Hot-Air Balloon
The story goes that in the 2nd century BC someone made an experimental hot-air balloon out of an empty eggshell. He emptied the egg white and yolk from a hole in the shell, and put a piece of burning wormwood inside the shell. As the air inside the shell was warmed, the eggshell was
lifted by the wind and rose in the air. The principle of the story was quite correct and imaginative, and some people at that time seemed to have noticed the phenomenon of the buoyancy of hot air, which is lighter than air. However, the experiment could not have been a success, for even all the space in the shell was hot air, the buoyancy was not enough to buoy the eggshell. According to historical records, the inventor of hot-air balloon was Zhuge Liang (181-234), a noted politician and strategist of the Three Kingdoms Period.
When commanding troops at the front, Zhuge Liang's health broke down from constant overwork . Before his death, he designed a light to puzzle the enemy: An oil lamp was installed under a large paper bag, and the bag floated in the air due to the lamp heating the air. After his death, the enemy was frightened by the light in the air, thinking some divine force was helping him. Later people named the paper-made hot-air balloon Kongming's Light (Zhuge Liang was also known as Zhuge Kongming). In the Five Dynasties Period, a woman warrior named Xin made a huge Kongming's Light with burning pine rosin under it to use it as a military signal. Fan Chengda, a poet of the Southern Song Dynasty, writes about Kongming's Light in a poem: "The candle shoots into the air and stays there." In the Yuan Dynasty, the hot-air balloon became popular throughout the country, and during festivals such balloons were launched, which attracted huge crowds of viewers. Joseph Needham noted that the invention of paper in China was several centuries earlier than its use in other countries; with paper people made lanterns, and some lanterns with very small hole in the upper part would rise and even float in the air due to the strong light and heat. |
