Of all the weirdness in the universe, the quantum mechanics phenomenon called “entanglement” may be the most mind-boggling. Physicists have long shaken their heads at the theory that two particles that become entangled will always and instantly mirror each other’s properties, no matter how far they are separated, which seems to go against all other physical understanding. 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…. But quantum mechanics allows for a third way to coordinate information [Nature News].
Einstein rebelled against the notion of quantum entanglement, derisively calling it “spooky action at a distance” [LiveScience]. Entanglement would look a lot less spooky if we could prove that an entangled object releases an unknown particle or some other signal at high speeds to influence its partner, giving the illusion of a simultaneous reaction [LiveScience]. But a new study shows that if some hidden signal is passing between the separated particles, it would have to travel at 10,000 times the speed of light. As this explanation seems impossible, the research team favors the alternate, weirder idea: that a measurement on one photon instantly influences the other [New Scientist].
Physicist Daniel Salart entangled [his] photon pairs using a source in Geneva, then passed them through fibre-optical cables of exactly equal length to the villages of Jussy and Satigny, which lie respectively east and west of Lake Geneva. Here, the photons’ entanglement was checked by an identical pair of instruments to reveal consistent entanglement of their photons, and the effects of the Earth’s rotation taken into account [Telegraph].
The study, published in the journal Nature [subscription required], shows that the particles did indeed mirror each other’s properties at the exact same moment even though they were 11 miles apart. The research team says their finding disproves the more comprehensible hypothesis–that the particles were sending signals at faster-than-light speed–and instead supports the stranger theory of instant communication. Dr Terence Rudolph of Imperial College, London, remarks that “any theory that tries to explain quantum entanglement… will need to be very spooky - spookier, perhaps, than quantum mechanics itself” [Telegraph].
For a look at what quantum entanglement means for the potential to teleport ourselves, check out the recent DISCOVER article, “Teleportation? Very Possible. Next Up: Time Travel.“
Image: flickr/Photo Mojo
August 13th, 2008 at 7:59 pm
Creepy, it appears Orson Scott Card actually wins a point in the “prescient Sci-Fi Author” column for the basic principle behind the “ansibles” used to communicate instantaneously in the Ender’s Game universe.
August 13th, 2008 at 10:53 pm
Left_Wing_Fox — I would throw some props as well to Ursula LeGuin, who coined the term “ansible” in the sixties. (OSC even had Graff explain in Ender’s Game that the “ansible” name for their technology had been lifted out of old book!) However, I believe LeGuin’s fictional technology requires at least one end of the communications link to be anchored on a planet or somesuch, while Card’s version does not. Of course the big problem with entanglement-based ansibles is that even if the particles are communicating instantaneously, our current model of quantum theory precludes the possibility of piggy-backing any additional information on the entanglement “carrier wave,” alas.
August 14th, 2008 at 2:28 pm
Wikipedia claims Orson Card was born in 1951, and the quantum entanglement was first theorized in 1936.
August 15th, 2008 at 10:39 am
qbsmd-
Well done….is there a question in there, or nothing more than a random fact? OK, I have one too!
Wikipedia says:
“Bagpipes are a class of musical instrument, aerophones using enclosed reeds fed from a constant reservoir of air in the form of a bag.”
Anyways, in Ender’s Game they claim that the buggers are why we figured out HOW to communicate faster than light. I guess now that means that we used them (the buggers) to figure out how to carry information using quantum entanglement as opposed to just taking measurments in two swiss cities.
August 15th, 2008 at 12:24 pm
Nitpick:
“it would have to travel at 10,000 times the speed of light”
Unless I misread the original article, 10,000 times the speed of light is the MINIMUM speed given the resolution of the equipment that was used.
August 15th, 2008 at 12:50 pm
These protons were separated by 11 miles through three dimensions in an arc that approximates the curve of the earth. We don’t know their exact distance from one another in terms of their x,y,z coordinates but these are not relevant.
What was discovered here is that the entanglement of these particles took place across another dimension, and that in this extra dimension these particles were separated by 1/10,000 the distance in three “natural” dimensions. Information traveled, via the entanglement, across this distance in the extra dimension, at or below the speed of light.
The real news here is that we can leverage this extra dimension for communication at the very least.
August 15th, 2008 at 1:13 pm
Incredible stuff
August 15th, 2008 at 2:26 pm
Hate to break it to you, but you can’t make a communication system with this. You cannot make an ansible using quantum entanglement this way. Anyway, Card’s ansible has a problem: if you can communicate faster than the speed of light, then you can send messages back in time. Card didn’t predict jack squat, and he either didn’t think very hard about the implications of ansibles or he just doesn’t know very much about relativity.
Let me put it this way: if the particles were really exchanging information, let’s have two spaceships flying by: one from particle A to B, the other from particle B to A. Both spaceships are at the midpoint, C, and travelling quite fast. One spaceship says, aha! information traveled from A to B, faster than the speed of light! The other spaceship says, aha! information traveled from B to A, faster than the speed of light!
Not all interpretations of QM have “wave function collapse”… in these other interpretations, things make much more sense and nothing travels faster than light speed.
Go take a look at http://en.wikipedia.org/wiki/Interpretations_of_quantum_mechanics
August 16th, 2008 at 5:27 am
“the particles did indeed mirror each other’s properties at the exact same moment”
What exactly does this mean? They both vibrated in the same pattern at the same time? Are they 100% identical? If one particle was disturbed, does it affect the other one? If not, couldnt the particles influence each other when together enough to seemingly still “communicate” when separated?
Am I missing something?
August 18th, 2008 at 2:06 am
I saw in one of the links, ‘…Dr Charles Bennett of IBM and others theorised that entanglement can make a “quantum phoneline” that could “teleport” the details (quantum state) of one particle to another over an arbitrary distance without knowing its state.’
While the article concludes that ‘the contents of those notes are beyond our control, and so can’t be used to transmit any useful messages.’, I certainly would rule it out. So, there’s a handy way to transmit binary data over arbitrary distances.. maybe? That would be nice.
Myke, I think what they are saying is that altering the state of one electron affected the other one, for reasons that can only be explained by their theory?
August 25th, 2008 at 8:13 pm
Faster than light travel is an appealing idea, especially 10000x light speed. However, although my knowledge in this arena is by no means professional, might I suggest that travel between two ‘points’ might not violate any rules if the travel occurs in dimensions other than 1-4.
October 11th, 2008 at 12:25 pm
I think the photons are separated in 3 dimensional space, but are in the same place in some other dimension. Extra dimensions also explains how small particles (e.g., electrons) can jump instantly from one place to another.