After the middle of the 19th century, with the invention of telegraph and telephone, and the discovery of electromagnetic waves, the field of human communication has produced a fundamental change in the realization of the use of metal wires to transmit information, and even through electromagnetic waves to wireless communication, so that the myth of the "smooth ear", "clairvoyance" has become a reality. Clairvoyance" in mythology became a reality. From then on, human information transfer can be separated from the conventional visual and auditory methods, with the use of electrical signals as a new carrier, with this brought a series of iron technology innovation, the beginning of a new era of human communication.
In 1837, the American Samuel Morales (Samuel Morales), who was a member of the American Academy of Arts and Sciences (AASA), was born. Morse (Samuel Morse) successfully developed the world's first electromagnetic telegraph. He used his own design of the code, can be converted into a string of information or long or short electrical impulses to the destination, and then converted to the original message. 1844 May 24, Morse in the Capitol, the Federal Supreme Court Chamber of the "Morse code" sent the first telegram in human history, thus realizing the long-distance The first telegram in human history was sent "in Morse code," thus enabling long-distance telegraph communication.
In 1864, British physicist J.c. Maxwell established a theory of electromagnetism, predicting the existence of electromagnetic waves, showing that electromagnetic waves have the same properties as light, and that both travel at the speed of light.
In 1875, a young Scottish man, Alexander. A.G. Bell invented the world's first telephone. A.G. Bell patented the invention in 1876, and the first long-distance telephone experiment between Boston and New York, 300 kilometers apart, was carried out in 1878 and was successful, and the famous Bell Telephone Company was later established.
In 1888, the young German physicist Heinrich Hertz (H.R. Hertz), who had been a member of the German Academy of Physics for many years, was founded. H.R. Hertz, a young German physicist, conducted a series of experiments with an electric wave ring and discovered the existence of electromagnetic waves, which he used to prove Maxwell's electromagnetic theory. This experiment sensationalized 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, Russia's Popov, Italy's Marconi invented the wireless telegraph, the realization of the radio dissemination of information, other radio technology also sprung up. 1904 British electrical engineer Fleming invented the diode. 1906 U.S. physicist Fessenden successfully researched the radio broadcasting. 1907 U.S. physicist DeForest invented the vacuum triode, the U.S. electrical engineer. In 1907, American physicist DeForest invented the vacuum transistor, and American electrical engineer Armstrong invented the super-aberrant receiver by applying electronic devices. 1920 American radio expert Conrad established the world's first commercial radio station in Pittsburgh, and since then the broadcasting business has flourished all over the world, and the radio has become a convenient way for people to learn about the current news. 1924, the first short-wave communication line was established between Nauen and Buenos Aires, and the first short-wave communication line between Nauen and Buenos Aires was set up. Buenos Aires between the establishment of the French in 1933, Clavell established between Britain and France and the first commercial microwave radio lines, promoting the further development of radio technology.
The discovery of electromagnetic waves also led to the rapid development of image dissemination technology, and in 1922, 16-year-old American high school student Philo Farnsworth designed the first image dissemination system. Farnsworth designed the first television facsimile schematic, applied for a patent for the invention in 1929, was ruled to be the first person to invent the television set. 1928 Westinghouse Zwolgin invented the photovoltaic picture tube, and with the cooperation of the engineering Van Vas, to achieve the electronic scanning method of television sending and transmission. 1935 the United States of America, New York, the Empire State Building to set up a television station, the following year successfully In 1938, Zwolgin made the first TV camera that meets the practical requirements. After people continue to explore and improve, in 1945 in the three-color principle of operation on the basis of the United States Radio Corporation made the world's first all-tube color television. Until 1946, the American Ross. Weimar invented a high-sensitivity camera tube, the same year the Japanese Professor Hachimoto solved the problem of home television reception antenna, from which a number of countries have established ultra-short-wave relay stations, television rapidly spread.
Image fax is also an important communication. Since 1925, the United States Radio Corporation developed the first practical fax machine, fax technology continues to innovate. 1972, the technology is mainly used for news, publishing, meteorological and broadcasting industries; 1972 to 1980, fax technology has been completed from analog to digital, from mechanical scanning to electronic scanning, from the low-speed to high-speed transformation, in addition to replacing the telegraph and for the transmission of meteorological maps, Press releases, photographs, satellite cloud charts, but also in the medical, library management, intelligence consulting, financial data, e-postal and other aspects of the application; after 1980, fax technology to the transition to integrated processing terminal equipment, in addition to undertake communication tasks, it also has the ability to image processing and data processing, to become a comprehensive processing terminal. Electrostatic copiers, magnetic tape recorders, radar, lasers and so on are important inventions in the history of information technology.
In addition, as the information ultra-far control of remote control, telemetry and remote sensing technology is also very important technology. Remote control is the use of communication lines to the remote controlled object control of a technology, for the electrical utility, pipeline, chemical industry, military and aerospace industry; telemetry is the remote need to measure physical quantities such as voltage, current, air pressure, temperature, flow, etc. into electricity, the use of communication lines to transmit to the point of observation of a measurement technology, for the meteorological, military and aerospace industry; remote sensing is an integrated Remote sensing is a comprehensive measurement technology, in high altitude or far away from the use of sensors to receive the electromagnetic wave information radiated by the object, after processing or can recognize the image or electronic computer with the recording tape, prompted by the nature of the object to be measured, the shape and dynamics of the change, mainly used in meteorology, military and aerospace industry.
With the high-speed development of electronic technology, military, scientific research urgently need to solve the problem of computing tools have also greatly improved. 1946, the United States of America University of Pennsylvania's Eckert and Moshiri developed the world's first electronic computer. The innovation of electronic component materials further promote the electronic computer towards miniaturization, high precision, high reliability direction. 1940s, scientists discovered the semiconductor material, made of transistors, replacing the tube. 1948, the United States of America, Bell Labs, Shawclay, Bardeen and Brattain invented the transistor transistor, so the transistor radio, transistor television, transistor computer quickly replaced a variety of vacuum tube. In 1959, the United States of America Kilby and Noyce invented integrated circuits, since the birth of microelectronics technology. 1967, the birth of large-scale integrated circuits, a grain of rice the size of a silicon wafer can be integrated into more than 1,000 transistors on the line. 1977, the United States, Japan, scientists made of ultra-large-scale integrated circuits, 30 square millimeters on the silicon wafer integrated 130,000 transistors. integrated on a 30 square millimeter silicon wafer with 130,000 transistors. Microelectronics technology has greatly promoted the upgrading of electronic computers, so that electronic computers show unprecedented information processing capabilities, becoming an important symbol of modern high-tech.
In order to solve the problem of resource **** enjoyment, a single computer soon developed into a computer network, the realization of data communication between computers, data **** enjoyment. Communication medium from ordinary wire, coaxial cable development to twisted pair, fiber optic wires, fiber optic cables; electronic computer input and output devices have also developed rapidly, scanners, plotters, audio and video equipment, etc., so that the computer as a tiger to add wings to deal with more complex problems. 20 century 80's the end of the rise of multimedia technology, so that computers have a comprehensive treatment of text, sound, image, film and television, and other forms of information, increasingly becoming the information technology. The ability to comprehensively process text, sound, image, video and other forms of information, increasingly becoming the most important and essential tool for information processing.
So far, we can initially think: information technology (Information Technology, referred to as IT) is based on microelectronics and optoelectronics technology, computer and communications technology as the support, information processing technology as the theme of the technology system, is a comprehensive technology. The close integration of electronic computers and communication technology marks the arrival of the digital information age.