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Magnetic Fluids
Polo writes: "Remember those magnetic sculpture things you can buy at the mall where these small metal pieces stay in one shape. Imagine doing that with Ferrofluids.
This is just too cool. Dan is the nerd's nerd." Well, can't get any higher praise that that, I suppose. :) I have a couple of neodymium magnets and yes, they are much fun. Never played with magnetic fluid though.
Japanese artists Sachiko Kodama and Minako Takeno did an art piece displayed at SIGGRAPH using ferrofluids. Memepool had some links about this back in august.
LS
There is a fine line between being a cultivated citizen and being someone else's crop. - A. J. Patrick Liszkie
Ferrofluids have been used in magnetic clutches. You have two plates facing each other with vanes on them. Put them in a ferrofluid tank. When the magnetic field is absent, either shaft will spin freely without effecting the other. Add a magnetic field and WHAM, the shafts are locked together. I seem to remember there being a problem getting a decent amount of shear strength though. There was an article on this in Scientific American a few years back in the Amateur Scientist column.
I've wrestled with reality for 35 years and I'm happy to say, I finally won out - Elwood P. Dowd
The "nerd's nerd" couldn't handle three measly hits? This has to be a "slashdotting" record. ;-)
crib
Please don't read my journal
At Berkeley, they use magnetic fluids to control movement of underground fluids without any contact. Interesting stuff. For an introduction to ferrofluids, see University of Wisconsin's excellent article.
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check this link. It's the first link on the page (which is unreachable by now).
I have a couple of neodymium magnets and yes, they are much fun. Never played with magnetic fluid though.
That explains the form errors trying to reply to this story.
Umm, Michael? Could you keep your fscking magnets away from the fscking servers? Thanks.
Soko
"Depression is merely anger without enthusiasm." - Anonymous
Check out this cool picture from Science Friday.
And a meatspace link: check out ferrofluids for yourself at the exploratorium -- if the exhibit is still there (it was maybe 4 years ago, upstairs), they have a tank of ferrofluid (with I think a lighter different-colored fluid floating on top). Pressing the buttons activates different electromagnets under the fluid, and it forms bumps on the surface (maybe protruding through the different colored liquid, as in the picture above, if I remember right). It's neat to see the surface of a liquid that is not flat, yet not moving. The exploratorium is well worth the visit if you're in the SF bay area.
HIV Crosses Species Barrier... into Muppets
I got the article in time. The pics not.
find it here
Never played with magnetic fluid though.
Michael can't have been to a science museum of late. I can remeber seeing small tanks of magnetic fluid that allow you to wave magnets around near them to see what happes in museums a couple of years ago.
Oh, and Wired magazine had a lovely picture of magnetic fluid in a beautiful state that was to be shown at Siggraph (See wired for article check here for video)
-- Mike
Lee Valley Tools, besides being a generally cool place with some delightful woodworking tools, has spherical magnets.
And, no, to presuppose the silly question I was asked earlier, of course one of the poles isn't in the centre of the magnet. If it were, how the hell would the flux lines get to the outside?!
These would be the equivalent of a bar magnet lathed spherical, allowing them to roll around and do other neat shit.
FWIW, Lee Valley also has awesome rare-earth disc magnets. I've got a handful of them. They can suck through a good 2" of wood. Damn near impossible to get off the fridge door. Does nasty shit to any nearby wallets, too. And don't even think about letting them near your monitor.
--
Don't like it? Respond with words, not karma.
just wait until this hits the infomercials.. they'll probably have some sort of offer for "therapeutic gel" that you bathe in. just toss your favorite electrical appliance in, and voila!
Actually I used to use the stuff for educational purposes and it is gross ass hell. Gets on everything and wont wash off. Fun for the first 30 seconds.
I got the video downloaded just in time...
here
---- Breakbeats are not just music...they're the soundtrack for my life.
http://homepage.mac.com/crayz/magnets/magnets.htm
Thank Apple for the bandwidth
8:15 Still slashdotted...Poor Dan the nerd's nerd doesn't have the server's server.
Damnit, Jim, I'm an anarchist, not a F@#$!^& doctor!
Fluids influenced by magnets have been around for a while.
One of the problems facing the space program in its earliest days was how to re-fire liquid fueled rockets in a weightless environment. If you think about it, just exactly how do you get the fluids in a tank half full of rocket fuel to take a position over and in the sump of the tank so the pumps can supply reliable measures of fuel and oxidizer to the engines combustion chamber.
The innovative solution was to mix the fuel and oxidizer with a ferrous based additive so that a large magnet at the sump of the tank would draw the fuel and oxidizer to the sump. This isn't a magnetic fluid but it is one of the ingenious solutions to a myriad of engineering challenges facing our space program.
A few friends and I bought a large bottle of the stuff, it's pretty neat to play with along with some magnets, but you need some SERIOUS power to get any real decent results, initially we were messing around with some discarded large speaker magnets and voice coils (fixed magnetic power). We went so far as to have ordered some higher power electromagnets and some extra hardware to control their strength. Unfortunately due to the recent events in our neighborhood (NYC) we haven't had a chance to experiment much more lately.
Oh and its more like liquid than goo, so dont get your hopes of creating a giant black goo monster up too high.
Anyway, if you want to pick some up for yourself try these places:
Edmund Scientific
(also has magnets, electromagnets)
Teacher Source
(this is where we got our large 1000ml bottle)
and more listed at the official ferroftec web site:
ferrofluidics
-nA
^nA! Creatures in my Head
Liquid mercury isn't affected by magnets.
-- MarkusQ
Better: send them to the airport.
-- MarkusQ
P.S. That begs the question--what comes after strip & cavity search?
And do we realy want to know?
Small Parts has an experement kit with 50cc bottle and some megnents to play with. Look at at the left bar and go down, it's under "DEMO KITS". I ordered one a while ago, it's pretty neet. ($50.00)
This has been around >15 years. In fact some of the tools that made the chips in your PC probably had ferrofluidic bearings. Because these liquids can be held in place by magnets, you can make a feedthrough into a vaccum chamber that can be rotated. The fluids have low vapor pressure so you can have a high vacuum system with a rotating shaft entering it - that's very difficult normally. The fluid seals between the shaft and the sleeve, where the air would normally leak in. Good down to about 10^-10 of an atmosphere. Try www.ferrofluidics.com .
Regards, John the semiconductor capital equipment designer.
-Fantastic Lad
42.
So when do we get to see them build the first Liquid Terminator out of this stuff?
I realize the first metal Terminator has yet to be done, but after Sony realizes that AIBO isn't very useful, I think we'll start seeing some really fun stuff walking out of their labs.
The whole Liquid Metal Morphing Killer Robot thing though, man... that's where it's at!
I can't wait until I have a barrels full of minions to call upon for my evil deeds!
"Everything you know is wrong. (And stupid.)"
Moderation Totals: Wrong=2, Stupid=3, Total=5.
AC: Don't use that phrase that way unless you want to look like an idiot.
While I don't particularly mind looking like an idiot, I doubt that my use of "begs the question" here will do it.
To "beg the question" is to speak as if you are addressing a point, when in fact you are not. The original poster suggested having someone drink magnetic liquid and then going after them with a magnet. We all know what the expected outcome was. Then I suggested sending them to the airport, as if I knew what the outcome would be (and was making a sly joke), when in fact I don't know what would happen. Thus I was begging the question.
What may seem odd here is that I didn't wait for someone else to point this out; I called myself on it. While this is about as common as someone saying "I'm full of shit here,..." or "If you'd like to hear a bogus view, I think..." that doesn't make it wrong.
-- MarkusQ