Observation is a prerequisite for discovery. In my free time, I observe objects in my life.

One day, I saw cracks in the wall. And as far as I can see, the cracks are all horizontal and not vertical.

Some cracks existed, but did not spread further. Speaking of this crack, I think of the shape of the coastline.

It can be said that they have the same effect. Of course, the cracks I see are very small, so I don't have to worry about them at all.

But I wonder why cracks appear? I asked people in Baidu, but I got three answers.

And all three answers are already written on paper. According to your own analysis and judgment, you can choose one of them to elaborate.

Mizukawa said quickly, and the three of them hadn't reacted yet. I think it's caused by uneven foundation settlement.

First of all, what is the settlement of the foundation? There are two ways to say this. One is caused by the rotation and revolution of the earth.

The second is caused by the movement of plates under the foundation. It is true that the rotation and revolution of the earth is continuous.

However, a simple example can show that this is not the case. We are all on Earth, and its rotation and revolution are also going on.

However, we are not feeling the impact of the Earth's movements. The plate is different, it is just below the foundation.

Although the speed of movement of the plates is extremely slow, it does not mean that there is no significant change in the pair. There is also a theory that an object under the foundation suddenly decomposes, causing a blank space under the foundation.

This gap led to the partial settlement of the foundation. And I think this statement is relatively logical. Liuzi Fenglai made a generous statement and was full of spirit.

I'm more inclined to the temperature difference. Of course, this refers to large temperature differences. Because at room temperature, there is a difference of less than 1 degree in the temperature of the whole part of the house.

When the difference is greater than 1, thermal expansion and contraction may occur. And there will be a visible change. Duenias, if thermal expansion and contraction really occur at the crack, heat transfer should occur.

As with the transfer of force, the transfer of heat should be irregular. The cracks in the house are usually horizontal, which means that the cracks cannot be caused by the temperature difference.

Actually, it's related to building construction. The surface of the wall is lime, and lime needs to be mixed with water.

There is a phenomenon here: quicklime absorbs water and becomes mature lime, so that the slaked lime can stay on the wall.

There is a rule on how much quicklime needs and how much water is needed, but it is naturally impossible for construction personnel to calculate the amount of water needed during building construction.

It is likely that the construction crew added too much water to the quicklime, and the evaporation formed a hollow drum. You're talking about natural factors, and I'm talking about artificial factors.

I think that's the real reason. You said that it was caused by the temperature difference, and the table experienced spring, summer, autumn and winter, so there should always be a large temperature difference!

However, in fact, there were no obvious cracks on the table. Apples and we have a gravitational pull, but how big is gravity.

When placed on two large celestial bodies, gravity is very cloudy. The reason you are saying is not unreasonable, it just doesn't apply to all objects.

The most direct explanation for the appearance of cracks in the wall is the high probability of cracks in hydrated lime. This brings us to the probabilities of necessity and chance.

Why? A coin is tossed upwards. In fact, no matter how you throw the word up, the probability is 50/100.

When you toss once, the result is word down. The second time is still face down, then the probability of word up is less than 50/100.

The probability in this case is the probability of chance. However, as the number of tosses increases, the probability of chance will get closer and closer to the probability of necessity.

And we often think of chance probability as inevitable probability, and the result is bound to go wrong. Mizukawa Yonemi said something amazing at the end.