Editing Talk:1248: Sphere
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This "a sphere is a surface and has no surface" is too much nitpicking. Wikipedia (http://en.wikipedia.org/wiki/Sphere) talks about calculating the surface area of a sphere. I think "surface of sth" is not very rigorously defined. Often two dimensional manifolds are called surfaces, and a sphere is one, and the surface (different meaning) of the earth is roughly a sphere. What a sphere doesn't have is a border. [[User:Peter|Peter]] ([[User talk:Peter|talk]]) 11:54, 8 August 2013 (UTC) | This "a sphere is a surface and has no surface" is too much nitpicking. Wikipedia (http://en.wikipedia.org/wiki/Sphere) talks about calculating the surface area of a sphere. I think "surface of sth" is not very rigorously defined. Often two dimensional manifolds are called surfaces, and a sphere is one, and the surface (different meaning) of the earth is roughly a sphere. What a sphere doesn't have is a border. [[User:Peter|Peter]] ([[User talk:Peter|talk]]) 11:54, 8 August 2013 (UTC) | ||
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The is trapped on the surface of this sphere, since you can walk on it forever, without ever leaving it[[User:Oscar|Oscar]] ([[User talk:Oscar|talk]]) 12:20, 8 August 2013 (UTC) | The is trapped on the surface of this sphere, since you can walk on it forever, without ever leaving it[[User:Oscar|Oscar]] ([[User talk:Oscar|talk]]) 12:20, 8 August 2013 (UTC) |