B Does Quantum Entanglement Suggest a Fake Universe?

[Sciencelad2798]

TL;DR Summary

I'm not really understanding it on a basic level

Most of my questions are from these articles: https://www.google.com/amp/s/www.sc...ird-wait-til-you-check-out-entangled-time/amp

https://www.scientificamerican.com/article/how-einstein-revealed-the-universe-s-strange-nonlocality/

https://www.livescience.com/quantum-entanglement-atomic-clock.html

I'm just confused on the logistics

 

[Nugatory]

You’ll need to understand superposition before you’ll be able to make sense of entanglement.

We have many older threads about how superposition works, but you might be better off with a more organized presentation of what QM is all about. There’s no substitute for a real textbook, but if you don’t have the math background (at least two years of college-level calculus) for that, Giancarlo Ghirardi’s book “Sneaking a look at god’s cards” will be way more helpful than any of the links in your post.

 

[Sciencelad2798]

You’ll need to understand superposition before you’ll be able to make sense of entanglement.

We have many older threads about how superposition works, but you might be better off with a more organized presentation of what QM is all about. There’s no substitute for a real textbook, but if you don’t have the math background (at least two years of college-level calculus) for that, Giancarlo Ghirardi’s book “Sneaking a look at god’s cards” will be way more helpful than any of the links in your post.

I'm not going to lie, I'm really only asking this question because I'm kinda having an existential crisis. I guess a more appropriate question would be, is entanglement and non locality some magical weird feature of the universe, or does it have theories that explain it?

 

[phinds]

I'm not going to lie, I'm really only asking this question because I'm kinda having an existential crisis. I guess a more appropriate question would be, is entanglement and non locality some magical weird feature of the universe, or does it have theories that explain it?

Entanglement SEEMS weird 'til you get it straightened out but there is absolutely NOTHING "magical" about it. It's a well understood phenomenon of particles. "Non-locality" is a bit of a loaded term since some people get confused early on and think it means entanglement can send FTL communication (it can't)

 

[DaveC426913]

Entanglement SEEMS weird 'til you get it straightened out but there is absolutely NOTHING "magical" about it. It's a well understood phenomenon of particles.

My knowledge may be out-of-date.

Is it understood - in the sense that we have an explanatory model - or is it still in the "shut up and calculate stage"?

 

[phinds]

My knowledge may be out-of-date.

Is it understood - in the sense that we have an explanatory model - or is it still in the "shut up and calculate stage"?

Well, I'm an engineer so I may have overstated the "explained" because to me if there's a working model that makes predictions (see Bells Theorem) then it's explained.

 

[StevieTNZ]

I'm not going to lie, I'm really only asking this question because I'm kinda having an existential crisis. I guess a more appropriate question would be, is entanglement and non locality some magical weird feature of the universe, or does it have theories that explain it?

Entanglement is a feature of quantum theory. And why are you having an existential crisis? I suspect more of a psychological issue than a genuine physics question.

 

[Sciencelad2798]

Entanglement SEEMS weird 'til you get it straightened out but there is absolutely NOTHING "magical" about it. It's a well understood phenomenon of particles. "Non-locality" is a bit of a loaded term since some people get confused early on and think it means entanglement can send FTL communication (it can't)

That makes sense but I'm still confused about some of the "weirdness" the articles I posted talk about. Mostly this one: https://www.google.com/amp/s/www.sc...ird-wait-til-you-check-out-entangled-time/amp

 

[phinds]

That makes sense but I'm still confused about some of the "weirdness" the articles I posted talk about. Mostly this one: https://www.google.com/amp/s/www.sc...ird-wait-til-you-check-out-entangled-time/amp

That's a pop-sci presentation so I didn't bother to read it. If you want to understand superposition and entanglement you just can't get it from pop-sci presentations, you have to buckle down with a real textbook.

 

[StevieTNZ]

That makes sense but I'm still confused about some of the "weirdness" the articles I posted talk about. Mostly this one: https://www.google.com/amp/s/www.sc...ird-wait-til-you-check-out-entangled-time/amp

That's simply standard entanglement swapping and delayed choice entanglement swapping. All part of QM predictions. @DrChinese may be able to elobrate further. He's well versed in such experiments.

 

[Nugatory]

I guess a more appropriate question would be, is entanglement and non locality some magical weird feature of the universe, or does it have theories that explain it?

Neither.

It’s not a magical weird feature of the universe, it is a surprising consequence of the physical laws that describe how the universe works. The surprise is because we have lived our entire lives interacting with objects large enough that quantum effects are unnoticeably small so we don’t naturally include them in our thinking (Imagine trying to explain to Aristotle’s contemporaries that when they throw a ball to the left the Earth under their feet will move to the right as a consequence of momentum conservation). So it’s not magic, but it is counterintuitive and requires unlearning some stuff that we’ve accepted without question.

But there’s also no explanation deeper than: These physical laws describe how the universe works but not why it works that way. No matter how deeply we probe for an explanation, eventually we”ll have to settle for “because that’s the rules”. Quantum mechanics is not unusual in this way; we’re comfortable with Newton’s law of gravity even though it doesn’t explain why masses attract but only quantitatively describes the fact that they do.

 

[Sciencelad2798]

That's a pop-sci presentation so I didn't bother to read it. If you want to understand superposition and entanglement you just can't get it from pop-sci presentations, you have to buckle down with a real textbook.

I started to research it a little bit more and traveled down the relativity and time dilation rabbit hole. Is there a simplier explanation for this? I hate to repeat this term again but it once again feels like magic in a way, was hoping there was a more logical explanation.

Sources: https://www.google.com/amp/s/www.space.com/amp/29859-the-illusion-of-time.html

https://www.dummies.com/education/science/physics/string-theory-unifies-space-and-time/

https://newatlas.com/space/stars-twisting-dragging-spacetime/

 

[PeterDonis]

I started to research it a little bit more and traveled down the relativity and time dilation rabbit hole.

What do relativity and time dilation have to do with quantum entanglement?

Sources

None of these (or indeed any of the references you have given in this thread) are textbooks or peer-reviewed papers. You should not expect to be able to actually learn the physics from sources like these. You need to start with the basics, which means an introductory textbook. I personally think Ballentine is a decent one for QM, but there are plenty of others.

 

[DrChinese]

That makes sense but I'm still confused about some of the "weirdness" the articles I posted talk about. Mostly this one: https://www.google.com/amp/s/www.sc...ird-wait-til-you-check-out-entangled-time/amp

Here is a proper explanation of entanglement across time:. 2 photons are entangled that have never existed at the same time. It is the source for one of the diagrams in the article you mention, and in fact is the original basis for the article.

https://arxiv.org/abs/1209.4191

"The role of the timing and order of quantum measurements is not just a fundamental question of quantum mechanics, but also a puzzling one. Any part of a quantum system that has finished evolving, can be measured immediately or saved for later, without affecting the final results, regardless of the continued evolution of the rest of the system. In addition, the non-locality of quantum mechanics, as manifested by entanglement, does not apply only to particles with spatial separation, but also with temporal separation. Here we demonstrate these principles by generating and fully characterizing an entangled pair of photons that never coexisted. Using entanglement swapping between two temporally separated photon pairs we entangle one photon from the first pair with another photon from the second pair. The first photon was detected even before the other was created. The observed quantum correlations manifest the non-locality of quantum mechanics in spacetime."

Note that entanglement across space and time is usually called "quantum non-locality" even though there can be a temporal component. Yes, quantum nonlocality operates somewhat differently than would be expected by classical or Einsteinian spacetime. However, there is no direct conflict (as their applicable domains are sufficiently different); and entanglement follows the normal rules of QM. Those rules have been around for about 90 years, and in fact Einstein co-authored a famous paper (nicknamed EPR) about entanglement in 1935.

 

[Sciencelad2798]

Here is a proper explanation of entanglement across time:. 2 photons are entangled that have never existed at the same time. It is the source for one of the diagrams in the article you mention, and in fact is the original basis for the article.

https://arxiv.org/abs/1209.4191

"The role of the timing and order of quantum measurements is not just a fundamental question of quantum mechanics, but also a puzzling one. Any part of a quantum system that has finished evolving, can be measured immediately or saved for later, without affecting the final results, regardless of the continued evolution of the rest of the system. In addition, the non-locality of quantum mechanics, as manifested by entanglement, does not apply only to particles with spatial separation, but also with temporal separation. Here we demonstrate these principles by generating and fully characterizing an entangled pair of photons that never coexisted. Using entanglement swapping between two temporally separated photon pairs we entangle one photon from the first pair with another photon from the second pair. The first photon was detected even before the other was created. The observed quantum correlations manifest the non-locality of quantum mechanics in spacetime."

Note that entanglement across space and time is usually called "quantum non-locality" even though there can be a temporal component. Yes, quantum nonlocality operates somewhat differently than would be expected by classical or Einsteinian spacetime. However, there is no direct conflict (as their applicable domains are sufficiently different); and entanglement follows the normal rules of QM. Those rules have been around for about 90 years, and in fact Einstein co-authored a famous paper (nicknamed EPR) about entanglement in 1935.

So basically you're saying it's not some weird feature of the universe, it's easily explained?

 

[Nugatory]

So basically you're saying it's not some weird feature of the universe, it's easily explained?

Well, "easily explained" is best judged by the explainee, and the perceived weirdness of a phenomenon is generally inversely proportional to the perceiver's understanding of the physical theory behind that phenomenon...

But with that said, entanglement is not some bizarre supernatural phenomenon. It is predicted and accurately described (I will not say "explained" for the reason I gave in #11 above) by the laws of physics, and once you understand these laws well enough to apply them to this particular problem, it is no more weird and incomprehensible than the elliptical orbits of the planets once you understand the law of gravity.

 

[DrChinese]

So basically you're saying it's not some weird feature of the universe, it's easily explained?

Nugatory is quite correct: "easily explained" and "weirdness" are in the eye of the beholder.

The point you might find useful is that entanglement was deduced as a consequence of the new quantum theory circa 1932, just 5 years in. That is quite an accomplishment, considering there was no experimental precedent for such phenomena. And in fact it took decades to put together a successful demonstration of entanglement, generally considered to have been in 1972. When theories make predictions that can be experimentally tested, and the tests confirm those predictions: well, that is great science!

https://www.rpi.edu/dept/phys/Courses/PHYS6510/FreedmanClauser.pdf

So is all this weird? I'd say most physicists see some angle that is hard to get a good handle on in their mind's eye. But they would likely say it is "well explained" by old fashioned quantum theory from nearly a century ago.

 

[Sciencelad2798]

Nugatory is quite correct: "easily explained" and "weirdness" are in the eye of the beholder.

The point you might find useful is that entanglement was deduced as a consequence of the new quantum theory circa 1932, just 5 years in. That is quite an accomplishment, considering there was no experimental precedent for such phenomena. And in fact it took decades to put together a successful demonstration of entanglement, generally considered to have been in 1972. When theories make predictions that can be experimentally tested, and the tests confirm those predictions: well, that is great science!

https://www.rpi.edu/dept/phys/Courses/PHYS6510/FreedmanClauser.pdf

So is all this weird? I'd say most physicists see some angle that is hard to get a good handle on in their mind's eye. But they would likely say it is "well explained" by old fashioned quantum theory from nearly a century ago.

So there's no "weird" implications that stem from this? Like a creator or a fake universe or anything?

 

[PeterDonis]

Moderator's note: A subthread about time dilation has been moved to a new thread in the relativity forum:

https://www.physicsforums.com/threads/confused-about-time-dilation.1009022/

 

[PeterDonis]

So there's no "weird" implications that stem from this? Like a creator or a fake universe or anything?

We have told you the physics. That's the only kind of question we can answer. Whether the physics seems "weird" to you is up to you. Questions about a "creator" or a "fake universe" are not physics questions and are off topic here.

I strongly suggest that you stop reading pop science articles and learn physics from textbooks and peer-reviewed papers.

This thread is closed.