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** happened: humans domesticated animals and plants and subsequently started to create 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 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.
Around 50 AD Heron of Alexandria, an Egyptian mathematician, created a number of highly sophisticated inventions such as a **vending machine** that accepted coins and gave out holy water, and a cart that could be "programmed" with strings to drive on its own.
In the 3rd century Chinese mathematician Liu Hui describes operations with **negative numbers**, even though negative numbers have already appeared before. In 600s AD an Indian astronomer Brahmagupta first used the number **[zero](zero.md)** in a systematic way, even though hints on the number zero without deeper understanding of it appeared much earlier.
Around 1450 a major technological leap known as the **Printing Revolution** occurred. Johannes Gutenberg, a German goldsmith, perfected the process of producing books in large quantities with the movable type press. This made books cheap to publish and buy and contributed to fast spread of information and better education.
During 1700s a major shift in civilization occurred, called the **[Industrial Revolution](industrial_revolution.md)**. It spanned roughly from 1750 to 1850. It was a process of rapid change in the whole society due to new technological inventions that also led to great changes in how people worked and lived their everyday lives. It started in Great Britain but quickly spread over the whole world. One of the main changes was the **transition from manual manufacturing to factory manufacturing** using machines and sources of energy such as coal. **[Steam engine](steam_engine.md) played a key role**. Work became more organized, society became industrionalized. This revolution became [criticized](ted_kaczynski.md) as it unfortunately opened the door for [capitalism](capitalism.md), made people less independent as everyone had to become a specialized cog in the society machine, at this time people started to measure time in minutes and lead very planned lives. People became enslaved by the system.
In 1712 Thomas Newcomen invented the first widely used **[steam engine](steam_engine.md)** used mostly for pumping water, even though steam powered machines have already been invented long time ago. The engine was significantly improved by [James Watt](james_watt.md) in 1776. Around 1770 Nicolas-Joseph Cugnot created a first somewhat working **steam-powered [car](car.md)**. In 1784 William Murdoch built a small prototype of a **[steam locomotive](steam_locomotive.md)** which would be perfected over the following decades, leading to a transportation revolution; people would be able to travel far away for work, the world would become smaller which would be the start of **[globalization](globalization.md)**. The railway system would make common people measure time with minute precision.
In 1792 Clause Chappe invented **[optical telegraph](optical_telegraph.md)**, also called *semaphore*. The system consisted of towers spaced up to by 32 km which forwarded textual messages by arranging big arms on top of the towers to signal specific letters. With this messages between Paris and Strasbourg, i.e. almost 500 km, could be transferred in under half an hour. The system was reserved for the government, however in 1834 it was **[hacked](hack.md)** by two bankers who bribed the tower operators to transmit information about stock market along with the main message (by setting specific positions of arms that otherwise didn't carry any meaning), so that they could get an advantage on the market.
By 1800 Alessandro Volta invented an **electric battery**. In 1827 André-Marie Ampère publishes a further work shedding light on [electromagnetism](electromagneticm.md). After this **[electric telegraph](telegraph.md)** would be worked on and improved by several people and eventually made to work in practice. In 1821 Michael Faraday invented the **[electromotor](electromotor.md)**. Georg Ohm and especially [James Maxwell](maxwell.md) would subsequently push the knowledge of electricity even further.
In 1822 [Charles Babbage](charles_babbage.md), a great English mathematician, completed the first version of a manually powered **[digital](digital.md) mechanical computer** called the Difference Engine to help with the computation of [polynomial](polynomial.md) [derivatives](derivative.md) to create mathematical tables used e.g. in navigation. It was met with success and further development was funded by the government, however difficulties of the construction led to never finishing the whole project. In 1837 Babbage designed a new machine, this time a **[Turing complete](turing_complete.md) general purpose computer**, i.e. allowing for programming with branches and loops, a true marvel of technology. It also ended up not being built completely, but it showed a lot about what computers would be, e.g. it had an [assembly](assembly.md)-like programming language, memory etc. For this computer [Ada Lovelace](ada_lovelace.md) would famously write the Bernoulli number algorithm.
1895 can roughly be seen as the year of **invention of radio**, specifically wireless [telegraph](telegraph.md), by Italian engineer and inventor Guglielmo Marconi. He built on top of work of others such as [Hertz](hertz.md) and [Tesla](tesla.md) and created a device with which he was able to wirelessly ring a bell at a distance over 2 km.
On December 17 1903 the Wright brothers famously performed the **first controlled flight of a motor airplane** which they built, in North Carolina. In repeated attempts they flew as far as 61 meters over just a few seconds.
Around 1915 [Albert Einstein](einstein.md), a German physicist, completed his **[General Theory of Relativity](relativity.md)**, a groundbreaking physics theory that describes the fundamental nature of space and time and gives so far the best description of the Universe since [Newton](newton.md). This would shake the world of science as well as popular culture and would enable advanced technology including nuclear energy, space satellites, high speed computers and many others.
Int 1907 Lee De Forest invented a practically usable **[vacuum tube](vacuum_tube.md)**, an extremely important part usable in electric devices for example as an amplifier or a switch -- this would enable construction of radios, telephones and later even primitive computers. The invention would lead to the [electronic](electronics.md) revolution.
In 1924 about 50% of US households own a car.
October 22 1925 has seen the invention of **[transistor](transistor.md)** by Julius Lilienfeld (Austria-Hungary), a component that would replace vacuum tubes thanks to its better properties, and which would become probably the most essential part of computers. At the time the invention didn't see much attention, it would only become relevant decades later.
In 1931 [Kurt Gödel](kurt_godel.md), a genius mathematician and logician from Austria-Hunagry (nowadays Czech Republic), published revolutionary papers with his [incompleteness theorems](incompleteness.md) which proved that, simply put, mathematics has fundamental limits and "can't prove everything". This led to [Alan Turing](turing.md)'s publications in 1936 that nowadays stand as the **foundations of [computer science](compsci.md)** -- he introduced a theoretical computer called the **[Turing machine](turing_machine.md)** and with it he proved that computers, no matter how powerful, will never be able to "compute everything". Turing also predicted the importance of computers in the future and has created several [algorithms](algorithm.md) for future computers (such as a [chess](chess.md) playing program).
In 1938 [Konrad Zuse](konrad_zuse.md), a German engineer, constructed **[Z1](z1.md), the first working electric mechanical [digital](digital.md) partially programmable computer** in his parents' house. It weighted about a ton and wasn't very reliable, but brought huge innovation nevertheless. It was programmed with punched film tapes, however programming was limited, it was NOT [Turing complete](turing_complete.md) and there were only 8 instructions. Z1 ran on a frequency of 1 to 4 Hz and most operations took several clock cycles. It had a 16 word memory and worked with [floating point](float.md) numbers. The original computer was destroyed during the war but it was rebuilt and nowadays can be seen in a Berlin museum.
In 1945 the construction of **the first electronic digital fully programmable computer** was completed at University of Pennsylvania as the US Army project. It was named **[ENIAC](eniac.md)** (Electronic Numerical Integrator and Computer). It used 18000 vacuum tubes and 15000 relays, weighted 27 tons and ran on the frequency of 5 KHz. [Punch cards](punch_card.md) were used to program the computer in its machine language; it was [Turing complete](turing_complete.md), i.e. allowed using branches and loops. ENIAC worked with signed ten digit decimal numbers.
On July 20 1969 **first men landed on the Moon** (Neil Armstrong and Edwin Aldrin) during the USA Apollo 11 mission. This tremendous achievement is very much attributed to the cold war in which USA and Soviet Union raced in space exploration. The landing was achieved with the help of a relatively simple on-board computer: Apollo Guidance Computer clocked at 2 MHz, had 4 KiB of [RAM](ram.md) and about 70 KB [ROM](rom.md). The assembly source code of its software is nowadays available online.
Shortly after, on 29 October 1969, another historical event would happen that could be seen as the start of perhaps the greatest technological revolution yet, the **start of the [Internet](internet.md)**. The first letter, "L", was sent over a long distance via **[ARPANET](arpanet.md)**, a new experimental computer [packet switching](packet_switching.md) network without a central node developed by US defense department (they intended to send "LOGIN" but the system crashed). The network would start to grow and gain new nodes, at first mostly universities. The network would become the Internet.
1st January 1970 is nowadays set as the start of the **Unix epoch**. It is the date from which [Unix time](unix_time.md) is counted. During this time the **[Unix](unix.md) [operating system](os.md), one of the most influential operating systems** was being developed at [Bell Labs](bell_labs.md), mainly by [Ken Thompson](ken_thompson.md) and [Dennis Ritchie](dennis_ritchie.md). Along the way they developed the famous [Unix philosophy](unix_philosophy.md) and also the **[C programming language](c.md)**, perhaps the most influential programming language in history. Unix and C would shape the technology far into the future, a whole family of operating systems called Unix-like would be developed and regarded as the best operating systems thanks to their minimalist design.
In 1983 **[Richard Stallman](rms.md) announced his [GNU](gnu.md) project and invented [free (as in freedom) software](free_software.md)**, a kind of software that is freely shared and developed by the people so as to respect the users' freedom. This kind of ethical software stands opposed to the [proprietary](proprietary.md) corporate software, it would lead to creation of some of the most important software and to a whole revolution in software development and its licensing, it would spark the creation of other movements striving for keeping ethics in the information age.
At the beginning of 1991 [Tim Berners-Lee](berners_lee.md) created the **[World Wide Web](www.md)**, a network of interlinked pages on the Internet. This marks another huge step in the Internet revolution, the Web would become the primary Internet service and the greatest software platform for publishing any kind of information faster and cheaper than ever before. It is what would popularize the Internet and bring it to the masses.
On 25 August 1991 **[Linus Torvalds](linus_torvalds.md) announced [Linux](linux.md)**, his project for a completely free as in freedom Unix-like [operating system](os.md). Linux would become part of [GNU](gnu.md) and later one of the biggest and most successful software projects in history. It would end up powering Internet servers and supercomputers as well as desktop computers of a great number of users. Linux proved that free software works and surpasses proprietary systems.
After this very recent history follows, it's hard to judge which recent events will be of historical significance much later. 1990s have seen a huge growth of computer power, video [games](game.md) such as [Doom](doom.md) led to development of [GPU](gpu.md)s and high quality computer graphics along with a wide adoption of computers by common people, which in turn helped the further growth of Internet. During the 90s we've also seen the rise of the [open source movement](open_source.md). Shortly after 2000 [Lawrence Lessig](lessig.md) founded [Creative Commons](creative_commons.md), an organization that came hand in hand with the [free culture](free_culture.md) movement inspired by the [free software movement](free_software.md). At this point over 50% of US households had a computer. Cell phones became a commonly owned item and after about 2005 so called "[smart](smart.md) phones" and other "smart" devices replaced them as a universal communication device capable of connecting to the Internet. Before 2020 we've seen a huge advancement in [neural network](neural_network.md) [Artificial Intelligence](ai.md) which will likely be the topic of the future. [Quantum computers](quantum.md) are being highly researched with already existing primitive prototypes; this will also likely be very important in the following years. Besides AI there has appeared a great interest and development of [virtual reality](vr.md), [drones](drone.md), electromobiles, robotic Mars exploration and others. However the society and technology has generally seen a decadence after 2010, [capitalism](capitalism.md) has pushed technology to become hostile and highly [abusive to users](capitalist_software.md), extreme [bloat](bloat.md) of technology causes highly inefficient, extremely expensive and unreliable technology. In addition society is dealing with a lot of serious issues such as the [global warming](global_warming.md) and many people are foreseeing a [collapse of society](collapse.md).
