via Ben Goldacre’s blog:

you’ll know – from pouring thick cream or shampoo – that a nice smooth stream of viscous liquid gunk tends to coil up as it lands on a surface. the awesome video below comes from an academic paper, which set out to explore that phenomenon by tipping a viscous fluid onto a moving belt. first you get a line, then some nice sine waves as the belt slows down, then some lovely, regular, reproducible coiling. i don’t mind telling you that i find this footage IMMENSELY satisfying.