Human beings have a long history of communication. As early as ancient times, people exchanged information through simple language, murals, etc. For thousands of years, people have been using language, symbols, bells and drums, fireworks, bamboo slips, paper books, etc. to convey information. Ancient people’s beacon fires, flying pigeons to convey messages, and stagecoach mail are examples of this. There are still some primitive tribes in some countries that still retain ancient communication methods such as drumming and trumpeting. In modern society, the command sign language of traffic police and the flag language used in navigation are just the result of the further development of ancient communication methods. The basic method of transmitting these information relies on human vision and hearing.
After the mid-19th century, with the invention of the telegraph, the telephone, and the discovery of electromagnetic waves, fundamental changes occurred in the field of human communication. It was possible to use metal wires to transmit information, and even conduct wireless communication through electromagnetic waves. Communication has made the mythical "ears to the wind" and "clairvoyance" become a reality. From then on, human information transmission could break away from conventional visual and auditory methods and use electrical signals as new carriers. This also brought about a series of iron technology innovations and began a new era of human communication.
In 1837, American Samuel Morse successfully developed the world's first electromagnetic telegraph. Using the electrical code he designed, he could convert the information into a series of long or short electrical pulses, send them to the destination, and then convert them into the original information. On May 24, 1844, Morroth sent the first telegram in human history "using Morse code" in the Federal Supreme Court Chamber of the Capitol Building, thus realizing long-distance telegraph communication.
In 1864, the British physicist J.c. Maxwell established a set of electromagnetic theories, predicted the existence of electromagnetic waves, and showed that electromagnetic waves and light have the same properties, and both propagate at the speed of light. .
In 1875, Scottish young man Alexander Bell (A.G. Bell) invented the world's first telephone. And applied for an invention patent in 1876. In 1878, the first long-distance telephone experiment was conducted between Boston and New York, which was 300 kilometers apart, and was successful. Later, the famous Bell Telephone Company was established.
In 1888, the young German physicist H.R. Hertz conducted a series of experiments using a radio wave ring and discovered the existence of electromagnetic waves. He used experiments to prove Maxwell's electromagnetic theory. This experiment caused a sensation in the entire scientific community and became an important milestone in the history of modern science and technology, leading to the birth of radio and the development of electronic technology.
The discovery of electromagnetic waves had a huge impact. In less than 6 years, Popov of Russia and Marconi of Italy invented wireless telegraphy respectively, realizing the radio transmission of information, and other radio technologies also sprung up. In 1904, British electrical engineer Fleming invented the diode. In 1906, American physicist Fessenden successfully developed radio broadcasting. In 1907, American physicist DeForest invented the vacuum triode, and American electrical engineer Armstrong used electronic devices to invent a superheterodyne receiving device. In 1920, American radio expert Conrad established the world's first commercial radio broadcasting station in Pittsburgh. Since then, the broadcasting industry has flourished around the world, and radio has become a convenient way for people to understand current affairs news. In 1924, the first shortwave communication line was established between Naun and Buenos Aires. In 1933, Frenchman Clavel established the first commercial microwave radio line between Britain and France, which promoted the further development of radio technology.
The discovery of electromagnetic waves also prompted the rapid development of image communication technology. In 1922, 16-year-old American middle school student Philo Farnsworth designed the first schematic diagram of a television fax. In 1929, he applied for an invention patent and was judged to be the first person to invent television. In 1928, Zvorkin of Westinghouse Electric Company in the United States invented the photoelectric picture tube, and cooperated with engineer Van Was to realize electronic scanning television transmission and transmission.
In 1935, a television station was set up in the Empire State Building in New York, USA, and the following year it successfully sent television programs to places 70 kilometers away. In 1938, Zvorkin produced the first practical television camera. After people's continuous exploration and improvement, in 1945, based on the working principle of three primary colors, RCA produced the world's first all-tube color TV. It was not until 1946 that the American Ross Weimar invented the high-sensitivity camera tube. In the same year, the Japanese Professor Hachimoto solved the problem of receiving antennas for home televisions. Since then, some countries have successively established ultra-shortwave relay stations, and television has rapidly become popular.
Image faxing is also an important piece of communication. Since the American Radio Company developed the first practical fax machine in 1925, fax technology has continued to innovate. Before 1972, this technology was mainly used in the news, publishing, meteorological and broadcasting industries; between 1972 and 1980, fax technology had completed the transformation from analog to digital, from mechanical scanning to electronic scanning, and from low speed to high speed. In addition to replacing telegraph In addition to being used to transmit weather maps, press releases, photos, and satellite cloud images, it is also used in medical care, library management, information consulting, financial data, electronic mail, etc. After 1980, fax technology transitioned to comprehensive processing terminal equipment. In addition to undertaking communication tasks, it also has image processing and data processing capabilities, becoming a comprehensive processing terminal. Electrostatic copiers, magnetic tape recorders, radar, lasers, etc. are all important inventions in the history of information technology.
In addition, remote control, telemetry and remote sensing technology as information super-remote control are also very important technologies. Remote control is a technology that uses communication lines to control remote controlled objects. It is used in electrical industry, oil pipelines, chemical industry, military and aerospace industry; telemetry is to measure physical quantities that need to be measured in a distance, such as voltage, current, air pressure, etc. A measurement technology that converts temperature, flow, etc. into electricity and transmits it to an observation point using communication lines. It is used in the meteorological, military and aerospace industries; remote sensing is a comprehensive measurement technology that uses sensors to receive objects at high altitudes or far away. Radiated electromagnetic wave information, processed or identifiable images or recording tapes used by computers, prompts the properties, shapes and changing dynamics of the object being measured, and is mainly used in meteorology, military and aerospace industries.
With the rapid development of electronic technology, the computing tools that are urgently needed for military and scientific research have also been greatly improved. In 1946, Eckert and Moshiri of the University of Pennsylvania developed the world's first electronic computer. Innovations in electronic component materials have further promoted the development of electronic computers in the direction of miniaturization, high precision, and high reliability. In the 1940s, scientists discovered semiconductor materials and used them to make transistors, replacing electron tubes. In 1948, Shockley, Bardeen, and Brattain of Bell Labs in the United States invented the transistor, and transistor radios, transistor televisions, and transistor computers quickly replaced various vacuum tube products. In 1959, Kilby and Noyce in the United States invented the integrated circuit, and microelectronics technology was born. In 1967, large-scale integrated circuits were born, and more than 1,000 transistor circuits could be integrated on a silicon wafer the size of a grain of rice. In 1977, American and Japanese scientists created a very large-scale integrated circuit, integrating 130,000 transistors on a 30-square-millimetre silicon wafer. Microelectronics technology has greatly promoted the upgrading of electronic computers, enabling electronic computers to display unprecedented information processing functions and becoming an important symbol of modern high-tech.
In order to solve the problem of resource sharing, a single computer quickly developed into a computer network, realizing data communication and data sharing between computers. Communication media have developed from ordinary wires and coaxial cables to twisted pairs, optical fiber wires, and optical cables; the input and output devices of electronic computers have also developed rapidly, such as scanners, plotters, audio and video equipment, etc., making computers even more powerful and capable of processing more complex issues. The rise of multimedia technology in the late 1980s has given computers the ability to comprehensively process various forms of information such as text, sound, images, film and television, and has increasingly become the most important and indispensable tool for information processing.
At this point, we can initially believe that: Information Technology (IT) is a technical system based on microelectronics and optoelectronics technology, supported by computer and communication technology, and with information processing technology as the theme. The general term is a comprehensive technology. The close integration of electronic computers and communication technology marks the arrival of the digital information age.