Talk:Direction (geometry)

From Wikipedia, the free encyclopedia
Jump to: navigation, search

vectors are defined by the magnetude and the direction

               ----------->   ( this dotted line represent a vector going to the right)
To the right of what? Which way is "to the right"?
I know it's "obvious" for someone sitting in front of the computer screen, but it's not so obvious in mathematics. You must define first one direction which you'll relate other directions to. --Sasq777 (talk) 13:34, 9 February 2010 (UTC)

symbolic/mythological relevance of the directions[edit]

is this appropriate to add? i have a lot of research together and am willing to get more.

--Harlequence 07:45, 20 May 2007 (UTC)

Do you mean mythological associations for the several Cardinal directions? I am not aware of any mythical attachment to the bare concept of direction. Eldereft 14:00, 20 May 2007 (UTC)

The picture's caption makes absolutely no sense whatsoever. Please consider rewording.

Absolute direction? Imprecise definitions.[edit]

Direction is the information contained in the relative position of one point with respect to another point without the distance information.

It might be true for a plane or Euclidean space, but what about elliptical/spherical surface/space? When two points on a sphere are the antipodal points, there are infinitely many ways to connect the two points by "straight lines" [which for the spherical surface are the great circles passing through that two points]. Which one of those lines define a direction then? They're all equal, but each in different direction [starting from one pole].

Directions may be either relative to some indicated reference (the violins in a full orchestra are typically seated to the left of the conductor), or absolute according to some previously agreed upon frame of reference (New York City lies due west of Madrid).

How is the other example different from the first? How is it "absolute"? I see it still relative: to the "previously agreed frame of reference".

Direction is often indicated manually by an extended index finger

Is this article really about geometry? Or maybe "common-sense intuitions"? --Sasq777 (talk) 13:46, 9 February 2010 (UTC)