Cross-camera tracking and frequency analysis of a cheap Slinky Wilberforce pendulum Pierre Devaux, Valentin Piau, Ombeline Vignaud, Guillaume Grosse, Renato Olarte and Alexis Nuttin Emergent Scientist, 3 (2019) 1 Published online: 01 February 2019 DOI: 10.1051/emsci/2018006