New Spacedrive Concept?

[kcdodd]

On the original topic, I don't see how this is more useful than, say, using the radiation from a light bulb to push a spaceship around.

[clonan]

On the original topic, I don't see how this is more useful than, say, using the radiation from a light bulb to push a spaceship around.

#1 This may be better at transferring momentum than radiation
#2 It might scale better which could yield a higher ISP
#3 It can be entirely contained inside the hull which could improve the strength of the hull (fewer big holes)
#4 There is no visible indication that the engine is running (other than the movement of the ship)
#5 it could provide better maneuverability since you could rotate the engine rather than rotate the whole ship
#6 It is just plain cool!

[wisnij]

Magneto Electric Quantum Wheel

http://nextbigfuture.com/2009/12/magnet ... wheel.html
http://arxiv.org/abs/0912.1031

I'm a bit late to the party here, having been away on vacation, but I only just read that article today and I'm trying to figure out how it squares with conservation of momentum. Say you've got a device using this principle on a spaceship; you turn it on and the thing gains momentum in the +x direction. What physical form does the equal-but-opposite -x momentum take? It's not immediately clear to me upon reading the paper. Is it just emitting electromagnetic radiation, or accelerating charged particles in the vicinity of the ship, or something subtler than that?