Chapter 3计算机科学技术史

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Algebrization of Logic
• The algebrization of logic, primarily the work of Augustus de Morgan (1806-1871) and George Boole (1815-1864), was important to the transformation of Aristotelian logic into moden logic and to the introduction of logic machines in the automation of logical reasoning.
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Modeled Mental Process
• Most of these automata modeled physical rather than mental processes. Of the latter variety were several attempts to construct talking automata and perhaps more importantly van Kempelen’s 1769 chess player, which though fraudulent（欺诈） (hiding a man inside the player) engendered（产生） a seventy-year debate over the possibility of mechanizing human thought processes.
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3.3 The Development of Logic and Its Mechanization
• Another line of development, sometimes closely intertwined（纠缠） with the automata tradition, was the effort to mechanize logic, historically regarded as the most central of the rational processes.
1769，我国处于清朝乾隆年间，国内无大事。
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Descartes’s Dualism（二元论）
• Perhaps influenced by the elaborate clockwork automata of his time, Descartes （笛卡尔）philosophy explained even the most complex physical processes of the universe in terms of clocklike mechanisms. But the maintained a strict mind-body dualism, denying that mental processes can be explained in mechanical terms.
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The Great Civic Clocks
• The great civic（市民） clocks constructed in major European cities, beginning in the thirteenth century, also are part of this tradition. Human and other figures ornamenting （装饰） the clocks became animated at the tolling （敲钟）of certain hours. For example, from the clock at Strasbourg （法国城市） the three Magi（祭司） emerged and a cock crowed each day at dawn. Over time, in the late Middle Ages and the Renaissance（文艺复 兴）, these clockwork automata became more elaborate and were built separately from the civic clocks.
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Algebraic-Logical Synthesis
• Leibniz was enamored（倾心） with the power that algebraic symbolism and method had added to geometry during the previous century. In his De Arte Combinatoria (1666) and in later fragmentary works he described an "algebraic-logical synthesis" by which one could reason mechanically in all fields as one could reason in algebra. The first step was to devise a universal language, his "universal characteristic," for expressing thoughts in an unambiguous, symbolic way. 1666，我国处于清朝康熙年间，国内无大事。
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Algebraic-Logical Synthesis
• Leibniz experimented with various linguistic schemes, e.g., representing primitive ideas by prime numbers and complex ideas by the product of these numbers. He also moved towards an algebra of logic by implicitly giving logical interpretations to the algebraic operators and relations +, x, -, =. But he never achieved substantial results, and this work became widely known only in the twentieth century when his fragmentary writings were first published.
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3.2 The Automata Tradition
• The automata tradition extends back into antiquity （古代）. In the Hellenistic（希腊） period complex mechanisms were constructed to give the appearance of human animation （活泼）. For example, around 200 B.C., Heron of Alexandria constructed a theater in which the god Dionysius would emerge and spray wine from his staff while the Bacchants（酒神） danced in his honor. These Hellenistic mechanisms were powered in many different ways: by falling water, sand, or mustard （芥菜）seeds; heat; atmospheric pressure; and in one case by a primitive steam engine.
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• The computer was not the first calculating technology able to make logical decisions. Many punched-card systems, relay (继电器式 计算器), and electronic calculators of the 1930s and early 1940s had rudimentary (基本的) logical capabilities. But there is an even earlier stream of development, beginning around 1800, having as its central purpose the construction of machines capable of making logical decisions.
Yunnan University
பைடு நூலகம்
A History of Computer Science and Technology
Dr. Tong Li
Fall 2007
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Chapter 3 Logic Machines
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3.1 Introduction
• Without the ability to make logical decisions, computers would have nothing more than an uncontrolled, raw arithmetic power, which would make them only slightly more useful than simple adding machines.