Trong vật lý hiện đại, người ta thường xét không gian trong mối liên hệ giữa ba chiều đó và chiều thứ tư, chiều thời gian và hình thành nên không-thời gian bốn chiều | CONCEPTS OF SPACE AND TIME 15 Table Main characteristics of the relative space-time view. Space and time are viewed as coexistence connection or togetherness relationships between changes and events Neither space nor time exists independently a Applied in studies of forms patterns functions rates and diffusion a Topological models a May involve non-Euclidean space or linear time a Process-based scenario a Analysis based on a process study Figure a New Zealand in absolute space b New Zealand in 1953 time space c New Zealand in 1970 time space. Reprinted by permission of Oxford Press. Source Gatrell 1983 p. 111 16 OBJECT-ORIENTED DESIGN FOR TEMPORAL GIS CHOOSING THE VIEW FOR A GIS Harvey argues that we have frequently assumed a particular spatial language . absolute view or relative view to be appropriate without examining the rationale for such a choice Harvey 1969 p. 161 . After all we should not discriminate one over another. They are complementary. As Peuquet 1994 points out the absolute view requires some sort of measurements referenced to a constant base implying non-judgmental observation. The relative view on the other hand involves interpretation of processes and the flux of changing patterns within a knowledge domain. However a question still remains about integrating absolute and relative views. How can we have both perspectives placed in the same representation Perhaps the answer lies in time geography Owing to the circumstances under which. Time Geography has been developed its contents and its applications to date there is a great danger that Hagerstrand s time geographic framework will be mistakenly construed as nothing more than a planning tool. On the contrary .the potential usefulness of the of much greater range Pred 1977 p. 213 . Consequently this book proposes that the concepts of Time Geography should be exploited by GIS to capture the absolute space-time view as well as the relative space-time view. The next section
