Classical Dynamics: Spinning Eggs — A Paradox Resolved
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|H. K. Moffatt and Y. Shimomura, Nature|
|"If a hard-boiled egg is spun sufficiently rapidly on a table with its axis of symmetry horizontal, this axis will rise from the horizontal to the vertical. Conversely, if an oblate spheroid is spun sufficiently rapidly with its axis of symmetry vertical, it will rise and spin about the vertical on its rounded edge with its axis of symmetry now rotating in a horizontal plane. In both cases, the center of gravity rises." In this "brief communication" article from volume 416 of the journal Nature, Moffatt and Shimomura provide an explanation for this paradoxical behaviour, through derivation of a first-order differential equation for the inclination of the axis of symmetry. Download the article as a PDF, or read a "science update" report of the research which explains the phenomenon in layman's terms.|
|Math Topics:||Differential Equations, Fluid Mechanics, Mechanics of Solids|
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