Possibilities

In the observable world that we inhabit on a daily basis, any given object typically has separate, well-defined sets of states: it either is or it isn’t. Everything else is merely variations on that theme.

In the domain of quantum mechanics, where effect can sometimes precede cause – and other such wacky constructs – states can actually be something quite a bit less defined: something in between. Instead of a ball being red or blue, for instance, it can be purple. But not just any one shade of purple: It can be more reddish, more bluish, or anything in between – at the same time.