Dear Matt Visser,
Maybe, complex numbers are already the minimal extension of the rational numbers? Anyway, already the extension of the natural numbers to the integer numbers may be interpreted as a trick to allow convenient calculation without shift operations.
In principle, 19th century physics could also be formulated without negative and complex numbers. This is not just an idea that I adopted from other engineers; it was also admitted by Pauli (cf. Der Pauli-Jung-Dialog). Don't get me wrong, I don't deny the practical necessity of using complex calculus.
While your superb essay confirms your excellence, you and virtually all physicists might nonetheless have failed to get aware of a trivial trifle; the use of complex calculus in physics and technology has been based on Heaviside's trick to attribute zeros to the not yet existing future and split the continued. This implies fourfold redundancy due to omission. Well, one can easily avoid the dilemma by following Einstein and Hilbert and denying the distinction between past and future. However, this way the logic consistency gets lost. Instead I prefer using complex calculus properly, step by step.
So far, nobody could show in what I am wrong when I state that cosine transformation of measured data is as good as their Fourier transformation.
MPEG demonstrated, it actually works. Therefore, I doubt with all unbelievable consequences that ict and ih are absolutely indispensable for physical reasons. Again, don't get me wrong. I don't claim that they can actually be replaced.
Faithfully yours,
Eckard Blumschein