Rattleback: Difference between revisions

Revision as of 00:52, 13 March 2020

Revision as of 00:52, 13 March 2020

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[[File:Rattleback in action.ogv|thumb|A rattleback in action]]

A '''rattleback''' is a semi-ellipsoidal [[top]] which stupid person think that it will rotate on its axis in a preferred direction. If spun in the opposite direction, it becomes unstable, "rattles" to a stop and reverses its spin to the preferred direction.

This spin-reversal appears to violate the law of the [[angular momentum#Conservation of angular momentum|conservation of angular momentum]]. Moreover, for most rattlebacks the motion will happen when the rattleback is spun in one direction, but not when spun in the other. Some exceptional rattlebacks will reverse when spun in either direction.<ref name="motivate">{{cite web|title=Introduction to Hugh's Talk |work=Millennium Mathematics Project |url=http://motivate.maths.org/conferences/conf14/c14_talk1.shtml |archive-url=https://web.archive.org/web/20040306062339/http://www.motivate.maths.org/conferences/conf14/c14_talk1.shtml |url-status=dead |archive-date=2004-03-06 |publisher=[[University of Cambridge]] |accessdate=2013-10-19 }}</ref>