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Monday, 14 December 2009

Does time have at least two dimensions?

This entry to my blog should be seen as thinking out loud (tol), work in progress or leaveit out lad (lol).

Police incidents, crime, police patrols and other police activities can be mapped because they happen at locations in space and geography. These locations are described by two co-ordinates - x and y, longitude and latitude, easting and northing, etc. Location therefore has two dimensions. If height is added there is a third dimension. Spatial statistics are based on analysis of distances between objects in real or conceptual space. Spatial auto-correlation is based on the observation that objects that are close to each other share similar conditions. This is true of weather, house prices, health to name three. Crime and police incidents are strongly spatially autocorrelated. I will explain why in later blogs.

Now time is traditionally seen to be linear and one dimensioned. There is also temporal auto-correlation based on the fact that events close in time share similar conditions. One of my colleagues in UCL Centre for Advanced Spatial Analysis (CASA), Fabian Nuehaus recently talked at a CASA seminar and reminded me that life is full of rhythms and cycles. That means that for instance Sunday morning is closer in conceptual time space for autocorrelation purposes to next Sunday morning than the next morning (Monday, as long as it is not a bank holiday). Equally 6pm in closer in rhythm space to the next 6pm than the next 6am. This means that time has at least two dimensions for analysis purposes. Can we map it and use spatial statistics to analyse it?

1 comment:

  1. You should definitely check out:
    Couclelis, H and Liu, X (2000) The geography of time and ignorance. 4th international conference on integrating GIS and environmental modelling (GIS/EM4). Banff, Alberta, Canada, Sept 2-8. 2000.