Ancient scholars discovered naturally magnetic lodestones over 2500 years ago. Physicists use magnetism often for their experiments. They can even be used to measure the magnetic field of the Earth! Just take some of your standard Silly Putty and blend in some black iron oxide. As far as experiments go, this is simple and safe, and the results look awesome.
A ferrofluid is a liquid made up of tiny iron particles suspended in oil. Its magnetic properties make it an ideal sealant for electronics, industrial applications, and even art. Create your own ferrofluid and watch as solid-like cones appear and alter according to the strength of the magnetic field. This project solves a challenge for the Physicist Skill.