If that other thing didn't break a rule in relativity, how about this?

[questionpost]

So as far as evidence is concerned, entangled particles determined each other's state upon dis-entanglement instantaneously,
so if we have one particle on Earth and another particle near a black hole, it wouldn't it still happen instantaneously? Would about inside a black hole?

 

[kith]

I'd say it would happen instantly. But situations which require both QM and GR are difficult to predict, because there is no theory of quantum gravity.

 

[strangerep]

So as far as evidence is concerned, entangled particles determined each other's state upon dis-entanglement instantaneously,

It's misleading to think of it that way. There is no causation between them, only statistical correlation. The latter can only be calculated by a third party in their common future light cones.

 

[questionpost]

It's misleading to think of it that way. There is no causation between them, only statistical correlation. The latter can only be calculated by a third party in their common future light cones.

It makes sense that relativity would play a part in our measurement, but the problem with that is that we measure the photons that bounced off the entangled particles and it still happens too fast for light to make that distance.

 

[strangerep]

It makes sense that relativity would play a part in our measurement, but the problem with that is that we measure the photons that bounced off the entangled particles and it still happens too fast for light to make that distance.

You're still thinking in terms of one particle "causing" something to happen at the other,
and vice-versa. Try to adjust your thinking to be in terms of ensembles of particles and statistical correlations only.

 

[questionpost]

You're still thinking in terms of one particle "causing" something to happen at the other,
and vice-versa. Try to adjust your thinking to be in terms of ensembles of particles and statistical correlations only.

I sort of see what your saying, but at the same time, doesn't entanglement only occur be-cause of an interaction and disentangle occurs be-cause of an interaction? Or at least, an interaction with a photon and your retina or whatever other force.
Like if we measure it, then it has 0 probability of existing in an undefined state or something like that?
Couldn't that statistic have only been gotten by observing interactions and causes and effects with entanglement though?

Or wouldn't it have 0 probability of being in an undefined state be-cause of an interaction?

 

[strangerep]

I sort of see what your saying, but [...]

Hmm. Sounds like I'm pitching my answers at the wrong level.

What's your background? How much quantum mechanics and special relativity have you studied, and from which textbooks?

 

[questionpost]

Hmm. Sounds like I'm pitching my answers at the wrong level.

What's your background? How much quantum mechanics and special relativity have you studied, and from which textbooks?

I haven't taken anything beyond a first year class for actual General Relativity and Quantum Mechanics but I know some of the mathematical properties described in QM. Most of my understanding comes from asking physicists questions in real life and I guess on forums.

I get the point of view your talking about, where it's not just some interaction, it's just a sort of probability shift. Even while considering that though, things still interact in the real world, so I'd kind of like to know how an interaction itself changes probability and whether that breaks relativity.
I suppose at this point if it's a probability shift it's not breaking relativity because information isn't traveling distance over time, kind of like how a sine wave on a graph doesn't actually necessarily represent position over time, those positions "just are" instantaneously equal to a point on a unit circle by the properties of math.

Even still, how does that "instantaneousity" in the real world actually get like, recognized by the universe?
Because a math equation itself it's anything to do with reality, it's just symbols.

 

[strangerep]

I get the point of view your talking about, where it's not just some interaction, it's just a sort of probability shift.

You might need to read up a bit on probability, including stuff like probability distributions, expectation values, and correlations. The latter are certain quantities which are calculated from probability distributions.

I usually recommend Ballentine as a QM textbook, but it's more upper-undergrad or graduate level. Maybe some of the other SAs here can recommended other books. Otherwise, try asking for recommendations over on the "academic guidance" forum.

Even while considering that though, things still interact in the real world, so I'd kind of like to know how an interaction itself changes probability and whether that breaks relativity.

In general, time evolution is determined by Hamiltonian operator. If the Hamiltonian contains a term representing interaction, then states can evolve into new states.

Probability distributions in QM are determined by (the square of) a product between states. So if you have an initial state, then allow it to evolve (interact), and then compare to all the possible other states, you get a probability distribution. (That's outrageously oversimplified of course.) Also remember that "initial state" should be thought of in terms of a large ensemble of identically prepared systems -- not a "one-off".

Importantly, such interaction terms in the Hamiltonian never break the underlying principles of relativity. (If they did, they'd be unphysical rubbish.) Indeed, relativity is one of the guiding constraints when constructing mathematical models of interactions.

Even still, how does that "instantaneousity" in the real world actually get like, recognized by the universe?

If by "instantaneousity in the real world" you mean instantaneous causation of effects on one particle by another, well, there is no such thing in the real world. Interactions happen as part of time evolution, which respects relativity.

(Sorry -- got to go now.)

 

[questionpost]

If by "instantaneousity in the real world" you mean instantaneous causation of effects on one particle by another, well, there is no such thing in the real world. Interactions happen as part of time evolution, which respects relativity.

(Sorry -- got to go now.)

So entanglement doesn't actually happen in the real world is what your saying, it's just how our math works?

 

[DaveC426913]

So entanglement doesn't actually happen in the real world is what your saying, it's just how our math works?

No, he's saying entanglement is not a cause-effect relationship between particles; it is a correlation relationship.

 

[questionpost]

No, he's saying entanglement is not a cause-effect relationship between particles; it is a correlation relationship.

But doesn't the measurement of one particle "cause" a particle on one end to be determined and therefore "cause" the probability of existing in an undefined state to be 0?

 

[DaveC426913]

But doesn't the measurement of one particle "cause" a particle on one end to be determined and therefore "cause" the probability of existing in an undefined state to be 0?

No.
[10 chars]

 

[Maui]

Most working physicists would give up realism to retain locality in epr correlations. However, this is not something they know, it's something they chose to believe in(it happens quite often, whether they admit it or not). For newcomers it's always difficult to separate the philosophy from the physics.

 

[questionpost]

No.
[10 chars]

Care to expand in any way shape or form?

 

[DaveC426913]

Care to expand in any way shape or form?

Well, I did, in post 11. You asked again if it's cause and effect. It isn't.

Can I shed more light on it? Not really. It's a subtle subject requiring a book's worth of explanation.

 

[questionpost]

Well, I did, in post 11. You asked again if it's cause and effect. It isn't.

Can I shed more light on it? Not really. It's a subtle subject requiring a book's worth of explanation.

There's not really any room to interpret dis-entanglement other than "a photon hits an entangled particle and then hits something which measures it, thus causing the probability of atoms existing in an undefined state to be 0".
unless of course you could care to elaborate on how exactly we aren't actually measuring something and thus leading it to its disentanglement.

 

[strangerep]

questionpost,

Try reading these Wiki articles first (especially the first one), then maybe come back with more questions if necessary.

http://en.wikipedia.org/wiki/Correlation_does_not_imply_causation

http://en.wikipedia.org/wiki/Bell's_theorem

http://en.wikipedia.org/wiki/Aspect_experiment

 

[questionpost]

questionpost,

Try reading these Wiki articles first (especially the first one), then maybe come back with more questions if necessary.

http://en.wikipedia.org/wiki/Correlation_does_not_imply_causation

http://en.wikipedia.org/wiki/Bell's_theorem

http://en.wikipedia.org/wiki/Aspect_experiment

Hmm, I see the point how it isn't a cause-and-effect by the notion that "a=b=c then a=c" is not information that is processed by means of distance over time such as with electrons and switches in a computer, although at this point I still can't completely give up the notion that "entanglement" and "disentanglement" still have real world meanings, especially considering that mathematics on it's own is utterly meaningless.

 

[strangerep]

I still can't completely give up the notion that "entanglement" and "disentanglement" still have real world meanings,

They do, but the "meaning" is in terms of "correlations", not instantaneous causation.

 

[questionpost]

They do, but the "meaning" is in terms of "correlations", not instantaneous causation.

Alright, then it doesn't violate relativity at this point.

Next, what about all those articles saying that scientists can send weak information or transporting photons (known as quantum teleportaion) by means of entangled systems?

http://www.physorg.com/news193551675.html

http://news.bbc.co.uk/2/hi/3576594.stm

http://physicsworld.com/cws/article/news/16883

And this isn't just your run-of-the-mill cnn misinterpretation, this is like, BBC and sites specifically tailored towards bringing accurate science news, it would take a little more than "that's crap" to dismiss it simply as pop-science.
I mean I already know the logic of originally how it shouldn't be possible, but a good theory should trump a law because a theory has more recent information and experiments in mind.

 

[StevieTNZ]

Alright, then it doesn't violate relativity at this point.

Next, what about all those articles saying that scientists can send weak information or transporting photons (known as quantum teleportaion) by means of entangled systems?

http://www.physorg.com/news193551675.html

http://news.bbc.co.uk/2/hi/3576594.stm

http://physicsworld.com/cws/article/news/16883

And this isn't just your run-of-the-mill cnn misinterpretation, this is like, BBC and sites specifically tailored towards bringing accurate science news, it would take a little more than "that's crap" to dismiss it simply as pop-science.
I mean I already know the logic of originally how it shouldn't be possible, but a good theory should trump a law because a theory has more recent information and experiments in mind.

Hardly news for people. Don't think anyone in the scientific community who is serious would dismiss these experiments as pop-science.

And I'm not entirely sure what you're getting at mentioning these experiments and saying "but a good theory should trump a law because a theory has more recent information and experiments in mind".

 

[questionpost]

Hardly news for people. Don't think anyone in the scientific community who is serious would dismiss these experiments as pop-science.

And I'm not entirely sure what you're getting at mentioning these experiments and saying "but a good theory should trump a law because a theory has more recent information and experiments in mind".

Well so far on this forum I have only encountered people who think sending information via entanglement is not possible. But, I don't get exactly why there is that general consensus here if these articles aren't really news to people unless people dismissed them simply as pop-science.

 

[StevieTNZ]

Well so far on this forum I have only encountered people who think sending information via entanglement is not possible. But, I don't get exactly why there is that general consensus here if these articles aren't really news to people unless people dismissed them simply as pop-science.

Not too clued up about quantum information. All I know is that physical properties of entangled quantum systems have been 'teleported' to the partner. Not the actual photon, etc - but the properties of it.

 

[StevieTNZ]

And this isn't just your run-of-the-mill cnn misinterpretation, this is like, BBC and sites specifically tailored towards bringing accurate science news, it would take a little more than "that's crap" to dismiss it simply as pop-science.

I read an article in Nature (or was it Science magazine), and when I followed up with the author of the paper referenced in it regarding what they were saying, turned out the article was complete bull.

 

[questionpost]

I read an article in Nature (or was it Science magazine), and when I followed up with the author of the paper referenced in it regarding what they were saying, turned out the article was complete bull.

I think news articles can easily get something wrong, but I don't think they just pull those articles out of thin air. Even if every article relating to sending information via entanglement is inaccurate, there's just no way there's that many different articles are just making it up, it has to be based on some real thing or experiment.