A rotating, non-inertial frame of reference makes ball playing difficult.For details on our setup, see http://sciencedemonstrations.fas.harvard.edu/icb/icb.do?keyword=k16940&pageid=icb.page80675&pageContentId=icb.pagecontent202048&state=maximize&view=view.do&viewParam_name=indepth.html#a_icb_pagecontent202048