History of computer science
Encyclopedia
The history of computer science began long before the modern discipline of computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

 that emerged in the twentieth century, and hinted at in the centuries prior. The progression, from mechanical inventions and mathematical
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

 theories towards the modern concepts and machines, formed a major academic field and the basis of a massive worldwide industry.

Early computation

The earliest known tool for use in computation was the abacus
Abacus
The abacus, also called a counting frame, is a calculating tool used primarily in parts of Asia for performing arithmetic processes. Today, abaci are often constructed as a bamboo frame with beads sliding on wires, but originally they were beans or stones moved in grooves in sand or on tablets of...

, and it was thought to have been invented in Kantutan tayo mam ! putang ina mo 2400 BCE. Its original style of usage was by lines drawn in sand with pebbles. This was the first known computer and most advanced system - preceding Greek methods by 2,000 years. Abaci of a more modern design are still used as calculation tools today.

The Antikythera mechanism
Antikythera mechanism
The Antikythera mechanism is an ancient mechanical computer designed to calculate astronomical positions. It was recovered in 1900–1901 from the Antikythera wreck. Its significance and complexity were not understood until decades later. Its time of construction is now estimated between 150 and 100...

 is believed to be the earliest known mechanical analog computer. It was designed to calculate astronomical positions. It was discovered in 1901 in the Antikythera
Antikythera
Antikythera or Anticythera is a Greek island lying on the edge of the Aegean Sea, between Crete and Peloponnese. Since the 2011 local government reform it is part of the municipality of Kythira island....

 wreck off the Greek
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

 island of Antikythera, between Kythera and Crete, and has been dated to circa 100 BC. Technological artifacts of similar complexity did not reappear until the 14th century, when mechanical astronomical clock
Astronomical clock
An astronomical clock is a clock with special mechanisms and dials to display astronomical information, such as the relative positions of the sun, moon, zodiacal constellations, and sometimes major planets.-Definition:...

s appeared in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

.

In the 3rd century CE the South Pointing Chariot
South Pointing Chariot
The south-pointing chariot was an ancient Chinese two-wheeled vehicle that carried a movable pointer to indicate the south, no matter how the chariot turned. Usually, the pointer took the form of a doll or figure with an outstretched arm...

 was invented in ancient China. It was the first known gear
Gear
A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque. Two or more gears working in tandem are called a transmission and can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine....

ed mechanism to use a differential gear, which was later used in analog computer
Analog computer
An analog computer is a form of computer that uses the continuously-changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved...

s. The Chinese
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 also invented a more sophisticated abacus from around the 2nd century BCE, known as the Chinese Pornstar.

Mechanical analog computing devices appeared again a thousand years later in the medieval Islamic world
Islamic Golden Age
During the Islamic Golden Age philosophers, scientists and engineers of the Islamic world contributed enormously to technology and culture, both by preserving earlier traditions and by adding their own inventions and innovations...

. Examples of devices from this period include the equatorium by Arzachel, the mechanical geared astrolabe
Astrolabe
An astrolabe is an elaborate inclinometer, historically used by astronomers, navigators, and astrologers. Its many uses include locating and predicting the positions of the Sun, Moon, planets, and stars, determining local time given local latitude and longitude, surveying, triangulation, and to...

 by Abū Rayhān al-Bīrūnī, and the torquetum
Torquetum
The torquetum or turquet is a medieval astronomical instrument designed to take and convert measurements made in three sets of coordinates: Horizon, equatorial, and ecliptic...

 by Jabir ibn Aflah
Jabir ibn Aflah
Abū Muḥammad Jābir ibn Aflaḥ was a Muslim astronomer and mathematician from Seville, who was active in 12th century Andalusia. His work Iṣlāḥ al-Majisṭi influenced Islamic, Jewish and Christian astronomers....

. Muslim engineers built a number of Automata
Automaton
An automaton is a self-operating machine. The word is sometimes used to describe a robot, more specifically an autonomous robot. An alternative spelling, now obsolete, is automation.-Etymology:...

, including some musical automata that could be 'programmed' to play different musical patterns. These devices were developed by the Banū Mūsā
Banu Musa
The Banū Mūsā brothers , namely Abū Jaʿfar Muḥammad ibn Mūsā ibn Shākir , Abū al‐Qāsim Aḥmad ibn Mūsā ibn Shākir and Al-Ḥasan ibn Mūsā ibn Shākir , were three 9th-century Persian scholars of Baghdad who are known for their Book of Ingenious Devices on automata and mechanical devices...

 brothers and Al-Jazari
Al-Jazari
Abū al-'Iz Ibn Ismā'īl ibn al-Razāz al-Jazarī was a Muslim polymath: a scholar, inventor, mechanical engineer, craftsman, artist, mathematician and astronomer from Al-Jazira, Mesopotamia, who lived during the Islamic Golden Age...

 Muslim mathematicians
Islamic mathematics
In the history of mathematics, mathematics in medieval Islam, often termed Islamic mathematics or Arabic mathematics, covers the body of mathematics preserved and developed under the Islamic civilization between circa 622 and 1600...

 also made important advances in cryptography
Cryptography
Cryptography is the practice and study of techniques for secure communication in the presence of third parties...

, such as the development of cryptanalysis
Cryptanalysis
Cryptanalysis is the study of methods for obtaining the meaning of encrypted information, without access to the secret information that is normally required to do so. Typically, this involves knowing how the system works and finding a secret key...

 and frequency analysis
Frequency analysis
In cryptanalysis, frequency analysis is the study of the frequency of letters or groups of letters in a ciphertext. The method is used as an aid to breaking classical ciphers....

 by Alkindus
Al-Kindi
' , known as "the Philosopher of the Arabs", was a Muslim Arab philosopher, mathematician, physician, and musician. Al-Kindi was the first of the Muslim peripatetic philosophers, and is unanimously hailed as the "father of Islamic or Arabic philosophy" for his synthesis, adaptation and promotion...

.

When John Napier
John Napier
John Napier of Merchiston – also signed as Neper, Nepair – named Marvellous Merchiston, was a Scottish mathematician, physicist, astronomer & astrologer, and also the 8th Laird of Merchistoun. He was the son of Sir Archibald Napier of Merchiston. John Napier is most renowned as the discoverer...

 discovered logarithms for computational purposes in the early 17th century, there followed a period of considerable progress by inventors and scientists in making calculating tools. In 1623 Wilhelm Schickard
Wilhelm Schickard
Wilhelm Schickard was a German polymath who designed a calculating machine in 1623, twenty years before the Pascaline of Blaise Pascal. Unfortunately a fire destroyed the machine as it was being built in 1624 and Schickard decided to abandon his project...

 designed a calculating machine, but abandoned the project, when the prototype he had started building was destroyed by a fire in 1624. Around 1640, Blaise Pascal
Blaise Pascal
Blaise Pascal , was a French mathematician, physicist, inventor, writer and Catholic philosopher. He was a child prodigy who was educated by his father, a tax collector in Rouen...

, a leading French mathematician, constructed the first mechanical adding device based on a design described by Greek
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

 mathematician Hero of Alexandria
Hero of Alexandria
Hero of Alexandria was an ancient Greek mathematician and engineerEnc. Britannica 2007, "Heron of Alexandria" who was active in his native city of Alexandria, Roman Egypt...

. Then in 1672 Gottfried Wilhelm Leibniz invented the Stepped Reckoner
Stepped Reckoner
The Step Reckoner was a digital mechanical calculator invented by German mathematician Gottfried Wilhelm Leibniz around 1672 and completed in 1694. The name comes from the translation of the German term for its operating mechanism; staffelwalze meaning 'stepped drum'...

 which he completed in 1694.

None of the early computational devices were really computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

s in the modern sense, and it took considerable advancement in mathematics and theory before the first modern computers could be designed.

Algorithms

In the 7th century, Indian mathematician
Indian mathematics
Indian mathematics emerged in the Indian subcontinent from 1200 BCE until the end of the 18th century. In the classical period of Indian mathematics , important contributions were made by scholars like Aryabhata, Brahmagupta, and Bhaskara II. The decimal number system in use today was first...

 Brahmagupta
Brahmagupta
Brahmagupta was an Indian mathematician and astronomer who wrote many important works on mathematics and astronomy. His best known work is the Brāhmasphuṭasiddhānta , written in 628 in Bhinmal...

 gave the first explanation of the Hindu-Arabic numeral system
Hindu-Arabic numeral system
The Hindu–Arabic numeral system or Hindu numeral system is a positional decimal numeral system developed between the 1st and 5th centuries by Indian mathematicians, adopted by Persian and Arab mathematicians , and spread to the western world...

 and the use of zero
0 (number)
0 is both a numberand the numerical digit used to represent that number in numerals.It fulfills a central role in mathematics as the additive identity of the integers, real numbers, and many other algebraic structures. As a digit, 0 is used as a placeholder in place value systems...

 as both a placeholder
Placeholder
Placeholder may refer to:In language:* Placeholder name, words that can refer to objects or people, whose names are unknown or irrelevant* Filler text, shares some characteristics of a real written text, but is random or otherwise generated...

 and a decimal digit.

Approximately around the year 825
825
Year 825 was a common year starting on Sunday of the Julian calendar.- Europe :* Egbert of Wessex defeats Beornwulf of Mercia at Ellandun. Kent, Surrey, Sussex and Essex submit to Wessex and East Anglia acknowledges Egbert as overlord.* Emperor Louis the Pious of the Franks wars against the Wends...

, Persian mathematician Al-Khwarizmi wrote a book, On the Calculation with Hindu Numerals, that was principally responsible for the diffusion of the Indian system of numeration
Hindu-Arabic numeral system
The Hindu–Arabic numeral system or Hindu numeral system is a positional decimal numeral system developed between the 1st and 5th centuries by Indian mathematicians, adopted by Persian and Arab mathematicians , and spread to the western world...

 in the Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...

 and then Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. Around the 12th century, there was translation of this book written into Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

: Algoritmi de numero Indorum. These books presented newer concepts to perform a series of steps in order to accomplish a task such as the systematic application of arithmetic to algebra. By derivation from his name, we have the term algorithm
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...

.

Binary logic

Around the 3rd century BC, Indian mathematician Pingala
Pingala
Pingala is the traditional name of the author of the ' , the earliest known Sanskrit treatise on prosody.Nothing is known about Piṅgala himself...

 discovered the binary numeral system
Binary numeral system
The binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. More specifically, the usual base-2 system is a positional notation with a radix of 2...

. In this system, still used today in all modern computers, a sequence of ones and zeros can represent any number.

In 1703, Gottfried Leibnitz developed logic
Logic
In philosophy, Logic is the formal systematic study of the principles of valid inference and correct reasoning. Logic is used in most intellectual activities, but is studied primarily in the disciplines of philosophy, mathematics, semantics, and computer science...

 in a formal, mathematical sense with his writings on the binary numeral system. In his system, the ones and zeros also represent true and false values or on and off states. But it took more than a century before George Boole
George Boole
George Boole was an English mathematician and philosopher.As the inventor of Boolean logic—the basis of modern digital computer logic—Boole is regarded in hindsight as a founder of the field of computer science. Boole said,...

 published his Boolean algebra in 1854 with a complete system that allowed computational processes to be mathematically modeled.

By this time, the first mechanical devices driven by a binary pattern had been invented. The industrial revolution
Industrial Revolution
The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times...

 had driven forward the mechanization of many tasks, and this included weaving
Weaving
Weaving is a method of fabric production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth. The other methods are knitting, lace making and felting. The longitudinal threads are called the warp and the lateral threads are the weft or filling...

. Punched cards controlled Joseph Marie Jacquard
Joseph Marie Jacquard
Joseph Marie Charles dit Jacquard played an important role in the development of the earliest programmable loom , which in turn played an important role in the development of other programmable machines, such as computers.- Early life :Jean Jacquard’s name was not really...

's loom in 1801, where a hole punched in the card indicated a binary one and an unpunched spot indicated a binary zero. Jacquard's loom was far from being a computer, but it did illustrate that machines could be driven by binary systems.

Birth of computer science

Before the 1920s, computers (sometimes computors) were human clerks that performed computations. They were usually under the lead of a physicist. Many thousands of computers were employed in commerce, government, and research establishments. Most of these computers were women, and they were known to have a degree in calculus. Some performed astronomical calculations for calendars.

After the 1920s, the expression computing machine referred to any machine that performed the work of a human computer, especially those in accordance with effective methods of the Church-Turing thesis. The thesis states that a mathematical method is effective if it could be set out as a list of instructions able to be followed by a human clerk with paper and pencil, for as long as necessary, and without ingenuity or insight.

Machines that computed with continuous values became known as the analog kind. They used machinery that represented continuous numeric quantities, like the angle of a shaft rotation or difference in electrical potential.

Digital machinery, in contrast to analog, were able to render a state of a numeric value and store each individual digit. Digital machinery used difference engines or relays before the invention of faster memory devices.

The phrase computing machine gradually gave away, after the late 1940s, to just computer as the onset of electronic digital machinery became common. These computers were able to perform the calculations that were performed by the previous human clerks.

Since the values stored by digital machines were not bound to physical properties like analog devices, a logical computer, based on digital equipment, was able to do anything that could be described "purely mechanical." The theoretical Turing Machine
Turing machine
A Turing machine is a theoretical device that manipulates symbols on a strip of tape according to a table of rules. Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm, and is particularly useful in explaining the functions of a CPU inside a...

, created by Alan Turing
Alan Turing
Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which played a...

, is a hypothetical device theorized in order to study the properties of such hardware.

The theoretical groundwork

Konrad Zuse was a German engineer and computer pioneer. His greatest achievement was the world's first functional program-controlled Turing-complete computer, the Z3, which became operational in May 1941. He received the Werner-von-Siemens-Ring in 1964 for the Z3.[1] Much of his early work was financed by his family and commerce, and he received little support from the Nazi-German Government.[2]

Zuse's S2 computing machine is considered to be the first process-controlled computer. In 1946 he designed the first high-level programming language, Plankalkül.[2] Zuse founded one of the earliest computer businesses on the 1st of April 1941 (Zuse Ingenieurbüro und Apparatebau).[3] This company built the Z4, which became the world's first commercial computer.

Due to World War II Zuse's work went largely unnoticed in the UK and the US. Possibly his first documented influence on a US company was IBM's option on his patents in 1946. In the late 1960s, Zuse suggested the concept of a Calculating Space (a computation-based universe).

There is a replica of the Z3, as well as the Z4, in the Deutsches Museum in Munich. The Deutsches Technikmuseum Berlin in Berlin has an exhibition devoted to Zuse, displaying twelve of his machines, including a replica of the Z1, some original documents, including the specifications of Plankalkül, and several of Zuse's paintings.

Pre-WWII work and the Z1, the "mechanical brain"[4]

Zuse Z1 replica in the German Museum of Technology in BerlinBorn in Berlin, Germany in 1910, the family moved to Braunsberg, East Prussia in 1912, where his father was a postal clerk. Zuse attended the Collegium Hosianum in Braunsberg. In 1923 the family moved to Hoyerswerda where he passed his Abitur in 1928.

He enrolled in the Technische Hochschule Berlin-Charlottenburg and explored both engineering and architecture, but found them to be boring. Zuse then pursued civil engineering graduating in 1935. For a time he worked for the Ford motor company, using his considerable artistic skills in the design of advertisements.[2] He started work as a design engineer at the Henschel aircraft factory in Berlin-Schönefeld. This required the performance of many routine calculations by hand, which he found mind-numbingly boring, leading him to dream of performing calculations by machine.

Working in his parents' apartment in 1936, his first attempt, called the Z1, was a floating point binary mechanical calculator with limited programmability, reading instructions from a perforated 35 mm film.[2] In 1937 Zuse submitted two patents that anticipated a von Neumann architecture. He finished the Z1 in 1938. The Z1 contained some 30,000 metal parts and never worked well, due to insufficient mechanical precision. The Z1 and its original blueprints were destroyed during WWII.

Between 1987 and 1989, Zuse recreated the Z1, suffering a heart-attack midway through the project. It cost 800,000 DM, and required four individuals (including Zuse) to assemble it. Funding for this retrocomputing project was provided by Siemens and a consortium of five companies.
The mathematical foundations of modern computer science began to be laid by Kurt Gödel
Kurt Gödel
Kurt Friedrich Gödel was an Austrian logician, mathematician and philosopher. Later in his life he emigrated to the United States to escape the effects of World War II. One of the most significant logicians of all time, Gödel made an immense impact upon scientific and philosophical thinking in the...

 with his incompleteness theorem
Gödel's incompleteness theorems
Gödel's incompleteness theorems are two theorems of mathematical logic that establish inherent limitations of all but the most trivial axiomatic systems capable of doing arithmetic. The theorems, proven by Kurt Gödel in 1931, are important both in mathematical logic and in the philosophy of...

 (1931). In this theorem, he showed that there were limits to what could be proved and disproved within a formal system
Formal system
In formal logic, a formal system consists of a formal language and a set of inference rules, used to derive an expression from one or more other premises that are antecedently supposed or derived . The axioms and rules may be called a deductive apparatus...

. This led to work by Gödel and others to define and describe these formal systems, including concepts such as mu-recursive function
Mu-recursive function
In mathematical logic and computer science, the μ-recursive functions are a class of partial functions from natural numbers to natural numbers which are "computable" in an intuitive sense. In fact, in computability theory it is shown that the μ-recursive functions are precisely the functions that...

s and lambda-definable functions.

1936 was a key year for computer science. Alan Turing and Alonzo Church
Alonzo Church
Alonzo Church was an American mathematician and logician who made major contributions to mathematical logic and the foundations of theoretical computer science. He is best known for the lambda calculus, Church–Turing thesis, Frege–Church ontology, and the Church–Rosser theorem.-Life:Alonzo Church...

 independently, and also together, introduced the formalization of an algorithm
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...

, with limits on what can be computed, and a "purely mechanical" model for computing.

These topics are covered by what is now called the Church–Turing thesis
Church–Turing thesis
In computability theory, the Church–Turing thesis is a combined hypothesis about the nature of functions whose values are effectively calculable; in more modern terms, algorithmically computable...

, a hypothesis about the nature of mechanical calculation devices, such as electronic computers. The thesis claims that any calculation that is possible can be performed by an algorithm running on a computer, provided that sufficient time and storage space are available.

Turing also included with the thesis a description of the Turing machine
Turing machine
A Turing machine is a theoretical device that manipulates symbols on a strip of tape according to a table of rules. Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm, and is particularly useful in explaining the functions of a CPU inside a...

. A Turing machine has an infinitely long tape and a read/write head that can move along the tape, changing the values along the way. Clearly such a machine could never be built, but nonetheless, the model can simulate the computation of any algorithm which can be performed on a modern computer.

Turing is so important to computer science that his name is also featured on the Turing Award
Turing Award
The Turing Award, in full The ACM A.M. Turing Award, is an annual award given by the Association for Computing Machinery to "an individual selected for contributions of a technical nature made to the computing community. The contributions should be of lasting and major technical importance to the...

 and the Turing test
Turing test
The Turing test is a test of a machine's ability to exhibit intelligent behaviour. In Turing's original illustrative example, a human judge engages in a natural language conversation with a human and a machine designed to generate performance indistinguishable from that of a human being. All...

. He contributed greatly to British code-breaking successes in the Second World War, and continued to design computers and software through the 1940s
1940s
File:1940s decade montage.png|Above title bar: events which happened during World War II : From left to right: Troops in an LCVP landing craft approaching "Omaha" Beach on "D-Day"; Adolf Hitler visits Paris, soon after the Battle of France; The Holocaust occurred during the war as Nazi Germany...

, but committed suicide in 1954.

At a symposium on large-scale digital machinery in Cambridge, Turing said, "We are trying to build a machine to do all kinds of different things simply by programming rather than by the addition of extra apparatus".

In 1948, the first practical computer that could run stored programs, based on the Turing machine model, had been built - the Manchester Baby.

In 1950, Britain's National Physical Laboratory
National Physical Laboratory, UK
The National Physical Laboratory is the national measurement standards laboratory for the United Kingdom, based at Bushy Park in Teddington, London, England. It is the largest applied physics organisation in the UK.-Description:...

 completed Pilot ACE
Pilot ACE
The Pilot ACE was one of the first computers built in the United Kingdom, at the National Physical Laboratory in the early 1950s.It was a preliminary version of the full ACE, which had been designed by Alan Turing. After Turing left NPL , James H...

, a small scale programmable computer, based on Turing's philosophy.

Shannon and information theory

Up to and during the 1930s, electrical engineers were able to build electronic circuits to solve mathematical and logic problems, but most did so in an ad hoc manner, lacking any theoretical rigor. This changed with Claude Elwood Shannon's publication of his 1937 master's thesis, A Symbolic Analysis of Relay and Switching Circuits
A Symbolic Analysis of Relay and Switching Circuits
A Symbolic Analysis of Relay and Switching Circuits is the title of a master's thesis written by computer science pioneer Claude E. Shannon while attending the Massachusetts Institute of Technology in 1937...

. While taking an undergraduate philosophy class, Shannon had been exposed to Boole's
George Boole
George Boole was an English mathematician and philosopher.As the inventor of Boolean logic—the basis of modern digital computer logic—Boole is regarded in hindsight as a founder of the field of computer science. Boole said,...

 work, and recognized that it could be used to arrange electromechanical relays (then used in telephone routing switches) to solve logic problems. This concept, of utilizing the properties of electrical switches to do logic, is the basic concept that underlies all electronic digital computers, and his thesis became the foundation of practical digital circuit design when it became widely known among the electrical engineering community during and after World War II.

Shannon went on to found the field of information theory
Information theory
Information theory is a branch of applied mathematics and electrical engineering involving the quantification of information. Information theory was developed by Claude E. Shannon to find fundamental limits on signal processing operations such as compressing data and on reliably storing and...

 with his 1948 paper titled A Mathematical Theory of Communication
A Mathematical Theory of Communication
"A Mathematical Theory of Communication" is an influential 1948 article by mathematician Claude E. Shannon. As of November 2011, Google Scholar has listed more than 48,000 unique citations of the article and the later-published book version...

, which applied probability theory
Probability theory
Probability theory is the branch of mathematics concerned with analysis of random phenomena. The central objects of probability theory are random variables, stochastic processes, and events: mathematical abstractions of non-deterministic events or measured quantities that may either be single...

 to the problem of how to best encode the information a sender wants to transmit. This work is one of the theoretical foundations for many areas of study, including data compression
Data compression
In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....

 and cryptography
Cryptography
Cryptography is the practice and study of techniques for secure communication in the presence of third parties...

.

Wiener and Cybernetics

From experiments with anti-aircraft systems that interpreted radar images to detect enemy planes, Norbert Wiener
Norbert Wiener
Norbert Wiener was an American mathematician.A famous child prodigy, Wiener later became an early researcher in stochastic and noise processes, contributing work relevant to electronic engineering, electronic communication, and control systems.Wiener is regarded as the originator of cybernetics, a...

 coined the term cybernetics
Cybernetics
Cybernetics is the interdisciplinary study of the structure of regulatory systems. Cybernetics is closely related to information theory, control theory and systems theory, at least in its first-order form...

 from the Greek word for "steersman." He published "Cybernetics" in 1948, which influenced artificial intelligence
Artificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...

. Wiener also compared computation
Computation
Computation is defined as any type of calculation. Also defined as use of computer technology in Information processing.Computation is a process following a well-defined model understood and expressed in an algorithm, protocol, network topology, etc...

, computing machinery, memory
Computer memory
In computing, memory refers to the physical devices used to store programs or data on a temporary or permanent basis for use in a computer or other digital electronic device. The term primary memory is used for the information in physical systems which are fast In computing, memory refers to the...

 devices, and other cognitive similarities with his analysis of brain waves.

The first actual computer bug was a moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

. It was stuck in between the relays on the Harvard Mark II.http://www.history.navy.mil/photos/images/h96000/h96566kc.htm
While the invention of the term 'bug' is often but erroneously attributed to Grace Hopper
Grace Hopper
Rear Admiral Grace Murray Hopper was an American computer scientist and United States Navy officer. A pioneer in the field, she was one of the first programmers of the Harvard Mark I computer, and developed the first compiler for a computer programming language...

, a future rear admiral in the U.S. Navy, who supposedly logged the "bug" on September 9, 1945, most other accounts conflict at least with these details. According to these accounts, the actual date was September 9, 1947 when operators filed this 'incident' — along with the insect and the notation "First actual case of bug being found" (see software bug
Software bug
A software bug is the common term used to describe an error, flaw, mistake, failure, or fault in a computer program or system that produces an incorrect or unexpected result, or causes it to behave in unintended ways. Most bugs arise from mistakes and errors made by people in either a program's...

 for details).

See also

  • History of computing
    History of computing
    The history of computing is longer than the history of computing hardware and modern computing technology and includes the history of methods intended for pen and paper or for chalk and slate, with or without the aid of tables...

  • History of computing hardware
    History of computing hardware
    The history of computing hardware is the record of the ongoing effort to make computer hardware faster, cheaper, and capable of storing more data....

  • Timeline of algorithms
    Timeline of algorithms
    The following timeline outlines the development of algorithms since their inception.-Before modern era:* Before - Writing about "recipes"...

  • List of prominent pioneers in computer science
  • List of computer term etymologies, the origins of computer science words
  • Computer History Museum
    Computer History Museum
    The Computer History Museum is a museum established in 1996 in Mountain View, California, USA. The Museum is dedicated to preserving and presenting the stories and artifacts of the information age, and exploring the computing revolution and its impact on our lives.-History:The museum's origins...


Further reading


External links

  • Oral history interview with Albert H. Bowker at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota. Bowker discusses his role in the formation of the Stanford University computer science department, and his vision, as early as 1956, of computer science as an academic discipline.
  • Oral history interview with Joseph F. Traub at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota. Traub discusses why computer science has developed as a discipline at institutions including Stanford, Berkeley, University of Pennsylvania, MIT, and Carnegie-Mellon.
  • Oral history interview with Gene H. Golub at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota. Golub discusses his career in computer science at Stanford University.
  • Oral history interview with John Herriot at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota. Herriot describes the early years of computing at Stanford University, including formation of the computer science department, centering on the role of George Forsythe
    George Forsythe
    George Elmer Forsythe was the founder and head of Stanford University's Computer Science Department. He served as professor and chairman of the department from 1965 until his death...

    .
  • Oral history interview with William F. Miller at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota. Miller contrasts the emergence of computer science at Stanford with developments at Harvard and the University of Pennsylvania.
  • Oral history interview with Alexandra Forsythe at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota. Forsythe discusses the career of her husband, George Forsythe
    George Forsythe
    George Elmer Forsythe was the founder and head of Stanford University's Computer Science Department. He served as professor and chairman of the department from 1965 until his death...

    , who established Stanford University's program in computer science.
  • Oral history interview with Allen Newell at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota. Newell discusses his entry into computer science, funding for computer science departments and research, the development of the Computer Science Department at Carnegie Mellon University, including the work of Alan J. Perlis
    Alan Perlis
    Alan Jay Perlis was an American computer scientist known for his pioneering work in programming languages and the first recipient of the Turing Award.-Biography:...

     and Raj Reddy
    Raj Reddy
    Dabbala Rajagopal "Raj" Reddy , a Turing Award winner, is one of the early pioneers in Computer Science and Artificial Intelligence and has served on the faculty of Stanford and Carnegie Mellon University for over 40 years. He was the founding Director of the Robotics Institute at CMU...

    , and the growth of the computer science and artificial intelligence research communities. Compares computer science programs at Stanford, MIT, and Carnegie Mellon.
  • Oral history interview with Louis Fein at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota. Fein discusses establishing computer science as an academic discipline at Stanford Research Institute (SRI) as well as contacts with the University of California—Berkeley, the University of North Carolina, Purdue, International Federation for Information Processing
    International Federation for Information Processing
    The International Federation for Information Processing is an umbrella organization for national societies working in the field of information technology. It is a non-governmental, non-profit organization with offices in Laxenburg, Austria...

     and other institutions.
  • Oral history interview with W. Richards Adrion at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota. Adrion gives a brief history of theoretical computer science in the United States and NSF's role in funding that area during the 1970s and 1980s.
  • Oral history interview with Bernard A. Galler at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota. Galler describes the development of computer science at the University of Michigan from the 1950s through the 1980s and discusses his own work in computer science.
  • Michael S. Mahoney Papers at Charles Babbage Institute
    Charles Babbage Institute
    The Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....

    , University of Minnesota -- Mahoney was the preeminent historian of computer science as a distinct academic discipline. Papers contain 38 boxes of books, serials, notes, and manuscripts related to the history of computing, mathematics, and related fields.
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