Thought this might be of general interest- This video http://scitation.aip.org/phf/gallery/2003-lorenz.jsp shows a ferrofluid under applied axial and rotating in-plane magnetic fields. A ferrofluid is simply a fluid that reacts to a magnetic field, a simpler demonstration is shown here: http://www.oberlin.edu/physics/catalog/demonstrations/em/ferrofluid.html The peaks representing the density of field lines. Does anyone know how to make this stuff?
I absolutely LOVE playing with ferrofluid! I also have a bunch of NdFeB magnets that I never leave home without. Our undergraduate physics majors use the big magnets to study the Hall effect or some other noble scientific pursuit, but I always just want to use the big magnets to play with my little magnets. Magnetism is so cool. Seriously though, if you actually want to get some good ferrofluid, it's best to order it. Unfortunately, the stuff Lensman linked to doesn't last very long. I still recommend making some! Of course, somebody had to make the ferrofluid your can order, so that means you can too. Here is a tutorial: http://chemistry.about.com/od/demonstrationsexperiments/ss/liquidmagnet.htm It can get a bit involved, but it can definitely be done. I've actually made something similar myself although I didn't follow this guide. You can also get both the magnets and the ferrofluid pretty cheap online.
