The hard-sphere system widely used in this group can be made large enough for study by light microscopy. At this size (radius around 1 µm) they sediment rapidly to form solid ''plugs'' which are generally thought to be ''randomly close packed'' (RCP). I will discuss RCP, and show that at least some sediments do not appear to arrange themselves this way. One possible explanation involves an analysis borrowed from simulations of granular matter (''bridging''). I will attempt to convince you that an explanation of this kind would carry some significance, and describe the usefulness of bridging as means of distinguishing between packings.
This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..