Figure 1 – Golden Christmas balls, Natick, MA. (C) DE Wolf 2016.

Figure 1 is another photograph of Christmas. These are golden Christmas balls. And of course, there are connotations or memories that they invoke. An obvious one is bubbles, perhaps a soapy foam. But for me, as a scientist, I cannot help but think of molecular packing. Spheres will tend towards close backing, and this reminds me very much of a crystal lattice, perhaps the molecular packing of a gold nanoparticle, and, of course, of planets.

Crystal packing is like its opposite, the random fractal. The crystal is supreme order and like the fractal occurs at all scales. And then there is the curious paradox that, in general, crystals are assembled by the fractal random process of diffusion. It is the ultimate example of order out of chaos. The structure of the crystal is locked within the physical properties of the individual atoms and they assemble like so many Legos according to physical law.