#64076 Ferroliquids

[Digit]

Re: Question 64076, now that we know how to make the liquid, how would one make a porcupine-shaped magnetic field in the space around the liquid?

[Digit]

Interesting, upon going to Ferroliquid, it looks like if you put a plain bar magnet underneath the liquid, it will assume a porcupine-like shape naturally.

[mic0]

I was wondering about that, too. Interesting!

[Digit]

The Wikipedia article says that shape's what happens when the forces by the magnetic field lines trying to maximize the amount of ferroliquid the field lines are passing through (which would cause as spiky a surface as possible) balance with the forces of the surface tension trying to minimize surface area (which would cause toward a smooth surface).

[NerdGirl]

I like your signature, Digit.

[Katya]

The Wikipedia article says that shape's what happens when the forces by the magnetic field lines trying to maximize the amount of ferroliquid the field lines are passing through (which would cause as spiky a surface as possible) balance with the forces of the surface tension trying to minimize surface area (which would cause toward a smooth surface).

This makes me really happy.

[Digit]

Thanks, NerdGirl. I haven't actually read any of Carl Sagan's books yet, but I liked the movie Contact and the autotuned song A Glorious Dawn made out of footage from Mr. Sagan's educational TV documentaries and featuring guest lyrics by Stephen Hawking.

I'm glad you're happy, Katya.

[mic0]

So, the phenomenon of the liquid becoming spiky with the magnetic field under it? Huge plot point in my dream last night. Except, instead of this ferroliquid, the material was play-doh. It was really awesome.

[Emiliana]

So, the phenomenon of the liquid becoming spiky with the magnetic field under it? Huge plot point in my dream last night. Except, instead of this ferroliquid, the material was play-doh. It was really awesome.

That ... is the coolest dream I have heard of in a long time.

[Tao]

Aye, if you use an electromagnet you can really get to see the effects of differing field lines on a ferrofluid, the stronger field, the more spikes you get, and they 'stand up' further. One of the earliest videos I'd seen on the subject simply used a speaker as a electromagnet, so the ferrofluid danced to the ebb and flow of the beat. Nowadays, it seems they've gotten somewhat more elaborate in their videos....

[Imogen]

someone make me one of these

http://www.youtube.com/watch?v=ikUya4KZ ... re=related

[Yellow]

Another cool video: http://kottke.org/11/08/magnetic-soap