First Object Teleported From Earth To Orbit (technologyreview.com) 212
Researchers in China have teleported a photon from the ground to a satellite orbiting more than 500 kilometers above. From a report: Last year, a Long March 2D rocket took off from the Jiuquan Satellite Launch Centre in the Gobi Desert carrying a satellite called Micius, named after an ancient Chinese philosopher who died in 391 B.C. The rocket placed Micius in a Sun-synchronous orbit so that it passes over the same point on Earth at the same time each day. Micius is a highly sensitive photon receiver that can detect the quantum states of single photons fired from the ground. That's important because it should allow scientists to test the technological building blocks for various quantum feats such as entanglement, cryptography, and teleportation. Today, the Micius team announced the results of its first experiments. The team created the first satellite-to-ground quantum network, in the process smashing the record for the longest distance over which entanglement has been measured. And they've used this quantum network to teleport the first object from the ground to orbit. Teleportation has become a standard operation in quantum optics labs around the world. The technique relies on the strange phenomenon of entanglement. This occurs when two quantum objects, such as photons, form at the same instant and point in space and so share the same existence. In technical terms, they are described by the same wave function.
A photon is not an "object" (Score:5, Informative)
Outside of an arbitrary definition that says a photon is an object because we say so, a photon is most certainly not an "object" using any ordinary definition of the term or even a definition that the vast majority of physicists would use (i.e. than an "object" has mass, which photons most certainly don't have or else they would never be able to travel at light speed).
Re:A photon is not an "object" (Score:5, Funny)
Re:A photon is not an "object" (Score:5, Funny)
the photon objects.
We looked into that, but couldn't determine where exactly this objection came from.
Re:A photon is not an "object" (Score:5, Funny)
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Photon: (waves)
Re:A photon is not an "object" (Score:4, Funny)
the photon objects.
We looked into that, but couldn't determine where exactly this objection came from.
...and then once we figured that out, we forgot how fast it went.
Re:A photon is not an "object" (Score:5, Interesting)
About 100 years ago Bertrand Russell pointed out that probability means we can't mathematically differentiate between chance and "free will." If you graph the choices a bunch of humans make, it comes out with the same Gaussian distribution as the photon spread pattern.
There seem to be many differences between "objects" at the atomic scale, and sub-atomic particles. Rather than being the same as teleportation of an object, this seems to be more the same as teleportation of intent; it has no weight at all. It is a measurable thing, but it is not guaranteed to have substance outside of a narrow context.
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Wow. That was deep.
This was not a sarcastic response. The lack of exclamation point after 'wow' indicates that I am deep in thought. There are numerous implications in the words you just wrote. Thank you for sharing (whether or not the future finds your words right or wrong).
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Check your fucking quantum privilege!
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It should not surprise you. Both the words "artificial" and "intelligence" are deep philosophical questions.
Given that artificial flavors are often quite distinguishable from the original they are trying to emulate, I am willing to accept that artificial intelligence is not equivalent to human intelligence or even mammalian intelligence. But I still expect there to be some reasonably high bar for what is intelligence even if it is artificial. Systems that employ problem solving and machine learning even if
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Yes it is : Photon photon = new Photon();
correcting a programming joke, IR AWESOME. (Score:3)
Photon new_photon = new Photon(old_photon);
after all, we're trying to duplicate the properties.
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Energy equals mass times the speed of light squared.
Thus, for a photon to have energy, it must have some mass.
Otherwise E=MC^2 is wrong.
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A photon has mass. It's both a particle and a wave.
Right, first of all, no, it absolutely does not have mass.
Secondly, the fact that it's both a particle and a wave (which is an oversimplification) has nothing to do with whether it should have mass or not.
A photon has mass. It's both a particle and a wave.
Ditto.
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Right, first of all, no, it absolutely does not have mass.
Photons have momentum, they have inertia, they are affected by gravitational fields, and they generate gravitational fields. You could say they have no "rest mass", but since they are never at rest that is meaningless. There are experiments that "stopped" light in a Bose-Einstein condensate, but really the energy was temporarily stored in the excited state of the BEC, and during that time, the mass of the BEC increased.
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You could say they have no "rest mass", but since they are never at rest that is meaningless.
It's not meaningless, it's very useful: it means the m0 in the mass-energy equivalence formula is zero (E^2 = p^2 c^2 + m0^2 c^4). It's a helpful quantity elsewhere in SR and GR as well. Whether one is referring to 'rest mass' or 'relativistic mass' when writing 'mass' varies on context in physics, but is important.
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A photon has mass. ...)
It simply had no rest mass (rest means 'resting'). In other words if you could stop it, it had mo mass.
But it is traveling with the speed of light. It has an impulse/momentum. Impulse/momentum implies mass.
It is only nitpicking americans with bad school education (and yes in 5 minutes a Phd in Physics with similar bad education tries to contradict me
Get it: it has momentum, so it has mass. Plain and simple. Photons count as massless in the standard model 'at rest', not while they are
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Please, tell me you're just trolling...
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(Sci-fi writers really love playing with things like tachyons, so you can blame the physicists for this one.)
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s/theoretical/hypothetical/
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Photon, numb nuts.
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No, a photon does not have mass. Its energy comes solely from its momentum.
The full formula is
E^2=(mc^2)^2+(pc)^2
where p is momentum.
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A photon has no mass, because it travels at the speed of light. Nevertheless, due to energy-mass equivalence, it can exert gravitational effects.
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Shit, genius.
Someone should really tell Einstein:
Photon
Composition - Elementary particle
Statistics - Bosonic
Interactions - Electromagnetic
Symbol - Î
Theorized - Albert Einstein
Mass - 0
Mass is a very different thing to being a particle.
And it's NOT a particle either. Or it wouldn't act like a wave. It acts LIKE a particle in some instances, and like a wave in other instances, but DOESN'T have mass. It's called the wave-particle duality, which still isn't fully explained but certainly doesn't require m
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A photon has no REST mass (mass at velocity = 0). It has mass due to velocity (special relativity), or as you mention, it has momentum, which implies mass. (momentum is mass times velocity, after all).
Heck, a photon carries energy, which implies mass as well (E=mc^2, energy and mass are the same). And its energy is related to its wavelength...
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E = \gamma m_0 c^2 for massive objects, where m_0 is their rest mass. Alternatively, E^2 = m_0^2 c^4 + p^2 c^2. In neither case do electromagnetic waves have mass. Indeed, for electromagnetic waves (or photons) E = pc because m_0 = 0. This does NOT mean that E = \gamma m_0 c^2 = pc = m c^2 with m_0 = 0 and \gamma = infinity (where you effectively have to assert that 0 * infinity = 1) so that you can conclude that p = mc for electromagnetic waves for some meaningful/useful definition of mass. Note wel
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All particles, electrons, protons, neutrons etc. p.p. behave like a wave in the right context.
And yes, photons have mass. They simply have no mass at speed 0.
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It's not that impressive. I launched them when I was a kid. The 2 stage models were a lot more prone to problems though, so I mostly just played with the smaller C engines which were more common and cheaper.
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So with all the arguments and the pulling out of Einstein, has anyone remembered that as particles increase towards lightspeed their apparent mass increases until they at light speed they'd have infinite mass, and thus never actually reach lightspeed?
Light ALWAYS travels through the vacuum at lightspeed. And if you haven't noticed, nothing is getting smashed around by infinite mass.
Just because something doesn't have mass, that doesn't mean it can't affect other
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Since most people get it wrong on how solar sails work (and I'm not going to explain them here). Instead let me give you an alternative example where force can be irrelevant to mass. Repulsion of magnets is the example I'd use. The mass of the magnet doesn't matter, rather it's the strength of the magnet. If you've played with simple magnetized iron compared to neodymium you know there is a huge difference that doesn't appear related to mass.
Feel like I need to go back to school (Score:4, Insightful)
in order to understand everything that was going on with the experiment. I wish the traditional media good luck in trying to translate all of that into an article for mass consumption.
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OH don't worry, they'll use some Star Trek clips and a car analogy and then move on to some other subject :)
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Also did faster than light communication! (Score:4, Insightful)
Obvious Question: (Score:2)
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Same photon/different photon with exactly the same properties (of which a photon has a limited and fixed number)... it's somewhat arbitrary and philosophical as to whether that makes it the same photon.
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Properties of a photon also include its location in space. There are plenty of photos with identical properties save for their location in space.
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In quantum mechanics, photons are indistinguishable. They are all excitations of the the same quantum field, so it isn't meaningful to assign individuality to each photon. Mathematically, if you interchange two photons, you have done nothing to the state of the photonic quantum field.
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They asked it.
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All photons of the Chinese government are bar-coded for inventory control reasons.
They're also limited to one photon per communication system.
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Nice try, but if that were true c would be infinite, gravitational lensing wouldn't be a thing, etc.
Time dilation of a traveler fartin' around the universe at (or near) c affects the traveler. That's the crux of "time is relative, the speed of light is constant". We're used to thinking of time as a fixed march of the universe and speed/velocity being relative, when in fact the opposite is true.
Quantum "teleportation" is badly misnamed (Score:5, Informative)
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Ok, can you put this into layman's terms, and tell
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I think I can speak for everyone when I say "not soon enough".
Somebody get this guy some pants! It's horrifying.
Star Trek is REAL. (Score:2)
yow, that sounds like an absolute Zippyism [zippythepinhead.com]
also, someone please quote me on that in their
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The end result is physically and fundamentally impossible to distinguish from "real", sci-fi teleportation though.
Re:Quantum "teleportation" is badly misnamed (Score:5, Informative)
Not really. The problem is that we didn't take a photon in the lab, and create an identical photon in space. We took a photon in the lab, created a photon in space, then made the photon in space identical to the photon in the lab. That's a bit like taking a block of marble and carving it into *exactly* the same shape as, say, Michelangelo's David, then claiming we "teleported" the statue. Even if the final product is molecule for molecule identical, few people would call it "teleportation". Teleportation would involve taking the particles from one location and transferring them to the other, in some kind of stream or through a wormhole or something. Note that this is probably impossible.
The key to quantum "teleportation" is that particles are indistinguishable except for a couple of quantum numbers, so if we take a particle and force it to have the same numbers as another particle, we've "teleported" it. Except that we can also distinguish particles based on position. Yes, it's true that you can take two electrons in two hydrogen atoms, exchange them, and you'd never know the difference. But we can still say the electron in that hydrogen atom over there is not the same electron as the electron in this hydrogen atom a million miles away. This isn't just a philosophical distinction: the two electrons really are different (i.e. have different quantum wavefunctions), at a physics level.
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In every day life, you also lose all of your original particles and are reassembled in a similar pattern from new particles, and go on thinking you're the same person. Teleportation only speeds the process.
Obligatory xkcd (Score:3)
https://xkcd.com/465/ [xkcd.com]
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However can you not even tell that quantum teleportation has taken place at all until the classical information arrives and tells you it happened? If you can't observe that anything has changed at all until someone else tells you it happened it seems to be a bit of a sham.
However
Re:Quantum "teleportation" is badly misnamed (Score:5, Informative)
You cannot tell that anything has happened by just looking at one of the entangled particles, no.
On a very brief and undetailed level, entanglement just says that measurements of particles A & B are correlated. What happens in an entangled measurement is vaguely like this:
Using further methods like mixing A with C and also B with D before measuring and other stuff, then telling each other what measurements of A&C resulted, it's possible to say that D4 == C4 exactly, 'teleporting' particle C4 (i.e. just reproducing the exact quantum state), but this requires measuring D1, D2, and D3 and thus destroying their state. It's more complicated than this, but resembles a logic puzzle.
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Anonymous PhD physicist here, and this is one of the better descriptions of this phenomenon I've read. It's important to note that nothing is being transported other than information - the first photon is not the second photon, but they are identical and in a quantum sense track the state of the other. In comparison to a Star Trek transporter, this would be like completely scanning an object, and transmitting that information to a second location where a perfect 3D printer duplicates the object. If this object happened to be a human (presuming we have 3D technology capable of that one day), you'd either have to destroy the first one to complete the teleportation (like in the Prestige - good movie if you've never seen it) or end up with two objects (I'll leave the bit about the "soul" out for those of you religiously minded). The key quirk of quantum entanglement is that the information seems to be transmitted instantaneously (my personal belief is that while entanglement violates the speed of light, it's speed is not infinite). I'll also add that thus far this effect is limited to photons, which themselves are pretty spooky particles in a quantum mechanical sense, doing all kinds of things that ordinary particles can't do. When the grand unified theory comes along, I suspect the wave/particle duality of light will collapse, resulting in something like "all matter is a manifestation of a superposition of standing wave fields", and we'll be back at Maxwell, but with a third, as yet unidentified, field structure.
Quantum entanglement does NOT result in information transfer. Not even if you call it "quantum teleportation". Information transfer happens as it does, at classical, non-causality-fucking speeds.
Claiming that "quantum teleportation" results in instantaneous or faster-than-light information transfer is wrong. It's like saying flipping a coin and seeing that it landed heads up results in instantaneous or faster-than-light information transfer regarding the bottom side of the coin. Even if the coin were a
Should I short sell transportation companies? (Score:2)
TL;DR Summery: (Score:5, Funny)
They pointed a flashlight at some satellite.
Ansible (Score:2)
Great job on whoever named this teleportation (Score:4, Informative)
Scientists: laypeople are twisting our words and making hyperbolic claims based on their misunderstanding of our research.
Other Scientists: Hey let's name this phenomenon after a fantastical and thematically similar yet completely unrelated concept in popular culture.
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The truth is that scientists want people to be intrigued by what they do. They want to accurately explain what they do, but need a hook to get people to listen. IAAS
Why orbiting? (Score:2)
What is the purpose of this experiment running from orbit, or from some greater distance than it had been done before? Was there some speculation that entanglement would no longer manifest due to distance or difference in velocity or within the vacuum of space or something?
Chinese Are Laughing (Score:2)
The Chinese people are on the slope to dominate orbital, and therefore international realtime communications.
Westerners on Slashdot spend their time bitching about the accuracy of a title of a paper.
This is how you lose.
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I'll be impressed (Score:2)
when they can teleport electrons, protons, and neutrons. Preferably a 200 pound mass of them that happens to be in the shape of a man. Until then, yawn.
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https://www.youtube.com/watch?... [youtube.com]
When can this be scaled up ... (Score:2)
to the point that we can teleport all politicians up there ... and then quickly destroy the machine before they figure out what we did and try to get back again.
Until Scotty finds Archer's dog (Score:2)
Not teleportation (Score:2)
Also, a scifi short story [wikipedia.org].
Very Funny, Scotty... (Score:5, Funny)
...now, beam down my clothes.
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Are you claiming you wouldn't be happy if a transportation company claimed instantaneous travel, cloned you, moved the clone then killed the original?
Pretty sure there's a book or story about that.. Some teleportation system malfunctions and the original isn't destroyed at the source, but no one knew that's how it actually worked.. That all these people teleporting about were just perfect copies of the one that stepped in and the one that stepped was in effect killed each time.
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I first came across Williams in the sci-fi anthology "Meeting Infinity" with the short story "All The Wrong Places", which is one of the best stories I've ever read. Very moving.
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Check out Peter Clines' "The Fold", and Blake Crouch's "Dark Matter" for interesting takes on the whole teleportation thing.
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Pretty sure there's a book or story about that..
There is a short story: Fat Farm [wikipedia.org], although that may just be ordinary biological cloning. I read it a long time ago.
It is also part of the plot of the movie The Prestige [wikipedia.org]. The basic premise of this movie is that it you could teleport and create copies of yourself, rather than using that ability to acquire vast wealth and power, you would use it in a medicore magic show to duplicate what another act does using identical twins. That movie should win a Golden Raspberry for "most ridiculous premise".
man, that is some dark shit. (Score:2)
The key unexamined aspect of Star Trek is that _EVERYBODY_ already knows all this, and they just doesn't care. They've been brainwashed by Starfleet to step into to the suicide booth without a second thought. Which gives you a pretty damning characterization of the pro-transporter lobby.
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Especially, when there were examples when the uh, suicide booth failed and the "clone" survived. https://en.wikipedia.org/wiki/... [wikipedia.org]
I would have my reservations too knowing that and having real examples of what could go wrong. "Safer than a shuttle", yea? For who.
Re:Stock Traders (Score:4, Informative)
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No-Communication Theorem [wikipedia.org]
In physics, the no-communication theorem is a no-go theorem from quantum information theory which states that, during measurement of an entangled quantum state, it is not possible for one observer, by making a measurement of a subsystem of the total state, to communicate information to another observer. The theorem is important because, in quantum mechanics, quantum entanglement is an effect by which certain widely separated events can be correlated in ways that suggest the possibili
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hmm i ment in the way of replacing something like this
Teleporting over long distances would still have to be faster than having a server in the same rack as the stock exchange server.
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Do you even think, creimer?
Can you educate yourself or do you need a box of crayons?
On a physical, financial exchange level, generally when you're talking about high-frequency trading you're talking about high-end servers such as HPG8s sitting in a rack, collocated at exchanges with a physical cross connect from the exchange into your rack. With that physical cross connect you can "order from a menu," Lauer says. "If you want a gigabit Ethernet, it costs you X. If you want 10-gigabit Ethernet, it costs you Y. A lot of these venues now offer 10-gigabit Ethernet; it'll go directly into your 10-gigabit Arista Switch ($13,000), which is just a cut-through switch that can route that packet in nanoseconds into your server, which has a kernel bypass mechanism right into memory, and you're looking at it within a handful of microseconds."
http://uk.pcmag.com/internet-products/12815/feature/inside-wall-streets-high-frequency-trading-technology-arms-r [pcmag.com]
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I personally like to educate myself with a box of crayons. Check mate atheists.
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You've got some derp on your chin. No, other side.
Re:Too many words, mismash (Score:5, Insightful)
Funny, I was thinking that this was one of the better summaries that I've seen on Slashdot lately. No click-bait, all the pertinent facts, and covers a subject that's actually news for nerds. The summary is plenty good enough to not have to RTFA, which should be the top criterion for all good Slashdotters!
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Except for that whole 'teleported' word.
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Technically, teleported is the correct word. We're talking teleportation in the scientific sense, not Star Trek teleportation -- not that the unwashed masses know the difference.
I'd actually say that "object" is the wrong word. I'm not sure I'd call a photon an object. "Particle" would be 1000% better, and much less confusing.
Re:Too many words, mismash (Score:5, Informative)
No not technically. Did particle A starting in position X end up at position Y? Was any information transferred or able to be transferred? Is faster than light communication possible? The answer to all these are no. Describing entanglement with teleportation is dumb.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Re:Too many words, mismash (Score:5, Informative)
No not technically. Did particle A starting in position X end up at position Y? Was any information transferred or able to be transferred? Is faster than light communication possible? The answer to all these are no. Describing entanglement with teleportation is dumb.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Actually, quantum information was transferred. Of course there wasn't faster than light communication as quantum teleportation relies on entanglement *and* a classical communication channel.
For each qubit of information that wants to be sent, one of a pair of entangled photons needs to be conveyed to the destination (which can be done at nearly lightspeed for photons in free-space). After this is conveyance is done, then anytime later, a qubit from a third photon can be "teleported" to the destination by use of a conventional communication channel (which obviously isn't faster than light speed).
The way this works is you jointly measure the 3rd photon and your local singleton of the previously entangled photon which yields one of 4 joint states. This doesn't tell you the original state of the 3rd photon, only the joint state relative to the entangled photon, (but in the process collapses the state of these photons).
You then send this description of the measurement (basically two bits of information) across a classical channel to the destination (at whatever speed you want).
To replicate the quantum state at the destination, you manipulate the phase of the previously conveyed/entangled photon (without measuring it) according to on the results of the relative (2-bit) state description. After this manipulation, this previously conveyed entangled-photon has a non-collapsed replicated quantum state of the original 3rd photon, but the state was transmitted/teleported to its destination over a classical channel.
You can read the details from their paper paper [arxiv.org]. Over 32 days, they managed 911 four-photon events and achieved an estimated accuracy of about 80% of conveying the quantum state (the theoretical limit accuracy of a conventional channel was about 66% w/o using information obtained using measurements of previously conveyed entangled photons).
Remember you can't simply pre-measure a quantum state w/o collapsing it to determine the accuracy rate, so accuracy was determined statistically using two entangled pairs (which is why they needed to create a four-photon-event and for which it was hard to create a process for).
Baby steps.
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Somebody upvote here. If I'm not mistaken, I just learned something very cool! Thank you.
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The problem is, elementary "particles" aren't particles in any meaningful way - the term just lingers in the vocabulary for lack of something better. For decades now it's been clear that QFT is right, and everything is a wave. There's no "duality", really, just waves that have some properties somewhat like what we might naively guess particles would have, if there were any particles. Heck, this whole "quantum teleportation" effect relies on the fact that "particle" isn't really correct.
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Because this is NOT teleportation. EVERY FUCKING TIME THEY DO THIS SAME SHIT AND CALL IT TELEPORTATION.
It's fucking NOT teleportation! And we're fucking sick of seeing the pop-sci HORSESHIT!
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Uh, I see photons all the time. I would have trouble seeing without photons.
Photons are quantum objects, but not physical objects. This is because the latter consists of matter and therefor has mass.
"Tangible object" is less rigidly defined, and one could probably make a case either way for photons being tangible.