Dear Richard the case you describe clearly belongs to the category of “fiat spatial objects” as defined by Smith and Varzi, as opposed to “bona fide spatial objects” i.e. common physical objects. Smith & Varzi introduce this concept in several papers of theirs - I am sending you, separately, a copy of one of these papers - i.e., loosely speaking, objects defined by artificial rules such as a law, a treaty, a cadaster definition, lines on a map etc. They remain fixed until some new regulation or a natural event changes their boundary.
The latter is the case, for instance, of the Alps border between Italy and Switzerland, which is currently being changed by global heating causing a large glacier to melt, altering the border line. As a consequence this has “moved” a mountain hut from Italy into Switzerland without any change in the border treaties nor, of course, any physical removal of the hut. I believe that at present the hut is partly in Italy and partly in Switzerland and it is slowly "going abroad", so giving diplomats the time to rearrange the border definition to keep into account the glacier change. People working in the hut have jokingly asked if they should use their passport to go to the lavatory. Apart from the above anecdote, fiat spatial objects are relatively stable in time although they may change at intervals. As such they are instances of E92 Spacetime Volume and have a 4-dimensional nature, one dimension along time and three along space. I will also send you a paper of mine with some suggestions on how to deal with this complexity in simpler cases. In sum, a space-time volume is a blob in the 4-dimensional space; if you like the image, E92 resemble a potato. Fiat spatial objects are a sort of approximation to this, as they remain (relatively) constant in time, with a possible discontinuity at fixed instants e.g. when a law (a treaty, whatever) changes their border definition. This act “slices" the potato into “cylinders”. For example the USA is a fiat object (it is also a number of other things, but that's another story). Ignoring small changes due to erosion of its coasts, it did not change since August 21, 1959 when Hawaii became a State; the last previous change being in January of the same year when Alaska was also proclaimed a state. Although changes occur so slowly, there is no doubt that they occur, and therefore make USA a Spacetime Volume. Best regards Franco Prof. Franco Niccolucci Director, VAST-LAB PIN - U. of Florence Scientific Coordinator ARIADNE - PARTHENOS Piazza Ciardi 25 59100 Prato, Italy > Il giorno 15 mag 2018, alle ore 18:13, Richard Light > <[email protected]> ha scritto: > > Hi, > > Further to my previous question, and following a trawl through CRMgeo, I have > another one. :-) > How should one represent an administrative unit (such as Burgess Hill, being > the entity which is managed by Burgess Hill Town Council) using the CRM? > It's not a place (certainly not as defined in E53_Place); nor is it an > E74_Group. It's the result of collective human actions and decisions. > Administrative units have a temporal dimension, so should be a subclass of > E7_Activity. They have physical extent (possibly changing over time). There > are different types of administrative unit, some of which are specifically > relevant to cultural heritage studies: registration districts; census > 'pieces'. > Administrative units are created, destroyed, merged with other administrative > units, etc. They have relationships with other administrative units, > both generic containment/adjacency ones, and also more specific 'administered > by' ones. > > Many local museum collections cite administrative units when recording > information about the provenance of objects ("metalworking tools from Little > Potton"). They are central to much genealogical research. > > What do others think? Out of scope? > Richard > -- > Richard Light > _______________________________________________ > Crm-sig mailing list > [email protected] > http://lists.ics.forth.gr/mailman/listinfo/crm-sig
