Watching Paint Dry

This movie demonstrates the processes occurring when emulsion-paint dries. Initially spherical beads of polymer based paint are suspended in water, but as the water dries the paint spheres come into contact and pack into an array approximating that of a cubic close packed lattice.

As the paint dries further the contact area between the paint balls increases, until all of the void volume has been lost. At this point each of the original paint balls will have adopted a dodecahedral close packing shape called a 'Kelvin solid', after Lord Kelvin, who first predicted the shape from studies of bubble packing in three dimensions.

This movie was prepared for Prof. Tony Ryan, for the Royal Institute Christmas Lecturer 2002.

Tony Ryan