Quantum Entanglement and Information

My understanding is that you can't send information instantaneously via quantum entanglement. Two entangled photons, for example, will both pass through horizontal polarizers or both will not pass through horizontal polarizers. Which of these occurs is completely random, so this information does you no good because you don't know which is happening at the other end.

Yeah, that's what my understanding is as well. I'm not sure what the author was up to but they really wrote about information being transferred a ton of times in that article. It made me start to doubt what I thought I was pretty sure about.

I lean towards your side of the story, but both of your links continue to reinforce the fact that I am an old classical physicist! I don't truly understand either article!

Classical physics can be equally bewildering fairly quickly. It's remarkable how complicated things as seemingly simple as three body problems are.

I note that they went from a "few" experiments to "two."

To me that's not worth thinking about just yet.

I've read a bit about the E-P-R Paradox and Bell's Theorem. So I get - or at least I think I get - the idea that there are no 'hidden variables' controlling the action of particles at the quantum level.

But we know that some aspects of nature are quantized. The charge of an electron, for example. Spin is another quantized property. We also know that some aspects of nature obey Heisenberg's Uncertainty Principle, namely that it is impossible to know both the position and momentum of a subatomic particle with a certainly greater than h/(2*pi), h being Planck's constant.

The 'information' sent via quantum entanglement is typically the polarization state of a pair of photons. When the polarization of one photon is measured, it's probability wave state collapses and the polarization is then known - and likewise 'instantaneously' the polarization of the other photon is known, even though that photon may be thousands of miles away.

But what if the polarization state is already determined (but unknown) at the point when the photon pair is created? If so, then measuring the polarization state doesn't cause the probability state to collapse 'randomly' (as far as the photon is concerned) it's merely random to the observer. Ergo, the other photon is not somehow instantaneously triggered into a given polarization state - that state already existed as far as the photon is concerned. (And since time is frozen for photons - they travel at the speed of light - the act of measurement is essentially simultaneous with the act of creation. So the notion that the polarization state is determined at the instant of creation seems to make sense to me.)

That's an interesting way of looking at it. Thanks!

Your last paragraph makes sense to me, but it is essentially describing local hidden variables. Unfortunately, experiments using Bell's theorem have ruled out local hidden variables.

I like the idea of no time passing in the photon's reference frame, but I believe Bell's theorem has been tested using electron spin, and electrons don't travel at the speed of light.

http://www.upscale.utoronto.ca/GeneralInterest/Harrison/BellsTheorem/BellsTheorem.html

Reality doesn't work the way we think it should. We describe electrons and photons like little billiard balls or like water waves depending on the circumstances. I keep thinking these are just analogies with things familiar to us and the reality is something totally different for which we have no analogy.

I would like to believe that we could understand reality, but the logical contradictions seem to indicate that we have gotten off the track somewhere.

I don't see why local hidden variables are required. If the photon's polarization state is real but simply unknown due to the measurement problem (and likewise for electron spin) then instantaneous communication is not needed.

If you want proof that quantum entanglement works, my dog knows 5 minutes before I arrive that I am coming home. Must be rubbing all sorts of entangled quanta on her when I pet her as I leave for work.

It's my understanding that information cannot be transmitted by entanglement. My first thoughts are, was this article peer reviewed? Not likely. Was it repeated by others? Not likely. Is it sensational? Yes. Will it sell magazines? Probably