Why Is The Sky Blue In The Daytime And Black At Night?

The sky is blue during the day because the sunlight bounces around in the air, and blue light bounces more than other colors. At night, there's no sun to bounce off, so it looks black.

Think of a big ball (the sun) throwing tiny balls (light rays) into the air. The air is full of tiny bits (molecules), and when the light hits them, they scatter, like when you throw a ball into a room with lots of little pieces bouncing around. Blue light scatters more than red or yellow, so it fills up the sky from all sides, making everything look blue.

At night, there’s no sun to send out those tiny balls anymore, so there's nothing to scatter, just darkness above you.