These wooden pieces are quite idiosyncratic!  Forget the theorem that a turning impulse is maintained.  The wooden rattleback has a mind of its own.  Even the Celtic Druids used its hidden characteristics to manipulate decisions in their favour.  To find out more about its workings, read the text by Dr. Christian Ucke (an expert in physical toys) or ask a physicist.  It’s all about rotation, friction and axis of inertia.

Size: 15 cm

Snakewood