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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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.

他在1904年就提出猜想：在四维空间，所有单连通的封闭三维面都能转化为一个三维球体。

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Create three cylinder objects and offset them behind our sphere.

在球的后面创建三个柱体，位置如图。

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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

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

Speaking of batteries, a new lithium-ion battery developed by USC utilizes nano-sphere technology to store three times more energy while cutting charge time down to just 10 minutes.

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