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A machine is a tool containing one or more parts that uses energy to perform an intended action. Machines are usually powered by mechanical, chemical, thermal, or electrical means, and are often motorized. Historically, a power tool also required moving parts to classify as a machine. However, the advent of electronics has led to the development of power tools without moving parts that are considered machines.〔 A simple machine is a device that simply transforms the direction or magnitude of a force, but a large number of more complex machines exist. Examples include vehicles, electronic systems, molecular machines, computers, television, and radio. ==Etymology== The word ''machine'' derives from the Latin word ''machina'',〔''The American Heritage Dictionary'', Second College Edition. Houghton Mifflin Co., 1985.〕 which in turn derives from the Greek (Doric , Ionic "contrivance, machine, engine",〔("μηχανή" ), Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus project〕 a derivation from "means, expedient, remedy"〔("μῆχος" ), Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus project〕). A wider meaning of "fabric, structure" is found in classical Latin, but not in Greek usage. This meaning is found in late medieval French, and is adopted from the French into English in the mid-16th century. In the 17th century, the word could also mean a scheme or plot, a meaning now expressed by the derived machination. The modern meaning develops out of specialized application of the term to stage engines used in theater and to military siege engines, both in the late 16th and early 17th centuries. The OED traces the formal, modern meaning to John Harris' ''Lexicon Technicum'' (1704), which has: :''Machine, or Engine, in Mechanicks, is whatsoever hath Force sufficient either to raise or stop the Motion of a Body... Simple Machines are commonly reckoned to be Six in Number, viz. the Ballance, Leaver, Pulley, Wheel, Wedge, and Screw... Compound Machines, or Engines, are innumerable.'' The word ''engine'' used as a (near-)synonym both by Harris and in later language derives ultimately (via Old French) from Latin ''ingenium'' "ingenuity, an invention". 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Machine」の詳細全文を読む スポンサード リンク
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