Newton's Cradle illustrates the principle of energy conservation stated by Newton in the 17th century (hence its name).
Raise the ball to the left and let it fall against the other four. Three balls will not budge but the one on the right recovers all the energy and rises up and the process is repeated. It falls back and hits the four balls with the ball on the left rising up.
If the first ball is dropped correctly, your "clock" can run for a full minute. Air friction is the only thing that stops the pendulum's movement.
This special variety comes with one metal rod bent into a Z-shape making it all the more beautiful to Watch.
Dimensions : 12 x 12 x 10 cm.
[$, £, CHF...]