  To most physicists, quantum mechanics must embrace the imaginary number i =
square root of minus one is at least a common belief if not a mystery. We use
the famous example pq -qp = h/(2 pi i) to demonstrate the possible elimination
of i when constructing this noncommutative relationship. We then discuss the
role of i in the formulation of Schroedinger's wave equation. Common to the
original development of these two quantum theories was the use of complex
exponential to represent the fundamental variables (i.e., p, q, and the wave
function). Understanding this complex function from the right perspective, as
we suggest in this essay, removes the mysteries surrounding the complex nature
of quantum mechanics.
