Gauss Rifle - il cannone magnetico

Gauss Rifle: "This very simple toy uses a magnetic chain reaction to launch a steel marble at a target at high speed. The toy is very simple to build, going together in minutes, and is very simple to understand and explain, and yet fascinating to watch and to use."

Come fabbricare un modello di cannone magnetico con un righello, qualche sferetta di metallo e alcune calamite. Spettacolare.