 In addition to the examples given above and several others to be mentioned below, other cases of explanation that have been extensively discussed include the FitzGerald-Lorentz contraction of bodies in special relativity (Colyvan 2001, 2002), the impossibility of crossing all the Königsberg bridges passing only once on any single bridge (Pincock 2007), the hexagonal shape of honeycomb cells (Lyon and Colyvan 2008), Plateau’s soap films (Lyon 2012, Pincock 2015a), and the location of the Kirkwood gaps (Colyvan 2010). 