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The Dean drive was a device created and promoted by inventor Norman Lomer Dean (1902–1972) that he claimed to be a reactionless drive.〔(【引用サイトリンク】title=Arcturas Project )〕 Dean claimed that his device was able to generate a uni-directional force in free space, in violation of Newton's third law of motion from classical physics. His claims generated notoriety because, if true, such a device would have had enormous applications, completely changing human transport, engineering, space travel and more. Dean made several controlled private demonstrations of a number of different devices, however no working models were ever demonstrated publicly or subjected to independent analysis and Dean never presented any rigorous theoretical basis for their operation. Analysts conclude that the motion seen in Dean's device demonstrations was likely reliant on unsymmetrical frictional resistance between the device and the surface on which the device was set, resulting in the device moving in one direction when in operation, driven by the vibrations of the apparatus.〔 ==Early publicity== The Dean drive obtained a good deal of publicity in the 1950s and 1960s via the columns and conference presentations of John W. Campbell, the longtime editor of ''Astounding Science Fiction'' magazine. At that time, Campbell believed that his magazine had to change society by helping breakthrough research that was rejected by "mainstream" science, and he promoted a series of far-reaching ideas that had dubious scientific basis, like dianetics, dowsing, the Hieronymus machine, or the Dean Drive. Campbell believed that the device worked and claimed to have witnessed it operating on a bathroom scale. The weight reading on the scale appeared to decrease when the device was activated. He subsequently published photographs of the scale with the drive stopped and running. The June 1960 cover of ''Astounding'' magazine featured a painting of a United States submarine near Mars, supposedly propelled there by a Dean drive.〔 Cover picture by John Schoenherr; the submarine is designated "USSS-1" and 578, so presumably modeled on .〕 Dean, who was trying to find potential buyers for his technology, was secretive about the details of how it was supposed to work, but it was said to contain asymmetrical rotating weights and to generate a great deal of vibration. Dean and Campbell claimed that Newton’s laws of motion were only an approximation, and that Dean had discovered a fourth law of motion. This has been described as a nonlinear correction to one of Newton’s laws, which, if correct, would allegedly have rendered a reactionless drive feasible after all. One result of the initial articles in Campbell's magazine was that two other researchers, William O. Davis and G. Harry Stine, visited Dean and witnessed a demonstration. Results of this visit were published in the May 1962 and June 1976 issues of the magazine, the name of which had been changed by Campbell from ''Astounding'' to ''Analog''. Davis witnessed a demonstration by Dean, and wrote: "It was the conclusion of both Harry Stine and myself that we had witnessed a real anomaly and that the possibility of fraud in the demonstration was slim."〔 Sci-fi writer Jerry Pournelle pointed out that Stine was well qualified to make a judgment on the device, but that he was more gullible than other persons.〔 Davis' 1962 article was titled, "The Fourth Law of Motion", and described a hypothesis in which Dean's device (and others) could conserve momentum invisibly via "gravitational-inertial radiation". One detail of Davis' hypothesis involved the forces of action and reaction — physical bodies can respond to those forces nonsimultaneously, or "out of phase" with each other. Davis' 1976 article, "Detesters, Phasers and Dean Drives", reported his tests with Stine, an engineer who built devices to test that aspect of the hypothesis. Stine said they were able to reliably create and reproduce a 3-degree phase angle in a linear system, which was not possible according to ordinary physics. But then they failed to reproduce the effect in a pendulum system, using a rocket-powered ballistic pendulum. The pendulum test would have proved beyond doubt that the Drive worked, but Dean refused to subject the original Dean Drive to a pendulum test. Campbell reported that he had seen the Drive subjected to a pendulum test, but Davis and Stine suspect that he only reported what Dean had told him and had never seen the actual test. Davis says the question can't be settled until the pendulum test is made. Their research was terminated in 1965 when the national economy took a downturn, and was never resumed.〔 The 1976 article was an attempt to get research restarted, but apparently failed. In 1984, physicist Amit Goswami wrote that "Dean's machine made such a splash with readers of science fiction that it is now customary in SF circles to refer to a reactionless drive as a Dean drive." 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「Dean drive」の詳細全文を読む スポンサード リンク
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