Fun with Ferrofluid

Ferrofluid is a liquid comprised of very small magnetic particles suspended within an oil. When a magnetic field is placed nearby the material and moved around, very interesting things happen. Ferrofluids are used in medicine, aerospace, construction and in the hard-drive within your computer. If you want to play with some yourself, you can purchase it for about $16 for 2 fluid ounces. See video below.