Q1:In the Kissing number problem for three dimensions, I hadn't heard that there was extra space between the 12 spheres around the central sphere. Does anyone know if the radius of the surrounding spheres be uniformly increased so they are all mutually touching, while still touching the (unchanged) central sphere? If so what is this new radius?
A1: If the radii of the surrounding spheres is r, then the central sphere has radius .