Rattleback

beeld wiebelsteen

2014, Portugese marble, 35*12*8 cm

At one of the conferences I attended as a TU Delft researcher, there was a small plastic item in the conference bag: a shape that defies the imagination of anyone who thinks he or she understands mechanics. Roughly the same form worked out in stone shows the same magic, which can be seen in the video. I now know the trick (the bottom is left-right symmetrical, but the mass at the ends of the shape is not) but real understanding is something completely different.