Why is the sea blue? It was the famous Indian physicist Raman who uncovered this mystery. 192 1 year, Raman made a research report on acoustics and optics at the Royal Society of Science, and returned to India by boat via the Mediterranean Sea. One day, the ship was sailing in the blue Mediterranean, and the fish-scale light spots danced on the deep blue sea. At this time, on the deck of the ship, the conversation between a young mother and her young son attracted Raman's great attention. "Mom, what's the name of this sea?" "Mediterranean." "Why is it called the Mediterranean?" "Because it is between Eurasia and Africa." "Then why is it blue?" ? The mother who answered her son's questions like a flood was stumped. In order to answer her question, the young mother had to turn to Raman, who was listening to their mother-son conversation beside her. Raman, who studied optics, confidently told the little boy, "The sea is blue because it reflects the color of the sky. The sky is blue. " Raman's explanation was recognized by the scientific community at that time. ? This explanation comes from the British physicist Lord Rayleigh. Rayleigh is a great scientist. He is famous for discovering inert gases. He used the theory that sunlight is scattered by atmospheric molecules to explain why the sky is blue, and deduced that the blue of seawater is the result of the reflection of the sky color. After answering the children's questions, Raman said goodbye to them and walked to the other side of the deck. But somehow, he always had some doubts about his answer, and then the boy's series of "why" echoed in his ear, and he felt a little guilty again. As a well-known scientist, he suddenly found himself unconsciously losing the boy's curiosity to pursue the unknown in the "known". Losing curiosity is undoubtedly a kind of sorrow for a scientist. Since then, in the face of success, Raman began to reflect on himself. ? After returning to Calcutta, Raman began to realize that there was insufficient experimental evidence for Lord Rayleigh to explain the color of seawater. He immediately set out to re-study why the sea water is blue. Starting with the interaction between light scattering and water molecules, according to the fluctuation theory put forward by Einstein and others, he carried out experiments and found that sunlight will scatter when it passes through water, ice and other substances, and obtained some relevant data, which proved that the mechanism that water molecules scatter light to make seawater appear blue is completely consistent with the mechanism that water molecules in the air scatter sunlight to make the sky appear blue. ? On the basis of this research, Raman further discovered the light scattering effect that is ubiquitous in solids, liquids and gases. This discovery is called "Raman effect" by the scientific community. The discovery of Raman effect provided strong evidence for the scientific community to finally accept the particle theory of light at the beginning of the 20th century. It was the question of the teenagers on the Mediterranean ship that made Raman climb the podium of the Nobel Prize in Physics on 1930, and made Raman the first scientist to win this honor in the history of India and Asia. Shortly thereafter, landsberg and others in the former Soviet Union also found this effect in crystals, so this effect is also called "joint scattering".