“Spooky action at a distance” is how Albert Einstein famously derided the concept of quantum entanglement—where objects can become linked and instantaneously influence one another regardless of distance. Now researchers suggest that this spooky action in a way might work even beyond the grave, with its effects felt after the link between objects is broken.
In experiments with quantum entanglement, which is an essential basis for quantum computing and cryptography, physicists rely on pairs of photons. Measuring one of an entangled pair immediately affects its counterpart, no matter how far apart they are theoretically. The current record distance is 144 kilometers, from La Palma to Tenerife in the Canary Islands.
In practice, entanglement is an extremely delicate condition. Background disturbances readily destroy the state—a bane for quantum computing in particular, because calculations are done only as long as the entanglement lasts. But for the first time, quantum physicist Seth Lloyd of the Massachusetts Institute of Technology suggests that memories of entanglement can survive its destruction. He compares the effect to Emily Brontë’s novel Wuthering Heights: “the spectral Catherine communicates with her quantum Heathcliff as a flash of light from beyond the grave.”
The insight came when Lloyd investigated what happened if entangled photons were used for illumination. One might suppose they could help take better pictures. For instance, flash photography shines light out and creates images from photons that are reflected back from the object to be imaged, but stray photons from other objects could get mistaken for the returning signals, fuzzing up snapshots. If the flash emitted entangled photons instead, it would presumably be easier to filter out noise signals by matching up returning photons to linked counterparts kept as references.
Still, given how fragile entanglement is, Lloyd did not expect quantum illumination to ever work. But “I was desperate,” he recalls, keen on winning funding from a Defense Advanced Research Projects Agency’s sensor program for imaging in noisy environments. Surprisingly, when Lloyd calculated how well quantum illumination might perform, it apparently not only worked, but “to gain the full enhancement of quantum illumination, all entanglement must be destroyed,” he explains.
Lloyd admits this finding is baffling—and not just to him. Prem Kumar, a quantum physicist at Northwestern University, was skeptical of any benefits from quantum illumination until he saw Lloyd’s math. “Everyone’s trying to get their heads around this. It’s posing more questions than answers,” Kumar states. “If entanglement does not survive, but you can seem to accrue benefits from it, it may now be up to theorists to see if entanglement is playing a role in these advantages or if there is some other factor involved.”
As a possible explanation, Lloyd suggests that although entanglement between the photons might technically be completely lost, some hint of it may remain intact after a measurement. “You can think of photons as a mixture of states. While most of these states are no longer entangled, one or a few remain entangled, and it is this little bit in the mixture that is responsible for this effect,” he remarks.
If quantum illumination works, Lloyd suggests it could boost the sensitivity of radar and x-ray systems as well as optical telecommunications and microscopy by a millionfold or more. It could also lead to stealthier military scanners because they could work even when using weaker signals, making them easier to conceal from adversaries. Lloyd and his colleagues detailed a proposal for practical implementation of quantum illumination in a paper submitted in 2008 to Physical Review Letters building off theoretical work presented in the September 12 Science.
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Add CommentWould this also explain how people are able to talk to the dead and how when an ol'coot decides to go somewhere at 25 mph, most of the town lines up behind him and goes in the same direction with him? This Spooky Action theory would just blow my mind if it is the cause for everyone following that ol'coot.
Reply | Report Abuse | Link to thisDid anyone else think 'spy rays' or is my head simply stuck in Thirties Science Fiction!
Reply | Report Abuse | Link to thisIn my graduate program, we are studying anxiety disorders. I recently learned there is a specific phobia that involves fear of infinity. After reading this article, I think I have it...
Reply | Report Abuse | Link to thisfrom YUMMYPASTA:
Reply | Report Abuse | Link to thisThere is an easy test for the reality of Quantum Entanglement: Transmission of Information. If Entanglement truly behaved as they describe, addition of a few lines of software code to their apparatus would suffice to transmit data. Claiming "action at a distance" without ability to transmit information is a fallacy. The scientific establishments acceptance and propagation of claims like those in this entanglement article demonstrates solidified dogma. Until we hear about the "Quantum Entanglement Radio" or "Quantum Entanglement Telegraph", these claims are not validated.
Found this note searching for more information on quantum illumination. This recent issue (Jan 09) of SciAm is also all about black holes versus "naked singularities." I wonder if "quantum holography" would offer a way to "see" the inside of a black hole.
Reply | Report Abuse | Link to thisHidden Objects Revealed With Quantum Holography
American Institute of Physics, Physics News Update
Number 566 #1, November 21, 2001 by Phil Schewe, James Riordon, and Ben Stein
http://www.aip.org/enews/physnews/2001/split/566-1.html
Truth continues to astonish
Reply | Report Abuse | Link to thisTruth continues to astonish
Reply | Report Abuse | Link to thisYummy - Entanglement is not up to debate! It is proved - there is theory and practice that Einstein wanted to, but could not refute. And "information" using quantum entanglement is used loosely. If I understand correctly, even though our bias is to think of the particles as distinct, really, they share quantum state, and should be considered one. The action at a distance tends to blow our minds because it tends to violate our precepts of locality... that "here" and "there" are mutually exclusive.
Reply | Report Abuse | Link to thisAt the risk of sounding metaphysical, I think everything is entangled from the quantum particles in the universe to the remote veiwer sitting in the government lab. Alot of the things that we know in this world as esp and intuition is the result of entanglement. What do you guys think? Am I crazy?
Reply | Report Abuse | Link to thisDear Yummypasta,
Reply | Report Abuse | Link to thisThe individual calculating circuits in a computer do not "transmit" intact "information" either because the inputs are can result in quite a complex array of outputs. The entanglement has been proposed as a way to detect eaves dropping on fiber optic lines precisely because of the fact that it's bad for transmitting intact information.
Dear Dray,
Reply | Report Abuse | Link to thisI don't think your crazy. However, part of the parallels we draw between math/science and these folksier subject areas might be due to the fact that scientists and mathematicians intentionally translate the concepts into something intuitive (for non-scientists like me). This way we get some appreciation for what they are doing (and they get funding :)).
This doesn't mean that science doesn't merge with philosophy. However, it's probably the case that if I fully understood quantum mechanics I would not be able to see a clear connection to ESP or intuition. A lot of this physics stuff sounds very dry... it's all about numbers and coming up with a "model" that happens to fit the facts. Then, it gets tested over and over until nobody alive can disprove it. Then, those equations are accepted theory until later proven false (or they get adjusted).
You never know, though!
So, let me get this straight...
Reply | Report Abuse | Link to thisThere was no experiment? Just equations?
Bleh.
Dear Editors:
Reply | Report Abuse | Link to thisNo one can beat "Spooky action at a distance," Albert Einstein's phrase for quantum entanglement, but
"quantum afterlife" demands its own verbal canonization. Fortunately, my muse told me to 'look in thy heart, and write,' so I did, as follows.
A PHOTON TO A SIGNIFICANT OTHER
Could it be we're so deeply entangled
We strike out a spark when we're jangled
That flits like a ghost
From pillar to post
When this loving relationship's mangled?
Stuart Jay Silverman
223 Rolling Trail
Hot Springs, AR 71913
Tel. (501) 760-2725
Reply | Report Abuse | Link to thisNo one can beat "Spooky action at a distance," Albert Einstein's phrase for quantum entanglement, but
"quantum afterlife" demands its own verbal canonization. Fortunately, my muse told me to 'look in thy heart, and write,' so I did, as follows.
A PHOTON TO A SIGNIFICANT OTHER
Could it be we're so deeply entangled
We strike out a spark when we're jangled
That flits like a ghost
From pillar to post
When this loving relationship's mangled?
Einstein said that under high-speed conditions, space-time is deformed. As the universe is shot through in all directions by light, space-time must surely be everywhere deformed? So perhaps entanglement is just our perception of locally deformed space-time, the two quantum objects perhaps being in the same place?
Reply | Report Abuse | Link to this"A Quantum Threat to Special Relativity," by David Z. Albert and Rivka Galchen (March PHYSICS) treats entanglement as a mechanism for the instantaneous teleportation of quantum states over arbitrarily large distances. However, as I explained in my paper "Entanglement Untangled" [Physics Essays, Vol. 19, pages 299-301 (2006)], entanglement is a conservation law which preserves quantum states over arbitrarily large distances, without any "spooky action at a distance." In photon entanglement experiments, for example, teleportation is an illusion caused by picturing the photons as widely separated particles, when in fact they are extended wave packets, so large in extent that they overlap completely, to the point where a measurement on one is a measurement on both. Quantum nonlocality is a reality manifested by the size of the wave packets, not by instantaneous teleportation, which Einstein correctly rejected as "spooky action at a distance." Quantum entanglement is a reality manifested by interactions and correlations between overlapping wave packets. In the photon experiments, preservation of entanglement is conservation of angular momentum, which follows from the Lorentz covariance of special relativity. Contrary to contradicting each other, quantum mechanics and relativity work together beautifully, as is already well known from the fact that relativistic quantum field theory is a strictly Lorentz covariant theory. -- Kenneth J. Epstein, Chicago
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