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Inventor:Samuel Morse
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The Telegraph improved so it appeared a lots of new advances. For example multiplexing, to send more than one message at the same time whith the same cable.
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This telegraph transports mesages to the other point of the continent (Eastern US-California)
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Thease improvement allows to connect 2 continents through the sea(America-Europe)
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JC Maxewell, a Scottish physicist, proposed the theoretical existance of electromagnetic waves.
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Alexander Graham Bell invented the telephone with cable. There is a cable conecting the 2 fixed telephones. The sound is transmited along the cable in a electrical signal form.
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Maxwell's theory was demonstrated by H.R Hertz. He detected electromagnetic waves in in a device located 30 cm from the emitter.
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Finally appeard the cableless phone. Martin Cooper is considered as the father of the mobile phone.
The coverage area for a mobile device is divided into hexagonal parts called cells.
If you call to an other phone the signal will be sent to the base estation(cell) and then to the central. The central sends the information to the base estation 2 and then to the recipient. -
The necessari technology was invented by many enginiers (John L. Baird, Charles F. Jenkins and Vladimir Zworykin)
The television consists in the transmission of sound and moving images.
