©2012, tesccc change grade 2 unit 7, lesson 1. ripple effect ©2012, tesccc
DESCRIPTION
Bicycle ©2012, TESCCCTRANSCRIPT
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Change
Grade 2 Unit 7, Lesson 1
Ripple Effect
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Bicycle
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Communication
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Ancient times
In ancient times, people recorded information on clay or wax tablets using sticks.
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100-1400
Once paper, pens, and inks were invented, people copied books by hand. Most people did not have access to information.
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Printing
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1400Printing PressIn 1439, Gutenberg invented a machine that used movable type. This printing press made information more generally available.
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1714Typewriter
The first typewriter was invented in 1714, but it did not become widely used until the 1800s. Now we use computers to type information.
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1838Telegraph (and Morse Code)
The invention of the telegraph allowed people to send information long distances by using bursts of electricity over wires.
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1896TelephoneInformation could be exchanged immediately with the invention of the telephone.
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Telephone
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1927Television
With the invention of television in 1927, visual information could also be shared.
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1940sComputer
The first modern computers were invented in the 1940s. They were as big as a room. Now, all sorts of information can be exchanged immediately!
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