The time between high and low tide can be calculated, and there is a big connection with the moon, did you ever think there was a connection between the sky and the earth?

Summer is a great time to go to the beach, where people can play in the water and sand. That year, after my high school exams, I cycled dozens of kilometers to the beach with my classmates to camp and slept in a tent overnight. (A friendly reminder that the mosquitoes at the beach are terrible. Remember to bring mosquito repellent equipment. Although I didn't sleep well, I felt quite peaceful inside. Listening to the sound of the waves and being in nature made a difference. Every time I went to the beach afterward, I would have a good taste of it. I'm sure some people will go to the beach because they like the sea, the environment, and the sound.

The tide rises and falls at the beach, and the waves keep lapping at the sand. Have you ever wondered why the sea keeps rushing towards the shore? Isn't the sea as calm as the lake? Because the wind carries the seawater with it? Because there are boats on the sea and the boats pass by, causing ripples. Many boats keep sailing, causing the sea to rush ashore and the waves to keep breaking. Even if this could be explained, how does that explain the fact that there are high and low tides?

Just guessing from thin air, I'm sure no one can guess why. The cause of the fluctuating waters is in the sky, the sun that lights and warms us during the day, and the moon that reflects light for us at night. The two may not seem to have anything to do with each other, but they are the origin of this.

A rising tide is called a tide. A tide is more than simply waves lapping against the beach, it is the vertical fluctuation of the sea, meaning that the water comes up and the water level rises. A rising tide in the morning is called a tide, and a rising tide in the evening becomes a tide, hence the name tide. Tides are created because of the tidal forces of celestial bodies (mainly the sun and the moon). And tides are cyclical, usually rising and falling twice a day, sometimes once. The biggest influence on the tides is the moon.

Ancient people have already discovered the relationship between the tides and the moon. In the Eastern Han Dynasty, Wang Chong wrote in his book "Analects of Heng" that "the waves rise with the moon". So our lunar calendar not only distinguishes between the phases of the moon, but also helps to record the tidal patterns, and the ancients had a basis for going to sea.

So how do the sun and moon affect the sea and cause the tides? This goes away from the law of gravitation. Simply put, the gravitational tidal force is affected by the mass of the celestial body itself, the gravitational force of the celestial body on the Earth, the distance between the celestial body and the Earth, and the difference between the celestial body and the gravitational force. So according to one set of calculations, the Moon has the greatest gravitational pull on the Earth, 2.17 times that of the Sun, and the other celestial bodies are almost negligible.

However, the tidal forces of the Sun and the Moon are not always in sync. Sometimes the two forces work together to form a combined force, and they combine to push the waters higher. Sometimes they interact with each other and become repulsive forces. Eventually, the tidal force of the Sun cancels out some of the tidal force of the Moon and the tides rise relatively low. The highest tides of the year are at the vernal and autumnal equinoxes because at these times the sun, moon, and earth are almost on the same plane and the tidal forces are greatest.

After the high tide comes to the low tide. The sea stops rising when it reaches its highest point and goes down to low tide. And there is a short equilibrium period between high tide and low tide, so the tide has to be stopped.

As we said earlier, tides are cyclical, does this mean that we can accurately calculate when high and low tides are? The answer is of course, yes, but there is one thing to be clear. Because each part of the Earth is affected differently by the gravitational pull of the Sun and Moon, it is important to calculate this according to where you are. There are three types of seawater fluctuations. The first type is the semi-diurnal tide, which means that it fluctuates twice a day. The second type is the full-day tide type, which fluctuates once a day. The third is the mixed tide type, with the first two tide types occurring accordingly over a month.

How do you calculate the duration of seawater fluctuations? One of the simplest formulas is that the highest tide time = lunar x 0.8 and the lowest tide time = highest tide time +/- 6h. The half-day tide type is a 12-hour cycle and the full-day tide type is a 24-hour cycle. The calculated time corresponds to the exact time of day when high tide can be seen. There are two other formulas with slightly different algorithms. From the first to the fifteenth day of the month, use (lunar date - 1) x 0.8 + 5h; from the 16th to the end of the month, use (lunar date - 16) x 0.8 + 5h.

Either way, it all boils down to local conditions and then calculations based on the formula. It only takes a day or two to calculate the exact time of high and low tides.

A final bit of trivia. In reality, tides refer not only to the fluctuations of seawater but also to the periodic movements and changes in the Earth's hydrosphere, lithosphere, and atmosphere, which are all tides of various kinds, collectively known as tides. As a complete science of tides, ocean tides, surface tides, and atmospheric tides should be studied as a unified whole. Perhaps more literally and in everyday use, so we habitually think of tides as the fluctuations of seawater.

I didn't expect that two seemingly unrelated things would affect each other. It proves that everything in the world is interconnected, maybe not directly, but after many times, you will always find that they are not far away. This is what makes the butterfly effect so real. One small change shakes up the whole of nature. It made me think once again if the world wasn't designed, why is it so sophisticated?

I think it's a summary of the main points :

1. Tides are not simply waves lapping against the beach, but vertical fluctuations of the sea, meaning that the water overflows and the level rises.

2. The morning high tide is called a tide, while the evening high tide becomes a tide, hence the name.

3. Tides are cyclical, usually rising and falling twice a day, sometimes once. The biggest influence on the tides is the moon.

4. Tides occur because of the tidal forces of celestial bodies (mainly the Sun and the Moon). The tidal force is affected by the mass of the celestial body, the gravitational force of the celestial body on the Earth, the distance between the celestial body and the Earth, and the difference between the celestial body and the gravitational force.

5. After the high tide, there is a low tide. The sea rises to its highest point and then stops rising, and going down is low tide. And there is a short equilibrium period between high tide and low tide, so the tide has to be stopped.

6. There are three types of seawater fluctuations. The first type is the semi-daily tide, which means that it fluctuates twice a day. The second is the full-day tide type, which fluctuates once a day. The third is the mixed tide type, where the first two tide types occur accordingly throughout the month.

7. The formula for calculating the ebb and flow of the tide, whichever it is, boils down to taking into account the local conditions and then calculating according to the formula. It only takes a day or two to work out the exact time of high and low tides.

8. Wherever there are periodic movements and changes in the Earth's hydrosphere, lithosphere, and atmosphere due to the gravitational forces of the Sun and Moon, there are various tides, always called tides. As a complete science of tides, oceanic tides, terrestrial tides, and atmospheric tides should be studied as a unified whole.