The Swedish geographerTorsten Hägerstrand created time geography in the mid-1960s based on ideas he had developed during his earlier empirical research onhuman migration patterns in Sweden.[5] He sought "some way of finding out the workings of large socio-environmental mechanisms" using "a physical approach involving the study of how events occur in a time-space framework".[6] Hägerstrand was inspired in part by conceptual advances inspacetimephysics and by the philosophy ofphysicalism.[7]
Hägerstrand's earliest formulation of time geography informally described its keyontological features: "In time-space the individual describes apath" within a situational context; "life paths become captured within a net of constraints, some of which are imposed by physiological and physical necessities and some imposed by private and common decisions".[8] "It would be impossible to offer a comprehensive taxonomy of constraints seen as time-space phenomena", Hägerstrand said, but he "tentatively described" three important classes of constraints:
capability constraints — limitations on the activity of individuals because of theirbiological structure and/or the tools they can command,
coupling constraints — limitations that "define where, when, and for how long, the individual has to join other individuals, tools, and materials in order to produce, consume, and transact" (closely related tocritical path analysis), and
authority constraints — limitations on the domain or "time-space entity within which things and events are under the control of a given individual or a given group".[9]
Examples of thevisual language of time geography: space-time cube, path, prism, bundle, and other concepts
Hägerstrand illustrated these concepts with novel forms of graphical notation (inspired in part bymusical notation),[10] such as:
thespace-time prism, which shows individuals' possible behavior in time-space given their capability constraints and coupling constraints;
bundles of paths, which are the conjunction of individual paths due in part to their capability constraints and coupling constraints, and which help to create "pockets of local order";
concentric tubes or rings of accessibility, which indicate certain capability constraints of a given individual, such as limited spatial size and limited manual, oral-auditive and visual range; and
nested hierarchies of domains, which show the authority constraints for a given individual or a given group.[11]
While this innovativevisual language is an essential feature of time geography, Hägerstrand's colleague Bo Lenntorp emphasized that it is the product of an underlyingontology, and "not the other way around. The notation system is a very useful tool, but it is a rather poor reflection of a rich world-view. In many cases, the notational apparatus has been the hallmark of time geography. However, the underlying ontology is the most important feature."[12] Time geography is not only about time-geographic diagrams, just as music is not only about musical notation. Hägerstrand later explained: "What is briefly alluded to here is a4-dimensional world of forms. This cannot be completely graphically depicted. On the other hand one ought to be able to imagine it with sufficient clarity for it to be of guidance in empirical and theoretical research."[13]
By 1981, geographersNigel Thrift andAllan Pred were already defending time geography against those who would see it "merely as a rigid descriptive model of spatial and temporal organization which lends itself to accessibility constraint analysis (and related exercises in social engineering)."[14] They argued that time geography is not just a model of constraints; it is a flexible and evolving way of thinking about reality that can complement a wide variety of theories and research methods. In the decades since then, Hägerstrand and others have made efforts to expand his original set of concepts.[15] By the end of his life, Hägerstrand had ceased using the phrase "time geography" to refer to this way of thinking and instead used words liketopoecology.[16]
Schematic and example of aspace-time prism using transit network data: On the right is aschematic diagram of a space-time prism, and on the left is a map of the potential path area for two different time budgets.[17]
Since the 1980s, time geography has been used by researchers in the social sciences,[18] the biological sciences,[19] and in interdisciplinary fields.
In 1993, British geographerGillian Rose noted that "time-geography shares the feminist interest in the quotidian paths traced by people, and again like feminism, links such paths, by thinking about constraints, to the larger structures of society."[20] However, she noted that time geography had not been applied to issues important to feminists, and she called it a form of "social science masculinity".[21] Over the following decades,feminist geographers have revisited time geography and have begun to use it as a tool to address feminist issues.[22]
GIS software has been developed to compute and analyze time-geographic problems at a variety ofspatial scales. Such analyses have used different types of network datasets (such as walking networks,highway networks, andpublic transit schedules) as well as a variety of visualization strategies.[23] Specialized software such asGeoTime has been developed to facilitate time-geographic visualization andvisual analytics.
Benjamin Bach and colleagues have generalized thespace-time cube into a framework for temporaldata visualization that applies to all data that can be represented in two dimensions plus time.[25]
In theCOVID-19 pandemic, time geography approaches were applied to identify close contacts.[26] The pandemic imposed restrictions on the physical mobility of humans, which invited new applications of time geography in the increasingly virtualized post-Covid era.[27]
^InHägerstrand 1983 andKuklinski 1987, Hägerstrand cites the writings ofAlbert Einstein andArthur Eddington ongeneral relativity as inspirations.Physicalist philosopher and sociologistOtto Neurath is cited inHägerstrand 1970. While these ideas are important sources for time-geographicontology, time geography should not be portrayed as exclusivelyphysicalist. Hägerstrand also citedphenomenologistMartin Heidegger andconservationistRachel Carson as major influences, along with numerous geographers (Kuklinski 1987, p. 507). "Hägerstrand wanted to stress the importance of the material aspects of the real world as the basis of life, with an imperative for researchers to take basic constraints into consideration: that natural resources, time, and space are limited... Nevertheless, Torsten Hägerstrand was not a hardcore materialist. His materialism is embedded in a deep concern for the importance of human experiences, reflections, and reasoning for the development of geographical knowledge." (Ellegård & Svedin 2012, p. 18)
Buttimer, Anne; Mels, Tom (2006).By northern lights: on the making of geography in Sweden. Foreword by Torsten Hägerstrand. Aldershot, England; Burlington, VT: Ashgate.ISBN978-0754648147.OCLC63187516.
Lewchanin, Shari; Zubrod, Louise A (July 2001). "Choices in life: a clinical tool for facilitating midlife review".Journal of Adult Development.8 (3):193–196.doi:10.1023/A:1009598425503.S2CID140944093.
Sunnqvist, Charlotta; Persson, Ulla; Westrin, Åsa; Träskman-Bendz, Lil; Lenntorp, Bo (April 2013). "Grasping the dynamics of suicidal behaviour: combining time-geographic life charting and COPE ratings".Journal of Psychiatric and Mental Health Nursing.20 (4):336–344.doi:10.1111/j.1365-2850.2012.01928.x.PMID22591326.
Tani, Sirpa; Surma-Aho, Outi (2012). "Young people and the hidden meanings of the everyday: time-space path as a methodological opportunity".International Research in Geographical and Environmental Education.21 (3):187–203.doi:10.1080/10382046.2012.698077.S2CID144455475.
Adams, Paul Channing (2009).Geographies of media and communication: a critical introduction. Critical introductions to geography. Chichester, UK; Malden, MA:Wiley-Blackwell.ISBN9781405154130.OCLC237788695.
DiSalle, Robert (2011). "Pitholes in space-time: structure and ontology of physical geometry". In DeVidi, David; Hallett, Michael; Clarke, Peter (eds.).Logic, mathematics, philosophy, vintage enthusiasms: essays in honour of John L. Bell. The Western Ontario series in philosophy of science. Vol. 75. New York: Springer. pp. 345–360.doi:10.1007/978-94-007-0214-1_17.ISBN9789400702134.OCLC719361722.
Li, Xia; Kraak, Menno-Jan (August 2008). "The time wave: a new method of visual exploration of geo-data in timespace".The Cartographic Journal.45 (3):193–200.doi:10.1179/000870408X311387.S2CID129750716.
Neutens, Tijs; Schwanen, Tim; Witlox, Frank (January 2011). "The prism of everyday life: towards a new research agenda for time geography".Transport Reviews.31 (1):25–47.doi:10.1080/01441647.2010.484153.S2CID129935266.
Rainham, Daniel; McDowell, Ian; Krewski, Daniel; Sawada, Mike (March 2010). "Conceptualizing the healthscape: contributions of time geography, location technologies and spatial ecology to place and health research".Social Science & Medicine.70 (5):668–676.doi:10.1016/j.socscimed.2009.10.035.PMID19963310.
Raubal, Martin; Winter, Stephan; Teβmann, Sven; Gaisbauer, Christian (October 2007). "Time geography for ad-hoc shared-ride trip planning in mobile geosensor networks".ISPRS Journal of Photogrammetry and Remote Sensing.62 (5):366–381.Bibcode:2007JPRS...62..366R.doi:10.1016/j.isprsjprs.2007.03.005.
