Comments on: Magnetic Movie

By: Nova Kid

Nova Kid — Wed, 10 Sep 2008 16:07:36 +0000

Wow! So great to find this site! I just saw the magnet movie and had the same question; is this animation or an actual “reading” of the magnetic fields?

Wouldn’t Tesla have loved this imagery! I often think about what he could do with the technology we have today…but it’s the dog chasing his tail, isn’t it? If it weren’t for Tesla, 99% of what these scientists use to test this stuff wouldn’t be available.

Off topic a bit, sorry.

By: solar girl

solar girl — Sat, 12 Jul 2008 15:23:38 +0000

@ Mike Torr
You’re thinking of contours of magnetic field strength, which would be surfaces in 3D, you’re right. Magnetic fieldlines are different though. At each point in space, the magnetic fieldline points in the direction of the magnetic field vector. In the solar corona, the magnetic field is the dominant force and so the charged particles of the plasma are constrained to travel along the magnetic fieldlines. So the fieldlines show the paths the particles would travel along.

By: Magically magnetic. « Communion Of Dreams

Magically magnetic. « Communion Of Dreams — Fri, 11 Jul 2008 14:04:01 +0000

[...] Bad Astronomy, MetaFilter, NASA, Phil Plait, Science, Society, Space, movies I love it! Via Phil Plait and MeFi, a lovely piece of artwork of the video variety: Magnetic Movie. From their site: The [...]

By: Mike Torr

Mike Torr — Fri, 11 Jul 2008 12:24:18 +0000

Thanks madge, and Gia – that makes a lot of sense. I don’t have a TV so I have to ask my parents to video this for me. I didn’t want to miss out!

By: madge

madge — Fri, 11 Jul 2008 05:20:50 +0000

@ Mike Torr
Gia says they haven’t been given a date for Big bang Night yet, but her guess is that it will be aired late August or Early September, Makes sense as that will be around the time the power up of LHC begins. Thanks Gia!

By: David Vanderschel

David Vanderschel — Thu, 10 Jul 2008 23:37:00 +0000

As I watched the film, I was comprehending the narration; but I was baffled by what, precisely, the animations were supposed to be representing in the apparent context. In the absence of any explanation of the import of the graphics themselves, I came away with a reaction much as Xerxes has expressed. However, I would not have been sufficiently confident to express the reaction as forcefully as he has. His confidence has enabled me to put my baffled state aside.

By: Mike Torr

Mike Torr — Thu, 10 Jul 2008 20:42:07 +0000

Nope, I checked the schedules. If it’s Channel 4, it’s not on 13th July.

By: Mike Torr

Mike Torr — Thu, 10 Jul 2008 20:38:16 +0000

Oh, hold on! Perhaps Sticks has the answer: is it Channel 4, as opposed to BBC4? They are different things

Thanks for the help, madge. I’m grateful that you saw my queries!

@Wayne:
Is it fair to say that magnetic field lines are always closed in the same way that map contours and isobars are always closed, and for the same reasons? I’m guessing that the use of /lines/ to show magnetic fields in 3 dimensions is a convenience for us, and in reality, they should be /surfaces/ of equal… er… field strength, I guess(?)

By: Sticks

Sticks — Thu, 10 Jul 2008 14:35:53 +0000

Wow this is from Channel 4, a British company

By: madge

madge — Thu, 10 Jul 2008 14:26:08 +0000

@ Mike Torr
Just had a thought about Big Bang Night on BBC4. According to Sky at Night magazine it’s due to air on July 13th but looking at the schedule that is bogus. I will try to go on Gia’s blog as one of the programmes being shown is The Big Bang Machine, an hour long documentary about CERN fronted by Mr Gia Dr Brian (swoon) Cox. So she might know more. If you are reading this Gia could you give us a heads up here?

By: Torbjörn Larsson, OM

Torbjörn Larsson, OM — Thu, 10 Jul 2008 12:39:17 +0000

That actually bothered me a bit in the video, but it’s fairly common to see in drawings and models.

Thanks, I had forgotten about that practice as well. One of Maxwell’s equations states that explicitly.

(That the divergence of the magnetic field is zero, i.e. there can’t be field lines starting or stopping in, diverging from, a volume. Or in other words, there are no magnetic charges that magnetic field can start and end on.)

So the truncated lines either matched other truncated lines from the same volume of space, or went off to infinity. Confusing; but OTOH the movie gets the complexity of some fields down pat. Don’t you just hate the nice idealized pictures of permanent magnets fields?

In fact it’s that exact question that lead Einstein to formulate Special Relativity!

Even more interesting, that velocity dependence shows why magnetism is our everyday low velocity relativity effect. If it had shown up as radiation all by itself (acceleration instead of velocity effect), it had been an effect of a fundamental force. (Say, like photon pressure.)

But instead you can derive the magnetic Lorentz force from the electric field and relativity.

Kind of, I guess, how in general relativity gravity isn’t a regular force, but the spacetime curvature particles like to follow. Einstein put the finger on what is fundamental (invariant) laws and what is perceived outcomes.

By: Brian

Brian — Thu, 10 Jul 2008 06:15:07 +0000

I had quite a hard time with electromagnetic fields in college physics — it all seemed so nonintuitive. I suspect a movie like this would have helped, by giving me a set of visual “symbols” for representing these things in my mind. And it would have also helped me to keep in mind the highly dynamic nature of real fields — a nice counterpoint to the artificially static fields that we constantly dealt with in our entry-level problem sets.

By: madge

madge — Thu, 10 Jul 2008 05:43:51 +0000

@ Mike Torr
I got the original date for Big Bang Night from Sky at Night magazine. I just checked BBC4 schedule and there is nothing listed for July 13th. I will keep checking and post on this blog as soon as I get a confirmed date.

By: Cindy

Cindy — Thu, 10 Jul 2008 01:24:36 +0000

Hmm, don’t know if this would help my students visualize magnetic fields or confuse them more.

By: shane

shane — Thu, 10 Jul 2008 01:10:47 +0000

May not attract the Electric Universe people but it may be more grist for the mill for the electro sensitives – they’re the ones that want to ban things like wi-fi because they have “allergies” to electronic fields.

By: Wayne

Wayne — Thu, 10 Jul 2008 00:14:35 +0000

ZorkFox,
Actually, magnetic field lines are always closed, it’s just when they don’t close onto the same object they are often referred to as “open” and they are usually truncated so that you don’t have to show them going off to infinity. That actually bothered me a bit in the video, but it’s fairly common to see in drawings and models.

By: Jack Hagerty

Jack Hagerty — Thu, 10 Jul 2008 00:13:02 +0000

The lady scientist says that “the sun’s magnetic field hairball gets messier and messier.” So the sun is now a Messier object?

- Jack

By: Jack Hagerty

Jack Hagerty — Thu, 10 Jul 2008 00:10:29 +0000

Oops. I see that Sili has already said that.

- Jack

By: Jack Hagerty

Jack Hagerty — Thu, 10 Jul 2008 00:08:59 +0000

Tim G Says: “What if you are moving at the same speed and direction as the charges? Would you not experience a magnetic field?”

You’re in good company, Tim. That’s exactly the question that Einstein asked himself that lead to Relativity Theory. Keep going!

- Jack

By: ZorkFox

ZorkFox — Wed, 09 Jul 2008 23:09:34 +0000

That’s TOTALLY spooky and awesome. I didn’t know field lines could just be sticking out into space without closing on something: all the diagrams I’ve seen in text books are always composed of neat (if wavy) bunches of lines that leave a planet/magnet at one pole and loop gracefully to the other pole.

By: Mike Torr

Mike Torr — Wed, 09 Jul 2008 22:25:18 +0000

I’m glad several people have stated that this is inaccurate because I was having a hard time understanding what was being shown to me. I now realise that what I was watching was more “Electric Sheep screen saver” than “Equinoxe”…

By: AJWM

AJWM — Wed, 09 Jul 2008 20:52:27 +0000

Very pretty, but WTF? The dancing lines had nothing whatsoever to do with the clear sources of EM fields in the pictures (wiring, lights, etc) nor were they influenced by any of the ferromagnetic stuff (eg the large toolbox) around.

Utterly useless at visualizing anything, except perhaps the artist’s imagination. The soundtrack was cool, but it didn’t fit the visuals (except occasionally).

Using this to get an understanding of magnetics is like watching Coyote/Roadrunner cartoons to get an understanding of Newtonian physics.

By: Xerxes

Xerxes — Wed, 09 Jul 2008 20:44:45 +0000

@Celtic Evolution -

You’re right. Their website does accurately describe the audio as the part that’s real. They don’t explicitly state that the animations are pure fantasy, but they don’t say it’s supposed to represent any real science either.

So wag-of-the-finger to BA for for saying it “uses animations based on magnetic measurements to visualize these fields”. It doesn’t!

By: Doc

Doc — Wed, 09 Jul 2008 19:57:04 +0000

I believe many (most?) of the sounds in the movie were natural (VLF) radio sounds – also known as ‘spherics (from “atmospheric”).

See http://www.altair.org/natradio.html for more info – it’s neat stuff.

By: Thomas K

Thomas K — Wed, 09 Jul 2008 19:50:58 +0000

Holy hell! Wildly enjoyed and I might have learned science in the process, but I’ll have to get back to you on that.

Stick Doctor Who in the middle of that and you have a whole episode.

Very cool, but also frightening. It is going to be an interesting day of swinging baseball bats at sadly invisible fields. And in this weather, I don’t know how I’ll stand wearing my tin-foil hat out and about.