[FoRK] Succinct Trig

James Tauber < jtauber at jtauber.com > on > Wed Jul 5 20:25:45 PDT 2006

>> And it's hardly a *topological* generalization. Topological   
>> generalizations ignore notions like that of a normal.
>
> In the topology of manifolds, you have vectors that
> are normal to generalized surfaces.

Only if you define a metric on the manifold. Manifolds in general  
need not have a notion of normals. And even manifolds are richer than  
mere topological spaces, so the notion of a manifold (much less an  
inner product) disappears under topological generalization.

The only concepts that survive topological generalization are  
topological properties (i.e. those that are only based on the choice  
of open sets) such as connectedness, compactness, etc.

James

More information about the FoRK mailing list