Project Blueprint Mini Newton's CradleThe Newton's Cradle teaches principles of physics in a fun, hands on way. Pull back the polished steel ball on one end and let it fall. When it hits, it transfers its energy to the ball at the far end of the line, setting it in motion. Experiment with releasing multiple balls at once and observe the effect. The Newton's Cradle makes a fun conversation piece, and fits perfectly on a desktop or coffee table.