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	Space-Time Cube	Gravity Model of Migration
Ämnesområde	Human Geography	Human Geography
Familj	Process / pipeline	Regression model
Ursprungsår	1970	1946
Upphovsperson	Torsten Hägerstrand (time geography); cube popularized by Menno-Jan Kraak	George Kingsley Zipf (formalized); analogy to Newton's law of gravitation
Typ	Spatiotemporal data structure and visualization framework	Spatial-interaction regression model for migration flows
Ursprungskälla	Hägerstrand, T. (1970). What about people in regional science? Papers of the Regional Science Association, 24(1), 6–21.	Zipf, G. K. (1946). The P1 P2 / D hypothesis: On the intercity movement of persons. American Sociological Review, 11(6), 677–686.
Alias	Hägerstrand Space-Time Cube, Space-Time Aquarium, Spatiotemporal Cube, Time-Geographic Cube	Migration Gravity Model, Demographic Gravity Model, Zipf P1P2/D Model, Gravity Model of Spatial Interaction (Migration)
Närliggande	4	4
Sammanfattning	The space-time cube is a framework from time geography for representing and analyzing phenomena that move and change over both space and time. Two horizontal axes carry geographic location and a vertical axis carries time, so each observation becomes a point in a three-dimensional x–y–t volume and a moving object traces a continuous 'space-time path' through the cube. Introduced conceptually by Torsten Hägerstrand in 1970 and turned into a practical analytic and cartographic tool by Menno-Jan Kraak, it underpins modern spatiotemporal hot-spot and trajectory analysis.	The gravity model of migration explains the volume of movement between two places as proportional to the product of their populations (masses) and inversely proportional to the distance separating them, by direct analogy to Newton's law of universal gravitation. Formalized for intercity movement by George Kingsley Zipf in 1946 and embedded in regional science by Walter Isard, it is the workhorse model of human geography for predicting migration, commuting, and other spatial-interaction flows.