National Geographic Photo of the Day

Saturday, March 21, 2009

Liquid Magnets (yes there's a video too)

No doubt we've all had our fair share of fun with solid magnets while we were little kids. But liquid magnets open up a whole new realm of fun ( the first thought that comes to mind is "Mercury Man" from Terminator 2)....

Ferrofluids are made up of particles of hematite, magnetite or other iron-containing compound with diameter less than 10 nanometers. These particles are suspended in an organic solvent or water or oil. A surfactant like oleic acid is added to prevent the particles from clumping together. These fluids respond to magnetic fields. They have a very high magnetic susceptibility and display superparamagnetism - its like paramagnetic behaviour on a bulk scale.

Under the influence of a magnetic field they tend to follow the lines of force and they'll stand up in spiny projections. Now these fluids have applications ranging from ultra-high end sportcar suspensions, and stealth aircraft to hard disks, speakers and cancer detection in medicine.

Most of us would rather be content with knowing the "cooler" aspects of this material. Below is a mesmerizing video of Ferrofluid in action with a magnetic field - its a piece of art that someone has created. I'm sure you'll enjoy it even if you aren't of a scientific bent of mind. :)


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