  The configuration space of n labeled disks of radius r inside the unit disk
is denoted Conf_{n, r}(D^2). We study how the cohomology of this space depends
on r. In particular, given a cohomology class of Conf_{n, 0}(D^2), for which r
does its restriction to Conf_{n, r}(D^2) vanish? A related question: given the
configuration space Seg_{n, r}(D^2) of n labeled, oriented segments of length
r, it has a map to (S^1)^n that records the direction of each segment. For
which r does this angle map have a continuous section? The paper consists of a
collection of partial results, and it contains many questions and conjectures.
