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history.md

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 This is a brief summary of history of [technology](technology.md) and [computers](computer.md) (and some other things).
 
-The earliest known appearance of technology related to humans is the use of **stone tools** of hominids in Africa some two and a half million years ago. Learning to start and control **fire** was one of the most important advances of earliest humans; this probably happened hundreds of thousands to millions years ago, even before modern humans. Around 8000 BC the **[Agricultural Revolution](agricultural_revolution.md)** happened: this was a disaster -- as humans domesticated animals and plants, they had to abandon the comfortable life of hunters and gatherers and started to suffer greatly from the extremely hard [work](work.md) on their fields (this can be seen e.g. from their bones). This led to the establishment of first cities. Primitive **writing** can be traced to about 7000 BC to China. **Wheel** was another extremely useful technology humans invented, it is not known exactly when or where it appeared, but it might have been some time after 5000 BC -- in Ancient Egypt **The Great Pyramid** was built around 2570 BC still without the knowledge of wheel. Around 4000 BC **history starts with first written records**. Humans learned to smelt and use metals approximately 3300 BC (**Bronze Age**) and 1200 BC (**Iron Age**). **[Abacus](abacus.md)**, one of the simplest devices aiding with computation, was invented roughly around 2500 BC. However people used primitive computation helping tools, such as bone ribs, probably almost from the time they started trading. Babylonians in around 2000 BC were already able to solve some forms of **[quadratic equations](quadratic_equation.md)**.
+The earliest known appearance of technology related to humans is the use of **stone tools** of hominids in Africa some two and a half million years ago. Learning to start and control **[fire](fire.md)** was one of the most important advances of earliest humans; this probably happened hundreds of thousands to millions years ago, even before modern humans. Around 8000 BC the **[Agricultural Revolution](agricultural_revolution.md)** happened: this was a disaster -- as humans domesticated animals and plants, they had to abandon the comfortable life of hunters and gatherers and started to suffer greatly from the extremely hard [work](work.md) on their fields (this can be seen e.g. from their bones). This led to the establishment of first cities. Primitive **writing** can be traced to about 7000 BC to China. **[Wheel](wheel.md)** was another extremely useful technology humans invented, it is not known exactly when or where it appeared, but it might have been some time after 5000 BC -- in Ancient Egypt **The Great Pyramid** was built around 2570 BC still without the knowledge of wheel. Around 4000 BC **history starts with first written records**. Humans learned to smelt and use metals approximately 3300 BC (**Bronze Age**) and 1200 BC (**Iron Age**). **[Abacus](abacus.md)**, one of the simplest devices aiding with computation, was invented roughly around 2500 BC. However people used primitive computation helping tools, such as bone ribs, probably almost from the time they started trading. Babylonians in around 2000 BC were already able to solve some forms of **[quadratic equations](quadratic_equation.md)**.
 
 After 600 BC the Ancient Greek [philosophy](philosophy.md) starts to develop which would lead to strengthening of rational, [scientific](science.md) thinking and advancement of [logic](logic.md) and [mathematics](math.md). Around 300 BC Euklid wrote his famous *Elements*, a mathematical work that proves theorems from basic [axioms](axiom.md). Around 400 BC **[camera obscura](camera_obscura.md)** was already described in a written text from China where **[gears](gear.md)** also seem to have been invented soon after. Ancient Greeks could communicate over great distances using **Phryctoria**, chains of fire towers placed on mountains that forwarded messages to one another using light. 234 BC Archimedes described the famous [Archimedes screw](archimedes_screw.md) and created an **[algorithm](algorithm.md) for computing the number [pi](pi.md)**. In 2nd century BC the **Antikythera mechanism, the first known [analog](analog.md) computer** is made to predict movement of heavenly bodies. Romans are known to have been great builders, they built many roads and such structures as the Pantheon (126 AD) and aqueducts with the use of their own type of concrete and advanced understanding of physics.