Dean drive

The Dean drive or Dean device was invented by Norman L. Dean, who called it a "reactionless drive" — a mechanical device that could use energy to produce linear acceleration without the use of any reaction mass. Such a device, if it existed, would revolutionize space travel, since most of a rocket's weight is devoted to carrying reaction mass. Such a device violates Newtonian physics.

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The Dean drive obtained a good deal of publicity in the 1950s and 1960s via the columns of John W. Campbell, the longtime editor of Astounding Science Fiction magazine. Campbell apparently believed that the device worked. He claimed to have seen it running on a bathroom scale and to have seen the reading on the scale decrease when the device was activated. He subsequently published photographs of the scale with the drive stopped and running. One cover of Astounding had a realistic painting of a United States submarine orbiting the Earth, supposedly boosted into orbit by a Dean drive.

Related Topics:
1950s - 1960s - John W. Campbell - Astounding Science Fiction - United States - Submarine

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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 known to contain asymmetrical rotating weights and to generate a great deal of vibration.

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Campbell and Dean claimed that Newton's laws of motion were only an approximation, and that Dean had discovered a fourth law of motion, a nonlinear correction to one of Newton's laws, which, if correct, would have made the Dean drive feasible. Skeptics maintained that there were many possibilities for illusory effects, involving interactions of vibration, friction, resonance with the springs of the scale, instantaneous photographs of an oscillating scale reading, and so forth, to say nothing of outright deception.

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It is said that Dean first invented a set of levers so that his invention would climb up a pole or rope (U.S. Patent 2,886,976, filed 1956, issued 1959). Later, he is said to claim that the machine with improvement could rise and float in the air without any supporting rope or pole. This set of levers and counterweights and gears was said to be based on a principle that was claimed to be "rectifying centrifugal force". The machine supposedly incorporated an electric drill so that applying alternating current line power to the motor would turn the Dean machine's input shaft, which would convert the rotational energy into linear force. Aligned properly, this linear force would counteract gravity and thus the scale would show a decrease in weight.

Related Topics:
1956 - 1959

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Purportedly, several groups (including Westinghouse and the U.S. military) were interested in buying the device, if it worked, for sums of half a million dollars or more. Dean's paranoia and insistence upon cash before showing the device, kept any of the possible buyers from seeing the device. When buyers became insistent, Dean also required the delivery of a Nobel Prize in Physics as well.

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Norman Dean never succeeded in making a sale. As of 1999, Dean's son, Robert, was still appearing at anti-gravity conferences and giving presentations about his father's device.

Related Topics:
1999 - Anti-gravity

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The noted science-fiction writer and critic Damon Knight had this to say about the Dean drive in a chapter called "Campbell and his Decade" in his collection of essays about the science-fiction field In Search of Wonder:

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:Oh, the Dean Machine, the Dean Machine,

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:You put it right in a submarine,

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:And it flies so high that it can't be seen--

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:The wonderful, wonderful Dean Machine!

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Ordinarily the fate of something like the Dean drive, now "officially" classed as a reactionless drive, is complete and utter obscurity. But there may yet be more to the story than the aforementioned epitaph. Research into reactionless drives has recently gained a new respectability.

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In a paper entitled "The Challenge To Create The Space Drive" http://www.grc.nasa.gov/WWW/bpp/TM-107289.htm Marc G. Millis argues that a prerequisite to achieving this breakthrough is a description of the specific problems to be solved. This would have been scientific heresy only a few years ago when ANY such description would have been viewed as irrelevant because a reactionless drive was considered a complete impossibility.

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There are many good arguments as to why the Dean drive is impossible. One of the most pursuasive of these centers on the Dean patent. The patented device doesn't work as advertised.

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A more circular argument is that the Dean drive can't work because nobody has ever constructed a reactionless drive that works. That argument is just plain wrong. One type of reactionless drive has already been built and demonstrated, the electromagnetic tether. http://www.bookrags.com/sciences/astronomy/tethers-spsc-04.html

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The other big argument against the Dean drive is that it can't transfer momentum and therefore can't possibly work. (Like moving a sailboat by sitting in it and blowing on the sails.) Ordinary reaction drives like the rocket transfer momentum to the rest of the universe by tossing out reaction mass.

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While most of the attention is on the rocket, which speeds away to adventures in outer space, the ejected reaction mass acts to transfer momentum in the opposite direction. Eventually this momentum is transferred to the rest of the universe, so the old-fashioned rocket drive actually works.

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The Dean drive seems to lack a mechanism for momentum transfer...

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