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The telegraph
The inventor was Samuel Morse
It was instantaneous, long-distance, inexpensive comunication,
Current comunication systems make it possible to comunicate with almost any area of the planet instantly and inexpensively.
- They used the Morse Code:
- It was based on using dots and dashes.
- This was a way to represent information that can be understood by the seder and the reciver.
- The telegraph was the begining of a technological revolution in communications. -
Fixed telephone
The inventor was Antonio Meucci, an unkown Italian immigrant.
But it was thanks to Alexander Graham Bell that the telephone was industrally produced, popularised and subsequently perfected.
- The telephone has tranformed to people's lives, without the telephone we couldn't do most of thinks that we do nowadays. -
Radio
Discovered by JC Maxwell, a Scottish phisicist.
- The radio is a telecommunications system that enables the transmission of remote signals through a type of electromagnetic waves.
- In 1887 H.R. Hertz demostred the hypothesis.
- In 1985 G.Marconi buil the first wirelesscommunication system.
- In 1906 R. Fessenden invented the radio we know today. -
Television
Invented by Jonh L. Baird, Charles F. Jenkins and Vladimir Zworikin.
- In the 30s television broadcasts began.
- In 1936 the first olympic games were broadcast.
- In the 50s and 60s came the popularization of the TV.
- Each point on the screan is a pixel, and a pixel consist of 3 lights emmiters, one red, one blue and one green.
There are diferent types of TV:
- Terrestial television
- Satellite television
- Cable television
- Internet television -
Mobile phone
The inventor was Martin Cooper.
Mobile phone, allows us to communicate through radio waves with people around the world.
- The popularization of the mobile phone began in the 1990s.
- In 2001, there were billions of mobile phones lines in the world.
- In 2008 there were 4 billions of mobile lines.
- Mobile phones are used for a lot of things nowadays, text messages, voice message, calls, etc.
There can also be coverage problems, that's because the radio waves become weaken with distance.
