Uploaded December 2025 | Updated September 2026, 2 weeks ago

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The Dzhanibekov effect (or tennis racket effect) is demonstrated by a couple of examples:

- Simplified wingnut
- Smartphone
- Extruded bronze moose

All these rigid bodies have an intermediate rotational axis which, upon rotation around them, exhibits instability such that conservation of angular momentum may appear violated. This effect has been known for centuries but perhaps popularised by people on space stations where this experiment is easily performed.

Beautiful song, made by @gpcbass , called "Visa från ingenstans". This song can also be found here: youtube.com/watch?v=cgmzudeyGGw

Visuals in Mathematica and FFmpeg