The development history of communication science

Human beings have a long history of communication. As early as ancient times, people exchanged information through simple language and murals. For thousands of years, people have been using language, symbols, bells and drums, fireworks, bamboo slips and paper books to convey information. Ancient bonfires, flying pigeons and post-horse mail are examples of this. Some primitive tribes in some countries still retain ancient communication methods such as beating drums and blowing horns. In modern society, the command sign language of traffic police and the semaphore in navigation are just the result of the further development of ancient communication methods. These basic aspects of information transmission depend on human vision and hearing.

/kloc-After the middle of the 9th century, with the development of telegraph and telephone and the discovery of electromagnetic waves, fundamental changes have taken place in the field of human communication, realizing the transmission of information through metal wires and even wireless communication through electromagnetic waves, making the mythical "clairvoyance" and "clairvoyance" come true. Since then, human information transmission can be separated from the conventional audio-visual way, using electrical signals as a new carrier, bringing a series of iron technological innovations and opening a new era of human communication.

From 65438 to 0837, American Samuel Morse successfully developed the world's first electromagnetic telegraph. With his own code, he can convert information into a series of long or short electric pulses and send them to the destination, and then convert them into original information. 1844 On May 24th, Morris sent the first telegram in human history in the conference hall of the Federal Supreme Court of the Capitol, thus realizing long-distance telegraph communication.

1864, the British physicist J.c.Maxwel established a set of electromagnetic theories, predicted the existence of electromagnetic waves, and explained that electromagnetic waves and light have the same properties and both travel at the speed of light.

1875, the Scottish youth A.G. Bell invented the world's first telephone. And applied for an invention patent in 1876. 1878, the first long-distance telephone experiment was conducted between Boston and new york, which are 300 kilometers apart, and it was successful. Later, the famous Bell Telephone Company was established.

1888, the young German physicist H.R. Hertz conducted a series of experiments with radio circuits and discovered the existence of electromagnetic waves. He proved Maxwell's electromagnetic theory by experiments. This experiment caused a sensation in the whole scientific community and became an important milestone in the history of modern science and technology, which led to the birth of radio and the development of electronic technology.