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EmDrive  (Source:
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: China isn't 40 years behind us anymore.
By DiscoWade on 2/10/2013 9:22:42 AM , Rating: 3
When I was in college, there was one type of question that really annoyed the students. If a teacher asked a question that began with "What do you think ..." the students were confused. They were used to being lectured to, to being told what to know. Now someone comes along and tries to get them to reason, they did not like that.

Have you noticed that?

In my opinion, a teacher should give you knowledge and show you how to learn. We should be taught how to verify facts and how to reason.

By StevoLincolnite on 2/10/2013 11:11:07 PM , Rating: 2
In my opinion, a teacher should give you knowledge and show you how to learn. We should be taught how to verify facts and how to reason.

People should be taught how to learn for themselves.


Everyone has access to the largest repository of information ever built by man (The Internet), yet so many people simply don't know how to tap into it to get the information and learn for themselves.

For example, my disc player in my car started playing up, so bought a new one, I had no idea what wires went where so I looked it up online and... Presto! Problem solved.

I think these days people should be taught at a young age on how to research online, they will be better for it for the rest of their lives.

"What would I do? I'd shut it down and give the money back to the shareholders." -- Michael Dell, after being asked what to do with Apple Computer in 1997

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