many mathematical objects come in continuous families, prompting the desire to define a ``universal family'' that contains each such object exactly once up to isomorphism. when this isn't possible (because the family would be too bad to be worthwhile -- i'll talk about this behavior), we can try to come close, by including only ``stable'' objects. frequently the universal family is constructed by starting with a bigger family that includes each object many times, then dividing by a group action that implements the isomorphisms. there are two ways to do this, one algebro-geometric (complex) and one symplecto-geometric (real), and i'll give some idea of why they agree. the main example will be the space of $n$ ordered points on the riemann sphere, modulo m\"obius transformations. these are unstable if