>> Gloranthan compasses - You actually need three different compasses to >> pin your location exactly, two will tell you that you are somewhere on
> Not in any geometry I'm familiar with, Euclidean or otherwise. Not even if
> you were willing to abandon the concept of the line as the shortest
> distance between two points. One of the fundamental axioms of any geometry
> is that two (different) straight lines meet at most once.
On the surface of the real world spherical geometry applies, a 'straight line' is a great circle, and great circles meet -twice-.
Andrew
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