The purpose of this paper is to introduce citation networks, a novel method for identifying field connections, and to elaborate a theory of spatiality that deploys the metaphors of bubbles and foams to imagine space and change. After introducing the method and theory that guide this investigation, the author will introduce and describe the foams of the research published in the "Journal for Research in Mathematics Education" ("JRME") and "Educational Studies in Mathematics" ("ESM") during the 2010s. In doing so, the author will show what topics of inquiry constitute the dominant research foci of the field, or at least of the field as it is published in these mainstream mathematics education journals. Then, using Larnell and Bullock's (2018) socio-spatial urban framework as a lens, the author provides a critical reading of the bubbles and foams to discern what is marginalized or excluded, namely the urban. After investigating the inclusion of "urban," the author concludes by situating the role of the "Journal of Urban Mathematics Education" ("JUME") as a place to blow bubbles and reconfigure what can be seen, said, thought, and done in the name of (urban) mathematics education research.