Why 5, 8 and 24 Are the Strangest Numbers in the Universe: Scientific American

Why 5, 8 and 24 Are the Strangest Numbers in the Universe: Scientific American: "If string theory is right, the octonions are not a useless curiosity; on the contrary, they provide the deep reason why the universe must have 10 dimensions: in 10 dimensions, matter and force particles are embodied in the same type of numbers—the octonions."