The Effects of an Invention or Innovation in Modern Life. (2)

　　In the ancient time, when the weather was hot, we used the fan to let us feel more comfortable by vibrating our own hands. But in modern life now, there is an great invention that has revolutionized the way we behave today which is called "air conditioner." It is so easy and convenient that we just need to insert the connector and click some buttons, then the cold air will come out from the machine. Air conditioners have been existed in everywhere, such as homesites, schools, and skyscrapers. It is hard to imagine that how we live without air conditioners. We feel annoyed when the whole body is moist and sticky especially in Taiwan, a island climate, in summer. Also, there are many modes we can choose what we need from it. For instant, we can select the eliminates wet mode when the weather is wet; it will have a good dream when selecting the comfortable sleeping mode. On the other hand, there are many drawbacks when using the air conditioner. In the early year of this invention, the refrigerant we used in the air conditioner produces enormous green house gases which could reduce the quantity of the ozone of the earth. The weather will become hotter and hotter if the ozone hole keep continuing expanding. This is a big disaster for all humanity. In recent years, people start to worry that the whole environment is getting worse. The original refrigerant are replaced by R-134a. Although it avoid damaging the ozone, the air conditioner still produce many heat when it works. The invention not only affect our life indoors but also change the global environment outdoors. How to reach the balance between conveinent life and the environment is a required course for all human being.