A counterintuitive toy: the bird that never falls down

J Fort, J E Llebot, J Saurina, J J Suñol
1998 Physics Education  
We describe a toy that has the shape of a bird. It has the intuitively astonishing property that, no matter how far away from the equilibrium position it is moved, it oscillates back to this position. We explain the behaviour of this physical system and use it to illustrate the concept of mechanical stability and the usefulness of making simple, idealized models for the description of complex systems.
doi:10.1088/0031-9120/33/2/013 fatcat:5pdrwzbawbad3ic4ob3tw355lm