Talk:Three-dimensional space

2d=3d

its said that a 3d object is said just to be several 2d ojects stacked ontop off oneanother to create thickness butt how can several 2d planes wth a thickness of 0 add up to be somthing that had thickness and thuss create a 3d object?

Because you're stacking together an uncountably infinite number of 2D objects. Infinity times 0 is not necessarily 0 (technically, it's undefined). Crispy (talk) 00:43, 26 March 2009 (UTC)

3d networks as spaces

This article may be improved by adding a mention of Graphs (ie networks of nodes or connectivity information) that have dimension of 3 through Dimensional_analysis. This type of structure is an alternative to the axis-based way of thinking about the dimensionality of space in the universe. See also Fractal dimension on networks. Danwills (talk) 03:51, 12 November 2008 (UTC)

The article would benefit from a link to Dimensional analysis, and but I don't think this application of dimensional analysis belongs in the article. --Una Smith (talk) 01:39, 2 July 2009 (UTC)

SVG Drawing

The article's first picture is badly in need of proper formatting to get rid of the "jaggies". I suggest conversion to SVG. - KitchM (talk) 21:44, 10 October 2009 (UTC)

Hypersphere

This space is above (in dimension) the sphere or the 2-sphere:

If the 2-sphere lives in her own but also can be viewed embedded in $\mathbb{R}^3$ and is defined as $p\in\mathbb{R}^3$ such that $p=(x,y,z)^{\perp}$ and $x^2+y^2+z^2=1$.

And the hypersphere -very well known to a real topo-geometer- is: a set consisting of point in the 4-dimensional euclidean space $\mathbb{R}^4$ which are equidistant to the origin, usually we take distance one. In other words: $p\in\mathbb{R}^4$ such that, if $p=(x,y,z,t)^{\perp}$ then $x^2+y^2+z^2+t^2=1$. So, i don't know why unsavvy geeks think they know and write lies, and only producing that math look stupid... well, that it seems a law in these wikiplaces. --kmath (talk) 22:28, 25 September 2011 (UTC)

Anyway not all is lost: check 3-sphere for education--kmath (talk) 22:37, 25 September 2011 (UTC)

4D Shadow

Just as a 3D object casts a 2D shadow (kinda) should it be noted that a theoretical 4D (not time) object would cast a 3D shadow? (kinda.) or is this all too original researchy? 74.132.249.206 (talk) 11:13, 15 October 2011 (UTC)

That wouldn't be about 3D, it would be about 4D. And there's already something at Four-dimensional space saying that. Dmcq (talk) 11:59, 15 October 2011 (UTC)

As a submersions of a 4-manifold into a 3-manifolds, in fact locally watching close the case R^4->R^3, worth to know, thinka--kmath (talk) 18:29, 31 October 2011 (UTC)