Quantum Entanglement: Einstein's "Spooky Action" Explained

[LaserMind]

Hello Moving On and Dr Chinese.
Yes, looks like the entanglement ends when one photon 'hits' a polarizer.
I am looking at how the entanglement ends at present, I assume there
could be no indication that entanglement has ended because that could transmit
information as bits - every time you observe one photon, then the other (light
years away) 'beeps' - metaphorically speaking - as its new wave function triggers our detection device - it cannot be possible I assume (in fact, I'm sure).

I am looking for the mathematics that compares a distant entangled photon and
the same photon one that's just been disentangled by its partner. Anyone help out here?

 

[LaserMind]

I mean, an enatngled wave packet would 'sort of' look like two individual wave packets connected by a very long thin wire - rather than just one packet with two 'bumps' in it (when they are born or very close together).

So the distant wave packet would 'not change' when it was disentangled by its partner?
Anyone got the QM mathematics of this?

 

[moving_on]

Thanks Dr Chinese,
I'm cool with that. Bit of a 'one hit wonder' eh?
Sorry to have banged on, but this was the one thing not made clear in my mind
by my rather less than technical reading (John Gribbin, Paul Davis et al)...
...and it took me a while to think of a set-up that would make it obvious!

 

[FreeTinker]

Hello everyone,

I recently found this forum and have a question about spooky entanglement. When I first heard of this I was very interested. How can changings in one particle effect another particle
even if they were separated by hundreds, thousands or even millions of miles. One explanation I heard was faster then light communication but how do they communicate and how can anything be faster then light. Since light particles are massless they are the fastest things in the universe with nothing being able to go faster. I on the other hand thought of something and would like to see if someone can give me their opinion. Could the reason they spooky entanglement accurs is due to another dimension. Could they be connect by another dimension which we are unable to sense. This could explain why changes in one particle efforts another particle

 

[wawenspop]

Hello everyone,

I recently found this forum and have a question about spooky entanglement. When I first heard of this I was very interested. How can changings in one particle effect another particle
even if they were separated by hundreds, thousands or even millions of miles. One explanation I heard was faster then light communication but how do they communicate and how can anything be faster then light. Since light particles are massless they are the fastest things in the universe with nothing being able to go faster. I on the other hand thought of something and would like to see if someone can give me their opinion. Could the reason they spooky entanglement accurs is due to another dimension. Could they be connect by another dimension which we are unable to sense. This could explain why changes in one particle efforts another particle

One entangled particle does not affect the other in the way you suggest.
If one particle is measured to have a state the other particle is then known to have
the complimentary state. Its actually knowledge about the other particles state becomes
known whereas it was not known before-hand.

How does it do it? IMO (not held by many) both particles are referenced to the same data
which is outside space-time so that both 'see it' wherever they are.

The physics community though is floundering about over a rational explanation - they
have none - only theories (crazier than mine :) ). But we know the maths of it well. Quantum computing relies on this strange fact of the universe to work.

If you look at the entanglement equation (that works in practice) there is no separation
factor between particles. No matter what. This is very suspicious to my way of thinking.
It means the 'universe' does not 'think' they are separated at all.

My data theory explains it easily. A computer could do the same thing when each particle was made by data in the computer. There is no spatial separation between bytes in a computer memory!

I suppose loop gravity is getting there very slowly, but they cannot see the wood for the trees.

 

[thenewmans]

Hello everyone,

I recently found this forum and have a question about spooky entanglement. When I first heard of this I was very interested. How can changings in one particle effect another particle
even if they were separated by hundreds, thousands or even millions of miles. One explanation I heard was faster then light communication but how do they communicate and how can anything be faster then light. Since light particles are massless they are the fastest things in the universe with nothing being able to go faster. I on the other hand thought of something and would like to see if someone can give me their opinion. Could the reason they spooky entanglement accurs is due to another dimension. Could they be connect by another dimension which we are unable to sense. This could explain why changes in one particle efforts another particle

Hi FreeThinker, original poster here. I’ll reply to your dimensions idea farther down. I hope you get a reply from Mr. Chinese. He has a great way of explaining things. You should know that the question you’re asking is in my opinion the great unanswered question about quantum physics. This has lead to a whole host of theories. They’re considered philosophies since they don’t make testable predictions. And that’s one reason quantum physics is described as a “complete” theory. Sometimes when this topic comes up, the thread gets kicked into the “PF Lounge>General Discussion>Philosophy” section. So you might want to look there. For a list of theories, search Wikipedia for “Interpretations of quantum mechanics.” Each of these interpretations is consistent with experimental results. In other words, they don’t conflict with each other.

As for your idea of using other dimensions, I think you might find a little bit of that idea in each of these interpretations. Plus your point about FTL travel is very good. Funny thing is no experiment conceived so far has been able to prove a conflict between quantum mechanics and relativity. The most famous of these is the EPR paradox. Search Wikipedia for that one too. Einstein and friends came up with this one in 1935. Nearly 30 years passed before Bell proposed a very logical explanation. Once you learn about that, you will find that the answers to your questions here become much more entertaining.

The Bell theory basically says that there is no FTL occurring since entangled particles cannot be used for communicating any information. If that sounds completely wrong to you, then you might have heard of quantum cryptography. That’s a common misconception that you’ll have to read about.

If you’d like me to go into more detail on any points, please post a follow-up!

 

[pallidin]

This is a fascinating subject to me. Thanks for the explanations.
As said, it is important to understand that, currently, though the phenomenon is clearly FTL and likely instantaneous, human-manipulative information transfer on that level does not occur.

 

[FreeTinker]

Hi FreeThinker, original poster here. I’ll reply to your dimensions idea farther down. I hope you get a reply from Mr. Chinese. He has a great way of explaining things. You should know that the question you’re asking is in my opinion the great unanswered question about quantum physics. This has lead to a whole host of theories. They’re considered philosophies since they don’t make testable predictions. And that’s one reason quantum physics is described as a “complete” theory. Sometimes when this topic comes up, the thread gets kicked into the “PF Lounge>General Discussion>Philosophy” section. So you might want to look there. For a list of theories, search Wikipedia for “Interpretations of quantum mechanics.” Each of these interpretations is consistent with experimental results. In other words, they don’t conflict with each other.

As for your idea of using other dimensions, I think you might find a little bit of that idea in each of these interpretations. Plus your point about FTL travel is very good. Funny thing is no experiment conceived so far has been able to prove a conflict between quantum mechanics and relativity. The most famous of these is the EPR paradox. Search Wikipedia for that one too. Einstein and friends came up with this one in 1935. Nearly 30 years passed before Bell proposed a very logical explanation. Once you learn about that, you will find that the answers to your questions here become much more entertaining.

The Bell theory basically says that there is no FTL occurring since entangled particles cannot be used for communicating any information. If that sounds completely wrong to you, then you might have heard of quantum cryptography. That’s a common misconception that you’ll have to read about.

If you’d like me to go into more detail on any points, please post a follow-up!

Thanks for the response. I haven't been to this site for a while which is why I never replied. I would love for you to go into more detail and I plan on looking up the epr paradox.

 

[thenewmans]

I think you should read a little on EPR and the bell theorem and then your questions will be specific.

 

[DrChinese]

If you look at the entanglement equation (that works in practice) there is no separation factor between particles. No matter what. This is very suspicious to my way of thinking. It means the 'universe' does not 'think' they are separated at all.

That certainly seems to be the case.

However, that separation you speak of has some VERY unusual characteristics. It is possible to entangle particles that have never interacted, through a process called entanglement swapping. It is possible to entangle particles that have never even existed at the same time. And it is possible to entangle particles AFTER they are detected.

Pretty spooky!

http://arxiv.org/abs/quant-ph/0201134

http://arxiv.org/abs/quant-ph/0409093

 

[budrap]

However, that separation you speak of has some VERY unusual characteristics. It is possible to entangle particles that have never interacted, through a process called entanglement swapping. It is possible to entangle particles that have never even existed at the same time. And it is possible to entangle particles AFTER they are detected.

Pretty spooky!

It is less spooky if you adopt the view that there are two distinct types of reference frames (RF) involved in these experiments:

1. The familiar 3-spatial + 1time dimension RF of material beings such as ourselves and our equipment.

2. The 4-spatial dimension, time independent RF of electromagnetic energy that is familiar from light cone analysis.

Entangled photons in RF #2 share a common instance regardless of their apparent spatial separation in RF #1.

Give it a try! It's kind of like Relativity Theory on steroids.