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> You might think that life in a three-dimensional torus

The author is talking about toroidal space which is confusing because a normal torus is a three dimensional thing with normal Euclidean geometry.

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That's not really correct. A torus is a 2-dimensional manifold that can be embedded into 3-dimensional Riemannian space. The author of the article is correct talking about a three dimensional torus as it's defined as S^1 x S^1 x S^1. You can also check the wikipedia page (https://en.wikipedia.org/wiki/Torus) that defines an n-dimensional torus in the same way.

True, but "a three-dimensional torus" is a doughnut.

donut is to torus as ball is to sphere, is that what you mean?

Thank you for explaining this, something was obviously missing. Living on a 7 meter torus would be challenging for many reasons, but seeing many cylinders or images of yourself wouldn't be some of them.

Exactly so. I wondered what the OP was talking about. Some mathematically-inclined friends on Twitter enlightened me.

https://twitter.com/lproven/status/1564613978155802631

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