In the last 10 seconds of the video,the guy says that the rotation is unstable, the the moment of inertia is intermediate, why is this so?

Is it as rotation from the other axes also contribute?

  • $\begingroup$ It is a known fact of Lyapunov stability analysis of permanent rotations arising from Euler equations for the components of angular velocity. In this approach permanent rotations are points in the space of angular velocity vectors. One sees that the permanent rotations around the axes with maximal and minimal inertia momentum admit Lyapunov functions so that they are stable. The remaining axis can be proved to be unstable with a general argument from first order ODEs. $\endgroup$ Commented Apr 28, 2021 at 7:38
  • $\begingroup$ Possible duplicates: physics.stackexchange.com/q/397971/2451 , physics.stackexchange.com/q/34364/2451 , physics.stackexchange.com/q/17504/2451 and links therein. $\endgroup$
    – Qmechanic
    Commented Apr 28, 2021 at 7:46
  • $\begingroup$ This video kind of explains this phenomenon youtu.be/1VPfZ_XzisU $\endgroup$ Commented Apr 28, 2021 at 9:35