Question:

Why does the Sun rise in the east and set in the west?

The Sun, the Moon, the planets, and the stars all rise in the east and set in the west. And that's because Earth spins -- toward the east.

For a moment, let us ignore Earth's orbit around the Sun (as well as the Sun's and solar system's revolution around the center of the Galaxy, and even the Galaxy's journey through the universe). For the moment, let us just think about one motion - - Earth's spin (or rotation) on its axis.

Earth rotates or spins toward the east, and that's why the Sun, Moon, planets, and stars all rise in the east and make their way westward across the sky. Suppose you are facing east - the planet carries you eastward as it turns, so whatever lies beyond that eastern horizon eventually comes up over the horizon and you see it!

People at Earth's equator are moving at a speed of about 1,600 kilometers an hour -- about a thousand miles an hour -- thanks to Earth's rotation. That speed decreases as you go in either direction toward Earth's poles. In the state of Texas, you'd moving at about 1,400 kilometers an hour due to rotation. If you're in southern Canada, you're moving at only about a thousand kilometers an hour. Now think about what would happen if you stood exactly at the North Pole. You'd still be moving, but you'd be turning in a circle as Earth spins on its axis.

You may wonder why you don't feel this speed: it's because human beings have no 'speed organs' which can sense absolute speed. You can only tell how fast you are going relative to something else, and you can sense changes in velocity as you either speed up or slow down. But we cannot really tell whether or not we are just moving at a constant speed unless something else tips us off!