Dear Bruce,
I don’t like to rain on your parade… but here are a couple of comments on your observations.
[MW>] <snip>
From my point of view – this seems more or less an impossible task – unless we are creating consensual agreements and stipulative definition systems. We can’t define “continent” in a universal or invariant or context-independent way. We are forced to define the term within the bounds of some social convention or agreement – something that “works in a particular professional domain or social context.”
[MW>] As I was sailing up the Devon coast the other day I remember looking at a particular lump of land/rock just offshore and wondering when a rock was big enough to be called an island.
I’ve been exploring the notion of ambitious computer-mediated projects that define concepts like “political issue” and “region of applicability” in some precise way. If we want to define an ideal form of cybernetic/electronic democracy or self-governance – we would want exact definitions of “regions” – maybe as legal entities, maybe as consensual agreements – so that we could put an issue like “global warming” or “climate change” in the right “region” – and also put a much more local issue like “where to put the stop sign” in the right bounded region.
[MW>] Most of these things are defined by fiat. There are even different choices made in different countries about where the boundary between land and sea is.
I’d like to see all of this mediated through GIS and “longitude and latitude” – which as somebody mentioned in the call, is defined in floating-point numbers – “accurate to within a specific number of decimal places”.
[MW>] It sounds as if you have the naive view that if two people are talking about the same Lat and Long they are talking about the same place. Sorry, not necessarily so. Lat and Long are relative to some ellipsoid, and historically different countries have picked different ones for their national and world maps, with significant differences. In the oil industry (where I come from) it is desirable to know the position of a drill bit in 3D relative to the surface with some precision, considerable care is taken selecting the most appropriate ellipsoid for where the drilling is taking place (which may be hopeless elsewhere). The good news is that since the early nineties with the advent of GPS most maps and charting systems have used WGS84. But you still need to check.
Regards
Matthew West
http://www.matthew-west.org.uk
+44 750 338 5279