Electronics(电子学) is the technology which marshals and controls electrons in materials, and today its applications seems to be boundless. The most striking application recently was the establishment of an electronic communications web around the world to make the moon landing possible. In the near future this web or a similar one will be used in a survey of the earth"s resources. (46) Satellites will not only record interesting geographical features but will be of invaluable service in reporting on outbreaks such as insect plague, plant disease, bush fire, and volcanic activity. Electronics is also the key to automation, where manual control of machines is replaced by electronics controls which are faster, and more accurate and reliable. (47) The automatic timing of traffic lights, the automatic mining and processing of ores(矿石) the numerical control of machine tools, the control of electrical power stations, the automatic monitoring of hospital patients" medical conditions, and the monitoring of plant and animal growth ate all examples of the rapidly growing applications of electronics in this area. (48) Apart from automation, other applications which arouse public opinion include satellites used for military purposes, electronic bugging systems and computer centers to record personal data on all citizens. As well as providing the nucleus for such data centres, computers will take over more and more of the routine operations of modem life. They seem destined to be the application of electronics which will have most influence on our lives in the coming decade. (49) Perhaps more significantly in the long-range view, they will extend man"s reasoning power as tools and machines have extended his muscles in the past and the telephone, radio, and TV are extending his senses at present. (50) Since electronics is used in so many activities and because it touches on many other subjects, it provides possible means of con tact between engineering and the social, natural and medical sciences.