Posted on 08/14/2008 5:42:56 PM PDT by LibWhacker
Quantum weirdness even stranger than previously thought.
Two photons can be connected in a way that seems to defy the very nature of space and time, yet still obeys the laws of quantum mechanics.
Physicists at the University of Geneva achieved the weird result by creating a pair of ‘entangled’ photons, separating them, then sending them down a fibre optic cable to the Swiss villages of Satigny and Jussy, some 18 kilometres apart.
The researchers found that when each photon reached its destination, it could instantly sense its twin’s behaviour without any direct communication. The finding does not violate the laws of quantum mechanics, the theory that physicists use to describe the behaviour of very small systems. Rather, it shows just how quantum mechanics can defy everyday expectation, says Nicolas Gisin, the researcher who led the study. “Our experiment just puts the finger where it hurts,” he says. The study is published in Nature.
Spooky and unsettling
In the everyday world, objects can organize themselves in just a few ways. For example, two people can coordinate their actions by talking directly with each other, or they can both receive instructions from a third source.
In both these cases, the information is communicated at or below the speed of light, in keeping with Einstein’s axiom that nothing in the Universe can go faster. But quantum mechanics allows for a third way to coordinate information. When two particles are quantum mechanically ‘entangled’ with each other, measuring the properties of one will instantly tell you something about the other. In other words, quantum theory allows two particles to organize themselves at apparently faster-than-light speeds.
Einstein called such behaviour “spooky action at a distance”, because he found it deeply unsettling. He and other physicists clung to the idea that there might be some other way for the particles to communicate with each other at or near the speed of light.
But the new experiment shows that direct communication between the photons (at least as we know it) is simply impossible. The team simultaneously measured several properties of both photons, such as phase, when they arrived at their villages and found that they did indeed have a spooky awareness of each other’s behaviour. On the basis of their measurements, the team concluded that if the photons had communicated, they must have done so at least 100,000 times faster than the speed of light — something nearly all physicists thought would be impossible. In other words, these photons cannot know about each other through any sort of normal exchange of information.
Framed
The team also ruled out other possible reasons for the apparently coordinated behaviour. For example, one could imagine that the photons might have shared information before they left Geneva — but Gisin’s measurements showed that they could not.
A second test ensured that the scientists in the two villages weren’t missing some form of communication thanks to Earth’s motion through space. According to Einstein’s theory of relativity, observers moving at high speeds can have different ‘reference frames’, so that they can potentially get different measurements of the same event. The Geneva results could possibly be explained if the two photons were communicating through a frame of reference that wasn’t readily apparent to the scientists."
But theoretical calculations2 have shown that performing tests over a full spin of the globe would test all possible reference frames. The team did just that, and they got the same result in all cases.
The bottom line, says Gisin is that “there is just no time for these two photons to communicate”.
The experiment shows that in quantum mechanics at least, some things transcend space-time, says Terence Rudolph, a theorist at Imperial College London. It also shows that humans have attached undue importance to the three dimensions of space and one of time we live in, he argues. “We think space and time are important because that’s the kind of monkeys we are.”
If you are baffled by the result, fear not — you’re not alone. “For me, honestly, it doesn’t make any sense,” says Gisin. “I don’t think we can today claim that we have a good story to tell how this all happens.” He hopes that the work will stimulate theorists to come up with new ways of explaining the spooky effect.
The article says the photons are “entangled” which means they are connected in some fashion.
The best analogy I can some up with is to imagine a 2 x 4 of infinite length. (we’ll ignore mass and rigidity in this example) If you move the 2 x 4, at any point along the length, it will communicate motion almost instantaneously. However, it won’t violate the laws governing the speed of light, even though a million miles away, it will be moving at the same time as the other end. Obviously, in this instance, distance matters. Two feet away won’t gain you anything. 200,000,000,000 feet away, though.....
Your thoughts?
The problem is I don’t think you can ignore rigidity. That’s too much of a simplification and undermines the analogy.
Didn’t someone write about this many moons ago? Something like a non-compressable fluid in a long tube as a circuit, or something? Fell apart with insufficiently rigid tube. Plus, any distance reasonable with current materials much cheaper w/radio, light, etc.
I swear, there’s a fallacy here, but I’m too sleepy, or dopy or one of them dwarves...
100,000 times faster than the speed of light? Wow... Only thing faster is the speed at which a LibTard mind slams shut in the face of logic.
Even if Feynman didn’t say it, I would still be confused.
I’m bumping too.
I prefer a universe that is casual. Those formal affairs are a pain...
A few considerations:
The 500 pound gorilla that still must be beat is “causality”. This boils down to cause and effect, with the idea that it is impossible to see the result before the cause of that result has happened.
This means that even if communication happens faster than light, you still can’t get the message before it has been sent.
The big question will be to see what happens when matched pairs are separated by more than 186,000 miles. The pair might communicate faster than light, but the information itself might not be part of that communication until a second has passed. And at twice that distance, two seconds, etc.
This would mean that not only is causality preserved, but the universal speed limit.
After I tried to beat up a 500 pound gorilla, I'd be a "casualty"...
I think what they stopped short of saying is that the communication path between the two photons took place in a different dimension where the speed of light is far greater than our three or four dimensiona.
Ansible
Or is it??
Next thing you know big foot is going to pop right out of that lab in Switzerland.
Yes, but is it floating-point or fixed-point?
At any rate; if they build a mother board with faster than light photons the next version of Windows will slow it down to molasses in January.
No point of reference is the true reality.
Re: big foot
No, he’s dead in Georgia. in an icebox. Or a costume shop.
Interesting question. On purely asthetic grounds I vote for trancententals all the way down.
Thanks BBell.
Spooky Physics: Signals Seem to Travel Faster Than Light
LiveScience | Aug 13, 2008 | Charles Q. Choi
Posted on 08/13/2008 12:11:36 PM PDT by decimon
http://www.freerepublic.com/focus/f-chat/2061306/posts
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