People who live by the sea must be familiar with high and low tides, and even know exactly when the sea rises and falls, so have you ever thought about what is the reason for the rise and fall of the sea? Why is there a high tide on the surface of the sea without wind and waves? After every low tide, where did so much sea go?
"The rise and fall of the waves, with the rise and fall of the moon"
In fact, the rising and falling tides of the sea are a cyclical phenomenon necessary every day, and people call it a tidal phenomenon, which has been very curious about in ancient China.
Therefore, in the "On Balance" of the Eastern Han Dynasty, there will be "the rise and fall of the waves, rising and falling with the moon", which means that the tidal phenomenon of the sea is related to the moon, and this statement was not confirmed until the emergence of gravity.
The moon as the earth's companion star, its gravitational force is not small, so the distance between seawater and the moon is different, the gravitational force is different, when the seawater is facing the moon, the gravitational force is the greatest, the seawater will be attracted to expand outward.
The place with the opposite side of the moon, although the gravitational pull of the moon is small, but the centrifugal force of the earth is very large, so it will also expand outward, so that the ocean distribution on the surface of the earth will show an oval shape, but because the earth is rotating non-stop, so this change in water level will also form a periodicity.
So, where does the sea water go after the tide falls?
After understanding the reasons for the formation of tidal phenomena, many people will wonder, where did so much sea water go after the tide fell? Will this reduce the amount of sea on Earth?
In fact, you don't have to worry, no matter how the sea rises and falls, the total amount of seawater on the surface of the earth has basically not changed, and those seawater that recedes at the time of the tide actually flows to the place where the gravity is larger.
To know that the world's oceans are connected, just like the principle of "water flowing low", where the gravitational force is large, the sea water will also be "sucked" over, forming a "rising tide" in another place, and so on and on and on.
Is tidal phenomenon good or bad?
However, this imagination was a threat in the past, because it only brought destruction to people, especially for fishermen who went out to sea to fish.
But with the continuous development of science and technology, human beings will be this uncontrollable tide "waste into treasure", which is the famous tidal power generation, it will provide more power to human beings.
Why is the sea blue?
At the same time, it is precisely because of this tidal phenomenon that many people like the sea and like its waves, but the sea we see is almost all blue, do you know why?
It should be known that the sea water itself is colorless and transparent, but in fact, its color will change with the movement, for example, in places far from the coast, the sea water generally appears dark blue, and near the shoreline, the color will change from blue to green, which is determined by the optical properties of the sea water and the suspended material contained in the ocean, the depth of the sea, and the characteristics of the clouds.
The reason why we see the sea is blue, it is because of the radiation and absorption of light by water molecules, primary school knowledge tells us that light is made of 7 colors mixed, of which the red to green wavelength range of light, is easily absorbed by water molecules, and the blue part of the light is reflected, so what we see is blue.
Final personal opinion:
The ocean has always been a mysterious existence in front of human beings, and there are many things we have to explore in this water that occupies 70% of the earth's surface.
From the tidal phenomenon alone, it is not difficult to see that the natural environment of the earth is actually affected by the entire solar system and even the universe, if we want to make our homeland longer, the protection of the environment should start from the individual, what do you think about this?