Get a lamp. And a football (soccer ball, for you Americans).
Turn on lamp. Hold football some distance from lamp.
Note that the side of the football facing away from the lamp is dark (assuming no other light source).
That's night.
As the football (earth) rotates the dark part comes round so that part is lit up by the lamp (sun).
That's day.
Sorry... But I think you got me all wrong!
I’m not referring to the surface of the earth being hit by the sun.
But rather on the SKIES during night time.
Okay, I have a lamp. And a football (soccer ball, for the Americans), inside a room.
Turned the on lamp. And the room is fully lit.
Held the football some distance from lamp(sun).
Saw that the wall on the dark side of the football (earth), has the ball’s shadow.
Brought the ball closer to the lamp, and it created a dark ambiance on the other side room but not pitch-black. And less than half of the room is dark.
Though the ball is bigger than the lamp in this experiment, the lamp still threw wider light that escaped beyond the ball’s circumference. Thus still, illuminating majority of the room.
Took instead a cellphone’s flashlight to illuminate about eighty percent of the ball’s surface... And viola!!! I was able to control the light not to leak beyond the ball’s circumference and making the other side of the room pitch-black!
Now, what do we make out of this???
Is our sun rather smaller and closer?