Re: Gisse's EM Equilibrium


"Randy Poe" <poespam-trap@xxxxxxxxx> wrote in message news:1177337644.500768.13260@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Apr 22, 3:13 pm, "g...@xxxxxxxxxxx" <g...@xxxxxxxxxxx> wrote:
On Apr 18, 9:36 am, Randy Poe <poespam-t...@xxxxxxxxx> wrote:



On Apr 17, 3:40 pm, "g...@xxxxxxxxxxx" <g...@xxxxxxxxxxx> wrote:

On Apr 16, 2:01 pm, "Randy Poe" <poespam-t...@xxxxxxxxx> wrote:
1. to visualize AND COUNT all the fields generated from an electron
(ac current) traveling along a copper wire (that's it, that's
all)..and which of these fields curl and which diverge(or converge)

A single electron?

Come on don't get technical you know that's impossible in a wire....

Ah, sorry, I missed that we were talking about a copper wire (it's
right there). I thought you were asking about the fields of an
electron in free space, which is different. OK, ignore what I said
below, I'll start again from scratch.

The standard assumption about a wire is that it is electrically
neutral. There are unmoving positive charges, and mobile negative
charges.

Now, in this wire, are you really meaning to ask about the fields
from a constant current? I'll assume you are. Totally different
question than the one I was answering before.

...Is there a magnetic field in a DC circuit since they say to use the
thumb (along the wire) in the right_hand rule for the direction of the
current (thus not AC...correct....unless they mean for each instance
of direction...but I doubt it)?

There is a magnetic field generated around a wire containing
a constant current. There is no electric field around a neutral wire.

There is an alternating magnetic field around a wire containing
an AC current. There are meters which measure the amount
of current in AC circuits by taking advantage of that.

http://www.measureamps.com/index.php?products_id=1555http://www.measu....

You just put this around the wire you want to sense.

(E_Field = electric field & M_Field = magnetic field)

Therefore:

a) Is there an E_Field ALL AROUND the copper wire?

Yes. At any point in space, the E-field is pointing
toward the electron, and it is varying in time.

Sorry, I don't know how I kept missing "copper wire". There is
an electric field all around a free electron. There is no electric
field around a neutral copper wire.

Ok another guy just said no wave involved, I hope he mis-informed me

I misinformed you.

since it varies it does involve wave(s) and a wavy shape?

When there is a constant current in a wire, the magnetic
field is constant, not changing. No there are no waves. No,
there is no "wavy shape".

A field is a group of waves (vectors)..correct?

No, a field is not a group of waves.

A field is a vector value assigned to every point in space.
It doesn't have to be wavy. It doesn't have to be changing
in time. From a single electron sitting still, the electric
field has constant magnitude k*q/r^2 at every point in
space of distance r from the electron, and the constant
unchanging direction is pointing toward the electron.

Roughly
speaking, it is strongest as the electron passes close
to that point in space, and weak as the electron is
farther away.

Did you really mean to ask about a single electron
or a constant current?

If I would mention a single electron then it would mean only as an
instance in time( a section of field can but surround one electron at
a time)

What? Nonsense.

b) Does this E_Field curl, diverge, or converge?

What do you mean by "does this E_field curl"?
Do you mean is the mathematical object called
"curl E" nonzero? What do you mean by "does this
E_field diverge"? Do you mean "is the mathematical
object called div E nonzero?"

I never heard of an E_Field (electric field) curling till Androcles
brought it up, thought he was drunk till I researched it and it does
curl???

I still don't know what you mean by "does it curl". You didn't
answer my question. Maxwell's equations relate certain things
to the mathematical objects called "curl E" and "curl B".
I'll ask again, what do you mean by "does it curl"? Do you
mean "is the vector curl E nonzero"?

The magnetic field B around a wire forms closed circles around
that wire. That field has a nonzero curl. One characteristic of
a field with a nonzero curl is that it has a nonzero integral
around closed loops. Roughly, that means it forms closed
loops without a source in that loop.

That kind of thing can happen with E-fields also. If you have
a wire loop, and a magnetic field varying inside that loop,
then a closed loop of current will be generated in the wire
loop. This is the principle of the wire loop antenna, and also
of the transformer.

Mathematically, the E-field in that loop has a nonzero curl.
There's no battery in that wire making the electrons flow.

The Maxwell's equation that predicts this effect is this one:

curl E = -dB/dt

That says when you have a changing magnetic field, you will
induce E-fields with nonzero curl, such as the ones that make
current flow in wire loops.

"They"(wikkipedia and left hand rule) say It curls after a magnet
field

No they don't. They may say something about the quantity
"curl E" but I'm sure they don't say "the E-field curls". If they
do, it is inaccurate and confusing. There is a field E. It
has a behavior. There is a vector quantity "curl E". It has a
behavior.

An electric field must be wavy,

There is no requirement that an electric field be wavy.

in fact I could swear it's the
Intensity versus time wave you see on an Oscilloscope or voltage over
time.

Yes, on an oscilloscope, a wavy electric field is wavy.

But there is no requirement that all electric fields be wavy. The
electric field between a pair of capacitor plates is a constant.
The electric field of an isolated particle is a constant.

I fail to see how a E-Field that is curled from a transducing coil

I've told you a number of times that this description of
the electric field being "curled" is meaningless, and I have
no idea how to respond to these meaningless statements.

can
become linear in the coil further on....meaning outside the coild the
E-Field is no longer a curl but instead observes the right hand rule
along the straight copper wire?

No idea what you are talking about. No idea what right-hand rule
you are referring to, or why this means to you that it "is no longer
a curl" since it wasn't a curl in the first place.

I said before that the E-field from a straight copper wire which is
neutral (as most wires are modeled to be), is 0. No right hand
rule. Just zero. Nothing.

A wire carrying a constant current has a B-field which forms
circles around the wire, and the direction of that field is given
by the right-hand rule.

Your questions bear very little resemblance to the things I'm
saying, so it's difficult for me to respond to them since I have
no idea what you are responding to.

- Randy

There is an electric field along the length of a copper wire through
which a current is flowing. There is a reversed electric field along the
length of the voltaic cell connecting the ends of the copper wire
through which a current is flowing.
Oh dear, does direct current flow from positive to negative or
negative to positive?
.

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