1
$\begingroup$

If so, would this “spooky action at a distance” still be spooky if that “distance” is actually shorter than it appears? Sorry if this is a Noob question. Just trying to understand how Entangled Particles seem to communicate faster than light.
Edit: The reason for asking this is Wormholes seem to be the only way Entangled Particles can "communicate" their spin states faster than light could travel between them. I used the word "communicate" at the time of asking because I thought information was transmitted between the Entangled Particles. However, from what I understand now, information is not being transmitted FTL. Rather, Entangled Particles are correlated in a way which doesn't require transmission... Unless I misunderstood that part too.

$\endgroup$

closed as unclear what you're asking by ACuriousMind, HDE 226868, Neuneck, gigacyan, Martin Aug 7 '15 at 13:07

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 1
    $\begingroup$ Somewhat related arxiv.org/abs/1306.0533 $\endgroup$ – ClassicStyle Aug 6 '15 at 3:15
  • 3
    $\begingroup$ Please indicate why you think that wormholes have anything to do with entanglement, or why you think entangled particles "communicate". Just asking if two random topics have something to do with each other is an unclear question. $\endgroup$ – ACuriousMind Aug 6 '15 at 11:39
  • $\begingroup$ There was a recent paper about some similarities between entangled states and wormholes in the AdS/CFT theory, but it was a pretty vague link that popular science articles jumped on. $\endgroup$ – Slereah Aug 6 '15 at 12:23
  • $\begingroup$ @ACuriousMind I edited my post to clarify what I meant. Please let me know if any part of it is still unclear. $\endgroup$ – Asim Deyaf Aug 6 '15 at 13:40
  • $\begingroup$ possible duplicate of Why is quantum entanglement considered to be an active link between particles? $\endgroup$ – Neuneck Aug 7 '15 at 10:08
6
$\begingroup$

No. Wormholes do not play a role in entanglement. In fact, entangled particles don't 'communicate' in the usual sense; instead, they show nonlocal correlations which can sometimes exceed what you'd expect from, say, a pair of boxes containing socks of different colours. What Einstein got wrong wasn't the 'spooky', it was the 'action' - neither particle acts on the other upon measurement.

$\endgroup$
  • 3
    $\begingroup$ This is the conventional viewpoint, but note that there is some new and interesting work being done that does suggest a connection between wormholes and entanglement: quantumfrontiers.com/2013/06/07/entanglement-wormholes $\endgroup$ – Rococo Aug 6 '15 at 4:19
  • $\begingroup$ Thanks for this clarification. I understand information outside the Entangled system can't be transmitted, but being that Entangled Particles are dependent on each other, information between them is transmitted, right? $\endgroup$ – Asim Deyaf Aug 6 '15 at 5:41
  • 1
    $\begingroup$ @Rococo : you could always ask a question about that "new and interesting work". $\endgroup$ – John Duffield Aug 6 '15 at 9:30
  • 1
    $\begingroup$ @AsimDeyaf No. They're not "dependent" on each other, and in fact (in the interesting cases) they are causally separated from each other. What happens to one has no bearing on what happens to the other one, at least until they've had time to communicate classically (and therefore subluminally). $\endgroup$ – Emilio Pisanty Aug 6 '15 at 11:46
  • $\begingroup$ Sorry for late response. Took me some time to understand that "correlation" does not require "a signal" to be sent from one Particle to the other. I gotta say, that's something that never even crossed my mind. Either I'm really stupid, or there are a lot more people who misunderstand this point. $\endgroup$ – Asim Deyaf Aug 8 '15 at 1:54
0
$\begingroup$

First off, I want to point out that the word communication is a bit misleading. You cannot communicate information through quantum entanglement (No-communication theorem)

If you try to measure the properties (spin) of, say, an electron $$|\psi_{electron}\rangle = \alpha |\uparrow\rangle + \beta |\downarrow \rangle, $$ you have the probability of measuring spin up as $ \alpha^2$, while spin down is $\beta^2$. For an entangled state of two particles, the quantum state is such that $$|\psi\rangle = \alpha | \uparrow_1 \uparrow_2 \rangle + \beta |\downarrow_1 \downarrow_2 \rangle. $$ So if you measure spin up on the first particle, then the second particle is, by construction, also spin up. You essentially have no control over which spins you measure and therefore cannot use this for direct communication. Now the question is: how do the two particles know, maybe through a wormhole?

* A relatively new interpretation in AdS/CFT and entanglement entropy proposes that entanglement is indeed equivalent to a wormhole geometry* (Maldacena, Susskind : http://arxiv.org/abs/1306.0533). But be advised here, the claim, also known as ER = EPR (Einstein-Rosen aka the worm hole = Einstein-Podolsky-Rosen aka entanglement) is a conjecture using the holographic principle. It states that two entangled particles in quantum mechanics is holographically dual to a wormhole geometry. Which means that entanglement between particles in 3+1 dimensions can be interpreted as some wormhole geometry in 4+1 dimensions.

Whether or not this is the actual physical phenomenon is something I do not know.

$\endgroup$
  • $\begingroup$ This is because entanglement can be thought of as a non-local (not always but at least in this case) phenomenon. Non-local physics is the reason why you have this "knowledge" between the two particles. You don't need to motivate wormholes, like @Emilio said. But in certain theories, one can explain and calculate properties of entanglement using wormholes, even though this is not the true physical picture. Such notions where you can describe one part of physics with a completely unrelated part is called duality. Under the AdS/Cft duality - entanglement can be described by wormholes. $\endgroup$ – user58089 Aug 6 '15 at 13:50
  • $\begingroup$ "How do the two particles know, maybe through a wormhole?" This was the question I failed to communicate as elegantly as you did. This may be one of those unscientific questions like, "What mechanism causes gravity?" Equations can explain how things are, not why things are. $\endgroup$ – Asim Deyaf Aug 6 '15 at 13:53

Not the answer you're looking for? Browse other questions tagged or ask your own question.