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Quantum Teleportation Sends Information 143 Kilometers
SchrodingerZ writes "Scientists from around the world have collaborated to achieve quantum teleportation over 143 kilometers in free space. Quantum information was sent between the Canary Islands of La Palma and Tenerife. Quantum teleportation is not how it is made out in Star Trek, though. Instead of sending an object (in this case a photon) from one location to another; the information of its quantum state is sent, making a photon on the other end look identical to the original. 'Teleportation across 143 kilometres is a crucial milestone in this research, since that is roughly the minimum distance between the ground and orbiting satellites.' It is the hope of the research team that this experiment will lead to commercial use of quantum teleportation to interact with satellites and ground stations. This will increase the efficiency of satellite communication and help with the expansion of quantum internet usage. The full paper on the experiment can be found [note: abstract only, full article paywalled] in the journal Nature."
Isn't this how the Ansible from Ender's Game works? Two particles made to be in the exact same state, despite being physically separated? Too bad we couldn't have put this type of technology on Voyager 1 and 2.
sudo make me a sandwich
Seems like a strange place to do quantum research.
So, it's not teleportation. Thanks.
If you are using quantum teleportation, why you even need a satellite???
Now, if we can just use it with missions further than the earth's orbit we'll be cooking with gas.
I wonder how much data can be transmitted with this technology.
I don't understand exactly what's going on, so that probably explains why I don't see the advantage of this.
From reading the abstract I get the impression that they are transmitting the information via lasers to the other location.
How is this different then using other frequencies in the spectrum? Aren't you still limited to the speed of light? So what is the advantage of this?
Seems like it adds complication without gaining much, other than being quantum.
Your 1ms ping time will be in compensation for your 80% packet loss.
Seven puppies were harmed during the making of this post.
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I've got some electrons that need to be in Indianapolis by 10!
"Quantum teleportation is not how it is made out in Star Trek though. Instead of sending an object (in this case a photon) from one location to another; the information of its quantum state is sent, making a photon on the other end look identical to the original."
So since matter is energy, if you can make the quantum state of object A identical to object B, IT'S THE REPLICATOR FROM STAR TREK ZOMFG I WANNA CHEESEBURGER
The difference here, from what I understand, is just this: When you fax something, you print ink/toner on another piece of paper somewhere else, that 'resembles' the original document. On different paper, perhaps written in Pencil, etc.
In this case, the photon at the end is made to be 'exactly identical'. So it would be the equiv of sending a fax of a pencil written document on cotton fiber blend paper. And getting a pencil written cotton fiber blend copy on the other end. That you could even still erase, since it's real pencil ;)
(OK OK, so that isn't possible ... yet .., this is just currently making a 'photon identical' ... but that's the conceptual difference)
Here is the paper pre-print on the Arxiv.
Free to read.
It's not quite as simple as teleportation, it's just given that name:
https://en.wikipedia.org/wiki/Quantum_teleportation
Most specifically:
"Suppose Alice has a qubit in some arbitrary quantum state
The components of a maximally entangled two-qubit state are distributed to Alice and Bob.
In the end, the qubit in Bob's possession will be in the desired state."
So what Alice is doing is actually modifying the REMOTE qubits to be identical to the LOCAL qubits AFTER the initial information exchange has occurred. You're now literally turning someone's remote blank paper into a copy of the document you have yourself by using a little set of numbers that you determined between yourself last week.
No they don't. The folks in Star Trek only communicate by audio when they are very close to each other (e.g. someone on a planet and a ship orbiting that planet, or two ships within clear visual range). They can pick up signals from light years away, but there is no indication that there isn't a lot of latency going on.
And as others have pointed out earlier in this discussion, quantum teleportation is not faster than light.
Pretty good is actually pretty bad.
The quantum state is copied (actually it's not copied, it's transferred - quantum copying would imply faster than light communication)
Going back to the more common example of momentum plus position, this would be like transferring the momentum and position from one electron to another (i.e. moving one electron into exactly the same place + velocity as the one you are "copying"). There is no measurement of position or momentum happening so the uncertainty principle is not violated and the transfer process changes the position and momentum of the original so you do not end up with two identical electrons.
Tim.
God said, "div D = rho, div B = 0, curl E = -@B/@t, curl H = J + @D/@t," and there was light.
...but doesn't that mean that information from the frame of reference of the sattelite will arrive 300ms in the future, or however long the dilatation of the gravity well of earth allows?
i am so very tired....
The reason why we aren't receiving radio signals from distant civilizations is that they're not using radios to communicate... they've figured out something better.
One of the solutions to the Fermi paradox is that civilizations invent something better than radio waves for communication, and thus the "radio window" is relatively brief, and so we won't hear anything because there's nothing to hear.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
This one actually explains it better: http://phys.org/news/2012-09-km-physicists-quantum-teleportation-distance.html No FTL communication but does give better security. Maybe better/faster compression to?
Sig. Sig. Sputnik
Can you imagine Xbox 360,000 Live gaming across the solar system.
Woot! ;-)
So basically - you start with two photons next to each, entangle them, then put one on a ship and it sails away. Then, you can tweak the one photon you kept, and every time you do, the other reacts as if you were the one tweaking it? Is it instantaneous? As in, could you put 32 of them side by side and create a 32 bit bus that spans any distance and yet provides connectivity as if where simply plugged into a USB port? Does the reaction on the other end diminish over distance? If not, why not use this to talk to a mars or lunar rover? No line of site necessary?
This really is an incredible phenomenon. I've read about it before, it just doesn't make sense to me.
/me sips his coffee and ponders a new sig...
it's exactly identical to the quantum state from point A before teleportation. But state A is modied, so after teleportation you have destroyed the state. (or modified the state to be more precise) So it's a copy at point B, but the original does not exists anymore.
For example, does it mean that it is like if I have a set of 2 blank pages. I give you one. You go home, I go home. Then later in that day, I write something on my blank page. At this exact moment, the same modifications are applied on your blank page ?
You destroy the copy on your end leaving the transmitted "copy" as the only one left. At least that's how Star Trek transporters work, sort of.
You have two cats, one live an one dead. You put them in identical boxes, shuffle them around, and send one random box to someone across the country. When they get the box, they call you up and ask, "what did you send me?" You open your box, and if it's a live cat, you say "I sent you a dead cat," or visa versa.
No cats were harmed in this description.
The only thing worse than a Democrat is a Republican.
Incorrect. The captain occasionally talks with star fleet command with near latency, but it's due to sunspace transmissions being FTL, not quantum teleportation. Once they get far enough out, the latency becomes big enough to be noticeable; see the Voyager series, or the episode of TNG with the Traveler.
For example, does it mean that it is like if I have a set of 2 blank pages. I give you one. You go home, I go home. Then later in that day, I write something on my blank page. At this exact moment, the same modifications are applied on your blank page ?
No, more like you have a set of 2 blank pages, and you write "A" and "B" on them. You then seal them in envelopes, shuffle them randomly, and give me one. We go to our separate homes. Later in the day, you open your envelope and see it says "B". You call me up and tell me on the phone that my paper says "A", even though I've not opened my envelope, and magically, you're right!
I should know better than to discuss Star Trek on Slashdot.
Pretty good is actually pretty bad.
No. You write what you want on your page, then decide that you want to send it to me. You mesure what you have written, your page turn gray (immediately), you send me light, my page has now what you have written. (at time T measurement + light travel time (+ a time >= 0))
The reason for using satellites is that many frequencies of electromagnetic radiation require line-of-sight for communication. Putting a satellite in space gives it line-of-sight to many points one the earth's surface which lack line-of-sight, otherwise I may be wrong, but I was under the impression that quantum teleportation does not have the same requirement of line of sight?
If it does not require line of sight, doesn't it completely obsolete satellites? Well, I suppose you might use quantum communications for the uplink, say from a newsroom or telecom center, but use EMR for a broadcast to satellite receivers. For a one-to-many transmission, that's still a good model, but for direct site-to-site communications, couldn't you use quantum communication directly (I hate the term quantum teleportation - if it's information, let's call it communication, not teleportation, less confusion).
This is a great step, but I think the next steps are to keep increasing the distance, so we can do tran-continental and trans-global communications directly with no satellites and no wires. How awesome would that be?
It's more like:
You have two pieces of paper that you "entangle" whatever that means in this case and give one away.
Then you go home and paint a picture on your piece.
You take a digital scan of what you've painted and send it to the person with the other piece of paper.
They "print" the scan onto their piece of paper but instead of just getting a digital print they get the identical picture, paint, brush strokes etc but your copy of the picture is destroyed in the process.
Basically you've managed to transfer a physical copy as though you posted it but all you've actually exchanged is information (plus the earlier preparation of a pair of blank sheets of paper)
Tim.
God said, "div D = rho, div B = 0, curl E = -@B/@t, curl H = J + @D/@t," and there was light.
And hence, there will not be any "expansion" of it. It is also basically impossible. The Internet is packet-switched. Any quantum-communication method (should it ever be more as a stunt, which is highly doubtful) would necessarily be circuit-switched. ATM demonstrated how bad an idea that is for end-to-end communication.
Summary: The usual quantum BS. Theory still says it is limited to light-speed (or rather cannot be used for communication at all), the communication is extremely sensitive to any kind of channel problems, bandwidth is low and there cannot be intermediate stations. On the other hand, there is zero need for this, classical technologies work quite well.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Who wants an autonomous Google car if we can have teleportation instead?
If Pandora's box is destined to be opened, *I* want to be the one to open it.
It is the hope of the research team that this experiment will lead to commercial use of quantum teleportation to interact with satellites and ground stations. This will increase the efficiency of satellite communication...
You can't send information via quantum teleportation, so exactly how do they plan to use it in satellite communication?
But if you didn't measure the original state, how are you sure you correctly recreated it, let alone perfectly recreated? "Have faith, it's science"
Two things to note:
First, they're not "teleporting" the photon. It's a quantum property (such as spin - which, also, by the way, doesn't have to do with the photon rotating in the way you'd think of, say, a ball spinning, but I digress) that is being "teleported" and applied to the target photon.
Second, when you send a fax, the "picture" (or the information to recreate it) is sent along the wires (or optic fibres, radio waves, etc.) through space from one location to the other. With entangled particles, the effect that alters the target particle's property doesn't travel through space. It just affects it directly. That's why it's instantaneous (as opposed to travelling at the speed of light or less, like your fax signal) and called teleportation. The downside is that this teleportation effect cannot convey information.
Yes yes, except it is not really a copy (lookup for no cloning theorem) as this is impossible
What happens is what you had at Alice's place is now at Bob's place, Alice has now just noise at her place, the original was 'destroyed'
This is sort of neat too because in this way it really is what one would expect for teleportation vs telecopy
They talk about quantum communications, but communications cannot occur faster than the speed of light, so what are they on about?
Also, they talk about hazy atmospheric conditions interfering with the experiment, but a major point of quantum intanglement is that the 'effect' does not pass through the interveining space, so how can atmospheric conditions interfer?
"... Wonton Burrito Meals. See you in class, Professor!"
OK, here are my questions:
Assume two entangled particles, two synchronized atomic clocks, and two observers. Each observer has agreed to measure the state of their particle at a predetermined time, relative to their atomic clock. Assume one observer/clock/particle is on a spaceship that has been traveling near the speed of light for some time.
What happens when the particles are observed? Will the results be the same, because somehow time is "linked" even though it seems to pass differently for each observer? Will the results be different, because the particles are somehow linked "instantaneously?" (What does that even mean in this context?)
If the former, what happens if the particle is brought back to Earth? We should find the atomic clocks were no longer synchronized. (This part has been tested, right?) If so, wouldn't that mean the particles were permanently out of sync, and that by observing one of them, one could predict the future state of the other? As in, predicting the future?
IANAP, just pointing out some apparent paradoxes that for all I know have been solved.
assert(birth_date<time-86400)
The practical application is that any teleportation/entanglement based Quantum Neural Networks (QNN) that happen to already exist on and around planet Earth communicate between nodes via quantum teleportation. Thus, the maximum Quantum Teleportation (QT) range is also the maximum distance between nodes. I happen to know that earth-orbital QT distances have been practical for one QNN for more than ten years, so it's about time that 'official' science caught up with this. Readers should note that the existence of ANY practical QNN remains classified, hidden, and secretive, although information about this advanced new (well, 22 years old, but newish) technology is gradually leaking out.
Note that, as several people have pointed out, there must be a [steganographic] classical back channel to actually accomplish communication between nodes.
You're thinking too small. Do a grep of the patent database and replace every instance of "Internet", "Online", "Wireless Communications", etc with "Quantum Teleportation".
Just, the time isn't right yet - patents have a shelf life. The trick is to file the patents just before the products hit the market. Timing is everything if you're going to troll.
that patent may or may not already exist... but i am sure if some one uses it... they will be sued.
So what happens if two particles or photos are entangled, and are seperated by enough distance that there is human-scale lag (say 1/2 second to one second), and both ends of the link attempt to transmit at about the same time?
Would that break the entanglement? Or would the information "pass each other" on the way, and each particle takes on the state that the other particle used to have - now they are still both entangled, but aren't in sync? Would a change to one without changing the other re-establish the synchronization? Would the changes oscillate back and forth in a sort of "standing wave"?
Here is the link to the paper on arxiv without paywall:
Quantum teleportation using active feed-forward between two Canary Islands
By the way nowadays almost all physics papers can be found as a preprint on arxiv, the difference to the puplished version is usually not significant for the layman.
Anyway, the main application of this is that you can use it to prepare entangled pairs of qubits to be used in various quantum secure communication schemes.
I'm not sure there's anything in science about FTL anything.
Actually, there is: they're called "tachyons". However they're just hypothetical particles at this point. But they were postulated by physicists, not sci-fi writers, so that seems to make them qualify as "anything in science".
(dammit Slashdot! Let me edit my damned posts already!!!)
You can edit your posts, it's called the "Preview" button. Once you hit "Submit" others start replying. If you then edit your post a little or a lot, the previous responders might have to edit theirs, ad infinitum (unless you have some kind of thread history like Wikipedia; which on /. would be an unreadable writhing mess--or is that what you're after, you devious wiggles).
And yet, there are other forums that manage just fine, even with editing enabled. It occasionally results in someone revising their statement to make themselves look less foolish, but that's moderated by others quoting their original statement to capture its unaltered idiocy. Hilarity typically ensues. The decision to allow editing or not is at the discretion of the site administrators for forum frameworks that allow it, and while some take Slashdot's (and your) stance, others do not. Commenters who spend more time on edit-friendly boards miss that feature when they come here, because they're used to it.
Please don't talk down to the people who want to edit their comments after submission; you may not prefer that style of forum, but many do and it's a valid preference.
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
.. I just quantum transport them
Most of the time, satellites are much more than 143 kilometres from their nearest ground station; even if they're orbiting at that kind of height, they spend nearly all of their time somewhere other than directly overhead. If you need further enlightenment, allow me to refer you to my esteemed colleague, Mister Pythagorus.
Chuck Norris: Socialism == a thousand years of darkness.
I think Douglas Adams got it right on that front. In Hitchhiker's Guide To The Galaxy he wrote about technology increasing at such a rate that the old "warships" which had been sent off to fight intergalactic wars arrived to find the wars had already been fought and won. Meaning, in 100 years from now our space travel technology will be so far advanced of the Voyager satellites that we could, essentially, travel out to them, pick them up, and return to Earth in 1/100th the time it took for them to travel the total distance they will have potentially travelled up to that time. Hypothetically speaking.
No one is rolling out FTL communication. It is sad to see how many "nerds" hear a piece of information, do not fully understand it, then fill in the details with their own hopes and dreams about a Star Trek future, then hold onto their beliefs so firmly that they won't listen to an accurate description of what quantum entanglement truly is.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year