaction Newton law ?
>>
>> 2. Excellent question. Does it apply to electromagnetic fields?
>
> As I understand classical fields, via field to the other objects that
> are causing the field.

What if one object suddenly moves VERY fast. It takes time for that
change to reach the other objects. Hence for that period action-reaction
fails.

> At least, I understood your setting as you avoided external field,
> or am I wrong ?

I didn't "avoid" anything. No external field was the condition set by
Salmon Egg.

[Poutnik]

benj posted Tue, 14 May 2013 17:36:44 GMT

>
> On Tue, 14 May 2013 08:33:19 +0200, Poutnik wrote:
>
>
> >> 1. Without an external field nothing moves the charged particle does
> >> it?
> >
> > A particle does not need a field to move, while moving. 1st Newton law.
>
> Sure, once moving they can coast, but what gets them going?

All the topic is rather tricky, as evaluating a single electron
is in various context out validity domain of a classical EM theory.

Classical physics with class EM theory knows 2 forces - gravity
and EM force. Neither gravity nor EM force cannot repel electron
from a nucleus, especially at relativistic speed.

>
> > And in classical sense even to start moving,
> > like electrons from beta decay.
>
> You say it's not a field that gets them going? I'm not so sure. Even if
> you pull a charged balloon with a string, down at the charge level it
> seems likely that it is electric field (qE) doing the acceleration. Is
> there some way "charge" can be mechanically attached to the balloon
> without electric fields? Maybe, but I doubt it.

I say no classical one in case of beta decay.
In usual cases, there is, of course, EM field.

The one of electron is locally much stronger than external fields.

> > At least, I understood your setting as you avoided external field,
> > deflection electron by usual way "vec F = q . vec v x vec B"
>
> Well that was the original proposition. The deflection of a moving charge
> due to it's own magnetic field not an external one. If a charge is moving
> in a given direction it represents a current. That current creates a
> magnetic field. What is the value of the magnetic field along the line of
> motion the charge is taking?

Well, I am not particularly good in Maxwell equations,
but I am not sure how well they deal with a single point charge.
They did not count with charge quantization.

But forward current of classical EM create coaxial circular M field.
It will not deflect it nowhere.

>
> >> > 2) What about action-reaction Newton law ?
> >>
> >> 2. Excellent question. Does it apply to electromagnetic fields?
> >
> > As I understand classical fields, via field to the other objects that
> > are causing the field.
>
> What if one object suddenly moves VERY fast. It takes time for that
> change to reach the other objects. Hence for that period action-reaction
> fails.

Well, as classical theory fails, it can afford failure
of classical A-R principle. But the change is mutual,
so are mutual the delays.

>
> > At least, I understood your setting as you avoided external field,
> > or am I wrong ?
>
> I didn't "avoid" anything. No external field was the condition set by
> Salmon Egg.

Avoiding in sense of respecting of the experiment settings,
not avoiding as personal approach.

--
Poutnik

[benj]

On Tue, 14 May 2013 20:29:36 +0200, Poutnik wrote:

> benj posted Tue, 14 May 2013 17:36:44 GMT

> Well, I am not particularly good in Maxwell equations,
> but I am not sure how well they deal with a single point charge. They
> did not count with charge quantization.

Point charges are imaginary and don't exist. They make all classical EM
undefined.

> But forward current of classical EM create coaxial circular M field.
> It will not deflect it nowhere.

Which is the answer (if I understand what I think you meant)!

[Poutnik]

benj posted Wed, 15 May 2013 03:20:33 GMT

>
> On Tue, 14 May 2013 20:29:36 +0200, Poutnik wrote:
>
> > benj posted Tue, 14 May 2013 17:36:44 GMT
>
> > Well, I am not particularly good in Maxwell equations,
> > but I am not sure how well they deal with a single point charge. They
> > did not count with charge quantization.
>
> Point charges are imaginary and don't exist. They make all classical EM
> undefined.

In classical EM, they do not exist, as were discovered much later.
And, they made classical EM undefined at atomic level.

>
> > But forward current of classical EM create coaxial circular M field.
> > It will not deflect it nowhere.
>
> Which is the answer (if I understand what I think you meant)!

--
Poutnik