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Author Topic: "NASA Confirms "Impossible" Propellant-free Microwave Thruster" - your thought?  (Read 1829 times)

Offline McKay

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I read in a few articles that popped up a few days ago in multiple news sites where it was said that NASA has confirmed a propellant-less thruster possibility. (this, for example: http://www.wired.co.uk/news/archive/2014-07/31/nasa-validates-impossible-space-drive ) They think the microwaves resonating might interact with the so called virtual particles of vacuum to create thrust, to push against.
What do you think about this? Have they found a long sought for way to push against space itself? Might this be better explained with un-popular pilot waves being produced and pushed against without matter particles? Or you think this is complete bogus?
I even read in a similar article where it was mentioned (of course, I cant find the exact one as there are quite many of them popping up) that using superconducting materials and some extra fine-tuning they could create a ton of thrust using one kilowatt of power, which seems rather too good to be true.


 

Offline alancalverd

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Nothing impossible here.

A rocket motor doesn't need anything to "push against". It works by conservation of momentum: if you throw stones or atoms out of the back of a spaceship, the spaceship moves forward so that the net change of momentum is zero.

Microwaves are electromagnetic energy - photons. The momentum of a photon of energy E is E/c where E is the energy of the photon and c is the velocity of light. So you generate lots of photons and squirt some out of the back of the ship, and the ship accelerates forward. There's no need for particularly large accelerating forces when exploring deep space: once you are in free fall, well clear of any convergent gravitational field, you can keep the engine running at low thrust continuously until the ship reaches a relativistic speed.

The reason for using microwaves rather than higher energy light photons is the efficiency of generating them from a purely electrical input, and the ease with which they can be focussed and directed. The nice thing about a resonant cavity is that it works best in a good hard vacuum - like space.
 

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