( adapted with permission from Pete's picture of a mug with leftover drinking chocolate dregs. )
Im not exactly sure what's going on. As the 'mud' evaporates, some kind of tension breaks up the film, leaving clear lines between patches of hardened residue. The interesting pattern is formed by the way these lines appear to join up like pathways, and the pattern repeating at smaller sizes towards the centre, with some visual similarity to the ants in sugar. Any further explanations would be most welcome, perhaps in the emergence group discussions at www.flickr.com/groups/emergence/.
Added to group: cream of the crop: as most favourited picture