# tennis racket theorem

> theorem that, in a 3d rigid body with 3 principal axes, rotation around 1st and 3rd principal axes is stable, but rotation around 2nd principal axis is not

**Wikidata**: [Q944604](https://www.wikidata.org/wiki/Q944604)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Tennis_racket_theorem)  
**Source**: https://4ort.xyz/entity/tennis-racket-theorem