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True or false: the bottom can be moved to Cone (disambiguation). 66.245.11.49 23:26, 11 May 2004 (UTC)[reply]

It certainly looks as if this is more than a disambiguation page.--Henrygb 10:14, 5 Jul 2004 (UTC)
Surely cone (disambiguation) must cover all meanings of "cone", not just the mathematical ones; so that page should be the same as this article.
Perhaps you meant to suggest that the mathematics meanings should be moved to a separate cone (mathematics) disambiguation page?
Jorge Stolfi 06:12, 12 February 2006 (UTC)[reply]


The geometric definition is not general enough

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Hi, I would like to ask something about the geometric definition of cone. Right now it's just connecting one point to the points of a set X. In general, one takes a space A, and a disjoint space B with a subset X, and connects all the points of A with X. If you agree with this it would be helpful for the discussion of singular quadrics and hermitian forms. Evilbu 2006-02-12 01:42:15 (UTC)

There is no page for that concept that I know of, although conic solid is a special case.
However, the name "cone" seems more appropriate for the case when A is a point. When A and X are arbitrary sets, calling the result a "cone" seems quite weird, like redefining "sphere" to include cylinders but not cubes.
By the way, your definition seems to be garbled. You probably meant "A and B are subsets of the same affine space X" and then you take the union of all segments with one end in A and the other in B. Correct?
All the best, Jorge Stolfi 06:12, 12 February 2006 (UTC)[reply]

Oh no no, I meant A and B are subspaces of the same projective spaces, and X is a subset of B, connect all points in A with those in X. An example :every singular quadric is a cone, with as space A its space of singular points, and the set X is some nonsingular quadric in some complementary space.Evilbu 10:36, 12 February 2006 (UTC)[reply]

OK. But shouldn't that be an affine space, rather than a projective space? (Projective spaces have trouble with line segments, right?) Or do you mean "connect with a straight line" rather than "connect with a line segment"? Perhaps this concept could be an article projective cone then? Jorge Stolfi 11:28, 12 February 2006 (UTC)[reply]

I see the trouble. I never meant anything about line segments. Just taking the entire line, and you don't care about between or higher or anything (you can't actually as the theory should also apply to finite fields and complex numbers). Yes, that projectice cone is a good idea.

So I did that. When you click on that link of projective cone you made yourself you should come on that page. Please take a minute (it is a stub) to read it and what should we do now. Is there a risk of confusion now? Can it be linked to here?Evilbu 13:46, 14 February 2006 (UTC)[reply]

I have linked the article from cone, and made some changes of notation and markup. By WP rules, the first paragraph should be a workable definition (fixed). The two subspaces must belong to the same space otherwise the line is not defined (fixed). It seems that the definition can be simplified to "the union of R and all lines joining a point of R to a point of A". Also what happens if R is empty - should we get empty, or A? Jorge Stolfi 16:07, 14 February 2006 (UTC)[reply]

Let us continue this debate on http://en.wikipedia.org/wiki/Talk:Projective_cone Evilbu 16:17, 14 February 2006 (UTC)[reply]

Requested move

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The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: moved. Jenks24 (talk) 07:03, 6 August 2012 (UTC)[reply]



– The geometric cone is clearly the primary usage here, so Cone should go to the geometric figure. Almost all other uses of cone derive from that one. If you look at traffic, the geometric figure gets 3x the hits: Cone (geometry) (68k) Cone (21k) --Obi-Wan Kenobi (talk) 22:49, 24 July 2012 (UTC)[reply]

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.