FOR REAL? A new experiment on photons sharing the quantum link of entanglement finds that quantum naysayers have to give up two cherished principles of reality, not one or the other.
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Reality just got a one-two punch. A new experiment has tried to suss out which of two counterintuitive ingredients is more basic to quantum theory, only to find that they go hand in hand.
Einstein was famously bugged by what are now well-established facts of quantum theory: the randomness of a particle's choices and the possibility of instantaneous linkages between far-flung light or matter. Experimenters now conclude that Einstein cannot even pick his poison, because allowing for instant links kills any simple notion of reality, too.
The team updated a classic 1982 experiment in which researchers measured the polarizations, or spatial orientations, of twin pairs of photons. In quantum theory, photons and other particles do not have definite values for properties such as location or polarization but rather acquire a specific property randomly when measured in an experiment.
"The big question always was … whether one can go beyond this probabilistic description," says physicist Markus Aspelmeyer of the Institute for Quantum Optics and Quantum Information in Vienna. Perhaps Einstein was right that "God does not play dice," and a photon has a true state that is somehow hidden from experiments.
Researchers learned that they could test a related question using photons that are entangled, meaning they are instantaneously connected over any distance in such a way that the measured property of one depends on the other—like a pair of dice that always comes up doubles.
In the 1982 experiment, if the photons "rolled doubles" more than a certain fraction of the time, it meant that particles violated something called local realism: the idea that influences between particles ripple through spacetime like waves (locality) and that particles have hidden nonrandom properties (realism).
But which assumption might be wrong? "It could still be possible," Aspelmeyer says, "that you maintain realism … and that you just relax this locality condition." So he, along with team leader Anton Zeilinger and colleagues, tested a proposed antiquantum model in which influences travel instantaneously but particles have real properties (no locality but realism).
They split red laser photons into entangled pairs and sent the twinned light particles along separate paths. They then measured the polarizations of the photon at different angles to see how often they scored "doubles," called correlations.
Aspelmeyer says the group's hunch was that "if you allow for nonlocal interactions, anything goes, [so] you can recover quantum physics completely" without losing a grip on reality. But, as in the older experiment, they once again saw more correlations than nonlocal realism allowed.
In other words, Aspelmeyer says, nonlocality is not enough to save realism from quantum theory. In effect, quantum naysayers like Einstein would have to swallow the spider of nonrealism to catch the fly of nonlocality. "You have to pay a price," Aspelmeyer says. "I'm still amazed [at the experiment's outcome], I have to say."
There are still other models of nonlocal realism that the experiment does not address, including some that are indistinguishable in principle from quantum theory, writes Alain Aspect of the Institute of Optics in Palaiseau, France, the leader of the 1982 experiment, in a comment published along with the findings in this week's Nature.
"The conclusion one draws is more a question of taste than logic," Aspect says. "But I rather share the view that such … experiments … allow us to look deeper into the great mysteries of quantum mechanics."
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5 Comments
Add CommentThe speed of light is is regulated by the Octave in which it exist. Thermal Energy is 30% less than that of visible light. It's place in the Spectrum is one half of an Octave lower. Prove it to yourself by looking at a single point of a well lit simple image,close your eyes,and wait. The energy stored will begin to decay. First there will be purple, then blue, and just a touch of green. you probally won't notice the green because it's too close to the thermal value of white light (yellowgreen). Then there will be a moment of darkness(white light inversed). Now you will see your image. All this will take just a few seconds. The image will like a negative. The colors are inversed because it drops half Octave. If you move your eye, your body, or your picture, the image will be blurred because you are 'mixing' the energies. A better way, is to use a timed flash. This way the image has less a chance to be purged by unwanted energy. With this method, you will be able to see a perfect negative of whatever you are looking at (with a little practice). The image will slowly decay . After the image is all but gone, it can be re-energized by shining a little light on your closed eyes.
Reply | Report Abuse | Link to thisMy name is Terry K., and I have the answer to it all,...just ask !
Hi Terry, anything you don't know, I do. We cover all knowledge. I disagree that Einstein has to pick a poison. What the above writer is doing is forcing a false choice. The "realism" position is being welded to the notion that probability is an absolute fact governing the way that the universe operates and not a construct of human consciousness.
Reply | Report Abuse | Link to thisSpecial relativity really says that there is no such thing as chance. The future exists and is fixed as surely as the past exists and is fixed. Everything is fixed. Spacetime is a frozen milieu along which the consciousness of the observer slides. Any idea we have that something called "chance" or "randomness" exists is nothing but an artifact of our consciousness drawing incorrect conclusions from the evidence of our memories. The fact that we "know" that a coin has a 50/50 chance of landing tails on our next flip or that a plutonium atom has a certain chance of decaying in the next hour does not mean that either event is not already fixed--it only means that our mental construct assumes nothing is fixed until we record it and reconcile it to our accustomed historical theories for such data.
Einstein saying time is equivalent to the other dimensions means time also is a fixed dimension. Our position along this dimension may change and this changes our view, but the universe as a whole is frozen. Not only that, it is tidier because there do not have to be branching universes nor any universes in which Schroedinger's Cat or any other unobserved phenomena is neither living nor dead nor up in the air in some type of suspension.
So, QM is exposed as the vastly over-complex and over-thought explanation for everything, rather like the Ptolemaic system. What does it matter that QM is very accurate at predicting future micro-events. The Ptolemaic system was actually very accurate at predicting planetary movements and tides--so much so that tide charts relied on Ptolemaic calculations deep into the 20th century. The verbal visualization of Ptolemy we now accept as somehow wrong-headed, but his mechanics cranked out the data as good as the Newtonian formula for a long time, especially since it turned out that Newton's view needed needed Einstein to fine tune it.
this condition, what ever it is, is so threatening to me that I often fail to understand the meaning of words when trying to read about it. - things take on their opposites in a weird dance.
Reply | Report Abuse | Link to thisit must be nonlocal.
the thing it really is, tho, is freewill.
Reply | Report Abuse | Link to thisFrom what I am beginning to understand...quantum is a word to describe scientist that have no answers and therefore make things up to earn a wage.
Reply | Report Abuse | Link to thisThey seem addicted to making the whole thing mystical, when as the above writer describes...everything is logical, everything has a cause and effect, everything is connected. This is surely the premis to stick with and when something unusual is witness...the response should not be 'oh look a new dimension' rather 'how is this connected to what we already know.'