In February 2004, the number of mobile phone users in China reached 282.3 million, and the number of global mobile phone users reached 65.438+35.4 million. Mobile phones have become an indispensable communication tool for people. Let's take a look at the development history of mobile phones first, so that we can have a clearer understanding of the evolution of information exchange and communication technology. 170 years ago, American painter Morse came up with the idea of applying electromagnetic theory to telegraph transmission during a trip to Europe. Morse invented "Morse Code" 1844 on May 24th. Morse's telegram sent the first telegram from Washington to Baltimore in human history. "What a miracle God has created! 1On June 2, 875, Bell accidentally spilled sulfuric acid on his leg while doing the experiment. He shouted "wow" painfully to his colleagues in the other room. Come and help me! And this sentence was transmitted to Walter who answered the phone in another room through the telephone in the experiment, which became the first sentence transmitted by human beings by telephone. 183 1 year, Faraday in Britain discovered electromagnetic induction. Maxwell further expounded the research results of Faraday and others with mathematical formulas, and extended the theory of electromagnetic induction to space. More than 60 years later, Hertz confirmed the existence of electromagnetic waves in experiments. The discovery of electromagnetic waves has become a turning point from "wired communication" to "radio communication" and the origin of the whole mobile communication. As a scientist said, "Mobile phones were born on the shoulders of telegrams and telephones. Wireless communication is impossible without the efforts of predecessors. 1one day in April, 973, a man stood on the street in new york, took out a wireless phone with about two bricks and began to speak. This man is Martin, the inventor of mobile phone. At that time, he was an engineer at Motorola. This was the first mobile phone in the world at that time. 1975, the Federal Communications Commission (FCC) of the United States determined the spectrum of land mobile phone communication and large-capacity cellular mobile phone, which made preparations for the commercialization of mobile phones. From 65438 to 0979, Japan opened the world's first cellular mobile phone network. 1982, GSM (mobile communication task force) was established in Europe. 1985, the first commercial mobile phone was born. It puts the power supply and antenna in a box, weighing 3 kilograms. The modern mobile phone was born in 1987. Its weight is still about 750 grams, which is like a big brick compared with today's mobile phone with only 60 grams. Since then, the "slimming" of mobile phones has become more and more rapid. 199 1 year, and the weight of the mobile phone is about 250g. 1in the autumn of 996, a mobile phone with a volume of 100 cubic centimeter and a weight of 100 gram appeared. Since then, it has been further miniaturized and lightweight, and 1999 has been lighter than 60 grams.