D'oh!

So the problem is not in radius but in what to display. https://wikimedia.mingle.thoughtworks.com/projects/mobile/cards/784 discusses how geo search can be made more useful for WV. Our present Nearby implementation that searches for primary coordinaes only is not helpful because the wiki consists of large pages with a lot of POIs around. My current work on porting to Elasticsearch would allow a sane spatial search for secondary coordinates, once it's complete we can experiment with adding a Wikiversity-specific mode for Nearby. With a lot of points around, there should be no need to have a continent-sized radius.