Electric field of the sun

I was just curious....

There is considerable discussion of the magnetic field of the sun, but
little or no discussion of the electric field of the sun. I was just
wondering if there was any knowledge or concensus about the electric
field of the sun among the participants here.

Tim

In message , Tim
writes
I was just curious....

There is considerable discussion of the magnetic field of the sun, but
little or no discussion of the electric field of the sun. I was just
wondering if there was any knowledge or concensus about the electric
field of the sun among the participants here.

Well, the sun is essentially a conductive plasma, so I doubt there's
much opportunity for the sort of charge separation that produces
electric fields. Typing your question into Google throws up a few
somewhat questionable web sites :-)
But I did find this very odd statement at
http://lunar.arc.nasa.gov/education/activities/active10a.htm
Every day the sun is radiating visible light at all times that the sun
can be seen. What you do not see is that the sun is also sending off
invisible electrical waves at all times that create an electric field
through the earth. That electric field is like the electrical field
that is created by the electric current flowing from the battery
through the coil of wire. You may know that the center of the earth is
full of molten metal and other material, much of which is iron, just
like the nail in the electro-magnet or the bar magnet. As the earth
orbits through the electric field of the sun, it causes each drop of
iron to line up, like tiny magnets, with one end facing in the
direction we commonly call North and the other end in the direction we
call South.
Surely that isn't right? Isn't the Earth's magnetic field produced in
the same way as the Sun's own field, because it's a conductor rotating
on its own axis?
--
What have they got to hide? Release the Beagle 2 report.
Mail to jsilverlight AT merseia.fsnet.co.uk is welcome.

Tim wrote:

I was just curious....

There is considerable discussion of the magnetic field of the sun, but
little or no discussion of the electric field of the sun. I was just
wondering if there was any knowledge or concensus about the electric
field of the sun among the participants here.



Your question is really a bit too vague, since you do not specify the
length
scale on which you want to know about the electric field. There is no
global
electric field on the Sun, since that would require the Sun to have a net
electric charge, which it does not have. There is nothing surprising in
this,
since in case the Sun did have a net charge, it would immediately attract
electric charges of the opposite sign and become neutral.

However the Sun does consist of a plasma, a gas consisting of positively
charged ions and negatively charged electrons. Over distances shorter than
the Debye length in the plasma you may have a surplus of positive or
negative
charges, but the Debye length is shorter than one meter even in the solar
corona, and therefore the role of electric fields can be neglected on the
Sun.

Ulf Torkelsson

Jonathan Silverlight wrote:

Well, the sun is essentially a conductive plasma, so I doubt there's
much opportunity for the sort of charge separation that produces
electric fields. Typing your question into Google throws up a few
somewhat questionable web sites :-)
But I did find this very odd statement at
http://lunar.arc.nasa.gov/education/activities/active10a.htm


Every day the sun is radiating visible light at all times that the sun
can be seen. What you do not see is that the sun is also sending off
invisible electrical waves at all times that create an electric field
through the earth. That electric field is like the electrical field
that is created by the electric current flowing from the battery
through the coil of wire. You may know that the center of the earth is
full of molten metal and other material, much of which is iron, just
like the nail in the electro-magnet or the bar magnet. As the earth
orbits through the electric field of the sun, it causes each drop of
iron to line up, like tiny magnets, with one end facing in the
direction we commonly call North and the other end in the direction we
call South.


Surely that isn't right? Isn't the Earth's magnetic field produced in
the same way as the Sun's own field, because it's a conductor rotating
on its own axis?


The Earth's magnetic field is produced by a dynamo in the interior of the
Earth. The way a dynamo works is quite more complicated than that it
would just be a rotating conductor, and all the details of the workings of
the dynamo has not been worked out yet. What seems to be clear though
is that the dynamo relies on the existence of differential rotation, which
can wind up the magnetic field and some more irregular, turbulent
motion, both of these conditions are fulfilled in the interior of the Earth
as well as on the Sun.

Having said this one should also keep in mind that the Sun is not only
emitting electromagnetic radiation, light, but also plasma, the solar
wind. The solar wind carries with it a part of the solar magnetic field.
Once the solar wind collides with the Earth's magnetosphere the
magnetic field of the solar wind will directly interact with the
terrestrial magnetic field, and in this interaction currents are generated
in the magnetosphere. These currents will in themselves be the source
of a new magnetic field, which can be strong enough to cause a
measureable distortion of the magnetic field at the surface of the
Earth.

Ulf Torkelsson