image is a derivative work of the following images: File:ElectricDisplacement_English.GIF licensed with Cc-by-sa-3.0, GFDL 2009-04-27T13:13:04Z 老陳 350x232
cos(time) return {'pos':(x,y), 'displacement': displacement, 'charge': charge} #in the middle... charge = 0 displacement = cos(time) #top part of short