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EmDrive  (Source: emdrive.com)
It's a a propellantless microwave thruster that defies Newton's laws of motion

Chinese scientists have taken on a heavily criticized space drive idea that could one day launch satellites, deep space probes and even flying cars.

The research team hails from Northwestern Polytechnic University in Xi'an, and was led by Yang Juan. What they developed was a propellantless microwave thruster called EmDrive, which is a controversial idea because it goes against Newton's laws of motion -- and many have claimed to create a "propellantless" thruster before and failed.

Newton's laws of motion are all based on the idea that firing propellant out of the back at a high speed will push a craft forward. While solar cells offer infinite power, thrust is limited by propellant. Many have tried to get around this, but several scams have made this particular field a joke in the scientific world.

While space drives tend to rely on Newton's laws of motion, the EmDrive is a closed, conical container that has a net thrust toward the wide end when filled with resonating microwaves. This goes against Newton, who said that no closed system could have a net thrust. However, EmDrive works because the microwaves have a group velocity (the speed of a collection of electromagnetic waves) that is greater in one direction than the other -- which is where Albert Einstein's theory of relativity comes in.

British engineer Robert Shaywer, who began looking at the concept of a propellantless thruster when he opened his own company called Satellite Propulsion Research in 2001, is the original creator of the EmDrive. He made demonstration thrusters to prove it could be done, and even made sure the test results were accurate (meaning, the results weren't affected by friction, ionization, air currents, electromagnetic effects or interference). The first, made in 2003, had a thrust of 16 mN. This was enough to show it could be done.

However, he received a ton of criticism for his idea and was ridiculed in his own country. But the Chinese team at Northwestern Polytechnic University believed in his research and took the project head on to author the latest study, "Net Thrust Measurement of Propellantless Microwave Thruster."

The Northwestern Polytechnic University team was able to create the EmDrive with 720 mN of thrust with a couple of kilowatts of power.

So what purpose does EmDrive have? It could halve launch costs of satellites because as much as half the launch weight of these objects are attributed to propellant.

Shawyer is even working on a superconducting thruster that could be ready as soon as 2016. It would boost the Q value of the cavity, which determines the amount of thrust produced. He said it could be boosted by a factor of several thousand, possibly equating to a tonne of thrust per kilowatt of power.

Source: Wired



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RE: Interesting...keep moving forward
By Shadowself on 2/10/2013 6:35:14 PM , Rating: 4
quote:
Research into Cold Fusion continues in private and government facilities and there is progress being made.
What progress? Have they made even a single model that works 100% of the time always giving positive net energy out -- or can be "started and stopped under the experimenter's direct control" always with positive energy out? Not that I've ever heard been aware.

I was at the University of Utah when this broke (doing work on a different set of nuclear experiments in the physics department). [[Hey, sometimes it takes going out to a backwater area of the world to do certain research!]] I knew the physicists that broke away from their own research to help Ponds and Fleishman properly implement experiments and eliminate external sources of error to prove it out. A couple of them were friends of mine. I was involved in a couple of conferences about it. Several organizations put a lot of money into it -- including the State of Utah. They spent several 10s of millions trying to prove it true. Everyone -- yes, everyone -- involved wanted it to prove out. It was going to change the world.

However, it was not just badly documented. The two "nuclear chemists" didn't even know how to properly measure total energy output (the real data point) versus transient power output as a function of transient power input (something that can easily fake you out and appear to give you results that are not real).

Sure there are a few labs still chasing this, but no one I know has seen any concrete evidence that "Cold Fusion" gives any net energy output over time. Not one single experiment.

And before you bring it up, Muon based fusion can work (and has been shown to work) at "room temperature". While this does work, it has no where near a positive energy outcome as the energy to create the base particles requires much, much more energy than you get out the each fusion.


RE: Interesting...keep moving forward
By tng on 2/10/2013 11:43:46 PM , Rating: 2
quote:
What progress?
Just what I have heard from better minds than mine...

Despite all that you have said, there is still money being put into this and has been since the original experiment. I will assume that someone sees some potential in it.


RE: Interesting...keep moving forward
By Shadowself on 2/11/2013 4:50:28 PM , Rating: 2
quote:
Despite all that you have said, there is still money being put into this and has been since the original experiment. I will assume that someone sees some potential in it.
Some people still put money into the Flat Earth Society too.


RE: Interesting...keep moving forward
By tng on 2/11/2013 10:28:53 PM , Rating: 2
While I have my doubts as well, I am reminded about scientists quoted in a NY Times article from the mid 1800's saying that no human could survive at a speed of 60MPH (the speed of a new train engine that was being introduced).


"Well, we didn't have anyone in line that got shot waiting for our system." -- Nintendo of America Vice President Perrin Kaplan














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