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Controlling the temperature is the only way for humans to obtain a comfortable living environment and preserve food, medicinal herbs and other items, but people in ancient times did not have so many modern methods, and could only control the temperature by reducing or increasing the heat.
In ancient times, people mainly made fires to keep warm, and sprinkled water to cool down, and some people even found that the water in the kettle would freeze in ancient times, but how to make the ice form faster?
This is a product of the exploration of the physical laws of heat by ancient physicists at the level of the time, so how did the ancients make ice from hot water?
Does this approach make sense?
What kind of enlightenment does this exploration in ancient times bring to the contemporary physics community?
1. How did the ancients control temperature.
Temperature control is actually closely related to our lives, as long as there is a need for certain physical and chemical reactions, there will be this demand, such as iron smelting, smelting furnaces for making various smelting raw materials, reactors for making chemical raw materials, and even kilns for making pottery, etc.
And in life, not to mention, whether it is cooking with fire, or heating and cold, or ironing shoes and clothes, all kinds of heat sources will be used.
Of course, the people of ancient China were no exception, and the ancient people carried out various explorations on how to control the temperature, and used the results of this exploration in various occasions and daily life, so that the lives of the ancients were greatly improved.
In ancient times, people mainly obtained the heat source by making a fire, because the heat source and the light source can be obtained together, so the ancient people would also use it for lighting at the same time when they made a fire, so that they could carry out some activities at night, such as studying, communicating, and so on.
The ancients had another trick in controlling the temperature, that is, it was used for cooling, because in ancient times, there were no high-tech products such as air conditioners, so the ancients would sprinkle a layer of water on the ground inside and outside the room in summer, and when the wind blows, the water will evaporate, and the evaporation process will absorb the surrounding heat, so that it can have a cooling effect.
In modern times, in order to control the temperature, we can use a variety of high-tech products, such as air conditioners, refrigerators, etc., and in some occasions, we can also use extremely cold substances such as liquid nitrogen.
The emergence of these high-tech products has greatly improved people's ability to control temperature, greatly improved the quality of human life, and also saved a lot of time, so that human beings can use this time to do more meaningful things.
2. How the ancients made ice.
In ancient times, it was very easy to make a fire, only some fuel was needed to obtain a flame, but these fuels were mainly dry materials such as firewood, so the ancients could only use this material to obtain a heat source, and because the flame temperature of this fuel was not particularly high, it was very difficult to make ice through this method.
However, ancient Chinese physicists tried to make ice from hot water, which may seem illogical, but it contains a wealth of physical theories.
In ancient times, "Huainan Wanbishu" recorded the method of using hot water to make ice, this ice-making method is called "summer ice-making", in this book describes in detail the process and method of making ice, you need some pottery first, and then you need some water, pour the water into the pottery, set fire to boil, and wait until the water boils, you can seal it.
The silk cloth is used to seal the pottery, and after the sealing, the pottery can be immersed in a deep well, but before being placed in the deep well, you need to wait for a while, about three days, and when there is no moisture left on the silk cloth, you can put it into the deep well.
After three days, the existence of ice cubes will be found in the pottery, and this ice cube is very thick, can reach seven or eight inches thick, it can be said to be very magical, the use of water evaporation to take away the principle of heat, but the range of use is relatively large, so the ice cubes made are relatively large.
In modern physics, the principle of summer ice making is very clear, because in deep wells, due to the depth of the water, so in this environment, the evaporation rate of water will be very slow, but when the water evaporates, it will take away part of the heat of the water.
This process is actually the process of turning a liquid into a gas, and in the process of turning a liquid into a gas, it will absorb heat, and this process is called "endothermy", so on the contrary, if it is a process in which a gas becomes a liquid, it will release heat, and this process is called "exothermic".
Therefore, when the water evaporates, it will absorb heat from the water, so that the temperature will be lowered, so that the boiling water at the bottom can evaporate faster, and eventually the water vapor will be brought to a higher position, so that the water vapor will become ice, which is the principle of summer ice.
3. The Interpretation of Xia Zaobing in Modern Physics.
However, modern physicists do not think that the ancients could succeed in this method, because in ancient times, the heat generated by burning materials was far from enough to evaporate water, and although the ancients carried out a large number of experiments, there were no good results.
If the heat generated by the burning material is sufficient, then the temperature of the water will rise rapidly, and when the temperature of the water rises rapidly, it will be very easy to evaporate, and even when the water is about to boil, water vapor will begin to be generated.
However, the ancients tried this method, but there was no result, so modern physicists believe that the ancients did not succeed.
Another physicist, Hong Zhenhuan, also studied Xia Bing, and he believed that Xia Bing could not succeed, because in ancient times there was no way to evaporate water at ordinary temperatures.
In the process of water evaporation, it will absorb heat, if in ancient times, there was no external force to intervene, then the process of water evaporation, will end quickly, when the water evaporates, it will condense, and finally form water droplets, that is, no water vapor is produced.
The current physicist Zhao Hongjun has conducted further research on Xia Zaobing, and he has linked Xia Zaobing with the "Jiaotang effect", believing that the product of Xia Zaobing is not an ice cube, but a solution that can absorb heat and evaporate.
At that time, when people in ancient times were boiling vinegar and other acidic substances, they would put vinegar into a furnace and boil it, which could speed up the evaporation of water and improve the efficiency of the furnace.
In the furnace, because the pressure of the steam is relatively large, the water can be evaporated quickly, but in the deep well, the pressure of the steam is relatively small, so the evaporation speed is very slow.
epilogue
Contemporary physicists have experimentally verified Xia Zaobing, that is, put boiling water into a clay jar to seal it, and then put it into a deep well for soaking, and after three days, it was found that some water droplets were indeed produced in the clay jar, but no ice cubes were formed, so he thought that the ancients were unsuccessful.
Although ancient Chinese scholars did not succeed in trying to make ice in summer, their exploration of the laws of thermodynamics laid the foundation for the subsequent development of science, and also reflected the spirit of exploration in ancient Chinese physics.
We should respect and affirm the scholars of antiquity, especially the physicists of ancient times, because although they did not achieve much at that time, they accumulated valuable experience and knowledge for the development of science, which we cannot ignore.
Although Xia Zaobing did not succeed in the end, this spirit of exploration inspires people to constantly challenge the routine and seek better scientific solutions, which is also something we should learn.