According to the first chapter of the book of Genesis of the Bible:
Evening or dark + morning or light = one complete day.
According to the science of electricity:
An atom with an odd number of electrons is negative.
While an atom with an equal number of electrons is positive.
When a stream of negative atoms and a stream of positive atoms come together in the clouds during a storm; they annihilate each other in a burst of light called lightning.
When contained within a battery they become the electric current, as they mingle together, that powers our electronic devices.
Our world, indeed, the entire universe is based and built upon a positive negative model.
Positive always gives.
Negative always takes but gives back as well.
Man is positive because he gives to woman.
Woman is negative because she takes what man gives to her then gives it back again.
As in the Wedding Song (one of my favorite songs a cousin of mine sang at my wedding):
Woman takes her life (or strength – my interpretation) from man and gives it back again.
Not only does this principle apply in a marriage but it also applies in friendships as well.