A storm rumbles in the distance. A giant windball is picking up all kinds of things. "If you want to, you can add something sticky," a Japanese friend tells me, "although by the time it reaches us it will probably have calmed down because not enough people will glue things to it." I am keen to see it and want to attach a sticky bun. "The windball will eventually divide into new ones like rivulets from a river," my friend says.