Quantum Entanglement?

[seer]

His example, could not be chance; the two half-coins will match every time.


You really are having a problem with this concept, aren't you? Forget movement, movement may or may not exist. We haven't found any physical connection, there may not be one. It ain't anything like our everyday experience, and our everyday experience is useless as a guide to what's happening. We see connections between events all the time but that does not mean that there must be a connection between entangled particles.

Ok, but there must be some kind of connection. If particle A is mirroring particle B's movement at a distance something must be triggering this. And the link in the OP post did say there was movement - spin:

they trapped qubits in diamonds and were able to establish a measurement of the qubits' spin. This measurement is the actual information that was "teleported," by way of a process called quantum entanglement. To simplify this idea a lot, entanglement is essentially what happens when one particle copycats another, even over a distance. Change the spin of one particle, the other instantly changes its spin to match.

It seems that movement, spin, is key to making this work. So if there is no physical connection over a distance how does one particle know when to, or reflect, the spin of the other particle?

[JonF]

Ok, but there must be some kind of connection.

No. You are trying to force the quantum world into your everyday experience. It cannot work.

If particle A is mirroring particle B's movement at a distance something must be triggering this.

No. You are trying to force the quantum world into your everyday experience. It cannot work.

And the link in the OP post did say there was movement - spin:

Ah, there's a giveaway that the link in the OP post is not to be trusted. Quantum spin is not movement of any kind. Nothing is spinning in the manner of a spinning top, or moving in any way we know of. It's a label for something that is somewhat analogous to the spinning of a top in that it has an axis but otherwise it is not at all like the spinning of a top.

Wikipedia:

In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei.[1][2] Spin is a solely quantum-mechanical phenomenon; it does not have a counterpart in classical mechanics (despite the term spin being reminiscent of classical phenomena such as a planet spinning on its axis).[2]

(emphasis added)

There are lots of words used in science and in QM that reflect an analogy or a whimsical choice. E.g. quantum color is not a color as we know it. Up, down, top, bottom,... quarks are not anything like our experience of those labels.

{ETA} From the OP link and your quote:

Change the spin of one particle, the other instantly changes its spin to match

That's an unjustified assumption. It has not been established that a particular spin exists before the change on one particle, so there may or may not be any change in the other particle.

It seems that movement, spin, is key to making this work.

No, spin isn't movement. And there are other quantum entanglements that do not involve spin.{/ETA}

So if there is no physical connection over a distance how does one particle when to, or reflect, the spin of the other particle?

Damn good question. For the umpteenth time, we don't know. But we do know that saying "there must be X because I see X all the time" is not valid in the quantum world.

[seer]

No. You are trying to force the quantum world into your everyday experience. It cannot work.



No. You are trying to force the quantum world into your everyday experience. It cannot work.



Ah, there's a giveaway that the link in the OP post is not to be trusted. Quantum spin is not movement of any kind. Nothing is spinning in the manner of a spinning top, or moving in any way we know of. It's a label for something that is somewhat analogous to the spinning of a top in that it has an axis but otherwise it is not at all like the spinning of a top.

Wikipedia:


(emphasis added)

There are lots of words used in science and in QM that reflect an analogy or a whimsical choice. E.g. quantum color is not a color as we know it. Up, down, top, bottom,... quarks are not anything like our experience of those labels.

{ETA} From the OP link and your quote:



That's an unjustified assumption. It has not been established that a particular spin exists before the change on one particle, so there may or may not be any change in the other particle.



No, spin isn't movement. And there are other quantum entanglements that do not involve spin.{/ETA}



Damn good question. For the umpteenth time, we don't know. But we do know that saying "there must be X because I see X all the time" is not valid in the quantum world.

Ok, I think I need to let this go. It is causing me a serious psychosis.

[Sparko]

Like he said, the math works but it makes no sense.

Quantum Mechanics reminds me of the time when astronomers believed in epicycles to explain the movement of the planets. The math worked (most of the time) but it was not really how things were. Simply moving the sun into the center of the solar system solved all of the weirdness.

Perhaps Quantum Mechanics is like that. We have math that works but it makes no sense a lot of the times. Maybe there is a simple solution that someone will come up with one day and everything will slide into place and it will make complete sense at that time. Or maybe not.

[JimL]

If I remember correctly, Little Monkey, in the past, said that quantum entanglement does not actually happen. But it seems that it does. This is really strange stuff. How is it possible for one particle to instantly copycat another particle even at a distance? How can something (like information) travel faster than the speed of light, travel instantly?

http://finance.yahoo.com/news/dutch-...212440375.html

Dutch Scientists Just Shattered Our Conception Of How Information Will Travel In The Future

The problem is that you are thinking of it in the wrong way. Entanglement doesn't mean instant faster than light communication. It means that, the 2 particles say, are parts of one and the same system. The whole system changes deterministically according to its wave function. That is one of the problems with the copenhagen interpretation of quantum mechanics, the idea that observation is the cause of reality, and the reality caused by that observation is in turn the cause of another reality on the other side of the universe. According to the many worlds theory of quantum mechanics the whole system is deterministic so that neither particle is the cause of the condition of the other, it just seems that way to the observer who is also a part of the same deterministic system. Not sure if that is perfectly clear, but i have little time right now so i'll look back to this later.

[seer]

The problem is that you are thinking of it in the wrong way. Entanglement doesn't mean instant faster than light communication. It means that, the 2 particles say, are parts of one and the same system. The whole system changes deterministically according to its wave function. That is one of the problems with the copenhagen interpretation of quantum mechanics, the idea that observation is the cause of reality, and the reality caused by that observation is in turn the cause of another reality on the other side of the universe. According to the many worlds theory of quantum mechanics the whole system is deterministic so that neither particle is the cause of the condition of the other, it just seems that way to the observer who is also a part of the same deterministic system. Not sure if that is perfectly clear, but i have little time right now so i'll look back to this later.

Sorry James, I think some one who knows more about this than either of us needs to explain it. JonF did a good job.

[Sparko]

Sorry James, I think some one who knows more about this than either of us needs to explain it. JonF did a good job.

and what am I? Chopped liver? I was the one who told you about the unicorn farts!

[seer]

and what am I? Chopped liver? I was the one who told you about the unicorn farts!

Ok, I forgot about that!