How does night happen and why?

Answer 1

The earth continuously orbits around the sun and at the same time spins on its axis. Every time we go completely around the sun a year elapses. Every time the earth spins around on its axis once, a 24 hr. day elapses. (Think of it like the earth is a spinning top circling the sun.) Night happens when the place on the earth you are at turns away from the sun. Sunrises and sunsets occur as we turn away from the sun.