I hate to be that one guy, but... ErM aKsHuLy, the concept of a number that, when multiplied by itself, would be negative, has been around for a while. If I remember right, when this one guy brought forward the idea, it was considered ridiculous, and Descartes called them "imaginary" and the term stuck. So, they didn't like the idea of it for a while, but imaginary numbers actually are quite useful in a lot of areas like engineering.☝️🤓