SoylentNews is people
SoylentNews
For the first time ever, Physicists at the University of Glasgow in Scotland have captured an image of a type of strong quantum entanglement referred to as Bell entanglement.
This is what it looks like
The particular type of entanglement investigated in the experiment, Bell entanglement, is named after John Stewart Bell, the author of Bell's Theorem which rules out local hidden variables as a viable explanation of quantum mechanics.
Bell formalised the concept of quantum entanglement and was a notable critic of Einstein's principle of local realism – both the assumption that nothing can move faster than the speed of light, and the assumption that a particle must objectively have a pre-existing value in order to be measured.
The researchers results (full article) were published last week in the journal Science Advances.
The image we've managed to capture is an elegant demonstration of a fundamental property of nature, seen for the very first time in the form of an image," said Dr Paul-Antoine Moreau of the University of Glasgow's School of Physics and Astronomy, and lead author of the paper.
"It's an exciting result which could be used to advance the emerging field of quantum computing and lead to new types of imaging."
Scientists are certainly burning the Type Ia Supernova (*) at both ends lately - from imaging black holes to imaging quantum entanglement.
(Score: 4, Insightful) by JoeMerchant on Sunday July 14 2019, @03:08AM (11 children)
I know, there's a whole community of "really smart guys" from Einstein on down who have looked at this and nodded, but, it all stems from Bell's Inequality:
And, still, they maintain that no information may be transferred faster than light across the quantum entanglement link - which would seem to be self-contradictory.
If there are no hidden variables, then the measurement at post-entanglement station A must be imparting some information that is being read at post-entanglement station B.
Do the measurement at A differently, and you get an observably different result at B. The only way this doesn't transfer information from A to B is if it is masked with randomness - you don't know what you're going to get at A, but once you get it, you know something about what you will see at B.
What is the difference between a measurement at A that is "unknowable until it is made" and hidden information? This is the bit that is always danced around.
I feel like all these physicists are getting off on their better and better measurement equipment, but failing to explain how they are not simply measuring hidden information in the entangled bits.
🌻🌻 [google.com]
(Score: 0) by Anonymous Coward on Sunday July 14 2019, @05:21AM
27 dimensions, a tetration of 3.
(Score: 2) by hendrikboom on Monday July 15 2019, @01:12PM (7 children)
And that is exactly why it doesn't transfer information from A to B. QM is rife with randomness, in exactly the right places.
(Score: 2) by JoeMerchant on Monday July 15 2019, @03:09PM (6 children)
That is the sound-bite, now: prove that the randomness wasn't simply a hidden state determined at the time of entanglement.
🌻🌻 [google.com]
(Score: 2) by hendrikboom on Monday July 15 2019, @04:25PM (5 children)
Sorry, I have to defer to the books here. The argument made sense to me when I read it decades ago, but I don't remember it. What I meant to point out here was merely that it wasn't contradictory.
(Score: 2) by JoeMerchant on Monday July 15 2019, @08:44PM (4 children)
What I wonder is... how many people, even experts working in the field, have truly questioned the results of modern experiments back to those first principles in the books, and how many of them are just writing grants to build ever better spin-meters.
I've never had access to books on the subject beyond wikipedia, and maybe the physicists I've discussed it with really do understand it and are just (typically) bad at explaining. It's just a vibe I've gotten from them - they have a really good handle on Monte Carlo analysis and particle cascade, but when they explain real demonstrations of Bell's inequality it sounds like more faith in statistics covering for imperfections in the method than solid grasp on their part.
🌻🌻 [google.com]
(Score: 2) by hendrikboom on Tuesday July 16 2019, @01:38PM (1 child)
Unfortunately, I have never found an intelligible explanation of entanglement that didn't start with the basic mathematics of quantum states.
If you're up to the math, try the beginning of Dirac's book on quantum mechanics. I believe it got to the fourth edition before Dirac died. It presents the basic formalism almost axiomatically. (If I recall correctly, the book also has an historical introduction -- I mean the chapter after that)
When I read it, I realized that it was the real stuff. But it left me wondering: This is elegant, but how could anyone possibly have thought it up?
(Score: 2) by JoeMerchant on Tuesday July 16 2019, @02:26PM
Even in Dirac's day, there were over a billion people, and a small but significant percentage of them with nothing better to do but formulate theory.
Appropriate to the subject of randomness: the infinite number of monkeys theory explains, to an extent, how it is that one of them eventually hit upon a theory that stands up to the tests thrown at it by subsequent monkeys, at least for a time.
🌻🌻 [google.com]
(Score: 2) by hendrikboom on Tuesday July 16 2019, @01:41PM (1 child)
The probabilities in state reduction are inherent to quantum mechanics. It isn't just a handwaving exercise to cover up experimental imperfections.
(Score: 2) by JoeMerchant on Tuesday July 16 2019, @02:22PM
Stated with an elegantly flourished waving of the hands, thank you.
🌻🌻 [google.com]
(Score: 2) by Rupert Pupnick on Monday July 15 2019, @01:40PM (1 child)
I’m willing to accept that there’s a subtle theoretical difference between “unmeasured” and “undetermined”. We’ve had a few posts in another article by some smart folks who expended significant effort to explain it.
What I’d like to know is how this distinction would manifest itself in a practical application, and whether it prevents or permits you to actually build anything useful with it.
(Score: 2) by JoeMerchant on Monday July 15 2019, @03:16PM
So far, the primary "spooky action at a distance" application advertised seems to be the transfer of randomness from A to B with some assurance that nobody has "read the mail" along the way... A and B can get simultaneous knowledge of each other's random state, though it is a bit unclear how they know if the state has been read before they read it.
Otherwise, there is a steadfast assertion that instant communication at a distance is impossible.
Still, one can always dream up applications, such as:
Alice and Bob live on opposite sides of Australia. Alice wants to send Bob a priceless diamond and part of the security for the shipment is a random selection of route. To both decide and communicate the route to Bob's people Alice sends entangled photons...
🌻🌻 [google.com]