killer-g, It's good to know you have interest in physics and you are thinking a lot...do carry on.

One day you may realise that in this world, which is apparently chaotic and uncertain, physics is one of the vehicles in the quest towards simplicity and clarity. So, any function established between variables would come in the domain of physics only if it is defining a certain physical activity or phenomenon. Two un-related phenomena, which do not have any practical or theoretical presence in relation to each other, if combined through maths, doesn't make anything simple. So, that's not physics.