Unfortunately this article repeats the same misconceptions about imaginary/complex numbers and their role in physics as most popular articles do. Imaginary num

Unfortunately this article repeats the same misconceptions about imaginary/complex numbers and their role in physics as most popular articles do. Imaginary numbers were invented too early, that is why the usual explanations following the historical development are so mysterious. The notion of Sqrt(-1) does not help to explain what they actually are. In fact imaginary "numbers" are not numbers. They cannot be ordered by size. Imaginary "numbers" are also not vectors in the geometrical sense. This is because you can multiply two geometrical vectors and get a scalar as result (scalar product). But if you multiply two imaginary "numbers" you get another imaginary "number", so this is different to a geometrical vector. In fact imaginary "numbers" are transformations or operators, because they multiply like operators/matrices and they act on geometrical vectors like rotation matrices. Group theory makes all that very clear: Imaginary "numbers" are just the elements of the group SO(2), the group of rotation operations in 2D (multiplied with a scaling factor). Regarding quantum mechanics what the scientists showed is, that a theory which does break SO(2) rotation symmetry (so called real quantum mechanics) does not describe nature. That should surprise no one as the SO(2) symmetry (or equivalently called U(1) symmetry (https://en.wikipedia.org/wiki/Circle_group#Isomorphisms https://en.wikipedia.org/wiki/Circle_group#Isomorphisms)) is necessary to describe conservation of the electric charge. (https://en.wikipedia.org/wiki/Charge_(physics)#Abstract_definition https://en.wikipedia.org/wiki/Charge_(physics)#Abstract_defi...)