* Earth's Rotation: Our planet spins on its axis, completing one rotation roughly every 24 hours. This rotation is what causes day and night.
* Perspective: As the Earth rotates, different parts of the planet face the sun. When your location faces the sun, it's daytime. As the Earth turns, your location moves away from the sun, causing it to appear to set.
* The Horizon: The horizon acts as a reference point. When the sun appears below the horizon, we perceive it as setting, even though it's still shining brightly.
Imagine this: Stand still and watch a friend walk past you. From your perspective, your friend appears to move, even though you are standing still. It's the same with the sun. We're on a spinning Earth, and the sun's position in the sky seems to change because of our rotation.
