干旱区生态环境知识资源中心

The term earth-air refers to the air inside the vadose zone. The observation of earth-air was called hou-qi, which was used to enact meter calendar in ancient China. Currently, however, as a detailed knowledge of hou-qi has been lost for a long time, it has been denounced as a pseudoscience, as earth-air is not scientifically and systematically monitored, and its characteristics and formation mechanism are unclear. We have attempted to scientifically monitor and measure earth-air pressure and reveal its formation mechanism. Results from a specially devised set of air pressure measurements show that the pressure exhibits daily and yearly pulses at different depths. The main cause of the pulsation is soil temperature variation, which results in the soil-combined water decomposing and air pressurization in warming, and water vapor recombining and air depressurization when cooling, leading to pulsation of the air pressure in the soil. Therefore, rather than a myth, hou-qi has great significance in the geosciences and studies of the ancient Chinese civilization.

Plain Language Summary The air inside the soil is called earth-air. The observation of earth-air was called hou-qi in ancient China, which was used to enact meter calendar. However, as detailed knowledge of hou-qi has been lost, it was thought to be one of the most astonishing frauds in the history of Chinese science in 2,000 years. A specially devised set of air pressure measurements show that there really exists the earth-air pulsation. This study presented monitoring real-time data interactions of soil physical parameters that explained the mechanism of pulsations of the air pressure in the soil. Heat transfer in the hetero-thermo-zone during the conduction process makes the soil temperature change cyclically on a daily/yearly basis. This results in the soil-combined water decomposing and recombining, leading to the earth-air pulsation. The earth-air pulsation is a basic natural law. Therefore, hou-qi is not a pseudoscience. Earth-air, rather than a myth, has solid scientific foundation.