>>11988021
you clearly never worked with second-order linear differential equations, which are essential in physics and in wave equation in particular. Using [math] e^{i\theta} [/math] saves you so much trouble when integrating/differentiation/doing algebra on it than sine and cosine.
>Made up bullshit
congrats, bro, so are all other numbers. One way to rigorously define natural numbers is through fucking empty sets.
https://en.wikipedia.org/wiki/Set-theoretic_definition_of_natural_numbers
Why aren't you flipping out on that, but complex numbers are a problem. Ah, let me guess, it's the word "imaginary". Are rational numbers actually rational? It's just stupid semantics.
>Exactly what does the imaginary unit mean?
It is an element of the set [math] \mathbb{C} [/math] with the property [math] i^2 = -1 [/math]. Now you can define this set using the algebraic definition in >>11987820.
>What does I in the Schrodinger equation mean physically?
what does force mean physically, you genius? Can you feel it? You feel acceleration, but that's it. The concept of force is completely useless in non-classical physics and even in some classical situations it is much more desirable to talk about energy and momentum, which are even more abstract than force.