Sunday, November 27, 2011

Random. Rainbow.

It's raining again. But the good thing is, there's a rainbow after the rain! It's so pretty. Too bad I don't have a real camera. A good one that costs over 3k MYR. This picture was taken by using my mobile phone, so the colour is slightly off here due to different colour settings.

Actually, it's a double rainbow, but the first one is not very clear. It's almost non-existent in this picture.

What makes a double rainbow?

Sometimes we see two rainbows at once, what causes this? We have followed the path of a ray of sunlight as it enters and is reflected inside the raindrop. But not all of the energy of the ray escapes the raindrop after it is reflected once. A part of the ray is reflected again and travels along inside the drop to emerge from the drop. The rainbow we normally see is called the primary rainbow and is produced by one internal reflection; the secondary rainbow arises from two internal reflections and the rays exit the drop at an angle of 50 degrees° rather than the 42°degrees for the red primary bow. Blue light emerges at an even larger angle of 53 degrees°. his effect produces a secondary rainbow that has its colors reversed compared to the primary, as illustrated in the drawing, adapted from the Science Universe Series Sight, Light, and Color.

It is possible for light to be reflected more than twice within a raindrop, and one can calculate where the higher order rainbows might be seen; but these are never seen in normal circumstances.

Our beautiful house after the rain.


FairyWhispers said...

wow, you're lucky to see a double rainbow


Aik said...

Yeah, I don't think I've ever seen it before.

瑞思 said...

I have seen it before~very beautiful~ :D