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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.
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.
If I'm reading this correctly, the exact same technology also enables faster-than-light communication.
Yep.
And if you can fling things around fast enough, faster-than-light communication enables future-to-past information transfer.
Bye, bye, grandma. (The grandfather paradox, female version, doesn't suffer from the "but it turns out grandpa was a cuckold" loophole.)
Fortunately for those of us who depend on causality for countinued existence, Bell's theorem says the radar doesn't really work.
(Though one that passes entangled photons past both sides of the plane, then measures their interference, might in principle detect the plane without exposing it to the photons. THAT one doesn't violate bell, lightspeed, or causality, but is pretty spooky.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
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!
It detects the plane if you don't look at the radar screen
Some drink at the fountain of knowledge. Others just gargle.
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.
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.
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
China both has and does not have a quantum radar.
They won't know until they open the box.
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.