More geeky math stuff:
Quaternions: upping the dimensions of complex numbers
The basic idea behind quaterions is: we see some amazing things happen when we expand the dimensionality of numbers from 1 (the real numbers) to 2 (the complex numbers). What if we add more dimensions?
It doesn't work for three dimensions But you can create a system of numbers in four dimensions. As with complex numbers, you need a distinct unit for each dimension. In complex, those were 1 and i. For quaternions, you need for units: we'll call them "1", "i", "j", and "k". In quaternion math, the units have the following properties:
1. i² = j² = k² = ijk = -1
2. ij = k, jk = i, and ki=j
3. ji = -k, kj = -i, and ik=-j
No, that last one is not an error. Quaternion multiplication is not commutative: ab &neq; ba. It is associative over multiplication, meaning (ab)c = a(bc). And fortunately, it's both commutative and associative over addition.
Huh.