the RF resonant cavity thruster works!
 

Researchers at NASA's Johnson Space Center in Houston have found that a microwave thruster system that requires no propellant does indeed generate a small amount of thrust, Wired UK reported Thursday (July 31). If the technology pans out, it could make spaceflight far cheaper and speedier, potentially opening up much of the cosmos to exploration, advocates say.


http://news.yahoo.com/impossible-space-engine-may-actually-nasa-test-suggests-060904380.html

thrusted

cavity thruster...hehe

A small amount of thrust will still take a long time to accelerate a large amount of mass. That rule does not change in space.

It never ceases to amaze/amuse me at the number of people who think they can get something for nothing. It takes EXACTLY the same amount of energy to push one pound one mile in space (or anyplace else) no matter what the propulsion method.

The difference is in EFFICIENCY yes you can power a ca with water for example no question about it but the energy it takes to convert the water to useable hydrogen and oxygen is more than the energy created to fuel the car meaning it isnt efficient.

solar cells, batteries and other components are for sure becoming more energy efficient and battery technology is the big hurdle for electric cars and such, its coming for sure. Pie in the sky get something for nothing wont ct it though. I have no idea if this cavity thruster is energy efficient but my bet is that it likely isnt.

Additionally the idea that it would "open up most of the Cosmos to exploration" is largely wishfull thinking considering that all but a very very small percentage of the cosmos is lifetimes away even at the speed of light....in fact much of it is so far out of reach that humans havent inhabited earth anywhere near long enough to even receive the data.