Layman's question re quantum entanglement

[Tom Nicholson]

TL;DR

I am aware that there are currently experiments ongoing to prove that quantum entanglement is real and there are also attempts to align Einstein and Bohr’s theories.
That’s the sensible bit and now for the layman’s attempt at asking something that may have no basis in reality OR may not have been considered. I would appreciate your thoughts –

Hi

I hope that you will humour me as I try, in layman’s terms to explain a question I have.

I recently watched BBC4’s excellent program about quantum entanglement and it got me thinking.

I am aware that there are currently experiments ongoing to prove that quantum entanglement is real and there are also attempts to align Einstein and Bohr’s theories.
[Mentors’ note: This post has been edited to remove a proposed theory that has not yet been published in an appropriate peer-reviewed journal as required by the forum rules]

Kind regards

Tom Nicholson

 

[Nugatory]

I am aware that there are currently experiments ongoing to prove that quantum entanglement is real.

”Currently”? That was settled at least seventy-five years ago. Even forty years ago, demonstrating entanglement was one of my undergraduate physics lab projects, and the hypothesis being tested was not whether entanglement was real. It was “Nugatory is competent to set up an experiment” and failure to reproduce the predicted results would not have been interpreted as evidence that QM was wrong but as evidence that I would make a crummy experimentalist.

You may be thinking of newer experiments based on Bell’s Theorem (google for it, and look at the web page maintained by @DrChinese and this layman-friendly article) which show that entanglement cannot be explained by any non-weird mechanism. These started in the 1970s; the conclusion has been generally accepted for decades although ever more refined experiments to close loopholes have been done much more recently.

 

[Tom Nicholson]

Thanks for your understanding response.

 

[PeroK]

Summary:: I am aware that there are currently experiments ongoing to prove that quantum entanglement is real

I recently watched BBC4’s excellent program about quantum entanglement and it got me thinking.

The first half of that programme was pretty good, but the second half, predominantly about the experiment with the quasars, was misleading. The vast majority of physicists would have had no doubts about the result. The business with the quasars was largely unnecessary. How is light from distant quasars more random than last week's football results?

The vast majority of physicists consider quantum entanglement very well established - especially following the experiments on Bell's theorem. Using light from distant quasars didn't change the experiment in ways that many physicists would recognise as significant.

The "loophole" is only a loophole if you allow some pretty strange philosophical ideas about how nature might work.

The programme would have been better if we had heard more from Sean Carroll. And, it was noticeable that he was not asked (or they didn't broadcast what he said) about the quasar experiment.

 

[vanhees71]

You may be thinking of newer experiments based on Bell’s Theorem (google for it, and look at the web page maintained by @DrChinese and this layman-friendly article) which show that entanglement cannot be explained by any non-weird mechanism.

It IS explained by a non-weird "mechanism" called "quantum mechanics"!

Is this BBC program accessible online?

 

[PeroK]

It IS explained by a non-weird "mechanism" called "quantum mechanics"!

Is this BBC program accessible online?

https://www.bbc.co.uk/iplayer/episode/m000db95/einsteins-quantum-riddle

 

[PeroK]

@Tom Nicholson This looks like quite a balanced view of what the experiment did achieve:

http://www.astronomy.com/news/2018/08/distant-quasars-confirm-quantum-entanglement

(I still think using last week's football results would have done just as well!)

 

[Tom Nicholson]

lol Thanks

 

[vanhees71]

https://www.bbc.co.uk/iplayer/episode/m000db95/einsteins-quantum-riddle

Thanks, but this doesn't work in Germany :-((.

 

[PeroK]

Thanks, but this doesn't work in Germany :-((.

Don't worry, I think you know most of it already!

 

[FactChecker]

(I still think using last week's football results would have done just as well!)

I disagree. Neither you nor I am skeptical of entanglement, but the goal is to convince even the hardest to convince. The issue is not the amount of randomness, but rather the amount of independence of the two random sources. I thought that the point was to get some random inputs from sources that are so well separated that no one would claim there was some single, non-quantum, cause for both inputs. The separation of the galaxies is so great that any single, non-quantum, cause would have to have happened billions of years ago.

 

[PeroK]

I disagree. Neither you nor I am skeptical of entanglement, but the goal is to convince even the hardest to convince. The issue is not the amount of randomness, but rather the amount of independence of the two random sources. I thought that the point was to get some random inputs from sources that are so well separated that no one would claim there was some single, non-quantum, cause for both inputs. The separation of the galaxies is so great that any single, non-quantum, cause would have to have happened billions of years ago.

How many people who were unconvinced before the quasar experiment are convinced by it? My guess is no one. If you disagree, then please find someone who has changed their mind!

If someone has the "SD" mindset, then they can say something in the detector and computer in the lab interprets the distant quasar signal - according to the unstated SD laws - in a way that is correlated with the local entangled photons.

 

[FactChecker]

How many people who were unconvinced before the quasar experiment are convinced by it? My guess is no one. If you diagree, then please find someone who has changed their mind!

Ha! Well, that's a good point. It might not have changed anyone's mind, just like there are "flat-Earthers" who will never change their mind. I think it is the "purest" approach that seems almost like a mathematical proof that appeals to me.