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Posted on 05/29/2014 5:34:05 PM PDT by SeekAndFind
Albert Einstein once told a friend that quantum mechanics doesn't hold water in his scientific world view because "physics should represent a reality in time and space, free from spooky actions at a distance." That spooky action at a distance is entanglement, a quantum phenomenon in which two particles, separated by any amount of distance, can instantaneously affect one another as if part of a unified system.
Now, scientists have successfully hijacked that quantum weirdness -- doing so reliably for the first time -- to produce what many sci-fi fans have long dreamt up: teleportation. No, not beaming humans aboard the USS Enterprise, but the teleportation of data.
Physicists at the Kavli Institute of Nanoscience, part of the Delft University of Technology in the Netherlands, report that they sent quantum data concerning the spin state of an electron to another electron about 10 feet away. The results can be replicated accurately 100 percent of the time, the team said.
Thanks to the strange properties of entanglement, this allows for that data -- only quantum data, not classical information like messages or even simple bits -- to be teleported seemingly faster than the speed of light. The news was reported first by The New York Times on Thursday, following the publication of a paper in the journal Science.
Proving Einstein wrong about the purview and completeness of quantum mechanics is not just an academic boasting contest. Proving the existence of entanglement and teleportation -- and getting experiments to work efficiently, in larger systems and at greater distances -- holds the key to translating quantum mechanics to practical applications, like quantum computing. For instance, quantum computers could utilize that speed to unlock a whole new generation of unprecedented computing power.
Quantum teleportation is not teleportation in the sense one might think. It involves achieving a certain set of parameters that then allow properties of one quantum system to get tangled up with another so that observations are reflected simultaneously, thereby "teleporting" the information from one place to another.
To do this, researchers at Delft first had to create qubits out of classical bits, in this case electrons trapped in diamonds at extremely low temperatures that allow their quantum properties, like spin, to be observed.
A qubit is a unit of quantum data that can hold multiple values simultaneously thanks to an equally integral quantum phenomenon called superposition, a term fans of the field will accurately associate with Heisenberg's uncertainty principal that says something exists in all possible states until it is observed. It's the same way quantum computing may one day surpass the speeds of classical computing by allowing calculations to spread bit values between 0, 1 or any probabilistic value between the two numbers -- in other words, a superposition of both figures.
With quibits separated by a distance of three meters, the researchers were able to observe and record the spin of one electron and see that reflected in the other qubit instantly. It's an admittedly wonky conception of data teleportation that requires a little head scratching before it begins to clear up.
Still, its effects could be far reaching. The researchers are attempting to increase that distance to more than a kilometer, which would be ample leeway to test whether or not entanglement was a consistent phenomenon and that the information was traveling faster than the speed of light. Such experiments would more definitively knock down Einstein's disqualification of entanglement due to its violation of classical mechanics.
"There is a big race going on between five or six groups to prove Einstein wrong," Ronald Hanson, a physicist leading the research at Delft, told The New York Times. "There is one very big fish."
The same question may have been asked of the guy who came up with the notion of a circuit junction being open or closed and how that could be used to store data and retrieve it.
“So, you now try to assign to me a specious position, that of not having read the article and thus not understanding what is being done.”
Are you trying to say you DO understand what quantum teleportation is?
If that were true, then you would know that it doesn’t involve FTL travel or transmission of information, and you wouldn’t be acting as if you have proved me wrong on my previous assertions by pointing to this (very poorly written) popular science article. So, yes I am saying you don’t understand the subject of the article.
From the article, snarky: “Still, its effects could be far reaching. The researchers are attempting to increase that distance to more than a kilometer, which would be ample leeway to test whether or not entanglement was a consistent phenomenon and that the information was traveling faster than the speed of light.”
Well, the article, as I said, and as many others on the thread have noted, is badly written and contains inaccuracies, such as the one you quoted. This is why it’s not the best idea to get your understanding of science from popular science articles. Especially if you intend to then go and opine to others who are more knowledgeable on the subject than you are.
Snarky to the end. What a way to live, always trying to put folks down to make yourself feel superior in your closed mind. And without knowing anything about their educational background! What a poster!
In the instant case, the distinction is not entirely nit-picky: these state vectors are entangled via their spin, and their is no discernible overlap of their spacial extent. That is, they "overlap" in Hilbert Space, but they don't "overlap" in Minkowski spacetime the way the electrons in an atom do.
You continually accuse me of snark, but you can’t help but try to put me down in every one of your posts. Now, I’m not snarky to everyone, but if you dish it out, I’m going to give it right back to you.
“And without knowing anything about their educational background!”
I really don’t need to know anything about your background to guess you aren’t a physicist, since you obviously are getting your knowledge of physics from poorly written pop-sci articles like this one.
Beam me up, Scotty. There’s no intelligent life down here!
See. There ya go, the first use. And a fine one at that.
No they don’t, I think you are missing the point of the experiment.
Nope, I am quite sure about this. The entanglement means that state changes are shared between the particles instantly, but if you try to read those changes on the other end, you run afoul of the uncertainty principle. So, it’s necessary to transmit some information about the changes you made through classic, sub-FTL methods in order to use quantum teleportation to transmit any useable information.
You don’t need to read the changes at the other end. Each side of the entangled pair records state change and compares it after the fact. That is sufficient.
“Each side of the entangled pair records state change and compares it after the fact. That is sufficient.”
No, it’s not, because if you are only reading the state change on your end, you have absolutely no way of knowing if the changes you are detecting are those caused by actions on the other side. The uncertainty principle, along with the observer effect, preclude that.
It doesn’t matter (at this point) what is causing the changes, the whole object of the test is to determine if the entangled pair changes faster than the speed of light.
Ah, I think I get you now. I thought we were talking about actually transmitting information with this method, which can be done, but not faster than light. Instead, they are just replicating the experiment from last year that appeared to demonstrate the state change itself is happening faster than light.
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