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China Says It Has Developed a Quantum Radar That Can See Stealth Aircraft (digitaltrends.com)
An anonymous reader quotes a report from Digital Trends: At a recent air show in the city of Zhuhai, state-owned Chinese defense giant China Electronics Technology Group Corporation displayed what it claims to be a quantum radar that's able to detect even the stealthiest of stealth aircraft. The company claims to have been working on the technology for years, and to have tested it for the first time in 2015. In principle, a quantum radar functions like a regular radar -- only that instead of sending out a single beam of electromagnetic energy, it uses two split streams of entangled photons. Only one of these beams is sent out, but due to a quirk of quantum physics both streams will display the same changes, despite being potentially miles apart. As a result, by looking at the stream which remains back home it's possible to work out what has happened to the other beam. According to a brochure from the China Electronics Technology Group Corporation, the new quantum radar could "solve the traditional bottleneck [of] detection of low observable target detection, survival under electronic warfare conditions, [and] platform load limitations."
They wouldn't admit this to the world if they really had it, and it really worked. Sounds like another Chinese hack to me.
A beam seems like a really inefficient way of searching for something in 3D space. Also, if only one beam is sent out what happens to the second entangled beam? Photons aren't known for sitting still.
I'm fairly certain entanglement is incredibly easy to break. While you can, in practice, beam stable entangled photons to a satellite, requiring enough going sideways through the atmosphere to then bounce off an object to then be read out without breaking the majority of entanglement seems unlikely. It's hard to enough to maintain entanglement in the extremely isolated confines of a quantum computer, just flinging it out into the atmosphere seems a lot harder?
Dwave also has developed a 1000 qubit quantum computer. And Musk is building a hyperloop tunnel system and a Mars colony. And soon we will have AI and self-driving cars. We live in exciting times, my friends.
Really, you quantum entangled two particles, sent one miles away and observe the other one to detect a plane. Doesn't observing of the other particle change the state of the entangled particle sent away? Plus there is the whole what if that particle hits anything else on the way, say a rain drop?
Sounds like they have been watching too much Sci-Fi or they just wanted to call it Quantum Radar when its just really an narrow band radar.
What's next, they are working on a Reverse Quantum Phase Radar Interference Detector to detect when their Quantum Radar is jammed? (hopefully it's snozberries jam).
Awesome, so this disproves bell's theorem and thus re-writes the laws of WM as we currently understand them.
Or at least the simplified description of this does. perhaps the real process is different.
Bell's entanglement experiment results in a rather cool result that even though one can have spooky actions at a distance, you cannot use it to transmit information. That is you can if you compare results at each end see that there was a measurement induced correlation in the photons but you can't determine this from the statistical distribution of measurements at either end by themselves.
Thus you can't possibly see the aircraft in the local beam due to changes in the remote beam.
Some drink at the fountain of knowledge. Others just gargle.
That isn't how quantum entanglement works. China Electronics Technology Group Corporation is betting that readers are stupid or ignorant or both. That's a relatively safe bet, too.
The radar might still work, since there are other ways to design good radar.
If I'm reading this correctly, the exact same technology also enables faster-than-light communication.
That's not was Bell's theorem shows... Not even close. Bell's theorem disproves local hidden variable theories.
You're right that you can't use entanglement to transmit information faster that light, but Bell's theorem doesn't have anything to do with it.
OTOH they probably aren't revealing the missing piece which is absolutely blockchain!
If you record both generation and detection events via a blockchain algorithm which is constantly monitored for qubit updates, in an active quantum system, then you should be able to instantly monitor all events within the operator's personal reality, simultaneously. Due to uncertainty principle an extra element is required to fix certainty for the observer.
This would be blockchain! Nothing is more certain today than blockchain integration, and that term alone just reeks of complex math.
Energy and sufficient photons could be harnessed from a local source of high temperature plasma, say about 10 million degrees. It's doable with say 10 second pulses.
Data collected would require quantum sorting as it no doubt be in the vicinity of n*LoC^n/t volumes.
Funding should be snap as the same system could be used for high speed trading of shares and with a little work, Lotto number prediction.
I'm certain this is a thing.
They had a similar story last year, and the year before. It's not true. If it was, the last thing they would do is tell everyone that they can see stealth plans (or at least how they did it so it could be duplicated/nullified.) But it's not true. It's designed to impress someone, I'm not sure who.
Your ad here. Ask me how!
Duffman/China, says a lot of things!
yes it is what Bell's theorem shows.
Here's how. Bell's theorem requires acting on the entangled pair in a way that will change the pair relationship. If you simply force one of the particles to a specific state then it breaks the entanglement and the other particle becomes independent. (thus no FTL info). And if you act on the entangled pair, then when you measure the local particle's state you also break the entanglement (thus no FTL).
here's a layman's description:
https://www.forbes.com/sites/c...
Some drink at the fountain of knowledge. Others just gargle.
But regardless of arguing over what is or is not rolled up in Bell's theorem at least we both agree on the general principle that there's no FTL.
Some drink at the fountain of knowledge. Others just gargle.
First photos revealed.
When all you have is a hammer, every problem starts to look like a thumb.
Actually you've got that exactly backwards.
Bell's theorem:
No physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics.
with superdeteminism being the notable exception.
From Wikipedia https://en.wikipedia.org/wiki/...
If a measurement setting in one location instantaneously modifies the probability distribution that applies at a distant location, then local hidden variables are ruled out.
Basically, Bell's Theorem states that quantum entanglement MUST transmit quantum information faster than light - without that, no theory can describe all observed quantum phenomena (unless the universe is absolutely deterministic with no possibility of free will - a proposition which is pointless to discuss further since the outcome of such a discussion is already predetermined)
Harnessing that fact to transmit classical information faster than light is a completely separate question. But nobody is claiming that is happening here.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
And contrariwise, just because you DO understand something, doesn't mean that it does actually exist.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
First let's not argue what or what not is in Bell's theorem given that we violently agree that you can't transmit information faster than the speed of light.
THe work surrounding bell's theorem seems to establish two things
1. state changes can be transmitted faster than the speed of light (as we both agree)
2. That the nature of the state changes cannot transmit information faster than the speed of light (I aver and I think you agree).
So however you want to state it, information can't be transmitted the way that was described in the article.
Some drink at the fountain of knowledge. Others just gargle.
think of the canonical radar screen with the rotating antenna. it's a beam. Sure you can now do phased arrays but beams were the original incarnation
Some drink at the fountain of knowledge. Others just gargle.
It detects the plane if you don't look at the radar screen
Some drink at the fountain of knowledge. Others just gargle.
You can only compare the result of the beams if you have both beams. You can't get information about the other beam from the one you hold onto alone.
... quantum bullshit detector.
They are mixing the science of quantum entanglement with fucking ballistic particles.
And "2015?" Goddam stealth anything bigger than mesoscopic size is Classical.
Why the simple hell didn't they mention blockchain?
It little behooves the best of us to comment on the rest of us.
PLA: We have not been able to figure out how to make stealth aircraft. We know our currently illegal expansion into the South China Sea will result in conflict in the next few years, with aircraft we cannot see. And our enemies will be able to see everything we have. So we have to figure out a way to make them think we're on equal footing, at least in terms of seeing aircraft, so they will delay stopping our imperial march through Southeast Asia.
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
The article gives a pretty poor, if not outright wrong, explanation of what quantum radar is supposed to be. The idea behind quantum radar is that the microwave signal sent out by the radar system is first generated by one half of an entangled photon beam, and this is done in a way that maintains the quantum state as the photon beam is converted into a microwave signal. When the microwave signal returns after bouncing off a target object, the system is then able to use a comparison to the other half of the entangled photon beam in order to filter out any background noise. This would prevent an enemy from being able to using signal jamming to interfere with your radar. It would also make it easier to detect a stealth aircraft because no stealth aircraft is 100% invisible to radar, and quantum radar would, in theory, be able to pick out very small radar returns, that would normally be lost in the background radiation.
The usage of the words "Chinese" and "developed" in the same sentence is sufficiently descriptive of the utility of the linked resource. Useless!
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If China is claiming the technology to " see " stealth aircraft is now a reality, why are they still spending big $$$$ on building stealth aircraft ?
China is fixated on image. They took that whole " fake it till you make it " saying to heart and desperately wants the entire planet to believe they are the most amazing, powerful and capable country in history.
It should be noted the term " Paper Tiger " originated in China. They should be all too familiar with what it means since they are basically the very definition of the word.
Unfortunately that’s not how quantum mechanics work. Just google why you can’t send information FTL and I hope it’ll make sense. They would have to measure reflected photons, hitting an object could change the distribution of their quantum state, which would show up as decoherence against the background.
(unless the universe is absolutely deterministic with no possibility of free will - a proposition which is pointless to discuss further since the outcome of such a discussion is already predetermined)
In this case whether or not the discussion occurs is also pre-determined along with the outcome.
Also I'm not sure what you expect from free will. Brains (yours or mine) are systems that take input (including the brain state/structure at time t), process it, and produce output. That output, whatever it is, is literally your (aka your brain's) will. The process could be either deterministic (output is determined by the input) or it could include some true randomness (noise/indeterminism). I'm don't know which is correct, but I don't see how your decisions containing noise is somehow a marvelous or obvious thing.
LOL China.
There are three parts to their claim and they're all pseudo-babble junk:
1. A "stream of photons" can detect a stealth aircraft from some useful distance
2. Photons can be entangled on the fly (in real "stream" speed)
3. The entangled stream at home can be analyzed on the fly (same speed)
1.
Can photons be entangled? Sure. Can they be entangled at the speed of light such that a "stream of photons" (going out sequentially at the speed of light) are all entangled... possibly, but not with current technology and not with 2015 technology.
Think of it this way... physicists spend days setting up a quantum entanglement experiment where they entangle ONE or even TWO and sometimes FOUR (http://iopscience.iop.org/article/10.1088/1402-4896/aa736d) photons. To entangle enough to create a "stream of photons" and then sweep the skies two or three dimensionally for stealth aircraft is orders of magnitude beyond current tech.
2. It takes experiments ages (in photon time) to get photons entangled. Our primitive tools (electronics) uses electrons in a wire, which are slower than photons in air or in vacuum. Our tools simply cannot hammer these fast-moving nails fast enough... so what we do is fire a crap-ton of nails at our slow moving hammer and hope we can hit one into the other into the detector.
3. See #2. We don't have the speed with our slow-moving tools to analyze a photon stream.
I'm calling physics bullshit.
Ehud
I was going to jump in with something about violating causality, then I thought, better wait for somebody who actually knows what they're talking about.
Maybe they will follow up with an improved perpetual motion machine or a breakthrough in cold fusion.
When all you have is a hammer, every problem starts to look like a thumb.
"Quantum Radar"? China, you can't just add sci-fi word to another word and hope it means something!
It must have been something you assimilated. . . .
This "Schrodinger's Cat Scan" radar doesn't seem credible to me.
What gave it away? (/sarc)
What I expect from free will is simple, if difficult to observe conclusively: that I could act in a manner other than I do. That my changing thoughts, aspirations, and ideals can influence my future actions. Or alternately, at the most simple, that my actions could not be perfectly predicted beforehand. Superdeterminism denies that - as every action I will ever make was known with absolute certainty from the first moment of the universe's existence. As such it completely denies the value of consciousness, as it can have no effect on your actions, or upon anything else - we're all simply complex automata and consciousness is an utterly superfluous side effect with no relevance to our existence.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Actually I remain unconvinced of the impossibility of transmitting information faster than light - all the proofs I've seen all rely on assumptions which seem overly conservative to me. Not that I'm expert enough to fully understand the proofs, but I'll trust the experts when they say "these are the assumptions this proof depends on"
--- Most topics have many sides worth arguing, allow me to take one opposite you.
He lives with his mother, so he has her at least. I suspect it's a Norman Bates type relationship.
Gene Roddenberry
it's to get the US to spend more money on defense instead of back home on the (floundering) economy.
It's a classic cold war technique. The goal is to make your opponent drive themselves into bankruptcy trying to match you. We used it on the Russians and it pretty much wrecked them.
Hi! I make Firefox Plug-ins. Check 'em out @ https://addons.mozilla.org/en-US/firefox/addon/youtube-mp3-podcaster/
China both has and does not have a quantum radar.
They won't know until they open the box.
They've developed quantum radar that can see invisible airplanes and yet they still can't drive...
*Note : Extreme use of sarcasm*
errr....umm...*whooosh* *whoosh* Is this thing on ?
We've got quantum BLOCKCHAIN radar. It not only detects stealthy aircraft, it can detect aircraft you don't even have but wish you did.
Don't disappoint your bird dog. Go to the range.
Harnessing that fact to transmit classical information faster than light is a completely separate question. But nobody is claiming that is happening here.
That is exactly what the summary is claiming is happening:
As a result, by looking at the stream which remains back home it's possible to work out what has happened to the other beam.
That is precisely what you cannot do: examining the photons you have doesn't tell you any information about what has happened to the photons you sent out, the only "information" it gives you is (basically) the what the state the photons you sent out will be if they haven't interacted with anything (you don't, however, know if they have interacted with something or not). Since the point of radar is to interact with whatever you're looking for, that makes it rather pointless.
Note that a "quantum radar" could maybe improve on classical radars by comparing reflected photons to give you more information about what exactly reflected them, but it's still only useful if you get some of the photons you send out back. Even then I doubt you could actually make such a system (I'm not entirely sure it's physically or even theoretically possible). I am sure, however, the Chinese don't have such a system: they would never publicly disclose it if they did. The only reason to brag about it's existence is to either convince other countries to waste time trying to replicate it, or to convince them their stealth fighters will be useless against the Chinese. Either way, it's a purely psychological move.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
Can it spot the alien DC-8s that have been circling earth for millions of years? Many without stewardesses or working restroom facilities. Really terrible service, that. It's enough to upset any tenhat alien. And make 'em hungry. Which explains why they've taken to sucking out the brains of our smartest politicians.
The Russians have won. They have made the world a cesspool of distrust, greed, fear and hate.
that I could act in a manner other than I do.
At a given time your (brain's) state is what it is. The inputs have been given. Are you saying that if you "ran the tape" twice, with everything precisely identical up to that time, you would expect to act in a manner other than you did? That, with every thought, feeling, experience etc - literally every single thing up to that time - precisely duplicated, you would make a different decision? Because to me that sounds indistinguishable from randomness.
That my changing thoughts, aspirations, and ideals can influence my future actions.
They can in either picture. Your brain is you. The state of your brain evolves over time. No non-determinism is required for this.
Or alternately, at the most simple, that my actions could not be perfectly predicted beforehand.
In principle or in practice? Life would be dull if we could predict everything in practice, but that's so far beyond the possible I don't see it as a real issue.
Superdeterminism denies that - as every action I will ever make was known with absolute certainty from the first moment of the universe's existence. As such it completely denies the value of consciousness, as it can have no effect on your actions, or upon anything else - we're all simply complex automata and consciousness is an utterly superfluous side effect with no relevance to our existence.
I don't find it problematic that my every action is determined from the start. I am my brain. As such I am making those decisions, albeit deterministically. That I'm aware of it is nice, but I don't see it as necessary.
Yeah, it must be tough to make a beam that can be rapidly moved back and forth through space.
The second beam isn't aimed at anything, but can be measured, to determine what happens to the first beam. That's what quantum entanglement is, in a very crude sense.
I don't respond to AC's.
The article's description is flat our wrong. The idea behind quantum radar is that the photons used to generate the microwave signal are first entangled with photons that are kept inside the system, and then when the system receives returning microwaves, it's able to compare them to the entangled photons and filter out background noise and enemy jamming signals. The filtering out of background noise is what in theory would allow quantum radar a greater chance to detect stealth aircraft, which normally rely on background noise to obscure their small radar cross section. That being said, just because the Chinese say they've invented it, obviously doesn't mean they have. In fact, I would guess if any major power does develop a working quantum radar, they'd keep it secret.
More likely, given the scientific capabilities of the U.S., Russia, and several others, the company is merely groveling befor their alleged government. Think Roger Rabbit, "Pllbbbbblleeeese give us some money to cover our mismanagement...see, we have Quantum Radar!!"
In particular, the quantum radar does not claim any FTL nonsense. A beam is sent out, and reflected from the target. A very weak reflection, in case of a stealth plane. The quantum radar is not faster, it is merely able to see that extremely weak reflection because it is not hampered by background noise (natural microwave noise or electronic warfare jammers).
Read the wikipedia article on quantum radar. The principle is so old it has a wikipedia page - the only "new" here is that China claims they have a working device. I would guess some others have these devices too, but are quiet about them.
I've never entirely agreed with that formulation. Any machine you can build that verifies this theory does so using only information that travels at the speed of light.
So your other explanation is that all the information flows in this experiment, from the entangled particle, through the physical apparatus remain entangled until the final green light goes on (Bell's theorem verified).
All it takes is a much larger view of entanglement.
I am not a physicist, but my semi-informed view is that you can't prove entanglement without your conclusion itself having becoming entangled with the entangled particles during its inception. Every information flow in the conclusion takes place at the speed of light.
It's only when you abstract the experiment from the experimenter that it becomes attractive to insert "and then a miracle happened" (because you didn't feel the urge to trace the entanglement back through macroscopic systems all the way to the green light bulb).
Even if I'm wrong, I'm 50% correct. Because any explanation of entanglement that posits the instantaneous modification of probability distributions at a distance needs to explain that our experimental verification of this doesn't contain a hidden back channel though regular, speed-limit obeying information flows.
In my view, all particles are entangled until proven otherwise. So any starting point where the pairs of entangled particles under test is the only source of entanglement you might potentially need to explain (in your apparatus) is a bizarre conceptual conceit.
I would also venture that in a universe where entanglement of all particles is the norm and not the exception (prove otherwise ...) that by the theory of entropic entanglement, all entanglements about which you lack special insight are indistinguishable from random background noise (hence the unknown entanglements can almost be universally neglected—except perhaps when you build a contraption with a green light that goes on to signal Bell's theorem confirmed, under the [sort of] faster-than-light school of interpretation).
Dear Richard Feynman,
I wish to build a black-box experimental apparatus to confirm Bell's inequality, one that is fully automatic, and the entire experiment ending with only the signal of a green or red light.
To ensure that I don't fool myself (this having a colossally low bar), I wish to confirm before beginning the test run that no two particles in the apparatus itself are themselves entangled, so that the only entanglement present in the system is the entanglement under test.
Please advise.
TIA,
a concerned fool
Perpetual motion is possible if you can figure out a way of feeding all the energy in the universe into your device. The motion stops when the universe ends... so perpetual...
Seven puppies were harmed during the making of this post.
Awesome, so this disproves bell's theorem and thus re-writes the laws of WM as we currently understand them.
I do not have the knowledge to know what is theoretically, never mind technically, possible. However, it is not just China that is working on this:
* https://uwaterloo.ca/institute-for-quantum-computing/news/quantum-radar-will-expose-stealth-aircraft
* https://www.bbc.com/news/technology-43877682
General informations:
* https://en.wikipedia.org/wiki/Quantum_radar
did you hear about China's doomsday machine?
This should be modded way up, even it it's an anonymous coward. The summary is indeed completely wrong, the radar actually works by comparing reflected signals to the signal that stayed home, thereby canceling background and jamming noise.
> we will have AI and self-driving cars.
Fusion-powered flying cars, please.
That is not what "free will" was about. You have free will if you can do what you want and others can't force you to do something else, even if the others are gods. Well, technically gods could make you do it, but they don't, because religious reasons to convince you that the gods are omnipotent, anyway.
You can't use entanglement to transmit data FASTER THAN LIGHT. Slower than light is possible. This quantum radar may be vaporware, but it is at least theoretically possible.
> That is exactly what the summary is claiming is happening:
No. The article says that information is recovered. It does not say it happens faster than light. In Earth distances, light is pretty fast, so you can IN THEORY have "real-time" radar that involves quantum entanglement. This might be vaporware, but at least the summary isn't making impossible claims.
>In this case whether or not the discussion occurs is also pre-determined along with the outcome.
Quite - so, *if* I have a choice, I choose not to have the conversation, since my choice disproves the premise. And if I don't have a choice, it doesn't matter.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
> Stealth airplanes: Announced and bragged about before deployment.
You've got that backwards. The Lockheed F-117 Nighthawk (stealth fighter) was deployed in 1983. It was Reve publicly in 1988, five years later.
> "Starwars" missile protection: Announced and bragged about before deployment.
Not quite. SDI was mostly bluffing and there was never a design, much less a deployment. It was a concept. At the time the program was shut down, it was estimated it would take another ten years to determine if such a thing were even possible. The US led the Soviet Union to believe we had some kind of proof-of-concept, but there was no such POC, just some ideas of different approaches being tested out.
Those two examples would suggest this rule:
Don't tell them about what you have.
Tell them all about what you'll never actually have.
That would be "heterodyne" lidar or some form of Optical coherence tomography (same priniciple). But not quantum
Some drink at the fountain of knowledge. Others just gargle.
The article doesn't say "faster than light", but it does claim (and I quote)
Only one of these beams is sent out, but due to a quirk of quantum physics both streams will display the same changes, despite being potentially miles apart. As a result, by looking at the stream which remains back home it’s possible to work out what has happened to the other beam.
which is exactly not how entanglement works (also, if it was, it would be FTL).
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
Remember China claiming that their jet fighters were attacked by a turbo-prop cargo plane?
OTOH they probably aren't revealing the missing piece which is absolutely blockchain
(Picture of Bad Hair Day Meme Dude) ... but it's blockchain."
"I'm not saying it's blockchain
A breakthrough in basic physics would also be helpful because the energy cost of producing a muon is 6 GeV while each D-T fusion yields .0176 GeV of heat and is captured by a helium nucleus on average once per 1-200 reactions. Generating electricity costs another factor of 2.5, so the energy gap is nearly an order of magnitude.
Store muons? I think that's a fanciful embellishment of your own, and thank you for explaining the length of a microsecond.
When all you have is a hammer, every problem starts to look like a thumb.
Information is a relatively abstract thing. ... if one photon gets forced to break its entanglement with the other one, you can see that at the other one. The trick is to have a way to keep an eye on a single photon ... which is not that easy.
Of course it can be transported faster than light. Qunatum entanglement breaks instantly
Another simple example is: you have a galactic mirror a few 100 million light years away, a pulsar or your torch light is moving a beam from left to right over it and you watch the reflection. That reflection can move with nearly any arbitrary speed ...
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
(you don't, however, know if they have interacted with something or not).
Of course you know.
Technically a photon hitting a metal surface is not reflected.
It is absorbed and recreated. Hence the entanglement with his "brother" breaks.
Other "ideas" about photons interacting with electrons, aka metallic surfaces, include that the photon changes its phase perpendicular to the surface. Aka it changes its polarization. Hence: it breaks entanglement with his "brother" or the "brother" changes polarization as well.
No idea about what you want to nitpick ... both beams still only travel with the speed of light. And that is the only thing important. If you want: you can assume the detection is delayed by a time interval according to the distance the first photon has traveled ... then you get rid of your "instant is impossible assumption".
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Ahh but mine can do work. The more work you ask it to do, the faster the universe ends :)
Seven puppies were harmed during the making of this post.