Slashdot Mirror
China's Radical New Space Drive
First time accepted submitter Noctis-Kaban writes "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 principles behind the EmDrive have serious theoretical problems, and the original builder and designer never tested it in a vacuum chamber.
Taking a sealed container and pumping a few kilowatts of microwaves into it, chances are any thrust developed is actually air that's getting heated up and expanding out of the container. Unless the EmDrive has been put in a vacuum chamber where this can be demonstrated to definitely not be the case (i.e. low enough that their couldn't be enough reaction mass) then it's not actually working.
Did he sell them a bridge too?
How about this headline: "Discredited British Engineer Finds New Scam Victims in China." His invention is "a closed, conical container which, when filled with resonating microwaves, experiences a net thrust towards the wide end." Sounds realistic.
"First they came for the slanderers and i said nothing."
...you'd think that if high energy in a closed, conical microwave cavity produced thrust, someone would have noticed before this. We've done a lot of work with microwaves.
I've fallen off your lawn, and I can't get up.
That effect would not last long. If it produces continuous low thrust in atmosphere, that can't be it.
More likely, as one of the groups that looked at this observed, is that all that RF (2kw) is simply interfering with the instrumentation.
I've fallen off your lawn, and I can't get up.
From the article: "Seems to violate law of conservation of momentum". - Yup it does. Imagine putting an invisible mass-less box around the entire system. Almost nothing comes out the back (only microwave energy - more on that later). The center of mass of the box accelerates. This is a violation of conservation of momentum - one of the most well understood and best tested laws in physics. If there were some exotic high energy physics effect proposed for this at least it might be worth listening, but this is just electromagnetism - very well understood. The "group velocity / phase velocity" is just jargon that has nothing to do with this since it is the Poynting vector that carries momentum.
You CAN make a reaction drive using photons (microwaves in this case), this idea has been around for many decades. The problem is that photons carry a lot of energy relative to their momentum so it takes an enormous power source to produce any thrust. So far no one has found a practical application where there was a large enough energy (and high enough power ) source to make this practical.
There have been a lot of experiments with microwaves - I've personally worked on a 600MW pulse microwave system. There have even been attempts at microwave driven spacecraft sails. Some early experiments seemed to indicate more thrust than would be expected from momentum conservation. Eventually this was tracked down to gas absorbed on the surface being heated and released by the microwaves - essentially a conventional rocket. With very high microwave powers you can generate forces in all sorts of ways in a closed laboratory environment that would not work in space.
This will not work.
If it really does work let's copy the design. See how the shoe feels on the other foot.
...as the point in interweb non-spacetime where/when slashdot's u-turn from interesting to crass became self-evident.
so long, /. been a fun 10 years. my gratitude, respect & good will as i permanently depart.
A surprisingly non-sceptical article; I'd expect a bit more critical thinking from Wired. Terms like "group velocity" and quantum theory", used vaguely, don't help you avoid the fact that conservation of momentum is fundamental to modern physics. It's just as inviolable as conservation of energy.
To put it another way, this article makes Wired look just as gullible as they would if they wrote "Scientists in China have built and tested a perpetual motion machine."
So they found the guy who invented the Triumph?
Have gnu, will travel.
First Thought: it is a new space colony ship where they throw the baby girls out the back for propulsion.
Well, that's what people have said about the Mach-Woodward experiments, but an opposed piston design is now being tried out to isolate any noise-producing effects for remediation:
http://arxiv.org/abs/1301.6178
http://emdrive.com/principle.html
That last paragraph intrigues me. Could someone who understands ring laser physics comment on this?
I want this EmDrive to be true, but I'll wait and see. On YouTube I saw a video of a prototype EmDrive rotating itself, but even if it's not fake I wonder if they have accounted for magnetic effects.
I want this to be true because space exploration would be tremendously faster if the spacecraft could accelerate the whole way without ever running out of reaction mass. Even if the acceleration was low, continuous acceleration would build to really fast velocities.
lf(1): it's like ls(1) but sorts filenames by extension, tersely
From TFA: 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.
That depends entirely on the power system needed to operate the drive. That's the real Achilles heel of various non chemical propulsion systems - they eat a lot of juice and the resulting power supplies negate most (if not all and then some) of the savings of not carrying conventional fuel.
It doesn't sound very sophisticated, are there plans anywhere so I can build one and see for myself?
If I had listened to all the people who said "you can't do that" or "It won't work" or "noone has ever done that", I would have given up inventing things long ago and taken up law so I could punish people for succeeding.
You never know what you will find until you conduct the experiments.
You never know how far you go until you finish failing.
The FAQ deals with conservation of momentum, allowance for bouyancy, electromagnetic effects, convection and other issues here: http://emdrive.com/faq.html. A fantastic picture of the device on this page: http://emdrive.com/.
Here are some of the FAQ answers:
Q. Why does the EmDrive not contravene the conservation of momentum when it operates in free space?
A. The EmDrive cannot violate the conservation of momentum. The electromagnetic wave momentum is built up in the resonating cavity, and is transferred to the end walls upon reflection. The momentum gained by the EmDrive plus the momentum lost by the electromagnetic wave equals zero. The direction and acceleration that is measured, when the EmDrive is tested on a dynamic test rig, comply with Newtons laws and confirm that the law of conservation of momentum is satisfied.
Q. Are there any convection currents which might affect the results?
A. Convection currents did not affect the results, as measurements were taken with the thrust vector up, down and horizontal. Test runs were also carried out using a thermal simulation heater to quantify the effects of change of coolant temperature.
Q. Have electromagnetic effects been taken into account? These include interactions between current-carrying conductors and between such conductors carrying RF currents and nearby metallic structures in which currents might be induced.
A. Stray electromagnetic effects were eliminated by using different test rigs, by testing two thrusters with very different mounting structures, and by changing the orientation by 90 degrees to eliminate the Earth’s magnetic field.
experiment (since IANAP), I do want to say that there seems to be a troubling trend amongst the best and the brightest in many STEM fields to mistake theory for reality. Theory is great and proceeds under the scientific method from empirical observation, but as we've seen throughout history, new phenomena and corner cases to arise and require theory to be amended.
It's fine to say "this is clearly unlikely to work under current theoretical understandings" but let's also refine and do the experiments to the best of our ability so that science remains scientific (i.e. nominally empirical and ultimately practical in nature). There's a difference between taking "current theory suggests this is likely to fail" as a statement of fact and mistaking theory instead to be *evidence* about experimental outcomes.
No theoretical argument can be evidence for the reality or unreality of phenomena, no matter how well-formed. That's not to say that we ought to mistake the phenomena at issue—it's obviously critical to be able to understand, rather than misconstrue, the reality that we observe—only that sometimes a generation or two of scientists seem to get complacent and imagine that they've got the world all figured out after all.
Let's continue to do, and—to the best of our ability and within reason (but with "within reason" here broadly defined—allocate resources for, actual experimentation and empirical observation of the world around us.
Not that we don't—but to my eye, the attitude that if theory doesn't support it, it's always a waste of money to test it out experimentally, is a dangerous one for the future of a science that is far less uniform, linear, and accumulative in its progress than we often tend to remember.
STOP . AMERICA . NOW
Wish submitter could have worked "radical" in there a few more times.
All the usual signs of pseudoscience.
Show it works (note : that is not the same as saying that you have shown it works), and I'll be interested. Until then, this goes in the cold fusion circular file.
Tony Stark's gonna be pissed when he finds out the Chinese are ripping of his arc reactor!
Microwave don't come out of the box. "law of conservation of momentum", is high school physics.
You CAN convert energy into thrust, it's called 'Radiation Pressure', so I can shine a torch on a scale in a vacuum and it pushes down the scale.
http://en.wikipedia.org/wiki/Radiation_pressure
I can shine a torch in space and generate an opposing thrust, however the effect is so tiny as to be useless. Does his apparatus improve it by group resonance? Don't know, but I can tell from reading your comment you're not even at the basic level of understanding.
It's all about the rare earth metals hoarding China is doing.
http://www.youtube.com/watch?v=dmLh1sSFs8Y
Is it non-sense time again? Flying cars are a bad idea for a large number of reasons. Those that still ignore this are not qualified to report on anything in science or technology.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
A Brit, Boeing, Russians, and now the Chinese all vying to be the first to a reproducible contraption.
There seems to be some preference by British WIRED in favor of the Brit innovator by the tone of TFA, but (presumably) experts have discounted his efforts upon scrutiny (I'm not sure I buy the supposed flippant dismissal scenario that WIRED had painted), so it's unclear whether Shawyer had in fact produced a working model (hopefully he had submitted his results in for peer review like the Chinese did)
..."Always listen to experts. They will tell you what can't be done, and why. Then you can go and do it anyway."
I'm not saying that any or all of the comments above are from experts. Nor am I saying that this "drive" will work either. I will say that If this drive works, a large proportion of the 'experts' are likely to say that it doesn't and that the evidence to the contrary is faked ("Don't show me a video of this working in a vacuum, you have to show me in person!" Sounds like you're offering to pay for a couple of people, yourself included, to go to space, do a space walk, to observe this working. Somehow I don't expect that will happen.) Initially a small number will allow that it's possible that this may work, but that they don't understand enough about the system to explain it. And there will be a few who say "I'm glad I put some money behind that project, if it was a wash, oh well. But it worked, now I'm flush."
As for me, it doesn't work with what I know of physics, but that doesn't mean my understanding of physics is complete. In fact I know it is not complete. If it works, great. If it doesn't, well there is likely to be another idea around the bend, similarly unlikely to be effective. I expect we'll give some of them a try too. And who knows, something might stick to the walls.
You never know...
Evidence?
http://michaelsmith.id.au
How can the group claim to have a Q-factor of 10^9 and also claim that the microwaves experience a Doppler shift each time they reflect off of one of the end plates? Those two items are typically mutually exclusive I thought.
... sort of. And it is established physics. See Swimming in Spacetime: Motion by Cyclic Changes in Body Shape, Science, 2/27/2003, by Jack Wisdom.
But this mechanism relies on general relativistic effects, and only works in curved spacetime. Momentum conservation is not violated, because while the location of the object changes, its momentum (thus velocity) does not -- it simply cyclicly translates itself through space.
My first thought reading about the EmDrive was that Shaywer had found a way to reproduce this effect using a microwave cavity. But unless I'm mistaken, this does not appear to be the case, and I don't follow the arguments that Shaywer's drive should work.
It blatantly violates conservation of both momentum and energy. It's advertised as being useful for spacecraft propulsion, changing the momentum of the spacecraft without emitting anything that would carry equal momentum in the opposite direction. If Shawyer's claims were true, an EmDrive placed on end in a gravity field would be either an energy sink or source (depending on orientation) with infinite capacity. I see no reason why anything else on the site should be treated as any more trustworthy.
You need to keep an open mind, but not so open that your brain leaks out. In this case the claim is so extraordinary: it violates one of the best tested physical principals that the evidence must be very strong. In the case of the FTL neutrinos a tremendous amount of effort went into finding a flaw in the experiment, and eventully one was found.
This type of impossible drive is very well known, to the point where it has the pun name cited in the subject of this post. It's right up there with perpetual motion machines, super carburetors, etc.
The only real question is whether or not the Chinese will take it far enough for Muddy Waters recommend a short on their stock. I don't think they'll even get that far.
Sorry, no. The whole point of skepticism is to assign a negative (false) value to anything but proven assertions. You may still be in the realm of empiricism, but you are not being skeptical.
Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
Seen it before. There is evidence to suggest that Einstein's theories are incomplete. He was not wrong in the sense that rocks will suddenly fly upwards. No source of "free" energy exists. Go troll elsewhere.
Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
From TFA: "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."
I'm sorry, how did we go from an expression of force to mass?
"So is the BSD licence even more 'free' (than GPLv2)? Yes. Unquestionably." --Linus Torvalds (TinyURL.com/2vugzl)
I wonder how many stars they charged to that British engineer for it.
RubbishRubbishRubbishRubbishRubbishRubbishRubbishRubbishRubbish
"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."
I don't know what this guy did in Astrium and I'm not really going to waste more time trying to find out. But from the above statement, it is clear that he doesn't have the faintest beginnig of a clue what he is talking about.
Having worked for Astrium (or any other space company/institution) does not guarrantee that you know much about space outside your own field of expertise. And some of these 'space engineers' or, as most journalists like to call the 'space scientists', often are not really that clued up on their own field.
From my perspective, Einstein muddied the entire subject by equating reality with what is observed and using that false premise
The new scientific method is here! Make some wild guess about how the universe must work because that's how you'd like it to work, then call all previous work foolish and flawed. Done. Wait, didn't we used to do something similar to that?
http://www.youtube.com/watch?v=dmLh1sSFs8Y
Someone backed a warship into San Francisco harbor. He got a signal "Excuse me, isn't it pointy end first."
I find it hard to believe that the Nation that is home to the Ministry of Silly Walks has ridiculed a scientist for his strange ideas. . .
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
Superconductors have been known to break "laws".
Few years back, another Chinese invented the "Qu Tube",
when you heat the tube at one end, the entire tube will heat up in an instant,
in some cases it even generated more heat than you put into it,
it broke at least 3 laws of thermodynamics, it was so hardcore nasa approved the grant to do research on it, and the results supported the claim:
Preliminary Results of an Experimental Investigation of the Qu Superconducting Heat Pipe - NASA Grant NCC 8-200
Of course, all these new superconductor techs are hidden from the public as usual so you never hear about all the "laws" they have been breaking.
Reactive propulsion precedes Newton and even Ptolemy. It's pathetic, really.
...
Essentially, Aristotle was right to insist that motion is caused.
You are reasoning with Aristotles thoughts, which precede Newton and Ptolemy. It's pathetic, really... ;-)
Trolling is a art!
Taking the opportunity to dismiss without evidence what you just asserted without evidence. ;) I had a look at the first two pages. Guy doesn't do himself any favours with his constant whinging about 'physicists' (they're all exactly the same, these ignorant greybeards) Why do two objects keep moving? Because it'd take a force (acceleration) to stop them moving. I remember that from school for fuck's sake.
This is a troll isn't it? ;)
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
not continue your comment from the subject line. Doing so makes it very hard to read. Just type the subject again if you feel the need to have its text be part of the comment.
Having a good bushy beard came in useful while reading this comment. I furrowed by brow and scratched my beard in scepticism.
Comparing philosophy to science and technology is a little unfair. Both are iterative processes - with philosophy you come up with a theory, ponder it, tweak it, and it evolves.
With science and technology you come up with a theory, ponder it, tweak it, test it, and it evolves.
The difference is that with philosophy that you only need a mind and will evolve rapidly. Whereas with science you have to test your theories by [usually] building it, which often requires materials and apparatus which have gone through a similar evolution. It makes the rate of progress far slower and highly dependent on the current level of technology.
The difference being that in rational (as in rationalism) systems there is such thing as absolute truth, and axiomatic truth.
With science (empiricism) the only truths are those which have been tested by experiment. Ideas are simply that, and have no inherent value.
The problem with empiricism is that your truths are only as good as your measurements (and they're always a little bit wrong). The problem with rationalism is that given the right set of axioms, you can literally prove anything.
Guess which epistemology is more useful? Hint: if you pick philosophy/rationalism, you're probably a dumbass. No really, I mean it.
As Mr. Chekov well knows, the EM drive was a Russian invention.
In Soviet Russia, the drive warps you!
Scruting the inscrutable for over 50 years.
I'm fascinated by your theory, but you provide no reasoning apart from simple assertion for any of the claims you make, and your explanation suddenly cuts off before you finish it 'for reasons that you're not prepared to explain'
Can you provide a single reason why anyone should take anything you say seriously?
Otherwise... good troll, that's 10 minutes of my life I'm never getting back
Business/App ideas are like arseholes: everyone's got one, they're mostly shit, but very rarely they contain a diamond
The one that he demonstrated on the 'Heretic' programme, many years ago, which he said didn't contravene any laws of physics, and provided reactionless thrust by using a gyroscope mounted on some type of moving arm (I can't describe it very well, you'd have to watch the programme to see it). Whatever happened to that?
Just get one of these things and test it under rigorous scientific conditions and scrutiny.
If it works, it works; If it doesn't it's back to the drawing board and we can all move on.
Al this fucking shitbrained arguing over nitpicky sematic points is just maddening. Put up or shut the fuck up, because we don't want to hear your not-based-on-anything-that-counts armchair scientist opinions.
yes, there was the famous "bolo propulsion" example, of a satellite made of 2 masses joined by a cable progressively making its orbit more eccentric. This is well known, and as stated only works in curved spacetime.
This is not a signature.
Congratulations! Thanks to guys like you, in a few years China will dominate the space while you and your peers will continue planting with yours hands and burning witches on Saturdays.
PS: Electromagnetic waves can serve as "reaction mass", see the case of the Pioneer spacecraft and the electromagnetic radiation emitted by it you know popularly as "heat".
Photons carry momentum and energy. When he talks about wave packets, he's talking about momentum.
Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
The stereotype is that Asians are the smart ones. Are you saying this guy is such a good scam artist that he can fool Chinese scientists? If he's not a great scam artist then you're implying that the Chinese scientists are stupid enough to be fooled by an average scam artist, How likely do you think either of these scenarios are? Would any respectable scientist put any more research into something that everyone on slashdot seems to be immediately dismissing as a scam because apparently everyone on slashdot is also a phd in physics and EM drives. If all of you are so fucking smart then prove him wrong. Replicate his experiments and then debunk them. I'm sure the chinese scientists are relatively familiar with scientific theory and have spent way more time and money trying to do that than you have writing your posts.
From my perspective, Einstein muddied the entire subject by equating reality with what is observed and using that false premise
Maybe he likes relativity more than he knows.
We've still got the Dean drive .
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
You can do a bunch of stuff in space (the real space we find out there, not the idealized vacuum). For example, in regions where there is a magnetic field you can run an electric current through a tether and convert electrical energy to kinetic energy, thereby providing propulsion to the tether system. This may appear to be reactionless, but it really isn't, and the physics is not controversial and very well understood.
The author of the article is a complete moron. The scientific community wanting him to prove that the engine works is wrong according to the dumbass author, they should have just taken the guys word for it.
He defined reality as there are actual objects out there with real, measurable properties. He'd prefer that they remain at the level of objects with mass and position.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
Isn't that a form of propellantless drive? What if you exploited that to create a very large, very hot surface?
"The momentum gained by the EmDrive plus the momentum lost by the electromagnetic wave equals zero."
The momentum of a photon is determined by its frequency, with p = hf/c.
If the microwave photons were transferring momentum to the drive they would change in frequency. This is (a) easily detected, and (b) in contradiction to the high Q values claimed for the device. If the frequency of the microwaves is changing, they would not continue to resonate, if it is not, they are not the changing in momentum.
From TFA, "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." The more momentum his drive "extracts" from the microwaves, the larger the change in frequency, the lower the attainable Q. Shawyer is contradicting his own FAQ.
Electromagnetic waves have energy. If they didn't, how does your radio/cellphone/wifi work? Those bits get shot through the air in the form of electromagnetic waves. Go get a spectrum analyzer and you will see all the crap we shoot through the air on EM waves.
I suppose that the Voyager isn't slowing down due to a similar effect... http://en.wikipedia.org/wiki/Pioneer_anomaly Emitting or reflecting light or electromagnetic energy creates thrust there... why not here?
Watch for Penguins, they eat Apples and throw rocks at Windows.
never understood that, and never took physics to a high enough level to figure it out....how does a massless quasiparticle have momentum?
The guy who said the election was rigged won the presidency with the second-most votes.
Q. Why does the EmDrive not contravene the conservation of momentum when it operates in free space?
A. The EmDrive cannot violate the conservation of momentum. The electromagnetic wave momentum is built up in the resonating cavity, and is transferred to the end walls upon reflection. The momentum gained by the EmDrive plus the momentum lost by the electromagnetic wave equals zero. The direction and acceleration that is measured, when the EmDrive is tested on a dynamic test rig, comply with Newtons laws and confirm that the law of conservation of momentum is satisfied.
that just makes it sound like you are blowing into your own sail.
I remember in Microwave engineering when the professor got up and explained that we can create phase velocities faster than light. Except, when you actually looked at what was really happening in the system, nothing was actually moving at faster than light. It only appears to move faster than light. Wikipedia mentions this effect with both phase and group velocities.
Reviewing the author's paper, I strongly suspect the author has gotten lost in his own math. It starts with a Newtonian premise, introduces Maxwell's equations in Newtonian form, and then adds relativity. If relativity is involved, Maxwell's equations in derivative form need to be applied from the beginning, otherwise interesting problems occur like omitting the mass change of the electrons.
Whatever is happening in this system, it isn't what the author of the paper describes.
I didn't believe it the first time, but now that this revolutionary new space drive has been published in Vogue, it's obviously worth a second look.
From reading the article and comments here, I am not sure if I am as strong of a disbeliever as the rest of slashdot. Here is my thinking, please let me know where I'm going wrong:
1. We know that light can exert pressure. This means that light has momentum (however tiny)
2. The device emits microwaves in a particular direction.
3. Microwaves are just EM radiation, like light.
4. Microwaves can exert pressure. So they have momentum.
5. Emitting microwaves can generate momentum in the emitter.
Posted as AC to, well, stay anonymous :)
The problem with empiricism is that your truths are only as good as your measurements (and they're always a little bit wrong). The problem with rationalism is that given the right set of axioms, you can literally prove anything.
Good, as far as you go. However this only addresses one small corner case of reality.
Guess which epistemology is more useful? Hint: if you pick philosophy/rationalism, you're probably a dumbass. No really, I mean it.
Outside of the small corner case of observable reality, the above rationale has no meaning. But this raises the question of whether reality extends beyond what can be observed. The most narrow-minded and dumbass view of reality is that things that cannot be observed do not exist; that only things that are subject to empiricism, to the scientific method, are real.
This is just so obviously false.... Science is the product of testing hypotheses. Those hypotheses are products of imagination. Imagination is not measurable in any way, and cannot be understood or even explored using any empirical method. At the very least, the universe is composed of things that can be manipulated with empirical methods plus imaginary "things". Since there is no limit to what can be imagined, reality is hugely, immeasurably, larger than the corner case where the scientific method can be effectively used.
One can say "Well, that's only your imagination, that is not real". But that is denying the source of the hypotheses that drive science. Which is a dumbass way of looking at things.
Or one can recognize that all of mathematics is a set of exercises in the disciplined use of imagination. I posit that anyone capable of comprehending this post will have just constructed a mental image of the set of all mathematical exercises--- by using their imagination to do so. Without mathematics, there would be very little science and almost no technology. The disciplined use of imagination is vital to a scientist's world view.
The appropriate question is not whether empiricism or philosophy/rationalism is more useful. That is a dumbass question, since empiricism depends on the disciplined use of imaginary constructs that are developed through various philosophies. It is a dumbass question because empiricism is a subset of philosophy, and a subset that depends on members outside of itself for its continuing evolution.
I do appreciate parent post's unique contribution to the discussion. "Dumbass" is a very effective way of describing a certain kind of thinking, but it is not a word I would have introduced myself. But since it was introduced, I am quite pleased to be able to make use of it.
Will
E=mc**2
Suddenly, "energy particles" can have mass properties, like momentum...
In Newton's physics this is impossible, of course. But today we use Einstein's.
Photons have no rest mass. Their mass is equal to their energy/Csquared. A function of frequency. Looking it up is left as a task for the reader.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
EM can serve as reaction mass, but it creates very little momentum.
This shows the problem :
http://en.wikipedia.org/wiki/Nuclear_photonic_rocket
PS. with antimatter/matter fuel a photonic drive would make sense.
I thought this was a new kind of a hard drive. Was looking to buy one on e-bay :-(
As well, there was an advantage in production that Phillips heads had over Robertson, in that the driver bit pops out of the screw head when the screw tightens up. In old production environments before the advent of accurate torque-limiting drivers for all stations, it was a handy way to determine proper screw torque.
I've heard that, but how did they deal with hex (or square) nuts and bolts which would have the same problem? Sounds to me like it was just an excuse made up to justify an economic or political decision on nonexistant technical grounds - as often happens.
- mechanics --- a Phillips driver will ``cam out'' when it hits bottom, making triggering the retraction of the tool easy, a Robertson requires a more sophisticated system to measure the torque, stop applying force, then pull out
Torque wrenches for bolts just have a firm spring between the driver and the handle - past the torque limit, the spring twists. I can't think of anything simpler. Maybe that's was just an excuse?
My Chinese is a bit rusty, but the triangular object on the right with the energy arrows flowing through it should be labelled "flux capacitor".
It is well-known that Photons do generate a tiny amount of thrust. Just recently there was a NASA paper about the "unexplainable" deceleration of the Voyager probes was (mainly) due to the infrared photon emissions of the RF power amplifier of Voyager's transmitter (which must be powerful to generate a signal to reach earth. RF amplifiers always generate lots of heat per watt of RF actually transmitted).
There is also the "Solar Sail" method of satellite propulsion, which is partially powered by photons:
http://en.wikipedia.org/wiki/Solar_sail
So this man has created something which emits lots of photons per second (RF is ALSO photons, just in massive numbers and at low energy levels per photon as compared to visible light or IR) and it generates thrust ? Yes, that sounds entirely plausible.
Let him prove his idea using one of these small satellites. I am sure the Chinese have some surplus money lying around for that. And yeah, cry me a river for those Brits who cannot afford to test their own innovations because they have pissed their treasure away by means of Banksterism.
My name is irrelevant, but I have a Dipl.Ing. (roughly a BS) in "technical" Computer Science and I had some real good physics teachers until class 13 in Germany.
Impuls eines Photons: p= h/lambda
Anzahl Photonen; E=n*h*f; n= E/(h*f)
Maximaler Impuls des "Klystrons": p= n* h/lambda = E/(h*f) * h/lambda = E/(f*lambda) = E/(f*c/f) = E/c [J/m]
For a 10kW RF "Klystron" and 1 day: 10000W*86400s/300Mm = 86400/30[W*s/km] = 2,88 [J/m]
Assume the sat weighs 500kg (there must be a little reactor to power this thing in deep space):
pSat = pPhoton
mSat*vSat = 2,88J/m
vSat = 2,88J/m / 500kg = 0,00576 m/s
So the sat accelerates by 0,00576 m/s per day or 2 m/s per year.
Not really impressive. It must indeed by an "unconventional" effect and as long as he it has not been experimentally proven, I would not believe it. Maybe this is just another "cold fusion" or "faster-than-light neutrino" story.
The Chinese government has reckoned that if they act like they're spending a lot of time, effort, and money on this thing, we'll spend a bit on it, distracting us from other things. Maybe they're really not spending any time, effort, or money on anything besides a smokescreen.
Whether it works or does not doesn't change what our life sciences focus for space needs to be—living with a constant >1g or more of "gravity". NASA spends a lot analyzing the effects of living with low "gravity", but space travel like that was done in the 60s and might be feasible for a trip to Mars, but that's about it. Blasting off and then coasting is a terrible way to travel. Some day, somehow, we're likely to figure out how to provide large amounts of thrust constantly for long periods of time. Accelerating at 1g to a halfway point and then decelerating at 1g suits our bodies, but accelerating at higher rates makes the trip a lot quicker. So... can people adapt to 1.5g or 2g or more over time? Someone must be studying this with mice in a centrifuge... Climbing stairs might be more tiring, but falling down could be a lot more hazardous than at 1g.
Wired should be ashamed for printing the story so uncritically.
Slashdot should be ashamed for posting it at all.
If I wanted to read this sort of nonsense, I'd be at Above Top Secret.
Americans and Britons are the Most Capable Scam Artists the world has ever seen. They have tricked Russia intro destroying itself by means of Marxism. They have tricked Japan and Germany into all sorts of strange stuff which reduces their fertility to something like one child per women, when 2.2 would be required to sustain a nation.
I have very little doubt that Anglosaxons will destroy China on the long run. Not by cruise missiles, Lasers and all that tech claptrap. Walt Disney and Hollywood will do it. And all the perverts like Charles Bukowski. The Chinese can such off every little detail from America by means of Viruses and other CNO stuff and all they will yield is poisonous information very much like the Volumes Of Redundant Nonsense of Marx. They will devour the "collected" nonsense and destroy their own nation by these means. Just wait and see.
Urrm, yeah. Like Cold Fusion, which is used in the Über-Secret F-1111. The F-22 is just a decoy that distracts people when they perform F-1111 operations out of Area-Fuck-One. Cold Fusion actually works and all the de-bunkers are paid by CIA. Indeedzz !
According to TFA, the EM waves are contained; they do not radiate beyond the device. The inventor is claiming thrust from an internally generated EM field reflecting off interior walls.
Horsefeathers
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Not here because the device is claimed to contain its electromagnetic energy by internal reflection. Nothing is (claimed to be) externally emitting or reflecting.
Contribute to civilization: ari.aynrand.org/donate
Well, then, if they build it, and it works, then the debate is done. If they can't, the debate is done. The best argument is a working engine. Let's see if they can do it.
If we are ever getting off this death trap before the next killer asteroid whacks us, we need lateral thinking. Good to know someone is trying something new, instead of recycling 1960's rocket designs. Rockets just aren't going to cut it. There's a loophole in the rules somewhere, and eventually, slowly, painfully, we will find it.
Probably won't be Americans that do it. We are too in love with our old successes. When we visualize radical change, it usually involves self-parking cars. Weird solutions will come from people who have no past to gaze back on.
They ain't laws of physics, they're just rough guidelines. We're not through warping the universe just yet. Just 'cause it doesn't exist doesn't mean it can't. The universe didn't have smart tweaky bags of carbon trying to change things before.
Your questions make no sense at all, even if they got rated insightfull. ... non of your proclaimed effects has any effect on a mechanical spring ...
How do you measure thrust? Wiht a simple mechanics, device called a spring
Next try?
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Sorry, you are wrong.
First off all I would stop using the word blantantly if you critic scientist, I would wager you would be 99.9999% wrong.
Did you even read the article?
I guess not. So I make it simple for you. The is an open chamber, emitting micro waves to the open end.
Ofc those waves cause momentum/thrust. And in that we have equilibrium of conservation of momentum.
Now lets talk about energy. Who claimed that this drives uses no energy? Some solar panels would be all it needs, or a nuclear reactor or some peltier elements or what ever.
Starting a posting whith "balantry conservation of energy" whith out even thinking about the topic in discussion is braindead stupid.
Anything claimed in this article definitely does not violate any law of conservation or thermodynamics. However it does not make it be true ... to disprove it you need to dig deeper into your pockets. But 5th grade physics is not enough for that :)
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
You are talking about photons?
Photons are considered to be massless if they rest. As soon as they are moving, they have mass. And they are always moving. And they are always moving at light speed.
So the mass comes from the wave length/frequency of the particular photon. The bluer/violetter the more heavy with gamma quants being the most heahy ones.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
You may as well ask, "What about magnetism? Why don't we get perpetual motion from that?"
You can't get energy for free. Yes, Casimir energy exists, same as magnetic and gravitational energy. But a book sitting on a table can't be used as an energy source just because it feels the force of gravity.
"But maybe we'll discover something else that will invalidate the conservation of energy!" Noether's theorem pretty much rules that one out. You know, that and every observation that humans have ever made.
Seriously, stick to cold fusion. It's more respectable.
Urrm, yeah. Like Cold Fusion, which is used in the Über-Secret F-1111. The F-22 is just a decoy that distracts people when they perform F-1111 operations out of Area-Fuck-One. Cold Fusion actually works and all the de-bunkers are paid by CIA. Indeedzz !
What is with the defensive attitude? Do you just enjoy the idea of staying dumb or are you getting paid for posting them? ;)
The room temperature super conductor is already being used by the gov for advanced tech.
One of the biggest reason these tech isn't available to the public is because they help objects stay invisible from radars, the materials are too effective at absorbing/transfering incoming energy.
Have fun being a sheep.
Qu Tubes for High Temperature Heat Rejection
In our proposed effort, we intend to perform high temperature (100-200 Deg C) characterization of an ultra-advanced heat pipe to determine feasibility of using it in high temperature space radiators. In previous work, we have shown that the so-called "Qu Tube" achieves exceptionally high thermal transport rates at lower temperatures. BENEFIT: Our innovation will significantly reduce the size of radiators used on spacecraft and satellites, thereby reducing their mass and their cost. It can also be applied in many industrial heat exchanger designs.
Energy is always ejected from a heat source, even if it's just as infrared-wavelength photons.
Watch for Penguins, they eat Apples and throw rocks at Windows.
EM radiation has to be released from the system to provide propulsion. The whole point of the EmDrive is that *nothing* is emitted, and the levels of thrust claimed are not consistent with a photon drive at the power levels used.
The last good idea they had was gunpowder (for bottle rockets).
This 'invention' is unlikely to change their record.
Okay, if it is being propelled from just thermal emissions, it would need to be much, much hotter to provide thrust on the order of millinewtons. Photons have momentum, but it's really, really tiny. You need hundreds of megawatts to get just one measly newton of thrust. And that is not the mechanism this guy is claiming.
If you don't understand any of my sayings, come to me in private and I shall take you in my German mouth.
Like this: http://www.youtube.com/watch?v=B707Ava4wrY
@20