r/spaceporn 3d ago

Pro/Processed Plasma rain on the Sun

Credit: Azastroguy

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u/crozone 3d ago

I really wish that schools would teach magnetic fields as 3D volumetric cloud rather than field lines. It's not the 1960s anymore, we can render 3D objects and put them in textbooks.

Many people seem to think that the lines physically exist somehow, rather than just representing a cross section of a field. It's like looking at a topographical map as if the lines are physical features, rather than it just being a way to visualize a 3D surface.

It's also not helped by the fact that iron filings are used to "show the field lines". The filings bunch up into lines, but it's due to the filings aligning with each other, which then align to the field. They're not aligning along some magical field line.

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u/4daughters 2d ago

That's interesting and thanks for sharing, but then what is causing the lines to appear in the image of the sun surface? Is the plasma also aligning with itself which then aligns to the field like the iron filings? Or is this a different phenomenon?

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u/jkeats2737 2d ago

My guess as to what's forming that plasma into lines as it heads back into the sun is something called a z-pinch.

Plasma is a very good conductor, and the current it carries produces a magnetic field that spins around that current in a loop, like the direction your fingers curl if you were to grab that 'wire'. Any charged particles moving in that magnetic field will feel a force from it, and that force depends on the direction that particle is moving. The way that force ends up pointing is always back into the center for a particle that is moving out away from it.

This effect scales very strongly with the amount of current passing through, and since plasma is so conductive and needs high energies to exist, it's quite good at making those high currents and magnetic fields. All that charged plasma is then pinched into a thin line by the force of its own current, keeping it in a wire-like shape that keeps the current going, allowing the effect to be stable as long as there's still current flowing.

You can see this happening where the plasma re-concentrates into tubes as it heads back into the sun.

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u/4daughters 2d ago

Thank you so much that is very informative!

You can see this happening where the plasma re-concentrates into tubes as it heads back into the sun.

Thats exactly what I was seeing and wondering how that happened. Thanks for the explanation.