The Creeping Virtuality of Place

Places are inherently dynamic. They also mediate between entities and events of significance to us, and space. They reflect a network of associations, involving landmarks deemed salient for various reasons. These are all properties assigned to a place by a speaker, and may or may not correspond to the properties assigned to a place by any other speaker. As a result, places have a subjective quality. These properties of dynamicity and subjectivity present interesting challenges when producing mashups that align different data sources. I propose addressing this by assuming that entities, following Hornsby & Egenhofer (2000), have histories, namely sequences of time intervals when they are predicated to exist. Places are entities with spatial properties that include topological relationships to other places, represented in terms of RCC-8 or the 9-intersection calculus, as well as distance and orientation relations. This spatio-temporal integration can avail of existing annotation schemes for space and time in natural language, but it leaves some open issues related to the representation of subjectivity.