Telecommunication

The earliest humans could communicate only by talking or gesturing face-to-face. Eventually people developed ways to send messages to each other across distances. Smoke and drum signals could carry messages over short distances. Written messages could be sent over longer distances but at slow speeds—only as fast as a horse could run or as a ship could sail. Thanks to electric and electronic inventions, communication today happens much faster and across greater distances. Communication using those inventions is called telecommunication.

Telegraph

In the 1830s Samuel F.B. Morse invented the telegraph, a machine that could send messages instantly over a wire. He used long and short electrical signals, called Morse Code, to stand for letters of the alphabet. Soon telegraph wires stretched across the United States. By 1866 telegraph cables under the Atlantic Ocean linked North America and Europe. (See also telegraph.)

Telephone

Alexander Graham Bell invented the telephone in 1876. Like the telegraph, the telephone allowed people to communicate over long distances that were linked by wires. The telephone improved on the telegraph, however, by sending the sound of the human voice for the first time. The voice was translated into electrical signals so it could travel over a wire.

Beginning in the 1970s portable telephones, called cellular phones, sent the sound of the voice in radio waves, not over wires. By the 1980s many businesses, using facsimile (fax) machines, sent pictures of documents over telephone lines. At about the same time, scientists developed fiber-optic cables, which carried telephone signals as rays of light. Fiber-optic cables improved the sound of long-distance telephone connections. (See also telephone.)

Radio and television

In the 1890s Guglielmo Marconi invented the wireless telegraph, or radio. Like the telegraph, his invention sent messages in code, not sound. In 1906, however, Lee De Forest created a way to send music and speech over radio waves. In 1926 the first U.S. network of radio stations, the National Broadcasting Corporation (NBC), began broadcasting radio programs.

Just as the telephone had competed with the telegraph, television competed with radio. By the 1930s people could send and receive pictures and sound by radio waves. In 1936 the British Broadcasting Corporation (BBC) started the world's first regularly scheduled television service.

Mountains and buildings often blocked radio and television signals, however, and the distance that those signals could travel was limited. By the 1960s communications satellites, orbiting Earth, could receive and send radio and television signals. Satellites allowed the signals to travel clearly over long distances. During the same period many cities began using insulated wires, or cables, to send clear television signals. Today satellites and cables link telephones and computers as well. (See also radio; television.)

Internet

The U.S. government developed the Internet in the 1970s and 1980s. The Internet allowed people in distant places to communicate through computers. The World Wide Web, developed in the 1990s, made the Internet easy to use for people at home, at work, and at school. Today people learn, send e-mail, and shop on the Internet. Telephone wires, television cables, fiber-optic cables, and satellites connect computers around the world to the Internet. (See also Internet.)

Article by britannica encyclopedia