Chinese scientists replicate reactionless drive

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nick012000 nick012000's picture
Chinese scientists replicate reactionless drive

http://www.wired.co.uk/news/archive/2013-02/06/emdrive-and-cold-fusion

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Scientists in China have built and tested a radical new space drive. Although the thrust it produces may not be enough to lift your mobile phone, it looks like it could radically change the satellite industry. Satellites are just the start: with superconducting components, this technology could generate the thrust to drive everything from deep space probes to flying cars. And it all started with a British engineer whose invention was ignored and ridiculed in his home country.

The latest research comes from a team headed by Yang Juan, Professor of Propulsion Theory and Engineering of Aeronautics and Astronautics at the Northwestern Polytechnic University in Xi'an. Titled "Net thrust measurement of propellantless microwave thruster," it was published last year in the academic journal Acta Physica Sinica, now translated into English.

The technology is controversial because of that key word "propellantless". Space drives rely on Newton's laws of motion: all are based on the principle of firing propellant out the back at high speed, pushing the spacecraft forward. Even with endless power from solar cells, thrust is still limited by the supply of propellant, even with high-velocity ion drives. Numerous attempts have been made to overcome this, from the infamous Dean Drive of the 1950's to Nasa's experiments with antigravity from spinning superconductors in the 1990's. All have failed, and the efforts of pseudoscientific cranks and scammers have left the field thoroughly discredited.

British engineer Roger Shaywer stepped into this dangerous field in 2001, after twenty years with European satellite firm EADS Astrium. He set up his own company, Satellite Propulsion Research (SPR) Ltd, with the aid of a modest grant from the UK's Department of Trade and Industry.

Shawyer aimed to develop an EmDrive: a closed, conical container which, when filled with resonating microwaves, experiences a net thrust towards the wide end. It seems to violate of the law of conservation of momentum, implied by Newton, which says that no closed system can have a net thrust. However, Shawyer says net thrust occurs because the microwaves have a group velocity which is greater in one direction than the other and Einstein's relativity comes into play. Group velocity, the speed of a collection of electromagnetic waves, is a tricky business -- a pulse of light can even have a group velocity which is greater than the speed of light -- but can it really cause net thrust?

Shawyer built a demonstration thruster to test the theory in 2003. The thrust was tiny -- 16 mN, equal to the weight of a couple of peanuts -- but enough to validate the concept. However, sceptics were quick to attack. None of them actually inspected the apparatus, but Shawyer was assailed from all sides online and in the science press. Criticism was unsophisticated: Newton said it was impossible, therefore he must be a fraud. Even the most advanced theoretical critique, produced by John Costella, a PhD in relativistic electrodynamics, amounted to arguing about the direction of an arrow on one of Shawyer's diagrams.

Shawyer continued to produce and test more advanced demonstrators, working out elaborate ways of ensuring that the test results are valid and not the result of air currents, friction, ionization, interference or electromagnetic effects.

Such effects can easily ruin experiments where small forces are involved. The Nasa investigation into supposed antigravity eventually found that the apparatus was actually causing electronic interference within the measuring system and producing false readings rather than negating the Earth's pull.

Boeing's Phantom Works, which works on various classified projects and has been involved in space research, went as far as acquiring and testing the EmDrive, but say they are no longer working with Shawyer.

In 2007 the Russian Research Institute of Space Systems launched an experimental micro-satellite called Yubileiny (Jubilee) with a "non-traditional" engine which, according to Director Valery Mesnshikov, functions without ejecting reaction mass. However, it was later stated that "further developments" were needed and nothing further appears to be been published on Russian reactionless drives.

Meanwhile, the EmDrive was picked up by Yang at Xi'an, who has a background in space propulsion systems.

The Chinese team took a cautious approach. They started with a new analysis in terms of quantum theory in 2008 which indicated that the theoretical basis was sound and net thrust is possible. The next paper in 2010 quantified the amount of thrust that could be produced, and stated that the team was getting positive experimental results. The latest paper describes their latest thruster and gives the test results in details, showing that with a couple of kilowatts of power they can produce 720 mN (about 72 grams) of thrust.

It may not sound very much, less than three ounces, but in space a little thrust goes a long way. Boeing's advanced XIPS thruster, which fires out Xenon ions at high speed, generates less than a quarter as much thrust from twice as much power. It's used to maintain satellites in position, or move them to a slightly different orbit. Crucially, Xips weights about twenty kilos, more than an equivalent EmDrive, and the propellant for prolonged operation can weigh much more.

Propellant can account for as much as half the launch weight of a geostationary satellite. This means that, in principle, fitting one with an EmDrive rather than a conventional drive, could halve launch costs. Shawyer notes that EmDrives no more powerful than the Chinese one could keep the International Space Station in position without the need for costly refueling.

Meanwhile, Shawyer is moving on to bigger plans. The amount of thrust produced by an EmDrive is determined by the Q value of the cavity, which measures how well it resonates. A tuning fork has a high Q value in air; put it in treacle and it is damped and does not resonate so well. By using superconducting apparatus, Shawyer says that the Q value, and hence thrust, can be boosted by a factor of several thousand -- producing perhaps a tonne of thrust per kilowatt of power. Suddenly it's not about giving a satellite a slight nudge, it's about launching spacecraft.

Shawyer estimates that the prototype superconducting thruster could be ready in 2016. Even the most hardened sceptic would find it hard to ignore a thruster capable of levitating itself in the air. However, the EmDrive cannot violate the law of conservation of energy. It can exert force, but accelerating a vehicle over a distance still requires a huge amount of power, and ultimately it still needs a big power supply. Personal EmDrive jetpacks are unlikely, but Shawyer has plans for a deep space propulsion unit, an EmDrive-assisted spaceplane capable of taking off from an a runway and travelling to Australia in three hours -- and a personal air vehicle the size of a car.

However, aerospace companies are not in a hurry to do business with Shawyer, and he will not be able to build the superconducting thruster without funding.

Yang's experimental work is continuing; she says she is not able to discuss her work until more results are published this year. There is also the tantalising prospect of a demonstration at an aerospace conference. This might make the EmDrive hard to ignore and force a showdown with skeptics. So far the reaction in the west to Yang's work has been muted -- perhaps polite disbelief would be the best description. 2013 may change all that.

If this pans out, then, given that Eclipse Phase has high-temperature superconductors, we can probably replace "Vector Thrust" with "Em Drive", and let all the synthmorphs fly in space.

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The Doctor The Doctor's picture
Disclaimer: I am not a

Disclaimer: I am not a physicist.

If this works it sounds like it would be useful for adjusting the orientation of satellites, which ordinarily requires the expenditure of propellant. Propellant tanks on deployed satellites are finite resources, and we are just now testing techniques for replenishing them. Stored power is much easier to restore through solar arrays. I do not know if it would work for maneuvering due to the amount of time it would take to accelerate the satellite, plus the amount of time to decelerate it.

If the technique works, that is. It reminds me of one or two things but I do not think my background is sufficient to attempt to draw parallels.



NewtonPulsifer NewtonPulsifer's picture
This thing isn't for real.

This thing isn't for real.

Its not just a convenient thrust source, it would have to upend some theories that have a great track record, like Relativity.

I can't put it better than this poster so I'll link his comment:

http://nextbigfuture.com/2013/02/propellentless-emdrive-research.html#comment-793232895

"I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve."- Isoroku Yamamoto

nick012000 nick012000's picture
My understanding is that it

My understanding is that it works because of general relativity, not despite it; the math apparently all checks out. Basically, what it does is pull itself up by its shoestrings, while using the fact it's using light-speed waves to do so to cause its "propeller" to form a different reference frame from the "receiver", allowing it to form an open system and actually propel itself.

Also, the conservation of energy/second law of thermodynamics aren't violated; basically, what it's doing is creating a "tank" of momentum that it pulls from to accelerate itself, rather than dumping mass out the back and relying on Newton's Third Law to do so.

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NewtonPulsifer NewtonPulsifer's picture
Take a 5 tonne ship.

Take a 5 tonne ship.

It accelerates to 10km/sec using its rockets, and is now a 2 tonne ship.

Its total kinetic energy of 100,000,000,000 joules (1x10^11 joules) (100 gigajoules)

Okay, we then turn on our emdrive. Lets say we get 1 newton per watt. We have 125kg of batteries that each hold 8 megajoules, so we have 1000 megajoules to work with.

Lets say our emdrive can take 100 kilowatt per second. So we thrust with it for 10,000 seconds, each second providing 100,000 newtons of thrust (this results in an acceleration of 100,000 newtons divided by 2,000 kg = 50 meters/sec/sec.)

Okay, so at the end of the 10,000 seconds, we are going 500,000 meters/sec faster (510 km/sec total). Now we have a kinetic energy of 2601x10^11 joules.

We went from 100 gigajoules to 260,100 gigajoules with the expenditure of 8 megajoules of electrical power.

Congratulations, you have a perpetual motion machine!

EDIT: Final gigajoules adjusted - was too low.

"I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve."- Isoroku Yamamoto

nezumi.hebereke nezumi.hebereke's picture
There's a couple of clues

There's a couple of clues that this isn't what it appears.

nick012000 wrote:

British engineer whose invention was ignored and ridiculed in his home country.

Quote:

Space drives rely on Newton's laws of motion: all are based on the principle of firing propellant out the back at high speed, pushing the spacecraft forward. ... Numerous attempts have been made to overcome this, from the infamous Dean Drive of the 1950's to Nasa's experiments with antigravity from spinning superconductors in the 1990's. All have failed, and the efforts of pseudoscientific cranks and scammers have left the field thoroughly discredited.

Quote:

Shawyer aimed to develop an EmDrive: a closed, conical container which, when filled with resonating microwaves, experiences a net thrust towards the wide end.

Quote:
It seems to violate of the law of conservation of momentum, implied by Newton, which says that no closed system can have a net thrust.

Quote:
a pulse of light can even have a group velocity which is greater than the speed of light

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None of [the skeptics] actually inspected the apparatus,

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Boeing's Phantom Works, which ... went as far as acquiring and testing the EmDrive, but say they are no longer working with Shawyer.

In 2007 the Russian Research Institute of Space Systems launched an experimental micro-satellite called Yubileiny (Jubilee) with a "non-traditional" engine which, according to Director Valery Mesnshikov, functions without ejecting reaction mass. However, it was later stated that "further developments" were needed and nothing further appears to be been published on Russian reactionless drives.

If this violates Newton's laws, which have been well-established for several hundred years now and their being overturned would be a MAJOR coup, that's a hint that something is not right. Referencing that it 'also Einstein' doesn't justify it, doubly so if it goes on to contradict Einstein by shooting light faster than the speed of light.

Is it possible that someone invented a way to transfer electric energy into motion more efficiently? Sure. But in this article, either the reporter has no idea what he's talking about, or the inventor doesn't.

(But still a good find, and a good thing to reference for filling in technical details 'on the fly'.)

Arenamontanus Arenamontanus's picture
Note the lack of successful

Note the lack of successful independent verification. Yes, they had an outside group look at it, but it did not actually say it worked. The original article is fairly credulous.

Extropian

NewtonPulsifer NewtonPulsifer's picture
I missed this part.

I missed this part.

"Boeing's Phantom Works, which ... went as far as acquiring and testing the EmDrive, but say they are no longer working with Shawyer."

Yeah, its bunk.

"I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve."- Isoroku Yamamoto

nick012000 nick012000's picture
NewtonPulsifer wrote:*snip*

NewtonPulsifer wrote:
*snip*
Congratulations, you have a perpetual motion machine!

Naturally, if you just pull the numbers out of your ass, you'll get results that don't make sense. Try again using the actual numbers that the Em Drive have demonstrated. Don't forget to make sure you're using realistic numbers for the batteries/solar panels, either.

Arenamontanus wrote:
Note the lack of successful independent verification. Yes, they had an outside group look at it, but it did not actually say it worked. The original article is fairly credulous.

Uhh, dude. This entire article is about how it did get a successful independent verification. The dude who originally invented it was British, and now some Chinese scientists have built their own larger version and confirmed that their version worked as well. Did you even bother to read the article? I named this thread what I did for a reason, you know. ;)

nezumi.hebereke wrote:
If this violates Newton's laws, which have been well-established for several hundred years now and their being overturned would be a MAJOR coup,

And indeed, their being overturned was a major scientific coup. Seven or eight decades ago. ;)

Quote:
that's a hint that something is not right. Referencing that it 'also Einstein' doesn't justify it, doubly so if it goes on to contradict Einstein by shooting light faster than the speed of light.

You're misunderstanding what they were talking about. They're just saying that it's using the group velocities of the light waves to achieve its effects, and mentioning other strange things that group velocities have been known to do as an example of why this is plausible. That you can produce a group velocity greater than the speed of light is well-established in the scientific literature; it doesn't break General Relativity because you are still incapable of transporting information faster than the speed of light.

Quote:
Is it possible that someone invented a way to transfer electric energy into motion more efficiently? Sure. But in this article, either the reporter has no idea what he's talking about, or the inventor doesn't.

I think the problem is more likely related to your own lack of knowledge than anything else, even if the scientific press has its well-known shortcomings.

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(But still a good find, and a good thing to reference for filling in technical details 'on the fly'.)

Yeah. That's why I started this thread.

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NewtonPulsifer NewtonPulsifer's picture
nick012000 wrote

nick012000 wrote:
NewtonPulsifer wrote:
*snip*
Congratulations, you have a perpetual motion machine!

Naturally, if you just pull the numbers out of your ass, you'll get results that don't make sense. Try again using the actual numbers that the Em Drive have demonstrated. Don't forget to make sure you're using realistic numbers for the batteries/solar panels, either.

Hey, at least I used numbers. If you can do better, please do. Why don't you try "using the actual numbers that the Em Drive have demonstrated. Don't forget to make sure you're using realistic numbers for the batteries/solar panels, either" that doesn't result in a perpetual motion machine?

"I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve."- Isoroku Yamamoto

Axel the Chimeric Axel the Chimeric's picture
If you pull magic numbers out

If you pull magic numbers out of your butt, use them to try and discredit a concept, and then someone calls you on the fact that your numbers are magic and you pulled them from said butt, the mature and adult thing to do is to apologize and then use the actual numbers, not throw the burden of proof on them. Using numbers doesn't give your concept validity if they're the wrong numbers.

The actual paper doesn't list the mass of the device itself, though it does list Shawyer's original design and pegs it at 100 kg, its acceleration at 0.002 m/s, its maximum thrust as 287 mN, and its power consumption as 1000W. At about 500 seconds, assuming consistent acceleration, this thing hits 1 m/s velocity. The kinetic energy stored in it is 50 J. To get to that speed, that thing has consumed something like 500 kJ of energy. Meanwhile, the Chinese design lists 2500W producing up to 750 mN and, assuming the same mass, the actual results aren't all that different; to get it to 1m/s takes about 133 seconds and eats 333.3 kJ, a significant improvement in efficiency but no less still having 50 J of energy stored in the device. Accelerate it to 100 m/s (a process that takes about 3.7 hours), the energy stored in the device becomes 500,000 J but the energy needed to put that there is 33 MJ.

Many things this is but perpetual motion it ain't.




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NewtonPulsifer NewtonPulsifer's picture
Axel the Chimeric wrote:

Axel the Chimeric wrote:

The actual paper doesn't list the mass of the device itself, though it does list Shawyer's original design and pegs it at 100 kg, its acceleration at 0.002 m/s, its maximum thrust as 287 mN, and its power consumption as 1000W. At about 500 seconds, assuming consistent acceleration, this thing hits 1 m/s velocity. The kinetic energy stored in it is 50 J. To get to that speed, that thing has consumed something like 500 kJ of energy. Meanwhile, the Chinese design lists 2500W producing up to 750 mN and, assuming the same mass, the actual results aren't all that different; to get it to 1m/s takes about 133 seconds and eats 333.3 kJ, a significant improvement in efficiency but no less still having 50 J of energy stored in the device. Accelerate it to 100 m/s (a process that takes about 3.7 hours), the energy stored in the device becomes 500,000 J but the energy needed to put that there is 33 MJ.

So.....run that thing until you hit 10km/sec....and recalculate that (input energy 3.33 gigajoules, kinetic energy 5 gigajoules). You've gotten more than you put in.

Quote:
Many things this is but perpetual motion it ain't.

No, it really is a perpetual motion machine.

P.S. Did you really miss the above or was that some sort of ironic joke post?

P.P.S. If it makes it easier to imagine then lets say we added a 900kg radioisotope thermal generator generating the needed electricity and ran it for longer, but it doesn't really change anything.

"I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve."- Isoroku Yamamoto

Axel the Chimeric Axel the Chimeric's picture
A problem I'm having is that

A problem I'm having is that the device isn't that efficient. It uses 2500 W per 0.75 N. The highest density battery I can find existing today is 43.2 MJ/kg. Each battery, therefore, provides 12.96 N of thrust. To get the billion Newtons of thrust you're talking about, the ship would need to weigh 77,160,493.8 kg, or 77,160.5 tons. Those billion Newtons would accelerate it to 0.07716 m/s. The vessel's KE = 229,693.8 J. for more KJ of energy than I care to calculate.

Hell, if we're really going to have some fun, I can even expand this to the sum amount of energy in the entire universe, calculated by one NASA astronomer as 4*10^69 J. If we, somehow, got an extra-universal vacuum, extra-universal matter, and an extra-universal EmDrive and compressed all the energy in the universe down into batteries made of this extra-universal matter and used it all in one amazingly trivial experiment, we'd have (short-hand) 9.26*10^64 batteries at a kg each and hence the same amount of mass. 1.2*10^66 N of thrust gets this thing to 12.95896 m/s. KE = 1/2 m*v^2 comes out to 7.77537*10^66 J, several orders of magnitude lower.

In short, even using ALL the energy in the known universe at the highest known battery density, this thing couldn't achieve over-unity. What you proposed was a situation in which we achieved 100% efficiency, which this device does not even come close to.

That said, I was an utter cock in my previous statement because I didn't realize what you were getting at and was a bit out of sorts. I apologize unreservedly for that.




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NewtonPulsifer NewtonPulsifer's picture
Shawyer is claiming he can

Shawyer is claiming he can get 31.5 newtons per watt with a very high Q superconducting version (using tech available now).

So 1 newton per joule is less than he's claiming he can achieve.

EDIT:

Here's a link for "Typically 3 tonnes of lift could be obtained from 1kW of microwave power"

EDIT2:

Axel the Chimeric wrote:

That said, I was an utter cock in my previous statement because I didn't realize what you were getting at and was a bit out of sorts. I apologize unreservedly for that.

Thanks, but no apology necessary. I have a pretty thick skin anyways, and I realize I don't always communicate well to my audience. I'm of the "If your audience doesn't understand you or misunderstands you" the burden of responsibility falls to the speaker school of opinion.

The flip side of that is I can be incessantly annoying in my barrage of questions to a speaker when I'm seeking clarity.

"I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve."- Isoroku Yamamoto

Axel the Chimeric Axel the Chimeric's picture
Hm. I must concede that, at

Hm. I must concede that, at the very least, the version Shawyer proposes would indeed be an over-unity device. That's too bad, it'd have been interesting.

Ah well. Again, my apologies.




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