Blue laser: refraction at the air-glass boundary

Blue laser: reflection on a glass surface

Prism

Photo by Jeffrey

Prism

 

... by Nicole

Optical Bench

A strong magnetic field

Electrostatic machine sparks

 

An electrostatic machine, or generator, works in a very similar way to the simple rubbing trick (see that post).  It collects electrons in one of the cylinders, and removes them from another one; the difference in electric potential causes a spark. 

 

Iron filings in the shape of a tree