In quantum mechanics,

the basic wave function has no physical meaning or significance. However,

represents the probability distribution of particle in a given space.
Probability

So when you will put a position and a time in

function, it will give you the probability of finding the particle at that particular position and at the given time.
I can't see the screw (if you'll pardon the expression), so I don't know a thing about it, and can't answer the question. There's no given information in the question.
I think sun because:
-Sun is the strongest force. It has the largest gravitational pull.
-the moon and Earth both depend on the Sun for different things.
-The sun is not greatly affected by the Moo or the Earth.
:)