Why is the mediterranean sea blue

The Indian physicist Sir Chandrasekhara Venkata Raman was on a cruise on the Mediterranean Sea in 1921. Some reports suggest it was his honeymoon. Others say the beauty of its deep blue opalescence captivated him. Whatever the reason, he dedicated the rest of his life to understanding its colour and discovered the so-called Raman effect. 

Light impinging on the surface of the Mediterranean Sea is scattered. Of this light, a small proportion is scattered in such a way that the frequency changes, causing it to look more blue than was the incident light. This shift in frequency causes the blue colour of the Mediterranean Sea. 

The Raman effect relates to scattering of light. Raman found that illuminating a transparent substance such as water causes a small proportion of the light to emerge 

Opalescence means the ability to show different colours, like the gemstone opal. We see different colours when viewing from different angles. 

Raman s studies of the Mediterranean Sea s colour led to the phrase blue-sky research, because his work at the time had no obvious contemporary application. 

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