Computer science PDF generated using the open source mwlib toolkit. See http://code.pediapress.com/ for more information. PDF generated at: Sat, 10 Dec 2011 02:24:16 UTC Contents Articles Main article 1 Computer science 1 Supporting article 12 History of computer science 12 References Article Sources and Contributors 18 Image Sources, Licenses and Contributors 19 Article Licenses License 20 1 Main article Computer science Computer science or computing science (abbreviated CS) is the study of the theoretical foundations of information and computation. It also includes practical techniques for their implementation and application in computer systems. Computer scientists invent algorithmic processes that create, describe, and transform information and formulate suitable abstractions to design and model complex systems.[1] [2] Computer science has many sub-fields; some, such as computational complexity theory, study the fundamental properties of computational problems, while others, such as computer graphics, emphasize the computation of specific results. Still others focus on the challenges in implementing computations. For example, programming language theory studies approaches to describe computations, while computer programming applies specific programming languages to solve specific computational problems, and human-computer interaction focuses on the challenges in making computers and computations useful, usable, and universally accessible to humans. The general public sometimes confuses computer scientists with other computer professionals having careers in information technology, or think that computer science relates to their own experience with computers, which typically involves activities such as gaming, web-browsing, and word-processing. However, the focus of computer science is more on understanding the properties of the programs used to implement software such as games and web-browsers, and using that understanding to create new programs or improve existing ones.[3] Computer science deals with the theoretical foundations of information, computation, and with practical techniques for their implementation and application. History The earliest foundations of what would become computer science predate the invention of the modern digital computer. Machines for calculating fixed numerical tasks, such as the abacus, have existed since antiquity. Wilhelm Schickard designed the first mechanical calculator in 1623, but did not complete its construction.[4] Blaise Pascal designed and constructed the first working mechanical calculator, the Pascaline, in 1642. Charles Babbage designed a difference engine and then a general-purpose Analytical Engine in Victorian times,[5] for which Ada Lovelace wrote a manual. Because of this work she is regarded today as the world's first programmer.[6] Around 1900, punched card machines were introduced. During the 1940s, as newer and more powerful computing machines were developed, the term computer came to refer to the machines rather than their human predecessors.[7] As it became clear that computers could be used for more than just mathematical calculations, the field of computer science broadened to study computation in general. Computer science began to be established as a distinct academic discipline in the 1950s and early 1960s.[8] [9] The world's first computer science degree program, the Cambridge Diploma in Computer Science, began at the Computer science 2 University of Cambridge Computer Laboratory in 1953. The first computer science degree program in the United States was formed at Purdue University in 1962.[10] Since practical computers became available, many applications of computing have become distinct areas of study in their own right. Although many initially believed it was impossible that computers themselves could actually be a scientific field of study, in the late fifties it gradually became accepted among the greater academic population.[11] It is the now well-known IBM brand that formed part of the computer science revolution during this time. IBM (short for International Business Machines) released the IBM 704 and later the IBM 709 computers, which were widely used during the exploration period of such devices. "Still, working with the IBM [computer] was frustrating...if you had misplaced as much as one letter in one instruction, the program would crash, and you would have to start the whole process over again".[11] During the late 1950s, the computer science discipline was very much in its developmental stages, and such issues were commonplace. Time has seen significant improvements in the usability and effectiveness of computer science technology. Modern society has seen a significant shift from computers being used solely by experts or professionals to a more widespread user base. Initially, computers were quite costly, and for their most-effective use, some degree of human aid was needed, in part by professional computer operators. However, as computers became widespread and far more affordable, less human assistance was needed, although residues of the original assistance still remained. Major achievements Despite its short history as a formal academic discipline, computer science has made a number of fundamental contributions to science and society. These include: • The start of the "digital revolution," which includes the current Information Age and the Internet.[13] • A formal definition of computation and computability, and proof that there are computationally unsolvable and intractable problems.[14] • The concept of a programming language, a tool for the precise expression of methodological information at various levels of abstraction.[15] • In cryptography, breaking the Enigma machine was an important factor contributing to the Allied victory in World War II.[12] • Scientific computing enabled practical evaluation of processes and situations of great complexity, as well as experimentation entirely The German military used the Enigma machine by software. It also enabled advanced study of the mind, and (shown here) during World War II for mapping of the human genome became possible with the Human communication they thought to be secret. The Genome Project.[13] Distributed computing projects such as large-scale decryption of Enigma traffic at Bletchley Park was an important factor that Folding@home explore protein folding. [12] contributed to Allied victory in WWII. • Algorithmic trading has increased the efficiency and liquidity of financial markets by using artificial intelligence, machine learning, and other statistical and numerical techniques on a large scale.[16] • Image synthesis, including video by computing individual video frames. • Human language processing, including practical speech-to-text conversion and automated translation of languages • Simulation of various processes, including computational fluid dynamics, physical, electrical, and electronic systems and circuits, as well as societies and social situations (notably war games) along with their habitats, among many others. Modern computers enable optimization of such designs as complete aircraft. Notable in electrical and electronic circuit design are SPICE as well as software for physical realization of new (or modified) Computer science 3 designs. The latter includes essential design software for integrated circuits. Philosophy A number of computer scientists have argued for the distinction of three separate paradigms in computer science. Peter Wegner argued that those paradigms are science, technology, and mathematics.[17] Peter Denning's working group argued that they are theory, abstraction (modeling), and design.[18] It has also been argued that they are the "rationalist paradigm" (which treats computer science as branch of mathematics, which is prevalent in theoretical computer science, and mainly employs deductive reasoning), the "technocratic paradigm" (which might be found in engineering approaches, most prominently in software engineering), and the "scientific paradigm" (which approaches computer-related artifacts from the empirical perspective of natural sciences, and identifiable in some branches of artificial intelligence.[19] Name of the field The term "computer science" was first coined by the numerical analyst George Forsythe in 1961.[20] Despite its name, a significant amount of computer science does not involve the study of computers themselves. Because of this, several alternative names have been proposed. Certain departments of major universities prefer the term computing science, to emphasize precisely that difference. Danish scientist Peter Naur suggested the term datalogy, to reflect the fact that the scientific discipline revolves around data and data treatment, while not necessarily involving computers. The first scientific institution to use the term was the Department of Datalogy at the University of Copenhagen, founded in 1969, with Peter Naur being the first professor in datalogy. The term is used mainly in the Scandinavian countries. Also, in the early days of computing, a number of terms for the practitioners of the field of computing were suggested in the Communications of the ACM – turingineer, turologist, flow-charts-man, applied meta-mathematician, and applied epistemologist.[21] Three months later in the same journal, comptologist was suggested, followed next year by hypologist.[22] The term computics has also been suggested.[23] In continental Europe, terms derived from "information" and "automatic" are often used, e.g. informatique (French), Informatik