NASA Eagleworks Has Tested an Upgraded EM Drive

An anonymous reader writes: A team of researchers at NASA's Eagleworks Laboratories recently completed yet another round of testing on Engineer Roger Shawyer's controversial EM Drive. While no peer reviewed paper has been published yet, engineer Paul March posted to the NASA Spaceflight forum to explain the group's findings. From the article: "In essence, by utilizing an improved experimental procedure, the team managed to mitigate some of the errors from prior tests — yet still found signals of unexplained thrust."

Comments

Controversial?

[Anonymous Coward]

If your source for saying it is controversial is a link to another slashdot article saying it has been tested successfully by a different lab before, you are just using the word wrong.

Re:Controversial?

[ganv]

There is a simple reason this is controversial. Any Electromagnetic drive that produces more than 3.34 nanoNewtons per Watt by EM emission is a demonstration of new physics that is not included in our amazingly successful theory of quantum electrodynamics (QED). (The simple calculation is here: https://www.physicsforums.com/... They use a reflecting mirror, so an emitting craft would have half the force.) QED has been very precisely corroborated, sometimes to more than 10 digits (see https://en.wikipedia.org/wiki/... ). Claims of macroscopic objects that violate quantum electrodynamics simply have an extremely high prior probability of being false. (Just like claims of perpetual motion etc.). It doesn't mean we know a priori that they are false. By all means, do the experiments more precisely. But this is a claim that requires extraordinary proof because if it is true it will upset a lot of what we have good reason to think we understand about how the universe works.

Re: Controversial?

[qeveren]

Uh... you can't be stationary in spacetime. Everything always moves at c.

Re:Controversial?

[cbhacking]

There's another weird aspect beyond that one: the EM radiation is released into a sealed (non-microwave-permeable) chamber. The QED thrusts ought to be canceled out by the photons reflecting off both ends of the chamber.

Given the thrusts in question, I'm not sure which is weirder, the presence of a net thrust at all given the chamber being sealed, or the roughly three orders of magnitude more thrust than a photon drive would have, but either one suggests that something very odd is happening here.

Re: Controversial?

[binarylarry]

Who is this Einstein guy all you kids keep bringing up? Is it someone on reddit?

Re:Controversial?

[ganv]

Has Unzicker really argued that QED is a grotesque kludge? He argues that string theory and other branches of recent high energy theory are modern religion, but I haven't heard that he attacks QED, which was developed around 1950 and is one of the most precisely experimentally confirmed theories of all time. Check out the Lamb Shift, the anomalous magnetic moment of the electron or the casimir effect for experiments that are accurately described by QED.

Re:Controversial?

[RockDoctor]

The QED thrusts ought to be canceled out by the photons reflecting off both ends of the chamber.

That would be true if the walls of the test chamber were perfect mirrors. Which is pretty unlikely.

Scientists

[skovnymfe]

It's like someone has posted a theory on the internet which is wrong, but not knowing where the thrust comes from means they can't explain to this person why he's wrong. And it irks them to no end.

Re:Scientists

[Twinbee]

This is such a tough cookie to crack that the best way we can solve is to keep grinding at the problem like this. Any attempt to diagnose the issue wholesale will clog up the 'machine', and ultimately slow progress down.

Re:Scientists

[jabuzz]

The problem is that extraordinary claims require extraordinary proof. This is an extraordinary claim because it at appears to violate one of the most sacred law of physics (the conservation of momentum) for which we have previously never had even the slightest hint might not hold.

That said unlike Mr. Rossi and his eCat for example there is no cloak of secrecy involved here. All details are out in the public for anyone to build one and test it out. This is where in part the fuss is arising because even the best labs are unable to show that it is baloney that every fibre of our beings tells us it should be.

In the end no matter how dear we hold the principle of conservation of momentum verified experimental results trump ALL theories without exception.

Personally I am highly sceptical of the EM drive. However I have to concede that the experimental results are so far with it, and thus further investigation is entirely warranted. In fact I would go further and say that further investigation is absolutely required.

Re:Scientists

[serviscope_minor]

And for those who don't understand why the conservation of momentum is one of the most "sacred" laws, you might want to check out Neother's theorem.

If this device is real, then it means that the laws of pyhsics are not constant but instead vary across time and space. The implications are vast, and the corollary of that is that it's a very, very, very well tested law.

It's hard to overstate how extraordinary the claims really are. And while ultimately experiment trumps all else, there have been a lot of experiments showing the contrary too and it's awfully easy to let errors slip in somewhere (see the recent articles on the number of incorrect papers being published).

Re:Scientists

[pla]

The problem is that extraordinary claims require extraordinary proof.

A working prototype counts as a pretty damned good proof of concept, at least until someone can demonstrate how it cheats.

Sure, someone might eventually figure out a way that it doesn't really cheat conservation of momentum - And that finding might have its own useful applications.

Re:Scientists

[jabuzz]

Sure verified experimental results trump everything. The problem at the moment is that the forces the device produce are very small 100uN. That means there is still the possibility that there are flaws in the experiment and the effect is not real. A bit like those superluminary neutrinos a while back.

My gut feeling at this point is stop messing about with an 80W drive, and build something a bit bigger say a few kW at least. That way the produced thrust should be large enough to rule out experimental errors. Of course this would require money...

Re:Scientists

[Beezlebub33]

One of two things is going to come out of this: they will determine that it's real, in which case we'll have some new physics to work with; they will determine it is experimental error, in which case we'll have a better understanding of how to measure small forces when the device is relatively large, in both air and a vacuum.

Either of these is a good thing; I'd bet on the second but would be happier with the first. In any case, the best course is to remain sceptically hopeful and continue testing.

Re:Scientists

[Anonymous Coward]

My gut feeling at this point is stop messing about with an 80W drive, and build something a bit bigger say a few kW at least.

OK, I'm going to go into some depth here because this is common sentiment, even from what I've read coming from Eagleworks, and it's probably wrong. Here's why I say that:

The inventor of the EMDrive is a retired aerospace engineer - he's too old to want to test anything but threw the idea for the EMDrive out there with a low-power test early in retirement as more or less an act of mental masturbation. Why is this important? Because his prior work, from which the EMDrive stems, is a laser-gyroscope functioning on the exact same principles as the EMDrive in reverse capable of measuring absolute accelerations based on relativistic effects without any outside coupling to the surrounding environment. Why is this important? Because it works so well it is in use in missile guidance systems and has been for decades. People tend to refer to Shawyer as a quack but he is the inventor of it, the invention came from sound and proven theory and all the hype about violating conservation of momentum isn't even correct based on the theory.

How does this relate to the "make it bigger" mentality? Shawyer's theory states the greatest way to improve thrust from existing models would be to make a perfect-Q cavity, at which point 1KW of power would be enough to lift a small car at Earth gravity. This isn't a difficult test - you just need a superconducting cavity. Thus far nobody has built an EMDrive with a superconducting cavity because they think Shawyer is just a crazy guy that stumbled into something interesting.

TL;DR: don't make it bigger, just make it superconducting.

Re:Scientists

[transfire]

"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." http://www.wired.co.uk/news/ar...

Re: Scientists

[Anonymous Coward]

Tesla (the person, not the company) had a lot of quackish experiments through which he learned a great deal about electromagnetism. Even just the small fraction of his work that panned out is worth it because it advanced EM (including RF) knowledge significantly enough to revolutionize telecommunications and more.

Next time you call or message someone on that fancy radio in your pocket, I hope you're less tempted to dismiss experimental research.

Re:Scientists

[angel'o'sphere]

The problem is that extraordinary claims require extraordinary proof.
This always repeated myth in /. is wrong.

A proof is a proof, regardless how extraordinary, extravagant or hillarious the claim is.

This is an extraordinary claim because it at appears to violate one of the most sacred law of physics (the conservation of momentum) for which we have previously never had even the slightest hint might not hold.
This is the second fault. You don't know how it works, but you already know it violates the law of conservation of momentum? How do you know that when you actually don't know _anything_ about the thing?

Rest assured: when we finally figure *if* it is working we will sooner or later figure *how* it is working and then we see: oops, it does not violate any conservation law.

Re:Scientists

[sjames]

Personally, I prefer to divide the claims. The primary claim is that the EM drive produces thrust that is not a result of lorentz force, air currents, or other conventional explaination. Some sort of new physics would be necessary for that to be true, but not necessarily anything crazy like violation of the conservation of momentum.

The most extraordinary claim would be that conservation of momentum is actually being violated. I haven't seen any attempt to perform an experiment that would demonstrate that. It's almost as if that claim has been tacked on to the actual claim in an attempt to discredit the whole thing. I have no idea why anyone would do that.

Re:Scientists

[sjames]

Important correction, if this device is real and the most outrageous explanation for it is assumed to be true ...

Re:Scientists

[sjames]

Look again at who is involved. These people are not basement psychoceramics looking for a wealthy backer.

Re:Scientists

[Wraithlyn]

THANK you.

Drives me nuts how people trot out this line of Sagan's like it's some inviolate law.

Evidence is evidence. It's absurd to change the standards of evidence based on your BELIEFS of what you think you should find. It's the most anti-scientific stance imaginable.

Re:Scientists

[serviscope_minor]

Doesn't really matter what the explanation is if it's generating thrust with no reaction mass: whatever the explanation it would be the biggest result of the last 350 years.

Re:Scientists

[tlhIngan]

It's like someone has posted a theory on the internet which is wrong, but not knowing where the thrust comes from means they can't explain to this person why he's wrong. And it irks them to no end.

And this is a good thing, This is just exactly how science works - people repeatedly testing it and testing it until we finally come up with a theory as to why it works the way it does, and what applecart gets upset because of it.

Perhaps there's some new science out there. Maybe. Or it's something that's just been unaccounted for. Or maybe it's a complete fraud. The best thing is, people are curious and they're trying to find out why. When that answer comes out, it means we've just increased our understanding of the world, which isn't a bad thing.

Re:Scientists

[Anonymous Coward]

1KW is about what you'd use for a microwave oven.
Thinking that amount of energy can lift a car IS crazy

Pfft, shows what you know.

One kilowatt (737.56 foot pounds per second, 1.34 British horsepower) will, if driving an (ideal) winch, lift a small car (say, a ton) at about 1/3 foot (4", or 10cm) per second. Half that speed for a mid to large sized car.

The trick is using an EM drive to move something as efficiently as a winch and cable.

Re:Scientists

[sjames]

It would be an extremely interesting result, but it wouldn't be as outrageous and unlikely as a violation of conservation.

For example, reaction against virtual particles or dark matter. Sure, that's very interesting new physics, but it's not so incredibly unlikely as violation of the conservation of momentum.

That's the thing. Nobody involved is making such an extraordinary claim as that. Rather, the extraordinary claim is being ascribed to them and then used to justify rejecting not only their results so far, but even the possibility that they will ever have results. It's well beyond skepticism.

Re:Scientists

[Dragonslicer]

This is an extraordinary claim because it at appears to violate one of the most sacred law of physics (the conservation of momentum) for which we have previously never had even the slightest hint might not hold.

No, we've been here before. Beta decay seemed to violate conservation of momentum and energy, and it took years before physicists discovered that there was another particle with no charge or mass that carried the missing momentum and energy. If these experiments turn out to be correct, we'll certainly end up with some pretty exciting discoveries, but throwing out conservation laws probably won't be on the list.

Re:Scientists

[pla]

I think you have that inverted. It doesn't count as anything until someone can demonstrate that it can't possibly be cheating.

Nope, not at all backward backward. Science needs to fit reality, we don't ignore reality because it doesn't fit our best models - That very attitude, that the High Priests of Science rule over their domain with an iron book, has done more to foster an anti-intellectual attitude in the modern world than the creationists could ever pray for.

Now, whether or not you can get anyone credible to even look at your prototype requires a level of plausibility; but unless you mean to accuse NASA of cheating itself, we have some pretty credibly folks looking into the EM drive on this one.

Re:Scientists

[jfengel]

A proof is a proof, regardless how extraordinary, extravagant or hillarious the claim is.

Well... yes and no. Even a mathematical proof isn't just a proof, because humans are involved in creating and checking it. A complex proof requires considerable work, and occasionally even a fairly sturdy result has to be withdrawn and reconsidered. Some examples.

Real-word experiments are never "proofs" in the mathematical sense. Directly, the only thing you can say about an experiment is "this thing yielded this result on this occasion". Everything else is extrapolation, and there are many different ways to extrapolate. The more you want to extrapolate, the the more work you're going to have to do to rule out the alternatives. When you want to extrapolate to something as big as "a new law of physics", you're going to have to rule out a lot of alternatives.

That's what "extraordinary claims require extraordinary proofs" really means. There are, at this point, a lot of far less extraordinary alternatives to "brand new physics", especially since the effect is such a tiny fraction of the input energy. The clearer you can isolate the effect, the more likely your particular extrapolation is the correct one.

Re:Scientists

[Anonymous Coward]

>The problem at the moment is that the forces the device produce are very small 100uN. That means there is still the possibility that there are flaws in the experiment and the effect is not real.

Jesus. Its depressing to read this shambles criticism for the hundredth time.
100 micro grams too hard to detect above noise?
Are you living in a time before ancient greece?
In 2012 the most accurate modern weighing scales could literally detect a septillionth of a gram ( Adrian Bachtold et all Barcelona ) .
100 micro newtons ( 10 milli gram equivalent, about the weight of a small insect ) is 10,000,000,000,000,000,000,000 times over the detection threshold of modern equipment.

In the 1950s and 60s the ion drive was developed and confirmed with thrusts of the order of 10 micronewtons - that's 10 times less than today's emdrives.

The popularity of this inane " emdrive thrust too weak to be detected " myth can only be because half of the critics have no grounding in physics or mechanics, and don't even use wiki ( never mind doing any study ) before they dismiss emdrive with the 1st dumb thought that pops into their heads.

Re:Scientists

[drwho]

Eh, don't like your characterisation of 'mental masturbation', but I'll skip over that and agree with other things you have said. In particular, the superconducting part.Niobium is old-school, and has to be cooled so close to absolute zero that it is expensive and cumbersome. That being said, it should be sufficient for a test of an emdrive - if thermal effects can be properly addressed. Magnesium diboride does not require quite as low a temperature, but is still difficult to get into the ultra-smooth, ultra-precise shape that a high-Q RF cavity needs to be. The cuprate superconductors, with their much less strenuous cooling requirements, are even more difficult to deal with, and superconductivity in them is destroyed under intense magnetic fields. The newest superconductor, plain old Hydrogen sulfide, only superconducts under extremely high pressure, and I don't see how that it's even remotely practical because of it.

No sum up: Please do use niobium now (niobium titanate) for an EMdrive. I believe that the Magnesium diboride (MgB2) fabrication methods will soon (in a year or two) be sufficiently advanced for use in an EMDrive, especially if there is more attention (money) put into the project if the niobium EMdrive is successful. Don't wait for other superconducting technology to mature before designing a practical EMdrive.

Re:Scientists

[TiggerTheCat]

Enough! Put one it orbit, turn it on and see if it goes somewhere.

Re:Scientists

[serviscope_minor]

Nobody involved is making such an extraordinary claim as that.

You missed the eariler claims where the results were "derived" using relativity. No vortual particles were involved.

For example, reaction against virtual particles or dark matter. Sure, that's very interesting new physics, but it's not so incredibly unlikely as violation of the conservation of momentum.

I'm pretty sure virtual particles don't work like that. They model the interaction of forces, if you're making them and sending them out somewhere they are real particles, and detectable.

I suppose rection against dark matter is the only possibility which isn't completely outlandish, being only 99.5% so. Still experimental error is still much more likely than random theory of the week giving amazing fundemental new physics.

Re:Scientists

[DrJimbo]

The problem is not the absolute smallness of 100 micro-Newtons. The problem is the relative size of 100-micro-Newtons compared to the forces that exist in the experimental apparatus. It is like confusing absolute signal level with the signal to noise ratio. Yes, we can easily measure the weight of a snowflake. But if the total thrust from this 100 watt drive is equivalent to the weight of a snowflake then I am exceedingly unimpressed. If you read the fine post that is linked to, you will see that this is literally down in the level of noise that can be produced by ground loops and so on. The author is basically saying that they tried to remove even more noise sources than last time and still have not yet tracked down what is causing the extremely tiny anomalous thrust they have measured.

I am a physicist so I am well aware of just how bloody difficult it is to track down and account for every form of noise and error in experiments like this one. Or in the experiment that measured neutrinos traveling faster than the speed of light. I am often cautioning my friends to not get too excited about weak experimental results like this that contradict foundational physical theories. I also cautioned people to not get too excited about the so-called "face on Mars" for the same reasons. Lots of fascinating things are seen in weak signals that are close to the experimental noise floor.

In addition, I have not seen any reasonable theoretical explanation for the anomalous force that is purported to power the EM drive. There is certainly no relationship between the purported physics of an EM drive and the actual physics of a ring laser gyroscope. Nor have I seen any reasonable theoretical explanation for why the thrust should scale as a large power of the input energy. Yet many people here who ignore the experimental challenges of measuring the weight of a snowflake on top of the forces acting on an apparatus dissipating 100 watts of RF energy seem to blithely accept these remarkable and, AFAIK unfounded, theoretical claims as gospel truth.

Re:Scientists

[sjames]

Even relativity based explanations would be less outlandish than a claim to violate conservation.

If it is virtual particles, it would be the second time they have had a measurable real world effect.

Re:Scientists

[angel'o'sphere]

As no one involved in the two EM drive principles I'm aware off ever claimed 'new physics' and both physical principles are explained with ordinary physic, I don't see your point ;)

It is the Nay-sayers who always claim (without giving any foundation) that this is new physics.

But if you see new physics, why don't you tell us wich?

Re:Scientists

[Anonymous Coward]

I agree with everything you've said, but for a test that might burn itself out after a short duration high-TC superconductors would be fine. The purpose would be a test to show whether the theory is sound or invalid, not to build a flying car.

Re:Scientists

[Lord Apathy]

Thus far nobody has built an EMDrive with a superconducting cavity because they think Shawyer is just a crazy guy that stumbled into something interesting.

At this point I don't give a shit if he is a kook that stumbled on it, dreamed it up, or it was given to him by enchanted faires he whistled up on his magical butt flute. Lets build a large prototype and see if it works.

Re:Scientists

[DrJimbo]

Because his prior work, from which the EMDrive stems, is a laser-gyroscope functioning on the exact same principles as the EMDrive in reverse [...]

This is complete hogwash. The effects cannot be related because the laser-gyroscope is based fundamentally on rotational velocities being absolute. Linear velocities (even without Einstein's relativity) are relative. OTOH, it makes some sense that an engineer who developed their intuition based on laser-gyroscopes would misapply that intuition to "invent" the EMDrive.

Shawyer's theory states the greatest way to improve thrust from existing models would be to make a perfect-Q cavity [...]

Can you point to an actual theoretical explanation/prediction of the effect? Shawyer himself said:

I am just a microwave engineer and all that matters is that it works.

This was in reference to his claim (in 2007) of creating a EMDrive that produced 0.1 Newtons (100,000 microNewtons, 1000 times larger than the effect measured in the post from the summary). Was that claim debunked or abandoned? If not, then why are we farting around with machines that only produce 100 micro-Newtons?

In 2012 there was a claim from China about producing an EMDrive that created nearly 1 Newton of thrust. Many people were dubious of this claim because the test wasn't performed in a vacuum so the thrust could have been created by thermal effects (like a Crookes radiometer). Now we are talking about better experiments where the effect has been reduced by a factor of 10,000 and is down in the noise level while the experimenters are working on decreasing the sources of noise. Everything about Shawyer's claim reeks of crockpottery. Sure, if something like this actually existed then it could be the gateway to interstellar travel. But that only makes these dubious claims more suspicious.

Re:Scientists

[Anonymous Coward]

>The problem is not the absolute smallness of 100 micro-Newtons. The problem is the relative size of 100-micro-Newtons compared to the forces that exist in the experimental apparatus.

Nope. i was hoping you'd be astute and be aware my last post refuted this criticism.
The Ion drive.. The input electrical power for ion drives is greater than for emdrives. The power to thrust ratio of ion drives is at least a factor of 10 less than emdrives. Yet in the 1950,60s they could discern the thrust from ion drive over noise.
Like for the emdrive, discerning ion thrust over noise is a problem of relative, as opposed to absolute, measurement. Albeit harder because it requires at least x10 accuracy.

I am an engineer and I'm here writing while i wait for my next set of error checks to finish. It's what I've spent most of my working life doing.

> weak experimental results
Emdrive has been experimentally verified by 5 institutions with results published.

> I have not seen any reasonable theoretical explanation for the anomalous force that is purported to power the EM drive
The only thing that critics have managed to say about emdrive theory over 10 years is " muh momentum "
You lot. Its either ironic or hypocritical of both; for over 2 decades I've read groups of physicists and engineer bicker, and physicists tend to scoff that engineers don't known relativistic theory like physicists do. Now an aerospace engineer has invented a device that extracts the 4momentum of light, converting it to 3momentum, and physicists dismiss it because it violates classical mechanics.
Doesn't it bother you that over 100 years ago physicists were able to show that classical mechanics could be violated by relativistic physics ( of which light and its interaction with matter is a base example ) ?
In other words, for over 100 years physicists have been telling everyone that classical mechanics can be violated by relativistic physics, mocking those who don't grasp it, then someone worked out an practical application, builds it, tests it, and shows it to the community ( physicists ) who inspired him... who then ridicule his invention because it does exactly what they professed was possible, but now they won't believe their own theory.

I hope history notes this hypocrisy, it would be judicious.

Also you're doing it wrong.
> I have not seen any reasonable theoretical explanation for the anomalous force that is purported to power the EM drive
As a skeptic you're supposed to look for a reasonable explanation in physics as to why it _won't_ work. ( hint : don't try " muh classical momentum " )
Physics started with a blank sheet of paper and worked its way up. If past physicists only considered phenomena that were already explained then it would never have started ( null theory doesn't explain anything )

Call it engineers intuition, but to my mind emdrive is not in the same category as the FTL neutrinos or the face on Mars. It's been tested for over 10 years, and the results are all positive. Complaining that there's a bit of noise and that you don't understand isn't much of a criticism, yet its all the emdrive skeptics have managed in over 10 years -> lame.

I'll bet emdrive works.

Re:Scientists

[serviscope_minor]

Even relativity based explanations would be less outlandish than a claim to violate conservation.

Not really, no, given that relativity has conservation of momentum rather thoroughly baked in.

Re:Scientists

[DrJimbo]

> I have not seen any reasonable theoretical explanation for the anomalous force that is purported to power the EM drive
The only thing that critics have managed to say about emdrive theory over 10 years is " muh momentum "

What else can we reply when there is no actually theory presented that we can reply to or refute? All we have to go on is some micro-wave engineer claims that he has invented a device that violates conservation of momentum without providing any reasonable theory for how it might work. Your attempt to blame the critics for the complete lack of theoretical underpinnings by the inventor is ridiculous. The inventor himself said:

I am just a microwave engineer and all that matters is that it works.

In addition, the Anonymous Coward engineer claims:

Emdrive has been experimentally verified by 5 institutions with results published.

(emphasis added)

Have experimental results been published? Yes. Has the effect been verified? No. Most of the extraordinary experimental results seem to have been either debunked or retracted, claims such as nearly one Newton of thrust by a paper from China which has been shrouded in mystery. The more recent and reliable Tajimar paper explicitly says:

... we successfully identified experimental areas needing additional attention before any firm conclusions concerning the EMDrive claims could be made. Out test campaign therefore can neither confirm or refute the claims of the EMDrive [...]

In one of their experiments their measured thrust was in the wrong direction! Their conclusion that the experiments need to be improved before they can be used to verify the EMDrive claims echoes what I already said (and you mocked) that the current experimental results are buried down with the noise. That is what the fine post linked to by the summary says as well. The experimentalists are working on beating back known sources of noise so they will eventually be in a position to confirm or refute the EMDrive claims. It is not all relevant if totally different experiments with totally different devices had better signal to noise ratios with similar input powers and output thrusts.

Your mocking, your ad hominem attacks, and your appeals to emotion and irrelevancies do nothing to bolster your argument. Your claims far exceed the claims of the very experimentalists whose work you (appear to) cite. You are, of course, free to believe whatever the heck you want but it seems your claims of experimental verification are greatly overblown. For me, the lack of theoretical underpinnings, the violation of the conservation of momentum, and the lack of experimental verification (as I cited above and from the fine post linked to in summary) all make me highly dubious that the effect is real.

Re:Scientists

[RubberDogBone]

It doesn't necessarily violate conservation of motion if the action and reaction are taking place in a way we didn't know about and therefore don't measure.

For example, if the EM drive is pushing against a force we don't perceive, then it IS having an action that conserves motion. We just aren't measuring it correctly so it merely appears to be happening by magic.

A real world example of this would be a linear motor. One of the fancy roller coasters will do for an example. The linear motors on the track push the coaster. We can see the motor and the ride carriage and measure the force and so on and it's clear electric power is making the magnetic field that does the pushing.

With an EM drive, we see movement (or at least thrust) happening but we don't yet see the other half of it, i.e. what it is reacting against. It is like the roller coaster is operating in fog and you can't see the trackway. The fog is our lack of understanding of the physics behind it. Not because we are dumb but because this is going to be some weird aspect of physics we never suspected before and apparently can't easily perceive with our normal senses, so literally nobody has ever even tried to come up with how it works.

In this way, it does not break rules. It's making new ones.

My suspicion is that the EM drive is reacting against some sort of background EM field that we don't yet know about.

Re:Scientists

[RubberDogBone]

Well the low output could be because we have only accidentally stumbled across whatever it happening. Once it is researched and fine-tuned and a better drive is built, it will likely be far more effective and efficient.

Science is full of examples where the first way of doing a process was terribly inefficient or plain wrong-headed but better and faster and smarter ways came along later. So I am not knocking their puny output power just yet. That it works at all is great. It means there is more to do.

Re:Scientists

[Anonymous Coward]

Can you point to an actual theoretical explanation/prediction of the effect?

Here's the latest one, though he's been saying for years that the key to making it more powerful is the Q value of the cavity because the thrust will scale exponentially with Q. On the same note: the claims of Shawyer and the Chinese team aren't absurd if you factor in the point that it would only take making the walls smoother and coating them with silver to improve upon copper cavities. There has also been substantial talk on the nasaspaceflight forums that you could improve things slightly (a few orders of magnitude) by tuning the size of the cavity to the frequency of the input due to destructive and constructive interference produced. While that potential optimization does nothing to explain the underlying effect, it is entirely possible the two groups either guessed the right size or hit it by chance.

Re:Scientists

[MouseTheLuckyDog]

I pretty sure that Shawyer read "relativity for Dummies" and now thinks he knows it inside and out.

Re:Scientists

[MouseTheLuckyDog]

The only thing that critics have managed to say about emdrive theory over 10 years is " muh momentum "

And the only thing historians can say about the Abraham Lincoln died from a gunshot wound theory over 100 years is "muh big hole in the head". What's your point?

...physicists tend to scoff that engineers don't known relativistic theory like physicists do. Now an aerospace engineer has invented a device that extracts the 4momentum of light, converting it to 3momentum, ...

Maybe it's because engineers keep saying stupid things like: extracts the 4momentum of light, converting it to 3momentum,
Good Lord, that is even worse then quantum vacuum virtual plasma .

Re:Scientists

[jabuzz]

It cannot be reacting against dark matter because it is located on earth and the biggest and I mean huge massive problem with the whole dark matter thing is that there is none of it on earth, or even anywhere in the solar system.

So something that is supposed to constitute over 80% of the entire matter of the universe is utterly absent in our solar system. We know it is absent because the primary reason for believing it exists is that we cannot explain observed galactic rotation with the amount of matter we believe exists in the galaxies (though we are using Newtonian mechanics rather than General Relativity to come to that conclusion which I regard as a problem in itself). However we know from observation of our own solar system that is is perfectly explained (well within observational error) using General Relativity. As such there is no missing mass in the solar system and hence no dark matter.

I my personal view the idea that there is something special about our solar system that means there is zero dark matter here or even in the vicinity of our solar system is too massive an ask and fails Occam's razor.

Re:Scientists

[beastofburdon]

I know, it's almost as if it were a religious argument.

Re:Scientists

[Immerman]

>problem with the whole dark matter thing is that there is none of it on earth

Where do you get that claim? As I understand it dark matter is expected to probably be pretty much everywhere within galaxies, including constantly flowing through the Earth. As for there being no obvious effect locally - that's because it's expected to be so diffuse as to have no measurable effect on such small scales - some tiny fraction of a gram per cubic kilometer if I recall correctly. It's only on the scale of hundreds of cubic lightyears that the mass begins to accumulate to the point where it begins to have detectable effects.

Re:Scientists

[drwho]

I agree, in that if the only difficulty with high-TC superconductors was burnout (assuming burnout happened after the time needed to conduct the experiment), then it would be worth constructing. But that's not the problem. The problem is that the high-Tc superconductors are ceramics, and getting them annealed at the proper dimensions and smoothness is difficult. An insufficiently constructed RF cavity of this type wouldn't burn out, it just wouldn't function with sufficient efficiency to properly demonstrate the capabilities of the EMdrive.

Compared with the difficulties of working with other materials, machining the RF cavity out of niobium titanate is not difficult. Maintaining the near absolute-zero temperature necessary for it to superconduct would be a problem, in that much liquid helium would be consumed - and not just because of the penetration of outside heat, but also because of heat generated internally when the device is used: any imperfections in the RF cavity's construction or the frequency and shape of the signal applied would end up causing part of the power to be lost to heat. However, if the device was at least sufficiently well constructed so that the heat generated was little enough to be compensated for in the cooling system, then the magnitude of the EFdrive's acceleration should be strong enough be readily observable, and well in excess of any thermal effects which might otherwise overwhelm the EMdrive effect.

Re:Scientists

[dl_sledding]

So far, it appears that this is one of those rare and precious, "Hmm... That's odd..." moments in science. But it could still turn out to be a previously unidentified flaw in the testing apparatus.

To me, this sums everything up and generates the excitement about this technology. Rare and precious indeed: that's what technological advances start out as, technology such as the MRI, for instance. In this day and age, with energy so important and becoming more expensive every day, this tech could be a game changer. We as a society need to support the research and give them the time and space needed to try to prove, and more importantly, try to disprove this. Everyone expects the latter, but think of the implications if they cannot. It is truly exciting, IMHO, even if it does fail.

Re:Scientists

[dl_sledding]

Sure, if something like this actually existed then it could be the gateway to interstellar travel. But that only makes these dubious claims more suspicious.

Don't even you see that as the exciting part, though? I mean, sooner or later, we as a species will stumble on that technology. And I expect "stumble" is the correct term for how it'll be found.

What if this is it? I mean, based on your statements (and I am in no way a scientist; I have neither the knowledge nor the experience to argue any of this on the level that you obviously can), most likely it's not, but just what if? Isn't that entirely what scientific research and experimentation is all about? Maybe it's just the stumble needed to find something else that IS the answer...

All my post is about is just to not consider the testing a waste of time and energy, which is what I sense you are saying. Allow the theory to be found wrong, that's OK. It's just another way to NOT make a light bulb, you know? Because the payback, if there is something there, is worth the cost, IMHO.

Re:Scientists

[pla]

When theory disagrees with reality, reality wins.

Re:Scientists

[Kester1964]

Cookies crumble; nuts crack.

Re:Scientists

[Wraithlyn]

Oh look, an attempt at proof-by-overly-simplified-analogy. How cute.

Results must be independently repeatable. That's not requiring extraordinary evidence, that's normal evidence.

Your coin toss example fails the basic, perfectly normal test of not being repeatable by a third party. Asking for someone else to repeat the result is not requiring "extraordinary" evidence, just the standard that everything else must meet.

physicists?

[ThorGod]

How does the "law of conservation of momentum" square with the the momentum imparted by photons? (iirc it's the light pressure from fusion that keeps stars from collapsing on themselves)

Re:physicists?

[rpresser]

Photons carry momentum away from the electron when they are emitted ("recoil") and to the electron that absorbs them ("pressure"). This momentum is real and measurable. https://goo.gl/CkjOxe

Re:physicists?

[Anonymous Coward]

Due to the photons being pushed forwards and backwards in the cavity, that cannot be the reason. Harold White postulates that the law of conservation of momentum is not affected, that the drive is indeed transferring momentum to space-time though an interaction with the virtual particles that are continuously popping and collapsing everywhere.

Re:physicists?

[tomhath]

Harold White postulates

In other words, he's making stuff up with nothing to support it.

Re:physicists?

[naasking]

iirc it's the light pressure from fusion that keeps stars from collapsing on themselves

It's ordinary pressure, not light pressure that keeps stars from collapsing.

Re:physicists?

[sjames]

Not really. More like he has shown some way that claiming the effect to be real is NOT equivalent to claiming that conservation of momentum is violated. Basically that the claim of the EM drive producing thrust is not as outrageous as the detractors claim it is.

Re:physicists?

[Fire_Wraith]

That's what you do as a scientist when faced with evidence that does not fit with the rules as you know them. You try and postulate reasons for why you might be getting those results. Some of those might be as simple as "the conditions for the original experiment didn't eliminate all external interference."

You then go back and conduct more experiments to try and prove or disprove some or all of those postulates. Rinse, repeat, refine.

It's like what happens when you discover that in certain conditions, the movement of certain objects violates the known rules of Newtonian physics. Fast forward a bit, and we wind up with Relativity (General and Special).

I don't even have a solid-state drive yet!

[Anonymous Coward]

My my how technology continues to march on. I haven't even upgraded any of my systems to the new-fangled solid-state drives. Is this new EM drive going to have a higher storage capacity or are they just faster?

Re: I don't even have a solid-state drive yet!

[Tablizer]

Hold on, I'm inventing the Placebo Drive. It works simply because you think it works. For once, marketers will be useful.

To boldly go where no man has gone before

[Anonymous Coward]

Really really slowly.

Re: To boldly go where no man has gone before

[Anonymous Coward]

You subestimate the effects of slight acceleration over long periods of time. Scale it up, make it more efficient, strap a nuclear reactor to it and bam, Mars on the cheap, interstellar travel starts to look feasible.

If it works at all, that is.

Re: To boldly go where no man has gone before

[tnk1]

Yes, even a slight constant acceleration gets us where we want to go if it remains constant over long period of time.

A reactionless drive, or perhaps a drive that simply reacts on an unknown principle, could allow us to build ships that could feasibly make interstellar trips. If you don't have to carry your reaction mass around with you and throw it out the back, you have a range only limited by the amount of energy you can produce, and the amount of mass you have to accelerate is significantly lessened. A small nuclear reactor on a ship would be heavy, but not as heavy as tons and tons of propellant and it could produce a significant amount of energy for decades.
   

Re:Mark my words from the future

[The Grim Reefer]

I find your ideas intriguing and would like to subscribe to your newsletter.

Re:Summary

[The Grim Reefer]

I can't say I've really followed this topic. However, it's a shame that we're so bombarded with crap these days that the default conclusion is that everything is BS unless it's unequivocally shown to not be. Even so, this is an independent organization (NASA) reporting on this and it appears that there may be something more to it than just being a hoax.

Oh God not again.

[delt0r]

There is a reason why it doesn't get past peer review. Things like last time, no statistically significant force, "but look its a force"! Sheesh.

Re:Oh God not again.

[tnk1]

It didn't get past peer review because:

1) they aren't presenting a theory as to what is causing it which can be evaluated.
2) the lack of said theory means that there is a violation of a well accepted principle of the Conservation of Momentum and no one is explaining why that isn't the case, or how that could be possible.
3) there is reason to believe that the experimental apparatus is unable to account for all variables and noise, particularly for the very small discrepancy which has been observed.

and of course,

4) they think it is quackery because of where it came from and don't want to be associated with it.

Re:Mark my words from the future

[geantvert]

Give us a break ... I mean ... line breaks!
 

Re:Mark my words from the future

[uncle slacky]

You are John Titor and I claim my $5.

An erg's worth

[ThatsNotPudding]

An erg, as my high school physics teacher related to us, is equivalent to one mosquito push-up.

Re:An erg's worth

[Tablizer]

Testing it in space may be the only way to know for sure. There's too many things on the ground to muck up tests when dealing with such a minute force.

Re:An erg's worth

[tnk1]

Not having a good theory to understand what is going on makes even a space test sort of iffy.

Someone was looking at building a cubesat to evaluate this, but space tests are expensive and mass budget is limited. Hopefully, they are able to demonstrate this properly without a space test, or they may never get their chance to test it sufficiently at all.

Re:An erg's worth

[Tablizer]

Eventually you need a "live" space test to know for sure. If ground tests keeping proving to be difficult due to darned gravity and nearby crap with static forces etc., then it may be more cost effective to test in space.

Vacuum drive

[Crowd Computing]

While the claim is extraordinary, the idea behind it isn't new, at least as a science fictional concept. I remember first reading about a vacuum drive in Arthur C. Clarke's Songs of Distant Earth, (c) 1986. In his acknowledgements, he credits a certain Shinichi Seike with providing the theoretical basis for the idea in a paper written in 1969 titled "Quantum electric space vehicle". Interestingly, I can't find any mention of Shinichi Seike in Wikipedia either as a standalone article or by typing in the name in the Wikipedia search form, which should turn up results for pages that contain both "Shinichi" and "Seike". Other references to him on the English language Internet appear mostly in poorly formatted web sites suggestive of the rebel science community

Re:Mark my words from the future

[delt0r]

Mark my words. You are just wrong and this is just *another* pile of BS.

Re:Summary

[serviscope_minor]

However, it's a shame that we're so bombarded with crap these days that the default conclusion is that everything is BS unless it's unequivocally shown to not be.

It's fair to assume that an extraordinary claim of this magnitude is wrong. Think about what it's saying. There have been a lot of very precise and importantly repeatable experiments performed in physics over the years. None have found a variation in the laws of physics over space or time. A single, new experiment reporting a minute force (100nN) claims they do in fact vary.

What's more likely? An experimental error in which 100nN on an 80W device (think about the relative scale of the device and size of the force) has been missed somewhere or the most ground breaking physics result of the last 350 years?

Other reasons to be suspicious: the device was first invented theoretically using relativity. This was clearly wrong as relativity has conservation of momentum baked in at a fundamental level (via Noether's theorem). Eventually someone found the specific mistake he'd made in the maths.

The device apparently works anyway but via a different mechanism. Either you've got the mother of all coincidences, or you've got a case of severe optimism mixed with the difficulty of measuring really tiny forces on large objects with a lot of power going through them.

Re:Summary

[delt0r]

Relax i did go to the effort of reading the material on this thing. I did also regret wasting that time on it. But this is just bogus, has all the hall marks of bogus (literally made up terms and math that doesn't work) and worse still. Very sloppy experimental work and plain misleading statements.

For example the german dude (has a patent on an antigravity device i may add), showed no force out of the errors, yet claimed there was a force anyway. btw NASA does not endorse these results. Reputations based on "but nasa.." are way out of line here. Also if your any good at science reputations are worth shit. Show me the data! They can't they don't have any. They have no plausible mechanism why it word work. 300 years of results need to be wrong if this is true.

This is why we have peer review. It doesn't mean the results are correct or right, but it does at least get rid of the first order bullshit. And this is it i am afraid.

Re:Mark my words from the future

[delt0r]

Also man up. Stop posting AC coward.

Re:Scientists and Conservation

[NReitzel]

At first glance this sounds for all the world like another perpetual motion machine. It deserves a second glance.

We (Physicists) know for absolute fact that a phenomenon called "dragging the metric" exists. The results are small, but every attempt at verification shows that the effect exists, and that general relativity predicts the magnitude of the effects. It is conceivable (though absolutely unverified) that a device might create it's own drag on the metric, and thus provide "impossible" thrust.

History is replete with experiments that show impossible results (two slit electron experiments, superconductivity) that have turned out to be true. Any experiment that provides verifiable evidence that contradicts theory shows that the theory is wrong, period. (Feynman Lectures)

The ostensible effect is small, and right up against the boundaries of bad science, but it needs to be verified, again and again, until the numbers either show that it doesn't exist, or show that it does. And if it doesn't exist, it's important to know -why- the results seemed to show it. This one is a long shot, but hey, -somebody- wins the lottery. Stick with it.

FYI

[transfire]

For all the naysayers on this thread, the phenomena has now been reproduced at least four times in separate labs. While it would be a violation of Newtonian physics, Newtonian physics is a generalization of Quantum physics, and Quantum physics is more amenable to such a possibility.

this post is the planet Venus, please ignore

[Thud457]

This idea is older than dirt, about time somebody actually tried it.

Now just hook up your Rossi E-Cat to it for power any you can fly your woowoo-mobile to meet the space brothers, just like on the Kansas album cover.

Would you like to know more?

why not bring your own surface

[SupRcoW]

if you insist on burning fuel, why not bring your own surface with the rocket, or ship. if you would spray a heavy particle mist under the exhaust, it might give a lot of extra thrust (super cooling air costs no extra Mass, you take it in on the fly), as heavy matter like a surface is needed, why not bring it with you? and if you spray a super cooled mist in front of the intended flight path, would the super fine, finer than air particles, not create a frictionless path to fly true? bring your own atmosphere? if the particles are misted over the hull you fly true super tiny particles mist with particles that have a smaller friction area than air molecules you move true (or smaller). you bring your own atmosphere. and why not use a sling? sling it up like goliath for a few won km's and THEN start the thrusters... saves some fuel and thus mass you need to bring up.... ah well.... a super hot focus point in front of the rocket/ship might push aside matter by expansion in front of the intended flight path as well, a very local hot pressure zone in the focus point. oh and instead of firing an arrow, might I suggest firing the bow itself using the surface to explode off of? nice 6D omnidirectional 6D aerodynamic shape.

Re:why not bring your own surface

[SupRcoW]

maybe even compress space material itself, if you have access to it.

Re:why not bring your own surface

[vbraga]

You know what is it? It's time to cut down on the LSD, buddy.

Re:why not bring your own surface

[SupRcoW]

added bonus, the mist around the ship can double function as a outside light insulating mechanism, creating camouflage for your smooth surfaced ship under the super cooled mist.

Re:why not bring your own surface

[SupRcoW]

you have some investments maybe? some interests? why not support new revolutionary ideas? you want to stay on the surface forever like where the No Ascension Surface Allowed company wants us?

Re:why not bring your own surface

[SupRcoW]

do you always "shoot down" new ideas for technology? im surprised you are not American.

Re:Scale it up

[SupRcoW]

we have been scaling up and got nowhere, maybe scale it down to nano scale and smear a 1000 nano engines out as a material over your hull, maybe some nano lung functions, some nana microscopes to capture vibrations, or whatever..... is it me or...

What's going on here?

[sjames]

This is genuinely confusing. Who the hell is claiming that this is a violation of the conservation of momentum? I haven't seen any such claims from any of the people actually doing the experiments. There's probably a zillion alternative explanations, all more likely.

Once and for all, this violation of conservation of momentum BS is a strawman.

why the controversy?

[Goldsmith]

First, I am a physicist.

Second, why is this controversial? Light (including microwaves) has momentum, and we absolutely use it to move things around. We have been using optical tweezers in labs for a long time. Without including pressure from photons, we wouldn't understand stars.

If you told me that a magnetron and horn antenna produced absolutely no impulse at all, I wouldn't believe you.

This is VERY interesting. How do you maximize thrust? But it's not shaking the foundations of physics.

Re:why the controversy?

[SupRcoW]

antigravity is a philosophy, make it as hard as possible to fall and re use falling energy for movement in other directions I think. if you are falling and make the path for friction as long and hard as possible, will it slow down the fall? enough to need less lift to stay afloat?

Re:why the controversy?

[Coren22]

This particular experiment doesn't allow the photons to escape. The device is a horn with no opening in it.

Re:why the controversy?

[MouseTheLuckyDog]

I am not very familiar with their mechanism, but from what I read, no light is emitted. So it is absolutely irrelevant that light has momentum.

Their claim is that they are extracting mommentum from the ( quantum )vacuum. Something very dubious.

Re:why the controversy?

[Goldsmith]

Yeah, ok, see that one's pretty hard for me to believe. I don't even believe they've tested for that yet.

They're getting a bunch of non-linear mixing and don't know what's coming out or where, or they're getting heating somewhere unusual,l or something like that. One way or another, there are photons coming off that thing as a result of powering up that magnetron.

Why aren't radio satellites pushed out of orbit?

[Bruce Perens]

If this works, why aren't the many satellites which run radio transmitters on similar frequencies pushed out of orbit to a measurable degree? It's the same mechanism as the "emdrive", but with the feed open rather than closed at the end.

Re:Summary

[Dragonslicer]

You know what they say : Science is rarely "Eureka!" and more often "Mmm, that's strange..."

And by "they", you mean Asimov: "The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' (I found it!) but 'That's funny ...'"

Re:Why aren't radio satellites pushed out of orbit

[Coren22]

Wasn't this effect measured on Voyager? It is an extremely small effect, but my understanding was that there is a measurable effect from the photon pressure generated by a radio antenna. In the case of the EM drive though, the photons can't escape the system and have not been measured escaping from the test setups.

Re:Summary

[drwho]

Unruh effect may be responsible for the EMdrive effect, and also may explain why galaxies don't fling themselves apart, without the need for bizarre concepts such as 'dark matter' and 'dark energy'. The problem with Unruh's theory is that we have lacked the ability to test it, until, perhaps, now - with the EMdrive. See this paper by McCulloch: http://www.ptep-online.com/index_files/2015/PP-40-15.PDF

Re:THIS. ISN'T. SCIENCE. It's SCIENCE-FICTION

[drwho]

Eagleworks is NASA. Not anyone can't just 'rent a NASA facility'. The crackpot, here, is you!

Re:THIS. ISN'T. SCIENCE. It's SCIENCE-FICTION

[drwho]

Wow, such anger, much distortion! It HAS been replicated. there IS published experiments, peer reviewed. Are Tajmar and Fielder not respectable enough for your tastes? Some people, which may include 'gavron', call themselves physicists but are really just engineers who took some physics in college, and now don't want to think that there's so much more physics that they have to learn. There are huge frontiers in physics, but there are usually are abstract and at one end of the scale or the other: cosmologic or subatomic. This area of exploration is human-scale, potentially disruptive, and that makes some old farts nervous.

Re:THIS. ISN'T. SCIENCE. It's SCIENCE-FICTION

[gavron]

No, it hasn't.

Stop making up stuff. Just because you post it on slashdot doesn't make it true.

This is 100% NON-REPLICATED NON-PUBLISHED NON-PEER-REVIEWED NON-SCIENCE.

I used block letters so there could be no doubt. You know?

Re:Scientists and Conservation

[slew]

This one is a long shot, but hey, -somebody- wins the lottery. Stick with it.

Bad analogy, often nobody wins the lottery, and they have a new drawing the next week with all the loser's money thrown in the pot to make it interesting for the new suckers...

Any experiment that provides verifiable evidence that contradicts theory shows that the theory is wrong, period. (Feynman Lectures)

Also not quite the right Feynman spirit. The easiest person to fool is yourself, so you need to avoid the Millikan-Ehrenhaft measurement problem...

Re:THIS. ISN'T. SCIENCE. It's SCIENCE-FICTION

[Nite_Hawk]

I used block letters so there could be no doubt. You know?

I know someone else who likes to randomly switch into block letters...

http://www.timecube.com/

Re:Scale it up

[SupRcoW]

I meant nano microphones, with plates that captures vibrations or signals, energy. when one can create a ring hall effect without the sound... and use the output....

Fight Club

[seoras]

When I saw this post my first thought was "Oh cool, a fight to watch". As usual it didn't disappoint.
It's like Dawkins -v- Christians. Neither side is going to win, both are pretty angry with the other.
A total waste of time and emotion.

When the hell did Science become an official world religion?
My guess is that it's a legacy from church persecution for challenging their version of "truth"

"He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you."
- Friedrich Nietzsche

Re: Experiments need time to be developped

[delt0r]

You are wrong, the force is statistically significant. Their measurement values are above the error bounds. They already have statistically significant results, it's just not big enough to rule out other influences.

So they have shown no such force by your own omission. Did you even read this out loud?

Also your wrong. They measure forces in the noise of their own instruments. Secondly their controls give forces of the same levels. That is in the fucking noise. I don't care if it is the noise of the instrument or the estimated systematic errors. *it* *is* *not* *significant*. They even fucking say that in the abstract!

Shit science is shit science.

Re:Summary

[tnk1]

Unlike the experiments that have been done by a number of quacks, experimentation is being done by third parties and are showing the expected results. This alone puts the apparatus above the quackery of various Cold Fusion devices, for instance. There's no secrecy or begging for grant money.

Nevertheless, all this means is that it is worth further investigation. There are significant amount of reasons to believe that this is not really working as suggested, but it is not a matter of "working because I said so".

Much of the controversy comes from the suggestion that this violates the Conservation of Momentum, but this comes from critics who don't see any other way that this could work.

However, the creators are suggesting no such thing. The reaction mass or what it is pushing against could exist via an unknown principle, thus maintaining conservation of momentum.

I tend to look at this is more interesting than the usual quackery, but as with the FTL neutrino experiment, I'm mostly just waiting for someone to tell me how they messed up the experiment apparatus.

But if they haven't screwed up.... hmm.

Re:Summary

[tnk1]

Eagleworks is an actual lab at the Johnson Space Center, and it does have a budget and NASA employees.

The problem is that their budget is very, very small, and that this is effectively something they are doing on their spare time.

There's real concern that such a small budget isn't enough to build sufficient apparatus to be able to adequately test the claims being made, and that's a pretty fair reason to believe that there is some error in the experiment.

However, this isn't the case of some guys from out of nowhere leasing a warehouse at NASA to make it look like they work for NASA.

Re:Mark my words from the future

[Man On Pink Corner]

I think he's channeling Timothy Dexter. The foil is always shifting but the tin remains the same.

Re:Why aren't radio satellites pushed out of orbit

[cbhacking]

You're confusing the EM Drive with a photon drive. The EM Drive requires a sealed resonant cavity. A photon drive requires an open-ended reflective emitter. Photon drives are, essentially, standard reaction drives that derive their thrust from the photons being shot out the back of the drive. The EM Drive - assuming it really works - is something else entirely, because there's nowhere for the photons to go; the net thrust they impart on the chamber seems like it ought to be zero.

As a side note, experimental results indicate that the EM Drive is about 400x the efficiency of a photon drive (1.3 microN / W for the EM Drive vs. 3.3 nanoN / W). This is one of the reasons (the other being that sealed cavity thing) that it's clearly *not* a photon drive in any sense we are familiar with.

The efficiency of photon drives is known very precisely, and can be taken into account with spacecraft... if such infinitesimal thrusts are even relevant. For satellites, the thrust generated by their antennas - which usually aren't even perfectly directional, and thus partially counteract themselves by sending some of the photons the wrong way - is probably lost in the noise of other trivial influences on their orbits.

Yelling online... you deaf or just dumb?

[cbhacking]

Yeah, you're full of shit.

NOT counting the inventors, it's been duplicated in four separate experiments at two different labs: China's Northwestern Polytechnical University in 2010, NASA's Advanced Propulsion Physics Lab (Eagleworks) in 2014 and twice in 2015 (the latter of which is the test being reported here).

Also, it's pretty clear you don't understand how scientific publication works. For that matter, you seem unclear on the entire concept of "science" itself. Publication is not, and can never by, science. Science is in the creation, testing, and refining or rejecting of theories. Publication is merely the process of distributing the result of science.

The problem is, nobody yet has a testable theory for how the drive works. They can (and have, repeatedly and replication) test *that* it works, but "I don't know why" is not a valid scientific explanation for an observed phenomenon, and will be rejected if anybody tries to publish "new space drive discovered" in a peer-reviewed journal. The theoretical explanation doesn't always come before the experimental results. However, the experimental results - not to be confused with the drive theory - can be and have been published.

Not having a scientific theory for an observed phenomenon doesn't make the phenomenon go away. It doesn't even make the phenomenon un-scientific. Not does it make measurements of the phenomenon unscientific.

Peer-reviewed publication of a tested theory is the end goal of science, but that doesn't make stuff which hasn't yet been published in a peer-reviewed journal "not science" any more than a person who hasn't yet returned home could be said to "not be vacationing".

Re:THIS. ISN'T. SCIENCE. It's SCIENCE-FICTION

[cbhacking]

So, if the replication in different labs, by different teams, using different test apparatus, doesn't constitute replication... what does?

As I said above, you're full of shit. You know what's less scientific than not publishing a theory? Sticking your hands over your ears and shouting really loudly that something isn't real, no matter how many times it's demonstrated.

You're an idiot, with no better understanding of science than a young-earth creationist.

How did you get to +4 insightful with that bs?

[friesofdoom]

You've totally missed the point of the quote. You have also missed the word "appears" in "because it appears to violate..." and the fact that it appears to violate such laws is the EXACT reason one needs some extraordinary proof that the claim is in fact correct. Wow, you failed on so much here and these morons gave you +4. Congratulations.

We are not dealing with mathematical proofs here, we are talking about the amount of evidence that is required to sway someone's belief. If I told you that I had corn flakes for breakfast, you wouldn't require much evidence/proof to believe me, but if I told you that I just came back from the planet Kolob, your personal threshold for believing me might possibly require more evidence than with the first claim. And by extraordinary, you can read that as "peer reviewed and triple checked for measurement errors" or "triple checked that there isn't a really thin string going off the to the side, being pulled by someone, or someone in the next room with a giant electromagnet" or whatever else anyone could use to fake this.

Would you accept photographs from Kolob as proof? If proof is proof, then my photos should suffice.

+4 lmao, what a JOKE.

Re:How did you get to +4 insightful with that bs?

[jabuzz]

That is exactly what I meant by extraordinary proof, and that people don't understand that is both sad and depressing if not unsurprising.

So a handful of unpublished results that have not been peer reviewed is insufficient proof. This needs multiple independent results, and frankly something more than 100uN of force produced.

Re:How did you get to +4 insightful with that bs?

[angel'o'sphere]

and the fact that it appears to violate such laws is the EXACT reason one needs some extraordinary proof that the claim is in fact correct.
Again: no it does not.
Ordinary proof is enough. There is only proof, in science we do not distinguish between "normal proof" and "extraordinary proof". Only idiots do that.
And again: because it appears to violate No, it does not appear to violate it It only could appear to violate the law of conservation of momentum if we new exactly how the apparatus worked and if we could observe such a violation. However both principles of EM drives I'm aware about: don't violate the law of conservation of momentum. Why don't you simply read about it instead of always comming up with false pretexts and false conclusions based on them?

Re:Why aren't radio satellites pushed out of orbit

[Bruce Perens]

For me to confuse an EM Drive with a photon drive, I would have to believe in the EM Drive. I happen to be a member of a private club called AMSAT that has its latest cubesat in orbit right now, and that is OSCAR 85 in a series running since 1963. Obviously, there isn't really anything standing in the way of testing this on a cubesat. I'm sure that if you can raise something's orbit that there will be a lot more attention. Until then, color me dubious.

Re:Why aren't radio satellites pushed out of orbit

[Bruce Perens]

The problem is that the asymmetry doesn't make a whole lot of sense.

I have no problem with the mission of investigating fringe theories. But I don't think they deserve a bit of publicity until they raise an orbit in space. I know a guy at CERN who had a bad connector, and it told them something was happening faster than light.

Re:Summary

[delt0r]

The Unruh effect simply does not fit the data. Nice try but no cigar.