It might be expressed differently, but the concept of addition seems very fundemental, and additive inverses (negative numbers) are a very real part of addition.
> It's silly to think that the sqaure root of negative one is something real to be discovered
If we assume the aliens also have a need for multiplication, combining it with multiplication we get polynomials, and to factor polynomials you need complex numbers.
Besides, if they think of quantum mechanics they'll surely need some way to express what we call the complex numbers too.
Even if they don't think of them as "numbers", they'll absolutely discover analogous concepts and theorems.
"They have the concept of "minus", which is just another way of adding with a negative."
You have chosen to generalize it into the anstract concept of negative numbers. That doesn't mean that negative numbers are a fundamental truth about nature to be discovered.
Think about it like functional programming. Is that discovering some natural law of computing? Or is it inventing a new way to express computation? Of course it must be the latter, because you can compute anything without the use of functions.
It might be expressed differently, but the concept of addition seems very fundemental, and additive inverses (negative numbers) are a very real part of addition.
> It's silly to think that the sqaure root of negative one is something real to be discovered
If we assume the aliens also have a need for multiplication, combining it with multiplication we get polynomials, and to factor polynomials you need complex numbers.
Besides, if they think of quantum mechanics they'll surely need some way to express what we call the complex numbers too.
Even if they don't think of them as "numbers", they'll absolutely discover analogous concepts and theorems.