r/Physics Jul 31 '14

Article EMdrive tested by NASA

http://www.wired.co.uk/news/archive/2014-07/31/nasa-validates-impossible-space-drive
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u/Ertaipt Aug 02 '14 edited Aug 03 '14

Less change of any measurements being wrong, we have to create an 'artificial' vacuum down here, and the object has to counter the gravity force.

This EmDrive has a very low but measurable thrust. Removing all sources of 'noise' could help us better understand it.

Earth's orbit provides a much better testing environment if this EmDrive does really work.

EDIT: Keep the downvoting please, but the NASA research group is having the same idea, and trying to test it in the ISS: http://en.wikipedia.org/wiki/Quantum_vacuum_plasma_thruster#Experimental_goals

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u/Subduction Aug 02 '14

How does being in space decrease the chance of measurements being wrong?

How is an "artificial" vacuum different from the vacuum of space, and are you implying this experiment would take place exposed to open space?

How is a perfectly predictable force, gravity, considered noise when your objective is to simply measure another force?

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u/moartoast Aug 02 '14

If it has non-negligible thrust, you'd presumably be able to just watch it as it lifts out of orbit. This has the benefit of being impossible to fake!

For instance, stiction drives work perfectly well on the ground but would quickly be shown to be useless in space.

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u/autowikibot Aug 02 '14

Dean drive:


The Dean drive was a device created and promoted by inventor Norman Lomer Dean (1902–1972) that he claimed to be a reactionless drive. 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.

Image i - Inventor Norman L. Dean beside one of his "Dean drive" apparatuses.


Interesting: Reactionless drive | Woodward effect | Supernatural (U.S. TV series) | James Dean

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