One problem with cross product, it only exists in three dimensions. | Hacker News

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Koshkin on Dec 7, 2017 | parent | context | favorite | on: Down with Determinants (1995)

One problem with cross product, it only exists in three dimensions.

wolfgke on Dec 7, 2017 | [–]

No, it exists in dimension 3 and 7:

> https://en.wikipedia.org/wiki/Seven-dimensional_cross_produc...

EDIT: Nore precisely: A common way to axiomatize the cross product yields a cross products exactly in dimension 3 and 7.

sixo on Dec 7, 2017 | [–]

A wedge product exists in all dimensions but only in 3 & 7 is it identifiable with a unique vector.

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