Since they are quite good opposites, the smart people who figured how all this worked decided on that and we stuck with it based on convention. Like how “Alice” and “Bob” were used in Computer Science since they are generic names beginning with the first two letters of the alphabet (it could have easily been any A and B name, but this is the convention!)
Similar can be said for magnets, the “North” and “South” poles are good opposites. If other people started the trend, we could have easily gotten something else, but this is the convention.
Since they are quite good opposites, the smart people who figured how all this worked decided on that and we stuck with it based on convention. Like how “Alice” and “Bob” were used in Computer Science since they are generic names beginning with the first two letters of the alphabet (it could have easily been any A and B name, but this is the convention!)
Similar can be said for magnets, the “North” and “South” poles are good opposites. If other people started the trend, we could have easily gotten something else, but this is the convention.
Another example, the use of “abc” and “xyz” in Mathematics. Or “ijk” as index variables when programming loops.