This knot have a special relation with the two bridge knots in three sphere S 3.

这种纽结同三维球面中的双桥纽结有着特殊的联系。

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In three dimensions, a sphere is likewise symmetrical under all rotations about its center.

在三维空间中，球同样是中心对称的。

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The equation smoothes out the irregularities of an object, transforming it mathematically into something that looks like a uniform three-dimensional sphere.

这个方程能消除物体间的差异，并能把物件精确的变形为一个统一的三维球体。

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The equation smoothes out the irregularities of an object, transforming it mathematically into something that looks like a uniform three-dimensional sphere.

ECONOMIST: Proof of the truth of the Poincar�� conjecture

His conjecture, made in 1904, was that in this four-dimensional world, all closed three-dimensional surfaces that are simply connected could be transformed to look like a three-dimensional sphere.

ECONOMIST: Proof of the truth of the Poincar�� conjecture

But Denmark has been boldest in trying to draw all three Baltic countries into the western sphere, military as well as commercial.

ECONOMIST: Nordic security: Getting better | The