[Edu-sig] Update from Urner

[Arthur Siegel]

>Nevermind if it looks more like lit than like math -- we can > always
explain that philosophy is the interface between >these two (has been for a
long time).

In fact a couple of references by you and others on the EDU-SIG list have
gotten me into looking at Wittgenstein.

Turns out projective geometry - at least by way of analogy to
language issues - is central to his thought.

Projective geometry is something I never encountered in
school - found it by myself mostly in dusty old books.  And become
fascinated by it.

PyGeo was built most fundamentally to help myself visualize
projective geometry concepts.

The PyGeo page starts by showing-off a five-point conic construction - a
fundamental projective geometry concept.

The duality of points and planes in three-space spun
me about when I was getting at it. Can't try to explain
the excitement I got from getting some grasp of that concept.

The fundamentals of projective grow out of what were originally artistic
investigations.

Where, why and when was all this purged from the the curricula?

Looks to me like it was core, standard stuff early in the century?