Complex numbers are just a mathematical convention. You can't have (-1) apples so you could say negative numbers are equally weird. Complex numbers are just wei

Complex numbers are just a mathematical convention. You can't have (-1) apples so you could say negative numbers are equally weird. Complex numbers are just weird in different way. Complex numbers are weird because we start with the square root of a negative number and then it turns out the same rules you invented for that actually then present rotations in a plane as well. That Sqrt(-1) is isomorphic with a 90 degree rotation on a plane of a vector length of 1 never seizes to amaze me. It's not a trick - all the math works and it's fairly obvious once one does all the math. But still it feels like a magician pulled a rabbit out of his hat each time I think about it. This rotation aspect is one of the main reasons why imaginary numbers are used so much in physics.