The "Math Horizon" image shows the projection of a sphere in four-space that has a single point of self-intersection at the center of the image. Bands on the surface are removed to help see the structure of the projection. Here, the image is being rotated in three-space around a vertical axis.

The "Math Horizon" image shows the projection of a sphere in four-space that has a single point of self-intersection at the center of the image. Bands on the surface are removed to help see the structure of the projection. Here, the image is being rotated in three-space around a horizontal axis.

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