Question

explain why the sky is blue and why the sunset is red (30 marks)

Answer 1

Hi Mate,

Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.

When light comes from the sun, all these light waves of different wavelengths travel through empty space. When they reach Earth’s atmosphere, the light waves can interact with particles in the air like dust, water droplets, and ice crystals. Because of the extremely small size of visible light waves (less than one millionth of a meter), these light waves also interact the tiny gas molecules that make up the air itself. The light waves bounce off these particles just like you might bounce and get jostled in a busy hallway. As the light waves bounce in lots of different directions, we say they have been scattered.

Within the visible range of light, red light waves are scattered the least by atmospheric gas molecules. So at sunrise and sunset, when the sunlight travels a long path through the atmosphere to reach our eyes, the blue light has been mostly removed, leaving mostly red and yellow light remaining. The result is that the sunlight takes on an orange or red cast, which we can see reflected from clouds or other objects as a colorful sunset (or sunrise).Small particles of dust and pollution in the air can contribute to (and sometimes even enhance) these colors, but the primary cause of a blue sky and orange/red sunsets or sunrises is scattering by the gas molecules that make up our atmosphere. Large particles of pollution or dust scatter light in a way that changes much less for different colors. The result is that a dusty or polluted sky is usually more grayish white than blue.

Hope This Helps You.......☺☺