Telegraph and Telephone

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Telecommunications is the word we use for the science and technology of sending messages using electricity.This includes the telegraph, telephone, radio, television, and computers. These instruments change information into signals that are sent over long distances, through wires, or through optical fibers, or by radio waves, or satellite. The information can be almost anything--voices, music, pictures, words, or computer data and it arrives almost immediately.

Anthropologists believe that until about 40,000 years ago humans were unable to speak as we do today. People communicated by grunting and gesturing, possibly imitating sounds found in nature. Early humans also painted and drew pictures of things they saw to tell stories.cave painting from france

Thousands of years after language developed, evidence of early writing appears. People living in the ancient Near East wrote using symbols or pictographs and later developed alphabets. They could now document their histories and pass on news and information.

Imagine living before the invention of electronic communication. You would be living without telephones, radio, television and computers. Most of our entertainment depends upon telecommunications. Yes, that’s right, if you lived two hundred years ago, before telecommunications, you would receive messages as handwritten letters delivered by people on foot or on horseback. You would be living without television, the world’s most popular form of entertainment. Use the history-line to learn about remarkable developments in the history of telecommunications and television.

Telegraph and Telephone

The first reliable electronic telegraph machines were built in the 1830s when an American named Samuel Morse developed a telegraph system designed to use a code of long and short pulses of electric current representing different letters. The code became known as Morse code. To send a message, an operator pressed a switch, sending a signal, which sent an electric current along a wire to the receiving machine.

example of morse code. morse code was developed in 1838.alexander graham bell, inventor of the telephone

Telegraphs required wires or cable, so in order to send telegrams (the name for the actual messages) across the ocean, the necessary cable was laid and telegrams could be sent between Europe and the United States.

The telephone quickly took over from the telegraph. In 1876, Alexander Graham Bell, a Scottish doctor, was working on a new type of telegraph when he accidentally spilled something on his clothes and called for his assistant, who was able to hear his voice over the wire. Like the telegraph, a telephone uses electricity flowing through wires, but it sends sounds instead of codes. When you speak into a telephone, the receiver changes your voice into an electric current and then changes the current back into a voice again at the other end. The ability to have two-way conversations by telephone over a distance brought people closer together.

Radiogugliemo marconi, 21 year old inventor

The next advancement in telecommunications was radio, the first wireless mode of communication. Radios send messages by radio waves instead of wires. German scientist Heinrich Hertz proved the existence of radio waves, which occur in nature.

In 1895, a young Italian named Gugliemo Marconi invented what he called “the wireless telegraph” while experimenting in his parents’ attic. He used radio waves to transmit Morse code and the instrument he used became known as the radio. In 1906, Marconi shared the Nobel Prize for physics with Ferdinand Braun, a German, in recognition of their contributions to the development of wireless telegraphy. Radio works by changing sounds or signals into radio waves, which travel through air, space, and solid objects, and the radio receiver changes them back into the sounds, words, and music we hear.

A radio broadcast is a one-way transmission, originating from a radio station. In the early 1920s, radio played an important role in people’s lives, and over 500 stations were broadcasting news, music, sports, drama, and variety shows. By the 1930s, most households in the U.S. and Europe had at least one radio. In the evening, the family gathered around a big “console” that was usually located in the living room, where they might spend hours listening to variety shows or comedies from favorites like Jack Benny or Edgar Bergen and Charlie from the 1930\'s

Everyone used their imagination to visualize all of the characters in their favorite shows. This was the beginning of the “Golden Age of Radio.” The Radio Corporation of America (RCA), parent company of the National Broadcasting Company (NBC), Columbia Broadcasting System (CBS) and the British Broadcasting Corporation (BBC) produced and commissioned shows like “The Lone Ranger”, “The Shadow”, “BBC Dramas”, “I Love a Mystery”, and there were even plenty of shows for children, such as “Let’s Pretend” and “Hop Harrigan.”

Television Invention

Television is a way of sending and receiving moving images and sounds over wires or through the air by electrical impulses. The big breakthrough in technology was the ability to send sound and pictures over the air. The word television comes from the Greek prefix tele and the Latin word vision or “seeing from a distance.” The TV camera converts images into electrical impulses, which are sent along cables, or by radio waves, or satellite to a television receiver where they are changed back into a picture.loggie baird with his mechanical tv system

As with most inventions, television’s development depended upon previous inventions, and more than one individual contributed to the development of television, as we know it today. People started experimenting with television during the 19th century. When you ask the question--who invented television, you may get a few different answers.

In England in 1878, John Loggie Baird, a Scottish amateur scientist, successfully transmitted the first TV picture, after years of work, in 1926, with his mechanical system. Baird’s system used a mechanical camera consisting of a large spinning disc, with a spiral of holes that Paul Nipkow had developed in 1884. This old mechanical technology was quickly replaced by superior electronic television.

Philo Farnsworth successfully demonstrated electronic television in San Francisco, in 1927. Farnsworth, at the age of fifteen, began imagining ways that electronic television could work. One day while working in the fields among rows of vegetables, he was inspired. He realized that a picture could be dissected by a simple television camera into a series of lines of electricity. The lines would be transmitted so quickly that the eyes would merge the lines. Then, a cathode ray tube television receiver would change those lines back into a picture. Initially, television was available only in black and white, even though experiments with color began in the 1920s; however, you could not buy a color television until 1953.farnsworth demonstrationg his television system

Nobel laureate Ferdinand Braun invented the cathode ray tube, the basis of all modern television cameras and receivers. Vladimir Zworykin improved television with the invention of a completely electric camera–the Iconoscope, and a receiver–the Kinescope, which both used a cathode ray tube. David Sarnoff, head of RCA and founder of the NBC television network, backed his powerful belief in the possibilities of television with financial backing by hiring Zworykin and purchasing the rights to use Farnsworth’s image dissector in RCA products. diagram of cathode ray tube

Broadcast Television

The first American television broadcast was exhibited at the 1939 World’s Fair in New York City. The fair’s theme was “Worlds of Tomorrow” and RCA set up twelve televisions, which broadcast events that were taking place at the fair. Millions of amazed people viewed television for the first time. a variety of early television sets

It wasn’t until after World War II that television sets and a variety of programming would be available in most American households. By the mid 1940s, the number of television stations grew. People could watch live shows like “The Texaco Star Theater” starring Milton Berle or “Uncle Miltie” as he was know by his fans. Shows like “The Jack Benny Show” and “Dragnet” were borrowed from network radio and transformed into television shows. Televisions were expensive and could cost almost as much as a car.

The 1950’s are considered “The Golden Age of Television.” Television sets were becoming more affordable and stations popped up in many parts of the United States. Suddenly, there were many more popular programs to watch. Like radio, television created new stars and featured variety shows, situation comedies, news, sports, dramas and children’s shows. Among the most popular were sitcoms like “The Honeymooners” with Jackie Gleason, “I Love Lucy” with Lucille Ball and children’s programs such and “Kukla, Fran, and Ollie” and “Howdy Doody,” and westerns like “Gunsmoke”.the etv broadcast from dreher high school

Until the 1960s all American television networks were commercial. In 1967, the United States Congress established the Corporation for Public Broadcasting (CPB) to help finance and direct the Public Broadcasting Service (PBS). Ten years earlier, in 1957, the South Carolina General Assembly gave permission to Henry Cauthen and Lynn Kalmbach to study and begin using television in South Carolina’s public schools.

Cauthen had a lot of support because his goal was to use telecommunications to improve education for South Carolinians. In 1960, the South Carolina Educational Television Commission was created. Public school teachers and South Carolina state agencies began to use the services of ETV. Now ETV broadcasts PBS shows like Zoom and Cyberchase.

Digital Television

We have come a long way and now, “The sky’s the limit.” We have regular television, known as terrestrial (land), cable which brings signals through underground cable, microwave signal transmission, and satellite. Today there are many satellites orbiting the earth. Transmitters on the ground are beaming signals up to the satellite, and then they are beamed back down to another receiver. etv satellites send and receive digital signals

ETV and PBS are making breakthroughs in making new types of television available. Digital television (DTV) and interactive television (ITV) are transforming TV as we know it. DTV will give us TV with high quality sound and picture. Digital technology also allows a lot of data to be transmitted into our homes to be used by the computer or television set. Interactive television uses digital technology and educational programming to make shows like Eye Wonder and Cyberchase an interactive adventure. The future of DTV is coming soon to a television near you!eyewonder and cyberchase explore math and science in the real world

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