How do we know that Quantum Entanglement isn't just some sort of synchronization?

Question

Supposedly, Quantum Entanglement is some sort of "spooky action at a distance" in which particles seem to somehow send signals to each other that would have to be traveling faster than the speed of light.

However, couldn't the "entangled" particles just have somehow become synchronized? Couldn't they just be undergoing their mutual activities in a coordinated fashion due to some sort of timing mechanism rather than due to some sort of signal mechanism?

Have there been any experiments done that have shown that the "Quantum Entanglement" effect must be due to some sort of communication between the particles?

Answer 1

hmmm, cool question. maybe they are following the rhythm of the universe together.

Answer 2

There is no signal mechanism involved in quantum correlations; that's what makes it "spooky".  A internal clock as you describe would be an example of "hidden variable theories". That catagory has been disproven on statistical grounds. Google that because I don't recall the details at the moment.

Answer 3

Entanglement is bullshit.

Take two cards: A♠ and A♥.

Shuffle the cards and seal them in two envelopes.

Keep one envelope and give the other to your friend.

You now have the envelope in state

Ψ1= (|A♠> + |A♥>)/√2

Your friend now has the envelope in state

Ψ2= (|A♠> + |A♥>)/√2

When your friend traveled to Beijing, open your envelope.

You card turns out to be Ψ1 = |A♥>

Question: what card has your friend,

that is what  is now Ψ2 ?

Answer 4

It's called Bell's theorem/inequality.  According to basic stats, if measurements were made on two particles (not using quantum theory) you would get a maximum 50% correlation.  According to Quantum doing the same experiment gives about 70%+.  It is really hard to understand without any quantum mechanical background, but it has been shown the there can BE NO hidden variable theory given our knowledge of Quantum (which is the most accurate way we know how to describe things right now).  

So either Quantum mechanics is incomplete and a wrong theory, or entanglement (on the surface) exists.

Answer 5

Everyone seems to dislike quantum entanglment (QE) because no one really knows what's going on. As one user stated, there can be no hidden variables in QE, not even a synchronization property. You may think of the randomness of QE like tossing two coins, but it's not.

Let's say we have two sets of two coins. One set are normal coins and one set are "Quantum Coins"  When we flip the two normal coins, we always get one head and one tails. The same result happens with the quantum coins. However, with the real coins, hidden variables are involved such as air currents in the room, the way we actually flip the coins, and maybe even a synchroniation mechanism. If we manipulate and understand the variables, we can predict the results.

However, with the quantum coins, there are no hidden variables involved. No matter how we flip the coins, or what environment we put them in, one is always head and one is always tails. Even if we put them on opposite ends of the universe where they cannot possibly send signals to eachother, they always give the usual result.

In other words, the toss is always COMPLETELY RANDOM, but always correlated in some way.  No signals, and no synchronization is involved. It's very hard to fathom how two things can be completely random yet always correlated, but QM is by far the weirdest thing in the universe and it makes people (like me) angry because we can never fully understand it due to the fact that it is based soley on randomness.