The Sun's magnetic field

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https://phys.org/news/2018-08-image-sun-magnetic-field.html#jCp

These fields are generated by the solar wind?
By the sun spinning does it generate another mag field?

Is this a good example of how hot objects loose their coherent magnetic field by misaligned temperature generated ad hoc domains making the overall magnetic field incoherent? Once the heat breaches the shell of the object the solar wind starts flowing and it disrupts the overall magnetic field. Earths core is hot and spins but the earth still has a coherent magnetic field is this because the heat hasn't penetrated the crust?
 

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  • #2
Drakkith
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These fields are generated by the solar wind?
I don't believe so. I believe they are formed from currents of charged particles inside the Sun.

Is this a good example of how hot objects loose their coherent magnetic field by misaligned temperature generated ad hoc domains making the overall magnetic field incoherent?
Not really. The Sun isn't composed of small magnetic domains like a magnetic metal is. If you cooled the Sun down its magnetic field would probably not get stronger.

Once the heat breaches the shell of the object the solar wind starts flowing and it disrupts the overall magnetic field.
This doesn't look correct to me. The entire surface of the Sun (the photosphere) is thousands of degrees in temperature and heat is constantly leaving in the form of electromagnetic radiation. There are no spots where the heat doesn't 'leak' out.

Earths core is hot and spins but the earth still has a coherent magnetic field is this because the heat hasn't penetrated the crust?
The Earth's magnetic field is generated from a dynamo effect, not because of the Earth's surface is insulating against heat loss. Besides, the Earth's crust still radiates energy from every location, just like the Sun does, so the heat has indeed 'penetrated' the crust. Most of the radiation is in the infrared region of the spectrum, versus the Sun's spectrum where most of the radiation is in the visible and near-IR parts of the spectrum.
 
  • #3
davenn
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OK lets get the image in here so it is easy for all to see
Note, despite the Aug 2018 date of the article .... modelling the magnetic fields like this has been done for quite some years

imagesunsmag.jpg



These fields are generated by the solar wind?
I don't believe so. I believe they are formed from currents of charged particles inside the Sun.

Agreed

The source of the solar wind originates in the solar corona, well above the photosphere ( the visible surface ) of the sun.
The corona is substantially hotter than the photosphere at more than 1 million K compared to ~ 5700 K for the photosphere.


By the sun spinning does it generate another mag field?

The sun does have an overall magnetic field ( not sure that solar rotation causes it tho?)
The magnetic fields you see in the above image are localised ones related directly to active regions.
These active regions are where the Suns magnetic field penetrates the photosphere and produces sunspots ....

Sunspots-24a151h.jpg



Now referring back to the first image, you will note something that stands out ...... areas of intense magnetic fields, the bright active
regions and areas of almost no magnetic field activity as in the upper left of the sun. These dark areas of no magnetic fields are called
coronal holes and show areas where the magnetic field lines are not connected as they are over those bright active regions.
Coronal holes are areas where the magnetic field streams out into space and with them high speed streams of solar wind ( much
higher than the average solar wind speed)
The avg speed is around 300 km/s and from coronal holes speeds often reach 800 to 1000 km / s
and occasionally up to ~ 1200-1400 km / s.


Earths core is hot and spins but the earth still has a coherent magnetic field is this because the heat hasn't penetrated the crust?
This is a bad assumption. Heat from the interior of the Earth DOES penetrate the crust .... have you
heard of volcanoes ??



Dave
 

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The Sun isn't composed of small magnetic domains like a magnetic metal is.
I was looking at the multiple domains on the image.
If you cooled the Sun down its magnetic field would probably not get stronger.
I was thinking the overall field would be more aligned with less disrupting ad hoc magnetic fields.
This doesn't look correct to me.The entire surface of the Sun (the photosphere) is thousands of degrees in temperature and heat is constantly leaving in the form of electromagnetic radiation.
Does electromagnetic radiation generate a magnetic field when moving?
The Earth's magnetic field is generated from a dynamo effect, not because of the Earth's surface is insulating against heat loss.
I know the magnetic field is not generated because the earth is insulating the heat, got more to do with the earth and core spinning? I'll check out the dynamo effect. I was thinking the insulation was not allowing the heat to influence the earths magnetic field and therefore making it more coherent.
If I go to space away from the earth and all the other objects of influence and take out my compass will the needle point to the suns north pole?
 
  • #5
Drakkith
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Does electromagnetic radiation generate a magnetic field when moving?
Not in the way that you're thinking. Electromagnetic radiation is a wave in the electromagnetic field, so one component of it is a changing magnetic field. But this doesn't set up a large magnetic field like moving charges do.

I'll check out the dynamo effect. I was thinking the insulation was not allowing the heat to influence the earths magnetic field and therefore making it more coherent.
Heat doesn't affect a magnetic field directly. Instead it affects the magnetic domains (in a magnetic solid like iron). An external magnetic field passing through a material at 2,000 degrees would remain unaffected.

If I go to space away from the earth and all the other objects of influence and take out my compass will the needle point to the suns north pole?
It will point along the local magnetic field lines, which would be the Sun's. This might point towards the Sun's north pole (which is a south magnetic pole, just like the Earth's north pole) but it may also point up and out of the plane of the solar system depending on where you are and the exact details of the magnetic field. Note that the Earth's magnetic field lines run roughly parallel to the surface when you're near to Earth, which is the reason we can use a compass to help us find direction. The needle doesn't actually point towards the north pole, it points along the magnetic field line. It's just that we're restricted to moving along the surface of the Earth, and moving in the direction of the compass needle moves us along the field lines towards the pole. However, if you're far from Earth and no longer restricted to moving on its surface, a compass becomes mostly useless as a navigation device.
 
  • #6
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The sun does have an overall magnetic field ( not sure that solar rotation causes it tho?)
Not in the way that you're thinking. Electromagnetic radiation is a wave in the electromagnetic field, so one component of it is a changing magnetic field. But this doesn't set up a large magnetic field like moving charges do.
If the sun and earths moving EM aren't generating their overall magnetic fields and earths magnetic field can also be generated without solar wind leaving the earth to carry it, what's carrying earths magnetic field? Not all magnetic fields require a moving charge to physically generate the field at that location in the field?

Can you think of the earths magnetic field as a electric field with moving charges constantly alternating between the north and south poles in the field and the moving charges physically generate the magnetic field?
 
  • #7
Drakkith
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If the sun and earths moving EM
I'm sorry I don't know what this is supposed to mean. EM is short for electromagnetic, but something that's a term that describes something, such as a field or a wave. It's not something in and of itself.

what's carrying earths magnetic field?
Nothing. An EM field requires nothing to 'carry' it.

Not all magnetic fields require a moving charge to physically generate the field at that location in the field?
Nope. And the way you've worded it makes it sound like a charge is required everywhere in a field in order to generate it. But that can't be correct, because there are often empty spaces between particles but the field is not zero between them.

Can you think of the earths magnetic field as a electric field with moving charges constantly alternating between the north and south poles in the field and the moving charges physically generate the magnetic field?
No, as the alternating charges would generate electromagnetic waves instead of a magnetic field.
 
  • #8
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I'm sorry I don't know what this is supposed to mean. EM is short for electromagnetic
Sorry, EM = EM radiation
 
  • #9
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not sure that solar rotation causes it tho?
If moving charged particles of the solar wind generate a magnetic field, what do the moving charges spinning with the sun generate?
And the way you've worded it makes it sound like a charge is required everywhere in a field in order to generate it.
Something needs to move the needle on the compass, a charge flowing between the poles would have the right moving directional momentum to physically move the magnetic needle to point north when the moving charges interact with the magnetic compass needles poles?
But that can't be correct, because there are often empty spaces between particles but the field is not zero between them.
Dark Energy?
This is a bad assumption. Heat from the interior of the Earth DOES penetrate the crust .... have you
heard of volcanoes ??
https://www.express.co.uk/news/world/968476/Hawaii-Volcano-latest-Mount-Kilauea-magnetic-field-compasses
 
  • #10
Drakkith
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Something needs to move the needle on the compass, a charge flowing between the poles would have the right moving directional momentum to physically move the magnetic needle to point north when the moving charges interact with the magnetic compass needles poles?
No, not at all. This doesn't even make any sense. You've simply strung together a series of science words without understanding anything about them. Instead, I recommend starting with more fundamental concepts before moving on. Otherwise you just skip over all of the basic concepts that you'll actually need to understand the more advanced concepts. As an example, if you remove the idea of a 'field' that serves as the medium for a force, you now have to replace that idea with something else that also works just as well. But we can already explain electromagnetism to an incredible degree of accuracy using the concept of a field. So accurately that we can't actually detect any difference between our experiments and our predictions.

Dark Energy?
Please don't make random guesses. It doesn't facilitate a useful and productive discussion. Remember that PF exists to teach science as it is currently understood and practiced by the mainstream scientific community. Throwing out random ideas before having a firm grasp on how mainstream science currently understands them does not meet our mission statement. I don't say this to be rude, only to help guide you towards actually learning real science, not the watered down stuff you find in 99.9% of youtube videos and popular science books.
 
  • #11
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No, not at all. This doesn't even make any sense.
To move something you need to transfer acceleration to that thing in the direction of motion?
Please don't make random guesses. It doesn't facilitate a useful and productive discussion.
Is there dark energy in "empty space" between objects in space where the field is not zero in mainstream science?
 
  • #12
Drakkith
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To move something you need to transfer acceleration to that thing in the direction of motion?
No. Acceleration is not something that can be transferred. Acceleration is the change in an objects velocity over time and occurs as the result of an applied net force on the object.

Is there dark energy in "empty space" between objects in space where the field is not zero in mainstream science?
Dark energy, as it is currently understood by mainstream cosmology, has absolutely nothing to do with this and discussing it without dedicating an entire thread to it would not be very productive. I say that because your question cannot be answered with a simple yes or no, as dark energy is not understood well enough to give concrete answers. However we understand it well enough to know that it does not have anything to do with the topic of this thread.

If you want to find out more about dark energy I suggest making a new thread in the cosmology forum asking for information and references. However, be aware that understanding dark energy at even a beginner level requires at least a basic understanding of many different advanced concepts, so don't expect to be able to spend a handful of minutes reading a couple of posts and come away with an understanding of dark energy.
 
  • #13
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No. Acceleration is not something that can be transferred. Acceleration is the change in an objects velocity over time and occurs as the result of an applied net force on the object.
A applied net force doesn't transfer acceleration to a object when moving it. wow...
 
  • #14
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A applied net force doesn't transfer a change in an objects velocity over time when moving it. wow...
 
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  • #16
Drakkith
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Looks like differential rotation generates a lot of friction?

What percentage of the suns temperature/heat is generated by friction?
As far as I understand it, none. I think it's likely that the differential rotation is caused by heat flow in the first place, so any energy generated by friction would just not add to a net gain in temperature overall. In the grand scheme of things, all of the energy from the Sun ultimately comes from nuclear fusion and the slow gravitational collapse that occurs in all stars (and gas giants too).

Does friction in stars generate static electricity?
Unlikely The Sun is composed of an electrically conductive plasma, so there should be no way for charge separation to occur, and thus no static electricity.
 
  • #17
https://phys.org/news/2018-08-image-sun-magnetic-field.html#jCp

These fields are generated by the solar wind?
It is somewhat of the opposite.


By the sun spinning does it generate another mag field?
No. The magnetic fields of the sun tangle (largely due to the sun rotating faster at it's equator). Eventually the lines break and you have a polar reversal. If I remember correctly, the same happens on earth but at a much slower rate.

https://scied.ucar.edu/magnetic-field-lines-tangle-sun-rotates
 
  • #18
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so there should be no way for charge separation to occur
Can the charge build up?
It is somewhat of the opposite.
I'll meet you at, two sides of the same coin? one view is from the magnetic field and one is from the electric field?
 
  • #19
Drakkith
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  • #20
davenn
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BeedS said:
https://phys.org/news/2018-08-image-sun-magnetic-field.html#jCp

These fields are generated by the solar wind?
NO, emphatically, NO

those field lines you see in that image …..

imagesunsmag.jpg


…. emanate from inside the sun and they puncture the photosphere mainly at active regions ( sunspots)


It is somewhat of the opposite.
Yes, totally agree


I'll meet you at, two sides of the same coin? one view is from the magnetic field and one is from the electric field?
No, that doesn't even make sense … please don't make things up, @Drakkith already warned you up the page about doing that.

it shows the magnetic field looping out of and back into the active regions


Dave
 

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What?
Is the sun charged? What determines if a object is charged?
No, that doesn't even make sense … please don't make things up
Who's making things up? I'm investigating whats probable... Are you saying there is no solar wind/electric charge coming from the bright active regions where the adhoc magnetic fields are in the image?
 
  • #22
davenn
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Are you saying there is no solar wind/electric charge coming from the bright active regions where the adhoc magnetic fields are in the image?
yes, that is what I am saying

The solar wind doesn't come from the active regions, rather, the active regions and their magnetic fields contain
( hold back) the solar wind from those areas.
There is low velocity ( ~ 340 km/sec, give or take a bit) solar wind coming from all over the surface of the sun,
except the active regions.
There are areas where the source of the solar wind is very much higher velocity … ~ 500 - 1000+ km / sec.
And that is from coronal holes, those very dark areas in that image. You can see, from the image, that there is almost
no magnetic fields associated with those coronal holes (black regions) and as a result the solar wind pours out of those areas.

The only significant time there are emissions of charged particles and EM radiation from the active regions is when
their magnetic fields get "kinked" up and they snap/collapse and there is a huge blast of particles and energy out into
space …. these occurrences are called solar flares.



Dave
 
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  • #23
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The solar wind doesn't come from the active regions
There is low velocity ( ~ 340 km/sec, give or take a bit) solar wind coming from all over the surface of the sun
A constant solar wind stream, can its density and speed change if the suns properties change making the constant flow a variable amount?
There are areas where the source of the solar wind is very much higher velocity … ~ 500 - 1000+ km / sec.
And that is from coronal holes, those very dark areas in that image. You can see, from the image, that there is almost
no magnetic fields associated with those coronal holes (black regions) and as a result the solar wind pours out of those areas.
I worked it out backwards that the electric charge was building up at the source of the flare/CME and creating more dense/faster solar wind and a strong ad hoc magnetic field. After all, we here on Earth aren't worried about the constant stream. The constant stream doesn't change erratically and cause electrical risks, ad hoc fields are more likely to cause electrical risks?


https://en.wikipedia.org/wiki/Geomagnetic_storm
"The solar wind also carries with it the Sun's magnetic field."

I see its called a Geomagnetic storm and not a Geoelectric storm.

https://en.wikipedia.org/wiki/Solar_wind
"Embedded within the solar-wind plasma is the interplanetary magnetic field."
 
  • #24
davenn
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A constant solar wind stream, can its density and speed change if the suns properties change making the constant flow a variable amount?

I will repeat … it is always variable

I worked it out backwards that the electric charge was building up at the source of the flare/CME and creating more dense/faster solar wind and a strong ad hoc magnetic field.
no, see my previous comments

https://en.wikipedia.org/wiki/Geomagnetic_storm
"The solar wind also carries with it the Sun's magnetic field."
yes

I see its called a Geomagnetic storm and not a Geoelectric storm.

yes, because it affect the Earth's geomagnetic field

https://en.wikipedia.org/wiki/Solar_wind
"Embedded within the solar-wind plasma is the interplanetary magnetic field."

yes
 

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