12 ms·

You can’t get entangled without a wormhole

80 points by geuis 13y ago

nsxwolf 13y ago
How do you entangle a pair of black holes?
- drawkbox 13y ago
  A portal, you can see it on the game Portal and Bugs Bunny ACME black holes, they only exist entangled. On a more serious note, maybe there is some underlying truth to that. The intense gravitational pull is actually something on the other side of a wormhole.
jchrisa 13y ago
Thanks for posting this. I'm not a physicist but I do enjoy reading about new explanations that simplify things. It wasn't clear from the article if this is all theory, or if there was some actual experimental use of electric fields and holographic mapping of particles? If so, can I see those maps? I would love to see the closest thing we have to a picture of a microscopic wormhole.
- andrewflnr 13y ago
  Now an MIT physicist has found that, looked at through the lens of string theory, the creation of two entangled quarks — the building blocks of matter — simultaneously gives rise to a wormhole connecting the pair. So, yeah, theory, and pretty far-out theory at that. I'm pretty sure the "holographic duality" thing is purely a theoretical device as well. It would be nice if they could get an experimental prediction out of this that could verify/falsify string theory without requiring a particle accelerator the size of the solar system.
  - Ygg2 13y ago
    > without requiring a particle accelerator the size of the solar system. Spoil sport. I was looking forward to RFHPC in the next millenia or so.
  - Steuard 13y ago
    Definitely pure theory, of a very abstract variety. But that being said, don't devalue gauge/gravity holography too quickly. Holographic arguments can be used to connect physical theories pretty similar to known, measurable particle physics to a gravitational/stringy theory (not a "theory of everything" variant, mind you) where some results are easier to calculate. Those methods are actually within spitting distance of being experimentally relevant today. (But even if these methods were to give an experimental prediction that was confirmed at RHIC or the LHC or somewhere, it would only be evidence supporting the math of string theory. It wouldn't be directly related to whether string theory is a correct theory of quantum gravity.)
Steuard 13y ago
It looks like the original research paper that this press release is talking about is here: http://arxiv.org/abs/1307.6850 http://arxiv.org/abs/1307.6850 The paper mentioned in the press release that it's directly building on (by Jensen and Karch) is: http://arxiv.org/abs/arXiv:1307.1132 http://arxiv.org/abs/arXiv:1307.1132 And the earlier research on entangled black holes that these studies of particles are extending is here: http://arxiv.org/abs/arXiv:1306.0533 http://arxiv.org/abs/arXiv:1306.0533 Now, none of that is likely to be readable to people who aren't string theorists: this is some pretty cutting edge pure theory, largely aimed at solving one of the major current puzzles in theoretical physics. One (older) collection of links to more accessible discussion of the firewall paradox is here: http://www.preposterousuniverse.com/blog/2012/12/21/firewalls/ http://www.preposterousuniverse.com/blog/2012/12/21/firewall...
monitron 13y ago
Could I ask someone with the necessary patience to explain why quantum entanglement as described here doesn't allow faster-than-light communication? I've been told that I'm misunderstanding something by guessing that it might, and if it can be expressed in layman's terms, I'd love to know why.
- mtgx 13y ago
  It says it does travel faster than light - instantaneously. He's just saying that according to Einstein's theory (nothing is faster than the speed of light), that shouldn't happen.
  - geuis 13y ago
    The "nothing faster than light" thing has been repeated so much that people just take it verboten. Its actually not specifically true. Electromagnetic fields can only propagate through a vacuum at roughly a max of 299,792,458m/s. Its super easy to slow light down. Sunlight does not travel at its max speed when it hits the ground. Its been slowed down by the atmosphere. The one thing that most definitely can, and has travelled faster than 299,792,458m/s is space itself. Indeed, space is expanding as we speak. You only have to worry about causality and referential frame violations if you physically are trying to move at high velocity. Wormholes are shortcuts through points in space. Its a different part of physics that doesn't get into the whole "faster than light" thing. Just sidesteps around it.
- stass 13y ago
  That's true that it allows faster-than-light communication is some sense, however it is not clear if it is possible to use quantum entanglement for faster than light information transfer: to extract the particle stat one has to perform a measurement which immediately destroys the state it is in.
  - loup-vaillant 13y ago
    It is unlikely that quantum entanglement allows FTL signalling of any kind. I also believe it is accepted among physicist that it doesn't allow actual FTL communication. The classic EPR experiment run thus: magically create a pair of entangled photons, send them in opposite directions. Have them pass through polarised filters of the same direction. Now, the instant a scientist on one side see the photons pass through the filter, she knows the photon on the other side won't get through (and vice-versa). You will notice that the photons don't travel faster than light. So, the obvious explanation will be some kind of common cause. A "hidden variable", that will kinda determine in which direction the photons goes through. Turns out, there is no hidden variable (Bell's Theorem). So, FTL? Not yet: there may be a third alternative: Many Worlds. Remember Schroedinger's cat? Well, after the experiment, there are two of them: the dead one, and the live one. (No, you don't get to see the other cat, just like your other self doesn't get to see yours.) Likewise, in the EPR experiment, the scientist merely learn in which blob they are. Though I believe we don't know exactly how decoherence works in this particular case. I'd be surprised however if it actually involved something as complicated as wormholes, or even another dimension.
wolfgke 13y ago
When I read this kind of (serious!) physical therories I really find it rather difficult to isolate them from crackpot theories (some crackpot theories are even more imaginative than this one). The only way I found is to consider from what institute/person the article is.
- Xcelerate 13y ago
  The best way is to learn the material yourself and then it becomes easy to separate real and crackpot theories. That said, that can take quite a lot of time, so reputation is indeed probably a good proxy.
- panzi 13y ago
  Exactly. But that they said FTL is a violation of general relativity made be doubt the article. General relativity does not disallow FTL, special relativity does. But that is about my extends of knowledge about these things.
  - gizmo686 13y ago
    I'm probably showing my ignorance of relativity here, but isn't special relativity just a special case of general relativity?
    - wolfgke 13y ago
      Under the assumption that panzi's statement is correct (I'm no physicist) in the limited context of special relativity FTL travel is impossible. But general relativity considers a more general context.
    - panzi 13y ago
      I'm not sure why general and special relativity are called like that. Special relativity is about movement and how that causes length contractions, time dilations and a change of mass of the moving object. General relativity is about how mass (even at rest) dilates spacetime. So general relativity is about black holes and worm holes and how space itself maybe "moves". There is no speed limit on how fast a region of space itself can move in relation to another region, thus it is ok that the universe expands at a speed where two regions are "moving" away from each other faster than the speed of light. So if you could move space itself you could implement FTL travel, because this is not movement at all in the sense of special relativity. Some scientists say one could do that if you could create matter with a negative energy density, whatever that might mean. I think our understanding of the universe does not exclude the possibility for such matter, but it doesn't predict it either. So unless new discoveries are made that lead to new theories that predict such matter FTL is in the realm of wishful thinking. That's what I could piece together from various (non science journal) news publications and YouTube videos (by PhDs, aimed at laymen).
brownbat 13y ago
> But what enables particles to communicate instantaneously — and seemingly faster than the speed of light — over such vast distances? As I have heard, entanglement doesn't provide FTL comms. It's like putting a red marble in one box, and a blue marble in another box, and shuffling them so you don't know which is which. Then you give one to a friend. Your box has a marble that's red with p 0.5. When your friend opens his box and says, "Hey, thanks for the cool red marble!" then your box now contains a marble that's blue, not red at all, as if by magic. But it's not magic, it's just how probabilities work as we learn more information about a system. That said, IANAQP, and Feynman gives some stern warnings against classical analogies for quantum stuff in his lectures, so big cube of salt.
- andrewcooke 13y ago
  entanglement does not allow faster than light communication, but it's also not like your boxes, which have a "hidden variable" (a known real answer). entanglement is a non-local effect that is deeply weird. both marbles are "bled" (or "rue") when they are put in the boxes. when the boxes open, one becomes red, and the other blue. even though they are now far apart. (and what this new work suggests, afaict, is that this is no longer so weird - they're actually close together if you go "through the wormhole", but that's just my vague understanding).
- gibybo 13y ago
  You are correct, information (at least in the classical sense) isn't traveling faster than light with entanglement. The marble analogy is good, but like most analogies, it breaks down at the edges. Quantum entanglement is a little bit more magical than just revealing the discreet state of an object, because it turns out the probabilities we expect don't match the probabilities that we measure when we do certain entanglement experiments: http://en.wikipedia.org/wiki/Bell's_theorem#Bell_inequalities_are_violated_by_quantum_mechanical_predictions http://en.wikipedia.org/wiki/Bell's_theorem#Bell_inequalitie... It seems that measuring a particle does indeed have some kind of effect on the particle that it is entangled with (or, at least, with the universe we are measuring it from) beyond just revealing information about some discreet state.
- nyan_sandwich 13y ago
DustinCalim 13y ago
Maybe they're the same particle... sort of like the single electron theory(since all electrons have the same mass/charge): http://en.wikipedia.org/wiki/One-electron_universe http://en.wikipedia.org/wiki/One-electron_universe
yk 13y ago
I tried to read the article, but the first paragraph already compelled me to rant. There is nothing 'mysterious' or 'strange' or 'bizarre' about entanglement. Lets look at the classical version, suppose there is a red billiard ball at the middle of a billiard table. I shoot a white ball, such that one ball ends up in the upper left pocket and the other ball in the upper right. Then the state space is white ball in the left pocket and red ball in the right pocket or the white ball in the right pocket and the red ball in the left pocket. Because of momentum conservation it is impossible to have both balls in the same pocket and billiard balls also do not spontaneously change their color. So the moment I do look at one ball, I know the color of the other. It is exactly the same thing with 'quantum entanglement,' some conservation law demands that certain outcomes are impossible, and therefore the possible states of the system are restricted compared to a 'arbitrary' configuration. ( In the billiard example, I put one ball in one pocket. And then roll a dice two determine where to put the second.) But on the other hand, claiming that entanglement is somehow 'bizarre' lends itself to a Einstein quote. And we know that Einstein quotes are the pinnacle of modern science journalism. [Edit] The parentheses are misleading. I mentioned a dice as a shorthand for arbitrary, not to imply that it has anything to do with some quantum process. So the point is, that in the classical case I follow a specific process, which leads to outcomes which are restricted compared to the case where I just put the billiard balls into arbitrary pockets.
- flebron 13y ago
  If that's all there was to entanglement, we would just use the term "ignorance of the actual state". The issue with entanglement is that the system will show properties of being in _both states at once_, which is distinct from being in one unknown state, which is your analogy. There's really no classical analogy that I know of that correctly fits entanglement in QM.
  - mck- 13y ago
    The most-cited analogy would be Shrodinger's Cat: http://en.wikipedia.org/wiki/Schr%C3%B6dinger's_cat http://en.wikipedia.org/wiki/Schr%C3%B6dinger's_cat
  - 13y ago
mcguire 13y ago
"To see what emerges from two entangled quarks, [Sonner] first generated quarks using the Schwinger effect...." Theoretical physicists are so cute. I don't believe anyone is generating entangled quarks here; all of this was done on something isomorphic to a blackboard.
JulianMorrison 13y ago
"Many worlds" makes this "instantaneous" communication moot, which is why I'm surprised so many physicists are barking up the other tree. In "many worlds" what actually happens when a thing "decoheres" is that the experimenter gets pulled into its superposition. So now instead of a dead-alive cat and one scientist, you've got one dead cat, one alive cat, one sad scientist, one happy scientist. Or from another perspective, a dead-alive cat and a sad-happy scientist - the superposition still exists, but the number of things inside it has increased. So, "I flip a coin and whichever it comes up, heads or tails, the other entangled coin flipped at the same instant comes up the the opposite, with instantaneous communication" is the wrong view. Rather, the coins are entangled (in the past), and observing them pulls the observers into the entanglement one atom at a time as the informational contagion spreads, so now you have world A, where scientists saw "heads, tails" and world B where the same scientists saw "tails,heads". The scientists got slurped in, but they are simply observing an entanglement that existed and still exists and which was established in the past. Only now they are observing it from inside. Quantum spooky action "at a distance" is local in "many worlds" and never needs to be faster than light.
- gibybo 13y ago
  Many worlds is also my preferred interpretation, but it really puts the weirdness of super position into perspective. If we really are splitting entire universes all willy-nilly like, maybe some of the other possibilities aren't so weird in comparison. Is causality-breaking FTL travel really more improbable than the universe splitting into infinite pieces just from the act of observing particles?
  - deleted 13y ago
    [deleted]
  - JulianMorrison 13y ago
    It isn't so much splitting as getting involved in other particle's business.
- snowwrestler 13y ago
  So what ends the entanglement? Or is the idea that particles once entangled are forever entangled?
gibybo 13y ago
Since this seems like a good place to ask: Does anyone know of an interactive simulator for replicating some of the tests of Bell's Theorem? I've seen lots of explanations and a fair number of computer simulations to show the disagreement between QM theory and local hidden variables, but none that are interactive. I'm thinking some simple web app with a diagram showing an entangled photon emitter with some polarizers and detectors. I could set the polarizers and detectors to arbitrary angles, emit entangled photon pairs one by one (or maybe even triplets) and have it accumulate the results side by side with the hidden variable predictions. I've fancied writing one for awhile, does it sound awesome to anyone else or just me?

80 points by geuis 13y ago

nsxwolf 13y ago

How do you entangle a pair of black holes?

drawkbox 13y ago
A portal, you can see it on the game Portal and Bugs Bunny ACME black holes, they only exist entangled. On a more serious note, maybe there is some underlying truth to that. The intense gravitational pull is actually something on the other side of a wormhole.

jchrisa 13y ago

Thanks for posting this. I'm not a physicist but I do enjoy reading about new explanations that simplify things. It wasn't clear from the article if this is all theory, or if there was some actual experimental use of electric fields and holographic mapping of particles? If so, can I see those maps? I would love to see the closest thing we have to a picture of a microscopic wormhole.

andrewflnr 13y ago
Now an MIT physicist has found that, looked at through the lens of string theory, the creation of two entangled quarks — the building blocks of matter — simultaneously gives rise to a wormhole connecting the pair. So, yeah, theory, and pretty far-out theory at that. I'm pretty sure the "holographic duality" thing is purely a theoretical device as well. It would be nice if they could get an experimental prediction out of this that could verify/falsify string theory without requiring a particle accelerator the size of the solar system.
- Ygg2 13y ago
  > without requiring a particle accelerator the size of the solar system. Spoil sport. I was looking forward to RFHPC in the next millenia or so.
- Steuard 13y ago
  Definitely pure theory, of a very abstract variety. But that being said, don't devalue gauge/gravity holography too quickly. Holographic arguments can be used to connect physical theories pretty similar to known, measurable particle physics to a gravitational/stringy theory (not a "theory of everything" variant, mind you) where some results are easier to calculate. Those methods are actually within spitting distance of being experimentally relevant today. (But even if these methods were to give an experimental prediction that was confirmed at RHIC or the LHC or somewhere, it would only be evidence supporting the math of string theory. It wouldn't be directly related to whether string theory is a correct theory of quantum gravity.)

Steuard 13y ago

It looks like the original research paper that this press release is talking about is here: http://arxiv.org/abs/1307.6850 http://arxiv.org/abs/1307.6850 The paper mentioned in the press release that it's directly building on (by Jensen and Karch) is: http://arxiv.org/abs/arXiv:1307.1132 http://arxiv.org/abs/arXiv:1307.1132 And the earlier research on entangled black holes that these studies of particles are extending is here: http://arxiv.org/abs/arXiv:1306.0533 http://arxiv.org/abs/arXiv:1306.0533 Now, none of that is likely to be readable to people who aren't string theorists: this is some pretty cutting edge pure theory, largely aimed at solving one of the major current puzzles in theoretical physics. One (older) collection of links to more accessible discussion of the firewall paradox is here: http://www.preposterousuniverse.com/blog/2012/12/21/firewalls/ http://www.preposterousuniverse.com/blog/2012/12/21/firewall...

monitron 13y ago

Could I ask someone with the necessary patience to explain why quantum entanglement as described here doesn't allow faster-than-light communication? I've been told that I'm misunderstanding something by guessing that it might, and if it can be expressed in layman's terms, I'd love to know why.

mtgx 13y ago
It says it does travel faster than light - instantaneously. He's just saying that according to Einstein's theory (nothing is faster than the speed of light), that shouldn't happen.
- geuis 13y ago
  The "nothing faster than light" thing has been repeated so much that people just take it verboten. Its actually not specifically true. Electromagnetic fields can only propagate through a vacuum at roughly a max of 299,792,458m/s. Its super easy to slow light down. Sunlight does not travel at its max speed when it hits the ground. Its been slowed down by the atmosphere. The one thing that most definitely can, and has travelled faster than 299,792,458m/s is space itself. Indeed, space is expanding as we speak. You only have to worry about causality and referential frame violations if you physically are trying to move at high velocity. Wormholes are shortcuts through points in space. Its a different part of physics that doesn't get into the whole "faster than light" thing. Just sidesteps around it.
stass 13y ago
That's true that it allows faster-than-light communication is some sense, however it is not clear if it is possible to use quantum entanglement for faster than light information transfer: to extract the particle stat one has to perform a measurement which immediately destroys the state it is in.
- loup-vaillant 13y ago
  It is unlikely that quantum entanglement allows FTL signalling of any kind. I also believe it is accepted among physicist that it doesn't allow actual FTL communication. The classic EPR experiment run thus: magically create a pair of entangled photons, send them in opposite directions. Have them pass through polarised filters of the same direction. Now, the instant a scientist on one side see the photons pass through the filter, she knows the photon on the other side won't get through (and vice-versa). You will notice that the photons don't travel faster than light. So, the obvious explanation will be some kind of common cause. A "hidden variable", that will kinda determine in which direction the photons goes through. Turns out, there is no hidden variable (Bell's Theorem). So, FTL? Not yet: there may be a third alternative: Many Worlds. Remember Schroedinger's cat? Well, after the experiment, there are two of them: the dead one, and the live one. (No, you don't get to see the other cat, just like your other self doesn't get to see yours.) Likewise, in the EPR experiment, the scientist merely learn in which blob they are. Though I believe we don't know exactly how decoherence works in this particular case. I'd be surprised however if it actually involved something as complicated as wormholes, or even another dimension.

wolfgke 13y ago

When I read this kind of (serious!) physical therories I really find it rather difficult to isolate them from crackpot theories (some crackpot theories are even more imaginative than this one). The only way I found is to consider from what institute/person the article is.

Xcelerate 13y ago
The best way is to learn the material yourself and then it becomes easy to separate real and crackpot theories. That said, that can take quite a lot of time, so reputation is indeed probably a good proxy.
panzi 13y ago
Exactly. But that they said FTL is a violation of general relativity made be doubt the article. General relativity does not disallow FTL, special relativity does. But that is about my extends of knowledge about these things.
- gizmo686 13y ago
  I'm probably showing my ignorance of relativity here, but isn't special relativity just a special case of general relativity?
  - wolfgke 13y ago
    Under the assumption that panzi's statement is correct (I'm no physicist) in the limited context of special relativity FTL travel is impossible. But general relativity considers a more general context.
  - panzi 13y ago
    I'm not sure why general and special relativity are called like that. Special relativity is about movement and how that causes length contractions, time dilations and a change of mass of the moving object. General relativity is about how mass (even at rest) dilates spacetime. So general relativity is about black holes and worm holes and how space itself maybe "moves". There is no speed limit on how fast a region of space itself can move in relation to another region, thus it is ok that the universe expands at a speed where two regions are "moving" away from each other faster than the speed of light. So if you could move space itself you could implement FTL travel, because this is not movement at all in the sense of special relativity. Some scientists say one could do that if you could create matter with a negative energy density, whatever that might mean. I think our understanding of the universe does not exclude the possibility for such matter, but it doesn't predict it either. So unless new discoveries are made that lead to new theories that predict such matter FTL is in the realm of wishful thinking. That's what I could piece together from various (non science journal) news publications and YouTube videos (by PhDs, aimed at laymen).

brownbat 13y ago

> But what enables particles to communicate instantaneously — and seemingly faster than the speed of light — over such vast distances? As I have heard, entanglement doesn't provide FTL comms. It's like putting a red marble in one box, and a blue marble in another box, and shuffling them so you don't know which is which. Then you give one to a friend. Your box has a marble that's red with p 0.5. When your friend opens his box and says, "Hey, thanks for the cool red marble!" then your box now contains a marble that's blue, not red at all, as if by magic. But it's not magic, it's just how probabilities work as we learn more information about a system. That said, IANAQP, and Feynman gives some stern warnings against classical analogies for quantum stuff in his lectures, so big cube of salt.

andrewcooke 13y ago
entanglement does not allow faster than light communication, but it's also not like your boxes, which have a "hidden variable" (a known real answer). entanglement is a non-local effect that is deeply weird. both marbles are "bled" (or "rue") when they are put in the boxes. when the boxes open, one becomes red, and the other blue. even though they are now far apart. (and what this new work suggests, afaict, is that this is no longer so weird - they're actually close together if you go "through the wormhole", but that's just my vague understanding).
gibybo 13y ago
You are correct, information (at least in the classical sense) isn't traveling faster than light with entanglement. The marble analogy is good, but like most analogies, it breaks down at the edges. Quantum entanglement is a little bit more magical than just revealing the discreet state of an object, because it turns out the probabilities we expect don't match the probabilities that we measure when we do certain entanglement experiments: http://en.wikipedia.org/wiki/Bell's_theorem#Bell_inequalities_are_violated_by_quantum_mechanical_predictions http://en.wikipedia.org/wiki/Bell's_theorem#Bell_inequalitie... It seems that measuring a particle does indeed have some kind of effect on the particle that it is entangled with (or, at least, with the universe we are measuring it from) beyond just revealing information about some discreet state.
nyan_sandwich 13y ago

DustinCalim 13y ago

Maybe they're the same particle... sort of like the single electron theory(since all electrons have the same mass/charge): http://en.wikipedia.org/wiki/One-electron_universe http://en.wikipedia.org/wiki/One-electron_universe

yk 13y ago

I tried to read the article, but the first paragraph already compelled me to rant. There is nothing 'mysterious' or 'strange' or 'bizarre' about entanglement. Lets look at the classical version, suppose there is a red billiard ball at the middle of a billiard table. I shoot a white ball, such that one ball ends up in the upper left pocket and the other ball in the upper right. Then the state space is white ball in the left pocket and red ball in the right pocket or the white ball in the right pocket and the red ball in the left pocket. Because of momentum conservation it is impossible to have both balls in the same pocket and billiard balls also do not spontaneously change their color. So the moment I do look at one ball, I know the color of the other. It is exactly the same thing with 'quantum entanglement,' some conservation law demands that certain outcomes are impossible, and therefore the possible states of the system are restricted compared to a 'arbitrary' configuration. ( In the billiard example, I put one ball in one pocket. And then roll a dice two determine where to put the second.) But on the other hand, claiming that entanglement is somehow 'bizarre' lends itself to a Einstein quote. And we know that Einstein quotes are the pinnacle of modern science journalism. [Edit] The parentheses are misleading. I mentioned a dice as a shorthand for arbitrary, not to imply that it has anything to do with some quantum process. So the point is, that in the classical case I follow a specific process, which leads to outcomes which are restricted compared to the case where I just put the billiard balls into arbitrary pockets.

flebron 13y ago
If that's all there was to entanglement, we would just use the term "ignorance of the actual state". The issue with entanglement is that the system will show properties of being in _both states at once_, which is distinct from being in one unknown state, which is your analogy. There's really no classical analogy that I know of that correctly fits entanglement in QM.
- mck- 13y ago
  The most-cited analogy would be Shrodinger's Cat: http://en.wikipedia.org/wiki/Schr%C3%B6dinger's_cat http://en.wikipedia.org/wiki/Schr%C3%B6dinger's_cat
- 13y ago

mcguire 13y ago

"To see what emerges from two entangled quarks, [Sonner] first generated quarks using the Schwinger effect...." Theoretical physicists are so cute. I don't believe anyone is generating entangled quarks here; all of this was done on something isomorphic to a blackboard.

JulianMorrison 13y ago

"Many worlds" makes this "instantaneous" communication moot, which is why I'm surprised so many physicists are barking up the other tree. In "many worlds" what actually happens when a thing "decoheres" is that the experimenter gets pulled into its superposition. So now instead of a dead-alive cat and one scientist, you've got one dead cat, one alive cat, one sad scientist, one happy scientist. Or from another perspective, a dead-alive cat and a sad-happy scientist - the superposition still exists, but the number of things inside it has increased. So, "I flip a coin and whichever it comes up, heads or tails, the other entangled coin flipped at the same instant comes up the the opposite, with instantaneous communication" is the wrong view. Rather, the coins are entangled (in the past), and observing them pulls the observers into the entanglement one atom at a time as the informational contagion spreads, so now you have world A, where scientists saw "heads, tails" and world B where the same scientists saw "tails,heads". The scientists got slurped in, but they are simply observing an entanglement that existed and still exists and which was established in the past. Only now they are observing it from inside. Quantum spooky action "at a distance" is local in "many worlds" and never needs to be faster than light.

gibybo 13y ago
Many worlds is also my preferred interpretation, but it really puts the weirdness of super position into perspective. If we really are splitting entire universes all willy-nilly like, maybe some of the other possibilities aren't so weird in comparison. Is causality-breaking FTL travel really more improbable than the universe splitting into infinite pieces just from the act of observing particles?
- deleted 13y ago
  [deleted]
- JulianMorrison 13y ago
  It isn't so much splitting as getting involved in other particle's business.
snowwrestler 13y ago
So what ends the entanglement? Or is the idea that particles once entangled are forever entangled?

gibybo 13y ago

Since this seems like a good place to ask: Does anyone know of an interactive simulator for replicating some of the tests of Bell's Theorem? I've seen lots of explanations and a fair number of computer simulations to show the disagreement between QM theory and local hidden variables, but none that are interactive. I'm thinking some simple web app with a diagram showing an entangled photon emitter with some polarizers and detectors. I could set the polarizers and detectors to arbitrary angles, emit entangled photon pairs one by one (or maybe even triplets) and have it accumulate the results side by side with the hidden variable predictions. I've fancied writing one for awhile, does it sound awesome to anyone else or just me?