Talk:Three-dimensional space

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 Field: Geometry


It's said that a 3D object is several 2D objects stacked on-top of each-other to create thickness but how can several 2D planes with a thickness of 0 add up to be something that has thickness and thus 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[edit]

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[edit]

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)


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)
Huh? Hypersphere refers to any number of dimensions, though n-sphere is a more common synonym. Indeed the former is sometimes restricted to 3 or more dimensions, but here we already state explicitly that n = 2. Double sharp (talk) 13:20, 28 August 2013 (UTC)

4D Shadow[edit]

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? (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)

Undid Vandalism, but ...[edit]

I undid some clear vandalism, but have no idea what the article is supposed to look like. I just did this 'en passant' and have other things I must do. Can some Samaritan look this over? DeepNorth (talk) 14:16, 11 November 2012 (UTC)

Merger proposal[edit]

This article should be merged with space as that article is also explicitly dedicated to three-dimensional space.Rgdboer (talk) 22:26, 5 November 2013 (UTC)

Nah, space focuses more on space in physics, that is, the spacetime with time held constant. This page is about a mathematical ideal, does not put physics and reality into account. In mathematics there are 4-dimensional space or n-dimensional, this page is for n=3. We collects its mathematical property, insights and geometries here. -- (talk) 20:47, 28 November 2013 (UTC)
I propose that we add a "for physical space, see space." redirect (something like that) and fix the leading paragraph, ie. put the description on physics a little bit lower than the mathematical description.
A section and paragraphs on the significance of 3-dimensional space in physics, and a redirect to space for detailed article. -- (talk) 20:57, 28 November 2013 (UTC)
Really late oppose, but I don't want this merged. I have the same reasons as "", in that this is a mathematical... thing. For example, four-dimensional space doesn't focus at all on the effects of physics, just a mathematical... thing. Pikachu Bros. (talk) 17:36, 19 March 2014 (UTC)

Yes, I see your point: parts of the other page having reference to physicality would not apply to this page. The WP:namespace logic is clear, and have taken down the merger tags. Thank you for clearing that up; three dimensions need not be materialized.Rgdboer (talk) 02:08, 24 March 2014 (UTC)