Absolutely marvelous animation - thank you! I did not know it is possible to capture the effect via NDSolveValue. I have not seen a single formula in Wikipedia. Putting your reference from your notebook here:
T.R.Kane and D.A.Levinson, Realistic mathematical modeling of the rattleback International Journal of Non-Linear Mechanics, vol.17, no.3, pp.175[Dash]186, 1982.
This post became quite popular on Reddit / Physics and someone has posted a related paper in the comments:
H. K. Moffatt, Tadashi Tokieda, Celt reversals: a prototype of chiral dynamics, Proceedings of the Royal Society of Edinburgh,138A, 361368,2008
