Have you ever seen a rainbow? Or wondered why there are rainbows? Well, rainbows usually appear when there is a conjunction of sunshine and rain. Which means that rainbows form when it is raining in one portion of the sky while the sun is shining in another. If you have never seen a rainbow, it is an arch of seven bands of colour, starting from red, orange, yellow, green, blue, indigo, and violet. .
If you have seen a rainbow, do you know how it is formed? The sun produces light, which is an electromagnetic radiation. It is not white like we think it is. It is actually seven colours, the colours of the rainbow. When light is passed through the two sides of a raindrop, it can be made to bend. The seven light frequencies are bent at different angles and are separated out. When the light is bending like this, it is called refraction. The different colours of the light spread out because of this refraction. The red light is bent the least and violet light the most, that's why the arch of the red light is the largest and the violet is the smallest. .
If you want to see a rainbow, the angle must be perfect so the sun will have to be behind you and the rainbow would appear in front. The centre of the circular arc of the rainbow is in the direction opposite the sun and the rain is in the direction of the rainbow. The direction exactly opposite the sun is called the antisolar point. Rainbows will always appear at that same angle from the antisolar point. If you are standing outside during the daytime, the antisolar point is marked by the shadow of your head. To see the light coming back from the raindrops, look 42 degrees away from that antisolar point. The angle of refraction is a fixed angle and will never change. .
The sunlight is refracted through drops of rain, which is why rainbows appear after or during rainfall. You wouldnt see a rainbow in the winter because the water droplets freeze into ice particles that do not produce a rainbow, but scatter light in other very interesting patterns.
