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Awesome Magnetism Video

zosima

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zosima
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Mar 1, 2008
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This was posted on the Bad Astronomy Blog, but If people haven't already seen it I thought they might appreciate* it. It is AWESOME!

http://www.semiconductorfilms.com/root/Magnetic_Movie/Magnetic.htm

Okay, I'm being somewhat self-serving too. The video was filmed at my former place of employment(Space Science Lab) and Alma Mater(UC Berkeley).

*Especially considering how much we argue about electromagnetism and plasma.
 
zosima said:
This was posted on the Bad Astronomy Blog, but If people haven't already seen it I thought they might appreciate* it. It is AWESOME!

http://www.semiconductorfilms.com/root/Magnetic_Movie/Magnetic.htm

Okay, I'm being somewhat self-serving too. The video was filmed at my former place of employment(Space Science Lab) and Alma Mater(UC Berkeley).

*Especially considering how much we argue about electromagnetism and plasma.
Click to expand...


Very cool. But...outside of the explanation provided, could you sum this up for the magnetically impaired?
 
thesyntaxera said:
Very cool. But...outside of the explanation provided, could you sum this up for the magnetically impaired?
Click to expand...

Well the narrators for the video do some good explanation.

Here's what they say on the site:
"The secret lives of invisible magnetic fields are revealed as chaotic ever-changing geometries . All action takes place around NASA's Space Sciences Laboratories, UC Berkeley, to recordings of space scientists describing their discoveries . Actual VLF audio recordings control the evolution of the fields as they delve into our inaudible surroundings, revealing recurrent ‘whistlers' produced by fleeting electrons . Are we observing a series of scientific experiments, the universe in flux, or a documentary of a fictional world?."

I didn't make it so I don't want to go too far out on a limb, but I *think* what they did is make audio recordings of various magnetic/plasma experiments at the lab, then added animations to go with the audio.

As they mention, magnetic fields are incredibly tricky to visualize and this video does a pretty good job demonstrating their dynamics and complexity.

Here's another good quote:
"In Magnetic Movie, Semiconductor have taken the magnificent scientific visualisations of the sun and solar winds conducted at the Space Sciences Laboratory and Semiconducted them. Ruth Jarman and Joe Gerhardt of Semiconductor were artists-in-residence at SSL. Combining their in-house lab culture experience with formidable artistic instincts in sound, animation and programming, they have created a magnetic magnum opus in nuce, a tour de force of a massive invisible force brought down to human scale, and a 'very most beautiful thing.' "
 
I realize I may not have actually spoken to the question you were asking before. The video shows the magnetic field lines from these experiments. Magnetic field lines are a way of plotting a magnetic field. You can think of magnetic field lines as the pattern that a bunch of iron filings would make if you placed the filings in the field.

Although magnetic field lines are not actually physical entities they are often treated that way in space plasma physics. Basically an assumption is made that ions are "frozen in flux" to solve magnetohydrodynamical equations. This means the plasma is treated as if it is directly tied to these lines. While this is an approximation, it is not too inaccurate.

Highly charged particles often gyrate around these field lines tracing out helical patterns(like the shape of DNA). Excellent examples of this phenomena in nature are the Van Allen Belts and the Polar Auroras.
 
Nice, but ... seems to me, it's not even close...

... to the real thing. We see strange leaps and arcs, open-ended tendrils and stuff. Very artistic, and very weird (nice-weird), and excellent use of tracking to keep the 3-D fx constant with the camera movements.

But I'm wondering wether the "illustration" of magnetic fields in this video isn't quite misleading, seeing how iron dust on top of a magnet or around a power line (ya know, those physics 101 experiments) tends to paint quite different pictures of field lines, doesn't it?
 
It looked like they visualized the motion of charged particles as following the magnetic field lines. That's incorrect. Charged particles will follow the E-field (electric) and bend around the H-field (magnetic). Basically, the H-field causes moving charges to twirl.

P.S. If magnetic monopoles exist, they will follow the H-field and bend around the E-field.
 
oops, nm. I think that the particle have a magnetic momemt (spin) that causes them to follow the H-field. That's probably what they were going for.
 
No I'm pretty sure they mean charged particles. The lorenz force acting on charged particles in a magnetic field tends to make them go in a helix around the lines of the B-field and as they're free to move in the direction of the tangent of the B-field they could be said to follow the lines of the B-field(even though they don't show any preference going with or against the lines of the B-field).
 
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