The Rainbow Spectrum

Recently, in Term 3, one of the subtopics under Physics in Science which I had learned was refraction. This was how I got to understand more about rainbows and spectrums. Actually, rainbows are very much similar to spectrums which are formed by shining white light through a prism at an angle. I find this topic absolutely interesting, as it is so amazing how white light can split up into different colours, and I would really like to find out more. Currently, I was taught that the splitting of colours is due to the fact that different coloured lights travel at different speeds when passing through an optically denser medium than air such as glass, and thus as they have different wavelengths, they travel at different velocities.

Similarly, rainbows are formed when the sun shines on droplets of moisture in the Earth's atmosphere.
The colours of rainbows and spectrums are as follows, red, orange, yellow, green, blue, indigo, violet. They are as such due to the fact that red light has the longest wavelength and violet light has the shortest wavelength, so violet light bends closer towards the normal.

Although most people will not notice it because they are not actively looking for it, a dim secondary rainbow is often present outside the primary bow. Secondary rainbows are caused by a double reflection of sunlight inside the raindrops, and appear at an angle of 50–53°. As a result of the second reflection, the colours of a secondary rainbow are inverted compared to the primary bow, with blue on the outside and red on the inside. The secondary rainbow is fainter than the primary because more light escapes from two reflections compared to one and because the rainbow itself is spread over a greater area of the sky.