In article ,
Spike wrote:

If that is so, then the possibility of a communication channel must
exist, the transmission mechanism of which is being used by the
particles .

It doesn't "must" exist.

The possibility of a comms system must exist using this effect. That the
engineers haven't found a way to exploit it is a different issue.

I think that if you study how entanglement and quantum particles
actually work, you'll understand that this is *not* the case.

A good question to ask here is: what is this change that takes place? It
is clearly measurable.

Here's a good video-and-animations explanation of the entanglement,
how we know it exists, and why it cannot be used to transmit
classical information faster than the speed of light.

https://www.youtube.com/watch?v=ZuvK-od647c

To sum it up: it's clearly measurable, but in order to show that it's
happening at all, you need to *compare* two sets of measurements - one
taken at each end of the experiment.

You cannot "see" the effect by looking only at the measurements taken
at one end of the experiment. Due to the nature of quantum mechanics,
the measurements taken at one end look entirely random.

The measurements you take at the other end of the experiment look
equally random, at the time that you take them.

It's only when you compare the two sets of measurements, that you can
see that they're "random, but opposite". And, you can't compare them
without sending one set of measurements to the other end of the
experiment... and this can't be done faster than lightspeed.

If the effect acts instantaneously over large distances, why can it not
be exploited?

What "effect" exactly?

You'll need to ask that of the PP, as he used the word in his
explanation. I was thinking of a comms system that uses the effect
(whatever it is) to transfer information.

See the video I posted, above, for a pretty good explanation of what
the effect is, and why it doesn't help us send messages faster than C.