Science!

November 10, 2011 11:57 AM

An illustration of two dimensional vibration. A really cool illustration of two dimensional vibration.
posted by jacquilynne (21 comments total)

They had one of these (mechanically operated, not the bow-driven type) at the Exploratorium when my parents used to take me there on a monthly basis. Just sitting unattended (like everything else there). You could fiddle with the knobs or stick your finger in it or whatever you wanted. I really hope it's still there.
posted by theodolite at 12:15 PM on November 10, 2011

Wow. Just, wow. How do you even find out that things do that?

(For quick reference, since I had to go do some quick research: Ernst Chladni on Wikipedia - he's the Father of Acoustics and the Father of Meteorites!)
posted by EvaDestruction at 12:21 PM on November 10, 2011

The photos remind me of Conway's Life for some reason.
posted by maryr at 12:25 PM on November 10, 2011

I played this video with my cat sitting on the bed, and she freaked the fuck out.
posted by bthrbt at 12:27 PM on November 10, 2011 [2 favorites]

Chlandi sand, more Chlandi sand, tibetan singing bowl, subwoofer under water and of course, acoustic levitation chamber.
posted by 3FLryan at 12:28 PM on November 10, 2011

You can't fool me. I've watched enough Supernatural to know what salt moving by itself means.

fuckin' black magic, I tells ya
posted by The demon that lives in the air at 12:28 PM on November 10, 2011 [1 favorite]

This is one example within the study of cymatics. My favorite is the resonating hexagon on the poles of Saturn.
posted by Blazecock Pileon at 12:29 PM on November 10, 2011 [2 favorites]

It reminds me of atomic orbitals.

For those not familiar with quantum mechanics, this is analagous to how electrons behave in atoms. Electrons, like all matter, have wave-like properties. They form standing waves around atomic nuclei, not unlike the structures formed by the salt grains here, only the patterns that electrons form are in three dimensions (and are correspondingly weirder).

The energy of the electrons determines how many nodes the standing waves form, just as the frequency of the sound waves in this demonstration determines the shape of the standing wave patterns. Notice that not every grain of salt falls perfectly into line—the lines are more like averages. It's that way with electrons too; the shapes they form are probability distributions, representing the likelihood that an electron will be found at a given point if measured.
posted by dephlogisticated at 12:32 PM on November 10, 2011 [6 favorites]

Cool video until I was murdered by my dog.
posted by resurrexit at 12:36 PM on November 10, 2011 [1 favorite]

(and are correspondingly weirder)

Note to science fiction art directors: you could do a lot worse than riffing on these for your next spaceship design. (Lose the teal and orange, though.)
posted by theodolite at 12:40 PM on November 10, 2011

Lose the teal and orange, though.

My brother is badly colorblind, he can tell the teal and orange apart.
posted by Confess, Fletch at 12:50 PM on November 10, 2011

this post, it vibrates?
posted by ninjew at 12:51 PM on November 10, 2011 [3 favorites]

The first .gif illustrating the guy with the bow, for some reason, called up from my brain the sound of Beavis and Butthead giggling.
posted by not_on_display at 12:53 PM on November 10, 2011

A 1 dimensional string has modes of vibration that are proportional to the length. The lowest frequency has a wavelength equal to the length of the string, the next highest is a wavelength half the length, the next is a third and so on.

When you have a 2 dimensional object vibrating, you have modes of vibration in every directions, again, proportional to the length along that axis. These waves can also cancel each other out or amplify each other, depending on if they're in phase or out of phase. The lines you see on the plate are the places where the vibrations are out of phase and cancel each other out (that is, one wave is moving up and another wave is moving down in the same place).

[i think i have that right, anyway]
posted by empath at 1:29 PM on November 10, 2011 [2 favorites]

Molecular orbital shapes get a whole lot weirder than the ones for just single atoms. Even something as simple as water gets some great odd shapes going on in its electron clouds.
posted by wanderingmind at 1:33 PM on November 10, 2011 [2 favorites]

Neat. Now I just have to scatter some sand on my desk and wait for the magic to happen, courtesy of the construction crew doing this just across the street,
posted by maudlin at 1:52 PM on November 10, 2011

Isn't this the guy from The Joy of Sex?
posted by the noob at 3:44 PM on November 10, 2011 [1 favorite]

They had one of these (mechanically operated, not the bow-driven type) at the Exploratorium

Heh. I just came in here to mention that.

I hope it's still there too. It's been way too long since I've been by.
posted by Tell Me No Lies at 4:32 PM on November 10, 2011

I really don't understand what is going on here, but it is some kind of visual representation of sound...? And this reminds me of it. And it is awesome, whatever it is.
(Also on vimeo here.)
posted by zoinks at 6:29 PM on November 10, 2011 [1 favorite]

zoinks, it certainly looks the part (except where audible frequencies drop and the the visual representations increase in frequency), and it's very nice as an ambient track. I love hearing representations of large scale phenomena, especially something like the solar/geo magnetic field - hints of reverberations unknown in daily life.
dephlogisticated, nice analogy!
posted by Tzarius at 3:04 AM on November 13, 2011

Laplacian eigenfunctions FTW!
posted by erniepan at 1:53 AM on November 14, 2011 [1 favorite]