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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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Interesting...keep moving forward
By Ytsejamer1 on 2/9/2013 11:28:19 AM , Rating: 5
I certainly wont' want to get into a debate on the details and whether this technology can work. My comment is more on a larger picture concept.

I'm glad people are still doing research on something where someone else or some governing science body already said, "nope, it won't or can't work". Science is never static...so what is false today, may ring true tomorrow.

I don't care where scientific discoveries come from. I'm just happy to see new things like this tried. At some point, something big will come of all the small discoveries.




RE: Interesting...keep moving forward
By tng on 2/9/2013 1:32:46 PM , Rating: 5
quote:
...he received a ton of criticism for his idea and was ridiculed in his own country.
Part of the problem with "Science" and scientists today is the knee-jerk reactions like this.

Instead of taking detailed accounts and duplicating/disproving the results, to many scientists nowdays will just say it breaks a law or goes against current theory, so it can't even be worth looking at. I guess the Chinese are more open to new ideas, if we are not careful, they will be running us in 20 years.


RE: Interesting...keep moving forward
By Shadowself on 2/9/2013 2:05:36 PM , Rating: 5
In this case, he has not performed any experiments that don't have significant flaws. Until he addresses those flaws in the experiments then no one is going to be willing to spend the time, money and effort to try to duplicate his claims.

As someone who has done what was once claimed "not possible" (it was in a rather obscure corner of physics), I can tell you the first thing you do is make your experiment as bullet proof as realistically possible. Then when someone finds an aspect for which you did not account, you redesign the experiment to handle that then redo the experiment. Rinse and repeat. Then, and only then, do you publish and go around claiming a new discovery. Otherwise it's "Cold Fusion" all over again.


RE: Interesting...keep moving forward
By EyeNstein on 2/9/2013 2:20:32 PM , Rating: 2
In this case the Chinese seem to have documented experiments. Including quantitative results of thrust/resonant drive effectiveness. It still bends some important laws but experiment always trumps theory.


RE: Interesting...keep moving forward
By Shadowself on 2/10/2013 6:20:07 PM , Rating: 5
quote:
It still bends some important laws but experiment always trumps theory.
ONLY -- truly ONLY -- if you run the experiment in such a way that other factors do not come into play and All -- truly ALL -- known external and internal methods that could produce the same type of effect are accounted for within the experiment design as well as fully documented in reports.

These guys have been asked legitimate questions about momentum transfer, ambient environment heating, etc. that they just wave their hands about and claim its either irrelevant or is such a small effect that it can be ignored.

The scientific and engineering communities at large are rightly scoffing at such blatant disregard for doing the experiments right and with enough formality and attention to all external sources of interaction.

This may prove to be real someday, but until they are willing to work through the setups in gory detail with outsiders and document how they have either FULLY accounted for or properly eliminated all forms of other possible sources of their claimed effect then it is just pseudoscience. Until that day, the scientific and engineering communities are right to treat it as such.


RE: Interesting...keep moving forward
By maugrimtr on 2/11/2013 8:51:45 AM , Rating: 5
The problem with these sorts of experiments is pretty simple. When you publish your results, you must immediately ensure that everyone else on the Planet can re-perform the exact same experiment and obtain the exact same result. A single documented experiment (subject to criticism - of a scientific nature) is just the beginning of the process we call the Scientific Method. Essentially, this boils down to the following: Propellantless thrust is impossible. It still is. One experiment simply casts a little doubt. Two independent experiments casts some serious doubt. Five experiments with ever more scientists suspecting it's real starts to qualify as scientific progression. One day, it may even graduate to being an observable "fact" (not Theory - if it works, it works - the Theory is about HOW it works).

Criticising Science for exhibiting traits like doubt and suspicion is mere ignorance. Scientists don't believe stuff - they KNOW stuff. Anything phrased as a belief is a THEORY (e.g. the theories of gravitation and relativity which are likely only approximations of some deeper truth).


RE: Interesting...keep moving forward
By nafhan on 2/11/13, Rating: 0
RE: Interesting...keep moving forward
By delphinus100 on 2/11/2013 10:14:24 PM , Rating: 2
quote:
Propellentless thrust is impossible? Not true. A laser or other light source aimed out the back would cause some small (but measurable) amount of thrust - with no propellent.


It depends on what you mean by 'propellant.' Photons do carry away momentum (solar sails could not work, otherwise), and that satisfies Newton's Third Law. They are the 'reaction mass.' That's what 'photon rockets' are about, and you described a crude but accurate form of one.


RE: Interesting...keep moving forward
By maugrimtr on 2/12/2013 8:36:53 AM , Rating: 2
Rocket which streams photons out the back is still streaming something, i.e. a propellant, out the back. Saying something is true does not make it true.


RE: Interesting...keep moving forward
By JKflipflop98 on 2/12/2013 10:03:46 AM , Rating: 2
Likewise, people have labelled things "impossible" for as long as they've been around. Things are impossible until they're not - just like propellantless thrusters. If you really understand science, you understand how dumb it is to call anything impossible.

Sailing around the world? Impossible once. Going faster than the speed of sound used to be impossible. Going to the moon? Same. And it won't be too long before I can add EM engines and FTL travel to that list.


RE: Interesting...keep moving forward
By 91TTZ on 2/12/2013 3:35:26 PM , Rating: 2
You seem to misunderstand basic science and the meaning of the word "impossible". You're confusing it with "not feasible".

At no time did anyone claim that sailing around the world is impossible.


By maugrimtr on 2/14/2013 9:33:04 AM , Rating: 2
In an infinite Universe with uncertain laws of Physics (the multiverse), nothing can ever be impossible.

That said, Science is a study of facts and evidence. You start with an assumption. Saying something is impossible is just such an assumption. It remains a truthful assertion UNTIL PROVEN OTHERWISE because it fits with what we already understand as being true.

If we took your approach, it misses the point of the Scientific Method. If you haven't proven it, it hasn't happened. It's one reason why a lot of social research appears to be self-obvious - we know that people deny Evolution because their reason has been overcome by blind faith. However, in Science that is NOT true unless it's proven, i.e. someone actually goes out, performs a poll, and collects hard data.


By nafhan on 2/12/2013 3:31:24 PM , Rating: 2
I've generally only seen the term propellant used for massive particles, but I wouldn't necessarily say your definition is wrong. It is however kind of irrelevant. You are probably looking for the term reactionless.

Anyway, the point I was making is that in both situations (photon drive and "EmDrive") you're deriving your forward movement from the expenditure of electrical energy. Thus both have the same advantage for space travel: no need to carry propellant mass . This sets both apart from standard chemical rockets, ion drives, and anything else that throws mass (i.e. propellant) out the back to move forward.

Photon drives and the "EmDrive" also have something else in common: neither are practical with current tech. :)


RE: Interesting...keep moving forward
By Ammohunt on 2/11/2013 2:00:04 PM , Rating: 2
On man by himself carving and moving 1,100 tons of coral rock to build the Coral Castle is impossible as well but Edward Leedskalnin did it and he wasn't even a Scientist.


RE: Interesting...keep moving forward
By JediJeb on 2/11/2013 9:00:42 PM , Rating: 2
Funny you get rated down and yet the object exists and no one has been able to explain how it was built.


By Ammohunt on 2/12/2013 11:02:08 AM , Rating: 3
yeah not sure what that is about. People around here sometimes have problems with hard truths; mostly likely derived from lack of life experience.


By nafhan on 2/12/2013 3:49:19 PM , Rating: 2
I think you're confusing impossible with impractical.

The naysayers in your example felt it was impossible because of the scale of the project. It's unlikely that anyone believed large amounts of stone cannot be carved (as there's plenty of evidence). The naysayers regarding the EmDrive are making the case that it actually can't be done, and that's largely due to lack of evidence.


By lawsonb on 2/18/2013 1:55:09 PM , Rating: 2
All of the posts shown are important, and to the point (more or less). I possess only an undergraduate degree in physics. But what I have learned is that to pooh-pooh some concept via a knee-jerk response, can be very dangerous. Should the claims of the proponent prove correct, then the scoffer(s) will suffer the egg-on-face syndrome. We must be extremely careful to avoid this type of sneering skepticism. There is a big difference between such baloney devices as the old "Dean drive", which clearly attempted (and failed), to thumb its nose at Newton's laws, and this concept which appears to depend on Einstein's theory. Now I am on both sides of this fence. All I can say is that: Elaborate claims require elaborate proof. I congratulate the Chinese for having the guts to investigate the Emdrive concept without carrying the cock-sure intellectual baggage that some many in the west are carrying. Even if this proves to be a blind alley, at least they are not so hide-bound as to dismiss it out-of-hand.
Imagine the fun we could have if this proves to be viable! Then Shawyer and his supporters could strut to-and-fro in front of their detractors and gloat!


RE: Interesting...keep moving forward
By Lord 666 on 2/9/2013 2:29:15 PM , Rating: 2
"Cold fusion"... Which the USN never stopped researching using similar methods that were used in 1989 but called a hoax back then.

There are two main reasons for knee jerk reactions; for protectionism of the status quo or to "submarine" ideas so they can be taken out of the public eye.


RE: Interesting...keep moving forward
By tng on 2/9/2013 3:35:16 PM , Rating: 1
Research into Cold Fusion continues in private and government facilities and there is progress being made.

Part of the original "Cold Fusion" issue was as the poster above mentioned, was that the original experiment was not detailed throughly enough in the paper that was published. This led to many different experiments many of which had negative results.

They have conferences on this now, although it is not called "Cold Fusion" anymore for obvious reasons.


RE: Interesting...keep moving forward
By JediJeb on 2/9/2013 7:04:53 PM , Rating: 2
I never understood how cold fusion was supposed to generate energy. If it does not produce heat then what energy did it produce? I seem to remember back then that the experiment showed Helium being produced at room temperature from supposedly fusing Hydrogen, but it took energy to make the reaction go, and seemed to me to be net negative on energy production.


RE: Interesting...keep moving forward
By Jackthegreen on 2/9/2013 9:37:16 PM , Rating: 3
The term "cold fusion" is meant to be about the initial state of the reactants. Normally fusion requires very hot temperatures, but the idea behind cold fusion is to try and get self-sustaining fusion to happen at more realistic temperatures like where water is a liquid under normal pressures. Once fusion has occurred the reactants do increase in temperature since that's how the released energy manifests. Some methods already exist, but they don't end up being energy-positive, hence why research continues.


By Shadowself on 2/10/2013 7:01:01 PM , Rating: 4
quote:
The term "cold fusion" is meant to be about the initial state of the reactants.
Not quite. "Cold Fusion" simply means you don't have to get the initial reactants into a plasma state before fusion can occur. The concept of "Cold Fusion" is that the nuclei fuse without having to be forced together under extreme temperature and pressure while in a plasma state. The concept is that the lattice nature itself combined with the specific atoms supposedly being fused set up a state that EM repulsion is overcome and the strong and color forces take over -- resulting in the nuclei being fused.

quote:
Once fusion has occurred the reactants do increase in temperature since that's how the released energy manifests.
Again, not quite. The "temperature" of the reactants in "Cold Fusion" is not the underlying issue. The question is how that gets transferred to the lattice. In most theories the resulting elements (the reactants are gone!) radiate their energy away to the crystal lattice in which they are held. The radiation is a combination of X- and Gamma-rays. Very little is radiated away as "phonons" or "virtual thermal particles", if you will. In most theories not much is transferred through motion of the particles and direct lattice collisions.

But then again, it's pretty much a useless discussion as no one has shown "Cold Fusion" to really, undeniably work.


By Reclaimer77 on 2/10/2013 6:29:44 PM , Rating: 2
quote:
I never understood how cold fusion was supposed to generate energy.


That's because you aren't one of the greatest scientific minds of our time, Keanu Reeves

http://davelozo.files.wordpress.com/2010/07/keanu....

Here he is now, making Cold Fusion a reality in the mid 1990's.


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).


By delphinus100 on 2/11/2013 10:07:32 PM , Rating: 2
quote:
Then when someone finds an aspect for which you did not account, you redesign the experiment to handle that then redo the experiment. Rinse and repeat. Then, and only then, do you publish and go around claiming a new discovery.


Which is pretty much what they did in CERN's FTL neutrino affair. And ultimately they found something disappointingly mundane that explained it...

But that's how the game is supposed to be played.

"Science is a way to not fool ourselves."
- Carl Sagan


By Mitch101 on 2/11/2013 9:46:44 AM , Rating: 3
Most scientists that collect a paycheck are just math and theory checkers they are rarely innovators. Polly wanna cracker because most just regurgitate what they were taught.

The older I get the more I discover there are few people who can actually think outside the box or color outside the lines.
quote:
which is where Albert Einstein's theory of relativity comes in.
Ill also say Al > Newton


By Any14Tee on 2/12/2013 8:19:01 AM , Rating: 2
Bumble-bees ain't suppose to fly!


By sixteenornumber on 2/10/2013 5:27:04 AM , Rating: 2
quote:
I don't care where scientific discoveries come from


+1

also, I'm very curious what the theoretical limit of this type of energy is. ie: n/watt at 100% efficiency


RE: Interesting...keep moving forward
By flubaluba on 2/10/13, Rating: 0
RE: Interesting...keep moving forward
By Shadowself on 2/10/2013 7:16:00 PM , Rating: 5
quote:
If we had accepted that rules could not be broken then no cars would be travelling at over 30mph, as that was the speed where everyone was told people would not be able to breath. yes crazy but it was a real Law that they said could not or should not be broken.
Name one -- just ONE -- legitimate scientist who supported this BS. The scientific community knew this was not true. Hell, anyone who had seen a cheetah run or seen a swallow dive knew that 30 mph was no kind of speed limit!

People confuse laws with scientific theories. And too many of the general public confuse "common wisdom" with scientific theory. They are three very, very different things.

"Common wisdom" is very, very often wrong. Some refer to them as "myths", and there is even a TV show out to bust most of these myths.

Scientific theory is sometimes wrong, but more often than not it just gets modified or tweaked when new, verified -- and independently reproducible -- data shows up.

Laws are never wrong. Laws are simply a statement of fact -- a statement of the data that has been recorded time and time and time and time again. There is the "Law of Gravity". Things fall toward each other. There is gravitational attraction. The theory is that it follows a simple inverse square relationship based upon some universal, measurable constant and the mass of the two bodies. That's the theory anyway. There have been some experiments in the last 30 years that may give an indication that the relationship is not a simple inverse square law, but the effect is so subtle that no one has been able to reproduce it with enough fidelity that the theory can justifiably be modified. The common wisdom is that different items are affected by gravity differently which is utter BS.

quote:
I suspect that if we had to ignore all the supposed laws we would be moving much faster in development of new technologies.
Now you sound like my crazy "inventor" friend who told me many, many years ago, "I'm not a physicist like you. I'm not bound by any of your laws." Yea, right. How's that jumping off a 1,000 foot cliff working for you?


RE: Interesting...keep moving forward
By theapparition on 2/11/2013 10:50:42 AM , Rating: 4
Completely correct.

quote:
Laws are never wrong. Laws are simply a statement of fact -- a statement of the data that has been recorded time and time and time and time again.

If you break a law, you go on trial. If you break a "law of nature", the law goes on trial.

As you correctly pointed out, laws are basically our tenants on how things work. Relativity was an example that violated traditional Newtonian physics, but our definition of the law was modified to account for it. The fundamental physics never change, but our understanding of the laws do.

As for this topic, I have no idea why this article is portraying this as some revolutionary or controversial advancement.

First off, it is not a closed system as it requires external energy to operate.

Secondly, the idea of propulsion from the emission of electromagnetic radiation is well documented. That is the basis for the solar sail. While photons do not have any mass, they do have impulse energy that can be transferred.

Thirdly, the speculation in that article that this work could provide launch capabilities is laughable.


By MZperX on 2/11/2013 12:56:26 PM , Rating: 2
quote:
Thirdly, the speculation in that article that this work could provide launch capabilities is laughable.

While we are well advised to use words like "never" rather sparingly, in this case I agree with you that the promise of propulsion such as this (assuming it turns out to be real and not a hoax) fall far short of launching spacecraft into orbit from the surface of the Earth. They are talking about thrust on the mN scale and even at the order of magnitude improvement projected, it would probably not be sufficient for any kind of launch.

That being said it could be useful for deep space probes, again if it works at all. The only launch I can imagine it being used for is departing from a halo orbit around a Lagrange point. It might have enough thrust to pull that off.


RE: Interesting...keep moving forward
By Shadowself on 2/11/2013 5:02:31 PM , Rating: 3
quote:
As you correctly pointed out, laws are basically our tenants on how things work.
Not true. "How" things work is the theory.

Pick up a rock and release it. I falls. Pick it up again and release it again. It falls. Do that one billion times and the rock falls every time. That's the LAW of gravity. Laws are the simple, observed facts. They don't change. Our understanding of HOW it works can change. The HOW is the theory.

Now "how" gravity works, e.g., the inverse square relationship (note I did NOT say inverse square LAW) is a theory. As I mentioned there have been a few experiments in the last several years that have cast a tiny bit of doubt on gravity following an inverse square relationship. So the Theory *MIGHT* need to be tweaked. However, the LAW still holds.

Unfortunately, as I mentioned before, many, many people confuse Physical Laws with Theories about the Physical Laws. They are not the same. Not even close.

quote:
Relativity was an example that violated traditional Newtonian physics, but our definition of the law was modified to account for it. The fundamental physics never change, but our understanding of the laws do.
No. Simply, No. The Law does not change. Newton's theory on how gravity works was flawed (mostly correct, but not quite). Einstein's theory of General Relativity modified Newton's theory. It did not change the law or modify our understanding of the law. Relativity modified the theory. It modified how we try to explain the law.


By theapparition on 2/19/2013 4:13:34 PM , Rating: 2
You're arguing semantics, and quite wrong at that I might add.

There is no such thing as a "Law" other than what we, as a human race, has determined to be a law.

The fundamental physics is the law, of which we only have a superficial understanding. We have then divided portions of that physics we think we understand into scientifically proven directives that we call "Laws". Your concept of a law as an observed phenomenon (eg drop rock billions of times) is incorrect and not supported by the scientific community. You can adopt your own bastardized definition of a "law" anyway you want, and then attempt to argue from that vantage point. I won't indulge you.

The quote I mentioned before about a scientific law going on trial if violated was from the late, great Carl Sagan. But I'm sure he had no idea what he was talking about.


By Adonlude on 2/12/2013 8:01:12 PM , Rating: 2
quote:
Thirdly, the speculation in that article that this work could provide launch capabilities is laughable.

Wait you mean payloads weigh more than 7/10th's an apple and space is more than 1 foot away?!?!


RE: Interesting...keep moving forward
By 91TTZ on 2/12/2013 3:33:27 PM , Rating: 2
quote:
Science is never static...so what is false today, may ring true tomorrow.


You mean what is unknown today may be known tomorrow. If we already know about it and know it is false the laws of logic or the laws of physics aren't going to change.


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