Naked Science Forum
On the Lighter Side => That CAN'T be true! => Topic started by: McKay on 15/08/2014 00:08:08
-
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.
-
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.
-
WOW NICE!
-
Nothing impossible here.
You didn't check how it "works", did you?
It's true that simply pointing a magnetron out of the back of the spaceship would provide thrust.
But that's not how the EM drive is said to work.
It bounces em radiation back and to inside a closed conducting container.
And that shouldn't produce any thrust.
I think it's fair to assume that, since we haven't heard much since this thread started 4 years ago, it probably isn't real.
-
This 2018 paper (https://www.researchgate.net/publication/325177082_The_SpaceDrive_Project_-_First_Results_on_EMDrive_and_Mach-Effect_Thrusters) raises doubts as to previously overlooked potential sources of error in prior experimental setups, but does not wholly refute the possibility.
-
This looks promising
-
This looks promising
No, it does not.