We typically draw the real and complex number lines orthogonal to one another, forming a plane. The big question is: does there exist a meaningful type of number line that we could use as an axis orthogonal to that plane? (I'm guessing no, but let's have some fun.)
I suppose we could use any type of number line we wanted, but I'm looking for the most "natural" choice. So let's hear your wildest guesses for what the z-axis could be.
