Sea water is blue from a distance, but it is transparent in a glass. Why? When we sail on the water by fishing boat or look at the distance by the sea, from a distance, the sea like the sea is blue, as natural as water, very beautiful and generous. As we all know, if you pick up a glass of seawater, you will find that the seawater is colorless and transparent. There is little difference in the color of drinking water seen in peacetime. Why do these glasses of seawater without transparent color gather together to establish a dark blue?

In summer, you run from the seaside to the seaside and swim to the coral reef by the seaside, where you gradually dive: 10 inch, 20 feet, 30 inches. At 30 feet, when you look back at your little friend, you will be surprised to find that everything has turned dark blue, even colorful swimsuits and skin exude dark blue. What is the reason?

It turns out that the white light we usually hear is actually a combination of seven colors of visible light: red, orange, yellow, green, cyan and purple. When these seven kinds of light are transmitted in the air together, a beam of white light is established. For their own "true face", the naked eye can not identify.

But when the sun conducts from gas to another substance, the situation is different. The sun shines on the river and presses the gas. Some of the light reflects home and the other part enters the water. Light entering water will be absorbed by water when it is transmitted. The absorption of light by water is related to the wavelength of light. It absorbs long-wave light (color light) quickly and short-wave light (high-definition blue light) slowly.

As soon as the light enters the river, it is gradually absorbed. When it reaches 25 inches, the colored light that can be distinguished by human eyes is absorbed and disappears. At a depth of 75 inches, yellow light is also absorbed. To 100 inch, only the light with shorter wavelength-cyan, blue and purple is left. /kloc-Dark blue below 0/00 inch.

If the deep layer rises again, the seawater will turn gray-green, dark gray, and eventually all the light will be absorbed and become gray-black. So every time the sea is crystal clear, the high-definition blue light slowly absorbed by water in the sun is reflected in front of everyone.

It is not difficult to see that the sea itself is not blue. Blue sea water is completely the distribution of sunlight and water. Scientifically speaking, it is caused by the different absorption of all kinds of light by water.