“…In terms of the Cartesian notation, ⟨q, e i q⟩ = 0 where e i = {i, 𝑗, k}, (12) and thus, we have that quaternions can be described as a four-dimensional real vector space. In the polar notations ( 5) and ( 6), we respectively obtain ⟨q, 𝜔q⟩ = 0, and ⟨q, q𝑗⟩ = 0, (13) and thus, the quaternions are described as two-dimensional real vector spaces. Considering that the space had originally four dimensions from (12), this conclusion seems to contradict our expectations.…”