What *is* quantum entanglement?

[@LookingGlassUniverse]

I'm making a live version of this course and the first cohort starts this week- I'm closing signups by this Tuesday (sorry, I know that's very soon!). The lectures will all be free and. available on youtube, so the course is just for those who want to go a bit deeper by doing homework problems, a weekly tutorial, and asking questions. If that sounds interesting to you, there's more information here: looking-glass-universe.teachable.com/p/quantum-mechanics-fundamentals

[@RussellCox]

I watched the video too late :(

[@SpotterVideo]

If Physicists describe electrons as point particles with no volume, where is the mass of the particle? Can one extra spatial dimension produce a geometric explanation of the 1/2 spin of electrons? The following is an extension of the old Kaluza-Klein theory. Can a twisted 3D 4D soliton containing one extra spatial dimension help solve some of the current problems in Particle Physics? What do the Twistors of Roger Penrose and the Geometric Unity of Eric Weinstein and the exploration of one extra spatial dimension by Lisa Randall and the "Belt Trick" of Paul Dirac have in common? Is the following idea a “Quantized” model related to the “Vortex Theory” proposed by Maxwell and others during the 19th century? Has the concept of the “Aether” been resurrected from the dead and relabeled as the “Higgs Field”? In Spinors it takes two complete turns to get down the "rabbit hole" (Alpha Funnel 3D--->4D) to produce one twist cycle (1 Quantum unit). Can both Matter and Energy be described as "Quanta" of Spatial Curvature? (A string is revealed to be a twisted cord when viewed up close.) Mass= 1/Length, with each twist cycle of the 4D Hypertube proportional to Planck’s Constant. In this model Alpha equals the compactification ratio within the twistor cone, which is approximately 1/137. 1= Hypertubule diameter at 4D interface 137= Cone’s larger end diameter at 3D interface where the photons are absorbed or emitted. The 4D twisted Hypertubule gets longer or shorter as twisting or untwisting occurs. (720 degrees per twist cycle.) If quarks have not been isolated and gluons have not been isolated, how do we know they are not parts of the same thing? The tentacles of an octopus and the body of an octopus are parts of the same creature. Is there an alternative interpretation of "Asymptotic Freedom"? What if Quarks are actually made up of twisted tubes which become physically entangled with two other twisted tubes to produce a proton? Instead of the Strong Force being mediated by the constant exchange of gluons, it would be mediated by the physical entanglement of these twisted tubes. When only two twisted tubules are entangled, a meson is produced which is unstable and rapidly unwinds (decays) into something else. A proton would be analogous to three twisted rubber bands becoming entangled and the "Quarks" would be the places where the tubes are tangled together. The behavior would be the same as rubber balls (representing the Quarks) connected with twisted rubber bands being separated from each other or placed closer together producing the exact same phenomenon as "Asymptotic Freedom" in protons and neutrons. The force would become greater as the balls are separated, but the force would become less if the balls were placed closer together. Therefore, the gluon is a synthetic particle (zero mass, zero charge) invented to explain the Strong Force. The "Color Force" is a consequence of the XYZ orientation entanglement of the twisted tubules. The two twisted tubule entanglement of Mesons is not stable and unwinds. It takes the entanglement of three twisted tubules to produce the stable proton. (The term "entanglement" here is similar to three twisted ropes wrapped around the others being "tangled", so that when you pull on one rope the others seem to be connected.)

[@PotentialSpaceEngineering]

@@LookingGlassUniverse why would I want to give my intellectual property to you and pay you too? Not interested.

[@RussellCox]

​@@PotentialSpaceEngineering What IP? Who's asking for money? 🤔

[@generichuman_]

I love how one electron is spin sad, and one is spin apathetic. There is no happy in quantum mechanics.

[@ExistenceUniversity]

Tell that to the Up and Charm quarks

[@tvuser9529]

Yeah, they're both... _negative_.

[@cademosley4886]

My interpretation is both of them are negative (as electrons), but the sadder one is also down ='( Then the meh one is negative, but at least up for today. = | Edit: But of course then they can be in other states as the video shows. That's just how they started their day.

[@PlaAwa]

that sounds a bit negative. didn't they have some sort of energy exchange during their entanglement dance? they knew who they were in that moment and didn't care about where the energy came from or who depended on the other's more... they may have been more or less apathetic before the entanglement but they knew who they were by the end of it.... and the little entanglement babies lived happily ever after. excuse my way of putting a positive spin on things.

[@ExistenceUniversity]

@PlaAwa no

[@Heidern98]

This might be my new go to video to introducing my friends and fam to help lure them into learning about Quantum Mechanics. Just wonderfully presented, in simple and understandable presentation. Respect.

[@CraigGidney]

At its most basic, entanglement means you can prepare two polarized photons that agree both horizontally and diagonally. If you pass them each through a horizontal polarizing filter, then they will either both pass through or both not pass through. Alternatively, if you pass them each through a diagonal polarizing filter, then they will either both pass through or both not pass through. A photon that 100% will pass through a horizontal filter is horizontally polarized, and horizontally polarized photons only pass through diagonal filters 50% of the time. So you can't make a single photon that will both 100% pass through a horizontal filter and 100% pass through a diagonal filter. For a single photon, will-pass-through-horizontal is incompatible with will-pass-through-diagonal. Despite that, you can make a pair of photons that simultaneously 100% agree on will-pass-through-horizontal and will-pass-through-diagonal. This gives an inkling of why entangled states are said to be fundamentally multi-particle states, rather than a combination of one-particle states. The amazing thing is that, combined with the postulates of quantum mechanics, simultaneously agreeing on will-pass-through-horizontal and will-pass-through-diagonal implies agreeing on will-pass-through-filter-with-angle-t for all t. Even more than that, it implies an agreement rate of cos^2(t/2) when passing through filters whose orientations differ by t radians. And this leads inevitably into violating Bell inequalities, winning certain coordination games more often than would be possible classically, by carefully choosing how to conditionally orient the filters.

[@auspiciouslywild]

Yeah, so my understanding is that you can't fully explain why entanglement is so special without this angle-dependent agreement rate you mentioned. Is that correct? I think it's impossible to explain why the up/down entanglement is different from two correlated coins. The entangled electrons aren't going to agree more or less than the coins. You could easily explain it with a hidden state. But looking at how two entangled particles "agree" at different angles is impossible to explain by hidden states, right? I guess unless that hidden state is some kind of function, but I suppose that solution quickly gets infinitely complex as you have more entangled states?

[@Jono98806]

@@auspiciouslywild Actually, you can tell the difference between entangled photons and the correlated coins because Bell's theorem. You have to understand probability theory to really understand the difference. It's about making many such measurements and taking averages. Bell's theorem actually rules out the possibility of hidden variables if you make the reasonable assumptions of "realism" (or the property that they definitely have a particular state whether our not you measure them) and "locality" (meaning that interactions cannot occur faster than light).

[@CraigGidney]

@@auspiciouslywild Each Bell inequality only requires certain angles to have certain agreement rates, so they technically don't need the general dependence. There are experiments like the GHZ test and the Mermin-Peres magic square game where the quantum strategies win 100% of the time, and so these especially don't require talk much about angle-dependent agreement rates. They only need to talk about points of 100% agreement, instead of the full curves.

[@auspiciouslywild]

@ Thanks for the explanation. The Mermin-Peres game looks super interesting, I’m gonna read more into that for sure.

[@Mentaculus42]

@@auspiciouslywild Hidden variables are ok providing they are “nonlocal” hidden variables. Entanglement is a type of correlation that can be non-locally maintained until interactions (measurements or environmental) disrupt the relationship.

[@mattwhiting2205]

The coins don't count as entangled because they are classically uncertain. How is that truly different from quantum superposition? If we could contrive some sort of wave-based interference experiment to determine the states of the coins, would that make them in true superposition and therefore entangled? What is the hard line here? Where do we officially get to say something is in a superposition vs something that is not? With elemental particles like electrons, we get it. But researchers have extended that up to larger and larger objects over time. If we take this to the logical extreme, the coins could theoretically be put into a superposition of heads and tails, couldn't they? What prevents that? Understanding that we would have to somehow isolate the coins from all outside interactions which would normally entangle their states with the states of the entire lab and the researcher with it... if we could contrive some way to truly isolate ourselves from becoming entangled with the coins, would they be in superposition at that point? This is Schrodinger's cat all over again. It is often said that the macroscopic cat isn't really in superposition because its atoms are entangled with the atoms of the box, and the box's atoms are entangled with ours. But if that's the case, the only reason the cat does not appear to be in superposition to us is because we are already entangled with the cat. If some observer could truly isolate themselves from that entanglement, couldn't they still observe the cat (or coin) in superposition?

[@Theo0x89]

How would observer observe the cat in superposition when they are truly isolated from the observed object? The whole point of Schrödinger's cat and quantum mechanics in general is that the superposition collapses when the object is observed. Whether two electrons (or larger objects) are in superposition depends on how they are prepared. When you don't know how they are prepared, then you have to make repeated measurements on many identically prepared pairs. It is not enough to simply check for opposite spins because electrons can be prepared like classical coins. For instance, you can check for a violation of Bell's inequality, which holds for classical objects but not for entangled electrons. You do the measurements with detectors that are rotated by a certain angle with respect to each other.

[@mattwhiting2205]

@@Theo0x89 exactly. That's my exact point. I find it very hard to explain myself though... If we take many pairs of entangled electrons, and test them at different angles, we will validate Bell's theorem - the state of the electrons were NOT just hidden from us (locally). They were truly in a superposition of states before we did the measurement. So let's just do that with coin flips. Make a machine to take pairs of coins and arrange them at random angles with a H and a T in each pair. We then test them at other angles. Since coins faces are not inherently quantum, we're going to find a coin that's at say 30 degrees off from heads, we'd presumably call that heads. In this experiment, it seems obvious to just say the angle of the coin was a locally hidden variable. The machine set it at an angle, we just don't know. I would expect the results would be 50-50... the coins are not quantum objects. Electron spin is quantum, but a coin is classical. Ok... why? My way of understanding this comes down to the math. You can express the state of an electron spin easily. You can express the state of a measurement result easily. You can express all combinations of spin + measurement fairly easily. When you do, you find the spins and the measurements are entangled with each other. There is no way for a spin-up to be paired with a measurement-down, but both spin-ups and measurement-downs exist... they just aren't paired with each other at all. When they do this with buckyballs, the math gets ugly, but the entire buckyball has been arranged so that a single quantum bit has been entangled with another buckyball. According to the math, we can then measure that quantum state and entangle our measured result with the buckyballs. Same deal. So... if we follow that logic, the key to this effect is that a pair of objects is entangled by a single quantum bit. Preserving a single quantum bit becomes harder and harder as the object gets more complex, but as far as I understand, there is no theoretical upper limit there. Presumably, we should be able to build a machine that encodes a single quantum bit of information into an entangled pair of coins. (Not realistic, but thought experiment.) If we could arrange things such that that quantum bit decides the orientation of the coins, aren't their orientations now entangled? If we then repeat the Bell's experiment, will we not then show that the coins are truly entangled?

[@SamAlegria-tg4qu]

So many videos in one month! Quantum quantum quantum!

[@LookingGlassUniverse]

I planned out a series of 10 videos and filmed the first 5 over a week. Got to film the next 5 once I finish editing these ones 😅

[@ainnovation6967]

All I can say is I like your voice.You may good at singing. Your husky voice fits it. BTW, I've been interested in quantum mechanics quite a long and youtube recommended you to me. You have a talent to explain it simply.

[@yiannchrst]

Thanks for the series! It has been really helping me in having a more nuanced understanding!

[@ai3t86]

My favorite technical definition of entanglement is that it is a nonlocal quantum resource that does not increase under LOCC (local operations and classical communication)

[@IrishCDevera]

This video is the best, I repeat the BEST in talkibg about quantum entanglement. Bravoooo

[@KayP1]

Still it's not known when or due to what circumstances we know that it's entanglement. At 4:42 she says that "it decides to change its state depending" after just flying by. How do we know the electron has decided to to so, that's still uncertainty. Unless there's a specific process of "entangling" electrons which is somehow mathematically explainable we have uncertainty. Scientist do such "entangling", so there seems to be an answer to the actual question what happens during: "flying by ... decides state ... depending"

[@jitteryjet7525]

Fundamental Reality is not stranger than we imagine, it is stranger than we CAN imagine. Well OK entanglement has a lot of interesting implications for locality and realism, but it has been pointed out the correlation is still CREATED locally.

[@GabrielPettier]

This does help a bit, although my classical brain really really want to understand entanglement as some sort of synchronization, that is brittle enough to break as soon as we interact on either side, and thus doesn't require any transmission of information. Of course, that's deterministic thinking, a big no-no in quantum, good thing i'm a mere computer scientist, not a quantum one. :D

[@JrgenMonkerud-go5lg]

a more appropriate coin analogy, would be to take them appart and then flip them, if they still only land one heads and the other tails, something strange is a foot.

[@drdca8263]

7:26 : I think the way this part was explained is a little bit… Well, there are two points to be made: 1) *If* they were both in the state |up>+|down> , then you would have a 25% chance of observing both to be spin down (if you measured each in the up/down basis) but, *this is not what we observe* . 2) And, furthermore, what we do observe is compatible with the “they ended up with opposite states” idea, and this fits better with the “no preferred bases”, etc. stuff. The way it is presented seems to kind of seem like it is going to go to the “if it was [thing other than what it is], we would predict [other observations] but we instead observe [actual observations].” , but then swerves? Like, it sounds like “If it were [some way other than how it is, we would expect to observe [thing we don’t observe], but, that doesn’t make sense as a thing we would expect to observe.”

[@PotentialSpaceEngineering]

It's called a strong match. Signal Coherence between containers at a distance.

[@ceo1OO]

on the contrary... i really did like her explanation of what is "NOT" entanglement... 10:37 lack of information between the systems doesn't count as entanglement... only a dependency between them does...

[@schmetterling4477]

Entanglement doesn't have anything to do with lack of knowledge.

[@hughobyrne2588]

So - not to be combative (thank you for your videos!), just to expand the conversation - to put forward a competing view to this explanation, as best I understand it and as best I can express it: 12:40 "It went from being in a superposition state ... to now, just being in the state, 'down'." Well, as far as you, the person who measured 'up', can tell, yes. It's a bit egocentric to think you, and your experiences, are all there is to the universe, though. How about: The electron that was not directly measured, remains in a superposition. Physics is local. It's true that *you* will only observe that electron as 'down', but quantum mechanics already has the language to express that: The 'you' that measured 'up' will only ever constructively interfere with this electron being spin down, and will only ever destructively interfere with the electron being spin up. The superposition and entanglement is there, it hasn't gotten smaller, it has gotten bigger, and you're part of it.

[@LookingGlassUniverse]

No problem! I happen to hold the same sort of view. I am most sold on Many Worlds interpretation (although I'm not totally sure) and I've made a few videos on it. But my intention in these videos is to teach quantum mechanics in the standard way with the standard interpretation of measurement collapse. My reasoning is that it's very hard to have a deep and nuanced understanding of QM without understanding this interpretation first.

[@ExistenceUniversity]

I am all in on Penrose's Twistor to Objective Reduction to Orchestrated Objective Reduction theories

[@ExistenceUniversity]

Physics is also non-local...

[@TedToal_TedToal]

If the other one remains in the entangled, superposition state, then when it's measured, at that time, there must be a determination of what the state of the first one was when it was measured earlier because that has to influence the state measured for the second one. That makes even less sense than the state of both of them collapsing simultaneously.

[@wmstuckey]

Another excellent video here. Since Mithuna explained the essence of quantum entanglement using spin, let me provide the counterpart in terms of quantum information theory using spin as I described it in the Comments of her video “What is Spin?” Suppose we have a pair of spin-entangled particles a la Mithuna’s example (call them A and B). Let Alice measure the spin of particle A and Bob measure the spin of particle B. The state Mithuna references is called the “singlet state,” i.e., A and B are always found to have opposite spins when measured in the same direction of space. This state represents the conservation of (zero total) spin angular momentum in any particular direction. So, Alice and Bob always get opposite outcomes when making their Stern-Gerlach (SG) spin measurements in the same direction and Mermin calls this “case (a)” in his famous paper, “Bringing home the atomic world: Quantum mysteries for anybody” Am. J. Phys. 49(10), 940-943 (1981). As Mermin points out, case (a) is actually quite easy to explain - the particles were simply emitted from the source with opposite “instruction sets” for how to respond to an SG measurement. The actual mystery of quantum entanglement resides in the fact that these opposite instruction sets don’t reproduce the quantum mechanical outcomes when different measurements are made, Mermin’s “case (b)” trials. Let me explain. Suppose Alice and Bob restrict their SG measurements to one of three directions in a plane: 0 deg (straight up), +120 deg, or -120 deg. Quantum mechanics says the probability of obtaining the different outcomes in case (a) is 100% while the probability of measuring different outcomes for case (b) is 25%. What do instruction sets give us? Look at the instruction sets [+ + -] for A and [- - +] for B. That is, when A is measured at 0 deg it gives + (where +1 = up with respect to SG magnets oriented in that direction), when A is measured at 120 deg it gives +, and when A is measured at -120 deg it gives - (where -1 = down with respect to SG magnets oriented in that direction). As you can see, B’s instruction set gives the opposite results for each of those directions. These instruction sets guarantee case (a) results, but what about case (b)? There we see that A and B’s instruction sets give opposite results when: A is measured at 0 deg and B is measured at 120 deg or A is measured at 120 deg and B is measured at 0 deg. All the other case (b) combinations produce the same outcomes for A and B, not opposite outcomes. That means Alice and Bob will obtain opposite outcomes in 33% of the case (b) measurements for these instruction sets. And, this 33% opposite outcome frequency holds for any pair of instruction sets where A’s has [two + and one -] and B’s has [one + and two -] or vice versa. The only other instruction sets are: A has all + and B has all -, or vice versa; and in those cases, we have 100% opposite outcomes for case (b). Thus, our “Bell inequality” for instruction sets says Alice and Bob must obtain opposite outcomes in more than 33% of case (b) trails. But, as stated above, quantum mechanics says you will only get opposite outcomes in 25% of case (b) trials, so quantum mechanics violates Bell’s inequality. So how can we explain the quantum mechanical outcomes for case (a) and case (b)? Well, if you try to explain the case (b) correlations via some dynamical effect, you end up with faster-than-light causal influences (nonlocality, what Einstein called “spooky actions at a distance”) or causes from the future with effects in the present (retrocausality, violating statistical independence) or superdeterministic causes that control both the measurement settings and the instruction sets (again, violating statistical independence). Physicists don’t like any of these options, so the mystery of quantum entanglement has no consensus solution even though it was introduced by Einstein, Podolsky and Rosen in 1935. So, let’s look at how quantum information theorists solve this mystery. Recall what I said about spin in the Comments of “What is Spin?”: you always get +1 or -1 (in units of h/(4*pi)) when measuring spin, no matter which direction you choose for your SG magnets, due to the observer-independence of h as demanded by the relativity principle. Now suppose Alice measures A at 0 deg and gets +1 and Bob measures B at 120 deg. Alice says Bob would have gotten -1 at 0 deg, i.e., the spin angular momentum vector of B is pointing straight down to conserve spin angular momentum vertically. So, when Bob orients his SG magnets at 120 deg he should get that -1 (downward pointing) spin angular momentum vector’s projection along the 120-deg direction of space, i.e., he should get cos(60) = +1/2 (at 120 deg everything is upside down for Bob). But, exactly as with spin for a single particle, Bob always gets +1 or -1, no fractions, so instead of +1/2 he gets 75% +1 and 25% -1 results that *average* +1/2. And that means he gets -1 in 25% of his case (b) measurements when Alice gets +1, exactly as predicted by quantum mechanics. [Likewise, Bob gets +1 in 25% of case (b) trials when Alice gets -1.] While Alice complains that Bob’s measurement outcomes are only averaging to what is expected for the conservation of spin angular momentum in case (b) trials, Bob can make the exact same argument about Alice’s results. So, whose data must be averaged to satisfy the conservation of spin angular momentum in case (b) trials? And what nonlocal or superdeterministic or retro causal mechanism is responsible for this ‘average-only’ conservation? According to quantum information theory, you’re asking the wrong questions. As with quantum superposition, quantum entanglement is not a dynamical effect, it is a kinematic fact resulting from the observer-independence of h as demanded by the relativity principle. Finally, this should remind you of length contraction in special relativity. There when Alice and Bob occupy different references frames via relative motion, they partition spacetime events per their own surfaces of simultaneity and show clearly that the other person’s meter sticks are shorter than their own. So, whose meter sticks are really short? And what causal mechanism is responsible for this length contraction? According to special relativity, you’re asking the wrong questions. There is no luminiferous ether shortening meter sticks in special relativity. Length contraction is not dynamical effect, it is a kinematic fact due to the light postulate as demanded by the relativity principle. [See our book, "Einstein's Entanglement: Bell Inequalities, Relativity, and the Qubit" Oxford UP (2024) for the details.] Physics is amazingly cool … when it makes sense :-)

[@schmetterling4477]

Wow, that was a lot of bullshit. ;-)

[@neoleo690]

So does entanglement mean that if you measure the spin of one entangled electron, it will impact how the other electron (the one that wasn't measured) behaves? If not, how is looking whether one coin is heads or tails any different from the entanglement talked about here?

[@askyle]

Tbh you can't distinguish between them just with up/down measurements. But if you change the measurement basis, you _can_ observe a difference. For instance, if you turn both detectors sideways (so you're measuring the spins left/right instead of up/down), the entangled electrons will _still_ have opposite spins, whereas the clasically random ones will have independent spins.

[@ExistenceUniversity]

This major issue with your phrasing is that you are presuming that you have two different objects. When you word it as "what I do to ONE, does it affect the OTHER?" The issue is which is which? Is there a difference between them? Or are they in this state 1 object non-locally existing? If you were to speculate with Penrose's and Hameroff's quantum consciousness ideas, you might imagine that if your consciousness is a quantum effect, your ability to feel your foot and head while ignoring your torso, would be like having a non-local quantum state of being at your head and at you feet at the same time. And that's not that difficult to think about.

[@mattwhiting2205]

"So does entanglement mean that if you measure the spin of one entangled electron, it will impact how the other electron (the one that wasn't measured) behaves?" No. Not in any way whatsoever. It's important to remember there is literally no information being transferred between the electrons. "If not, how is looking whether one coin is heads or tails any different from the entanglement talked about here?" Great question. The thing that makes entanglement different is that the electrons are still both in superpositions of multiple states whereas the coins are each just in one state. entangled electrons: superposition of states opposite coins: one state each So the follow up is, "what's the diff?" LGU explains this in some of her videos, but it's pretty tricky. Veritasium has a video, "Quantum Entanglement & Spooky Action at a Distance" that's pretty easy to follow. When particles are in a superposition, the state is still indeterminant. It isn't just that we don't know, we can actually show that the particle hasn't decided yet. That's what's special here. Superpositions can interact in ways that plain old states cannot.

[@peetiegonzalez1845]

It means you can imply how the other electron will behave (or already did behave). But the order in which you measure them doesn't matter, so you can't say "impact" or "effect" because we define positive spacetime as the direction of causality. You just have to get the information about both of them to the same place in order to compare. Which of course you can't do faster than light and/or back in time.

[@TedToal_TedToal]

When you measure one, it absolutely influences how the other one behaves.

[@jimbuono2404]

If you entangle two electrons, separate them and measure one to have an up spin, you know the other has a down spin. If you then change the spin on the up electron to a down spin, does the other one, which had the down spin, change to an up spin.

[@ai3t86]

No, the other remains down. Flipping one spin locally does not alter the state of the other spin.

[@jimbuono2404]

@@ai3t86 So much for 'spooky action at a distance'. Thanks for getting back to me.

[@wanfuse]

So would you say the two entangled particles share a common probability distribution and are on opposite sides of the distribution? metaphors reflect how entanglement reduces their individuality, tying them to a shared "address" or "result" in the quantum system, much like how memory or operations unify elements in programming. Or as a dimensional collapse to a single surface dimension, or a pinching of items in space time. quantum systems challenge our classical notions of separation and locality. Seems to suggest that perhaps every item stays in the exact space time point and perhaps it moves with the particle and not the particle moving in space time.

[@7177YT]

What exactly constitutes the (first) measurement? The first interaction the particle has which is influenced by the entangled state? The way you explain it you'd think you need a conscious observer to define spin for both by determining apin for one of them.

[@drdca8263]

It doesn’t matter which is first. The two measurement events can be spacelike separated.

[@7177YT]

@@drdca8263 Thanks, but that's not what I'm asking. What does constitute a measurement at all. I can't be sure that my measurement is the one breaking the entaglement, how would I know that another interaction of that electron already broke the spell and determined it's spin? I'm interested in questions in directions of the Wigner's Friend paradoxon, i.e. how long entaglement survives anyway. If the entagled electron feels even the slightest whiff of a magnetic field, it has to react according to it's spin, so entanglement has to break right away.

[@drdca8263]

@@7177YT Well, the exact details are something people reasonably disagree about, but generally, it’s a “decoherence” kind of thing. If you can draw a boundary between system and outside-environment where you are part of the outside-environment and the particle is part of the system, and nothing that was significantly entangled with the property of the particle in question has had that property of it involved in an interaction with something in the outside-environment, then it “hasn’t been measured”.

[@buckminsterfullerene2294]

Does greater the distance apart create less entanglement?

[@LookingGlassUniverse]

Nup, it’s the same amount no matter how far

[@lightlegion_]

You excel at what you do!

[@PotentialSpaceEngineering]

You are smart. So, this will help your explanation. It's called connecting the quanta dots. Schematic Drawings •-•-•-•- What is this line of beats connected to? It's called the Photonic Field, A huge ocean. Just like the oceans or lakes start with one drop of water and become part of a huge vast amount of water. One photon drop of light into a bigger Light stream, lake or Ocean.

[@vicenterivera188]

The entangled electrons communicate through wormholes

[@ahmadmujtaba5901]

So when we measured one of the two entangled electrons and there is a 50% chance of it being up or down and let say we get up state, then does it mean that the other particle no longer has 50-50 chance of either state. it will be a 100% down state?

[@TheMemesofDestruction]

This is the most adorable explanation of entanglement. ^.^

[@emiliomagris8753]

I got distracted by the 100 lire coin 😅where did you find it?? By the way will the next video explain how the 2 electrons communicate the collapse of state?

[@LookingGlassUniverse]

I got it in a market in Italy. The shop keeper just gave it to me free :) No one knows how the electrons do their communication exactly

[@BleachWizz]

1:35 - may I disagree for a second and if I'm wrong please I'd love an explanation. because I thought it would be easier to differenciate suporposition from entanglement exactly with that argument. Entanglement means there's correlation between both states, the difference is with the coins you have a fixed state but with the particles you'd have a superposition. But entanglement means exactly that, figuring out one also makes you sure about the other, in the superposition state you would then have a superposition where up-up and down-down components are 0; the coin having a fixed state is the point that breaks the analogy but what's happening in the solution set is the same thing. Even though the coins can't be like particle entanglement their connection kinda means the same thing. Like if you pair up heads with up and tails with down then there should also be a valid connection between the outcomes of the coin and the particle tangles.

[@brookswift]

What's missing from this video is a discussion of the hidden variables theory of quantum mechanics and how bell's inequality and experiments like the quantum eraser are able to prove that there are no hidden variables.

[@yiannchrst]

Hey, no expert here, but - from what I got - the difference between entangled particles and the two coins is that the entangled particles are in a superposition, which is not the same thing as being in one of the states OR the other, as we saw in the previous video. I hope my explanation is helpful (if it's correct that is 😅)

[@LookingGlassUniverse]

@@yiannchrst Yeah, I think you put it a lot clearer than I did in the video. The coin and the entangled particles are pretty similar in that they're correlated. But the reason is different. The coin is correlated only because you don't know something. The entangled particles are correlated because of superposition- even though you do know the exact state

[@askyle]

​@@LookingGlassUniverseI think it would have been helpful to show an experiment that can distinguish between a (classically) random choice between "up-down" and "down-up", versus a pure entangled "opposite spins" state; eg measuring the spins sideways (so in the former case the spins become independent of each other, but in the latter they remain correlated). That wouldn't rule out hidden variables, but it would show that there's at least _something_ different between classical uncertainty and quantum entanglement.

[@Spoony412]

This. Reminds me of using a steel rod. Pounded against the wall and it is instantaneous. There are more examples of a steel rod vibrating from end to end.

[@gregorykrajeski6255]

Popular explanations always focus on entanglement of two particles. In principle three or more particles can be entangled, or in the extreme the entire universe. Perhaps wave form collapse is the act of becoming mutually entangled with the quantum system.

[@schmetterling4477]

Yes, everything is entangled (which doesn't matter), but nothing ever collapses. ;-)

[@JrgenMonkerud-go5lg]

now if you think the superposition of up and down is a different state than just a mix of up or down, then there must be some action to change the state on the other side. but this is a very loose argument, my longer one is better.

[@Zeeraha]

I am still not convinced that entagled electrons truly stay in a physical superposition. I wish for a better explanation how do we prove they are still in a superposition states of up and down. When two electrons are entangled, I believe one is determent to be in up state, while the other is determent to be in down state (as an example). It is just that no one can know the true state of one of them until you measure them. If you eg. you take one electron, and you flip its spin, and after you measure it, both electrons will be in the same state, up or down. No matter how many times you repeat the experiment, electrons will end up in the same state (case where the entanglement leads to the opposite state). This means that collapsing the wave function by flipping the state of one electron does not lead to some random outcome. Of course, we could say that the flipping of the state of one electron instantly changed the state of the entangled electron, which is now e.g. 1 light year away, but we know this physically can not be possible.

[@TedToal_TedToal]

But it IS possible and has been proven! The experiment has been done. The reason Bell's inequality allows you to distinguish between the two possibilities is that the prediction when the measurement angles are randomly flipped DIFFERS between quantum mechanics vs. if hidden variables were true. And the experiment finds that qm gives the correct prediction. This is why the experiment is so extremely disturbing to anyone who understands it and is the kind of person who is bothered by two objects influencing each other instantaneously across the universe. Not everyone is bothered by that. I am though. Read the great (short) paper: www.physics.wisc.edu/courses/home/spring2020/407/experiments/bell/Bell's%20Theorem%20Background%20Papers/READ_THIS_FIRST_Mermin_reality_Phys.Today.38.38.pdf

[@quantum4everyone]

The standard way to do this is via a quantum eraser, which removes the entanglement, leaving a product state superposition, which shows entanglement. Of course, you have to believe that the way it is erased is not just creating a new product state entangled state, but it results from erasing the entanglement. The best example to think of this is a two slit experiment with polarizers. You can find many videos on this on you tube and a nice scientific american article on it.

[@NotHardyToonz]

How to make data transmitter and receiver with entangled particle please 😭

[@John_Fx]

Could one say that the second electron "Peeked" into the superposition of the first electron without forcing its superposition to collapse?

[@schifoso]

12:20 If you measure the electron on the left, you say it collapses the superposition. How do you know that the electron on the right is no longer in a superposition unless you measure it?

[@brothermine2292]

Measure both, and compare the results. They will have opposite spins.

[@pluto9000]

How did the apathetic electron decide to be different to the sad electron? How did they become entangled?

[@buckminsterfullerene2294]

So if we had a bundle of electrons we could build a device to communicate instantly, real time, this would revolutionise data movement and communications no mater where you are in the universe?

[@ExistenceUniversity]

11:00 This is Hidden Variables, which Bell's inequality and the Non-locality works have shown to be incorrect. 11:50 This is Non-locality.

[@coreyanderson3288]

You would be right if she was talking about the quantum particles, but she was talking about the classical coins.

[@SuperSerNiko97]

@@coreyanderson3288 yeah but she says there is some fundamental difference between the two examples, while that has never been proven experimentally

[@ArnMH81]

What if the coin is still flipping, is it in superposition?

[@jamesmcclain5005]

It sounds like entanglement is a valence state in full electron shells where these electrons must be in different states. This unfortunately is a very localized state.

[@Spoony412]

I think you should talk more about very high. Energy light longitudinally pulse preturbating magneto dielectric. Spacial counter spacial reference plots

[@npjay]

correct me: two entangled electrons one on earth and another on mars which are in superposition , if we measure electron on earth and it collapses or whatever it will have one definite state, at the same time electron on mars without measurement collapses to opposite state or only after measurement it will collapses to opposite state ..?

[@schmetterling4477]

Yes, you are completely wrong. You are also certifiably mental if you think that you understand physics. You are not even using the words right. Even ChatGPT is smarter than you. ;-)

[@ThatTimeTheThingHappened]

I want to see the equipment one would use and the instrument they use to do this experiment. Can you do this with light or only with electrons?

[@hankdewit7548]

For electron spins they would use a Stern-Gerlach apparatus. You can do similar experiments with light but then you are measuring polarization and a polarizing filter.

[@SepiaSapien]

I love your channel!

[@parmachine470]

"Where's the beef??" Their relation to each other was set when one decided to not be like the other. Magic of course. This deal got "Queered" when the second measured the first so as not to be like it.

[@Mentaculus42]

An orthodox explanation that would warm Bohr’s ego. Now explain it from Bohm’s perspective which Bell actually preferred.

[@dimastus]

Thanks for the video. I saw similar explanations on YT for a long time, but I have never captured the idea of separating the entangled particles. When we are talking about 'up' and 'down', these notions imply some axis. But how can we assure that these axes in our separated labs are the same? (Especially in the curved space-time). And how can we even transport these entangled particles without interacting with them? ... so my problem is the good old 'interaction-measurment'

[@drdca8263]

It is ok to interact with it in some ways, as long as this interaction doesn’t depend on the spin in any way.

[@hankdewit7548]

Yes the axis is very important. The |up> |down> states are two quantum mechanically orthonormal states and are the basis vectors for any orientation of the electron spin. But they are not the only ones. We could also have a |left> and |right> orthonormal pair of states that are equally good basis vectors to describe the electrons spin. Whatever the real spin orientation of an electron is, whenever it is measured it will only be in terms of the basis vectors, thus you will only ever measure UP/DOWN with respect to the measuring apparatus. If we pass an electron through a Stern-Gerlach apparatus oriented in our defined UP/DOWN direction we can separate the electrons into pure |up> and |down> spin electrons. If we just use the |up> electrons and pass them through another Stern-Gerlach apparatus oriented in the same way we would see all the electrons with spin |up>. However, if we pass them through an apparatus oriented 90° to the first we would see half the electrons be |left> and half |right> randomly. You question about curved space-time is interesting. I suspect if we could do these experiments in strong gravitational fields we might learn something about quantum gravity, but that's way outside my understanding of QM.

[@dimastus]

@@hankdewit7548 I see, thank you!

[@davidhall7275]

Is spin the direction of the magnetic moment of an electron? Are you sure about that?

[@schmetterling4477]

Yes, we are sure that she does not understand physics. She looks cute, though, and she knows that's enough to impress people on the internet. ;-)

[@martincotterill823]

So it is spooky action at a distance, instantanious transfer of information, isn't it?

[@merchantservices100]

How can a particle spin be up or down in space? It doesn't make any sense. It's only measurable because of a gravitational force acting on the observer. If you conducted the experiment on board a space ship with no gravity. It's spinning in all directions simultaneously. The measurement is only relative to the astronaut depending on where they are floating around the particle on a X y z axis. If the astronaut floats to different x y z coordinates around the particle the measurement of spin changes. So it's not absolute.

[@babavura2662]

So is it definitely our measurement that cause the collapse of the state? Can you elaborate on that in another video please? I love the fact that any stupid question I ask (like this one) if forgiven when its Quantum Mechanics :)

[@donaldhobson8873]

"Measurement" and "collapse" aren't things. Whats happening is that you get entangled with the particle. You can write the particles state is heads in your lab notebook, but that brings the notebook into the large and rapidly growing entanglement.

[@jumu7983]

It's been nice to see you making videos about quantum topics again! I didn't realize elections came in moods other than crying and sad, but meh was a very electron-like mood as well. Low energy, I'm guessing.

[@LookingGlassUniverse]

Low energy- that’s so good!

[@StevenBrener]

I always wonder on what basis does entanglement get initiated between particles. And, what are the limitations to how many particles can get entangled.

[@ai3t86]

You can get as many entangled particles as you want. No rule forbids that

[@StevenBrener]

@@ai3t86but what determines which particles get entangled?

[@ai3t86]

@StevenBrener That's a great question! The main factor that determines how particles get entangled is the interactions between them (and how long you let the system evolve). Different interactions and duration can generate different patterns of entanglement. However, even if many-body entanglement is generated, it is still extremely challenging to ceritify its presence, both experimentally or theoretically, due to its complicated nature, let alone knowing the entanglement pattern. So far, we are lacking a universal method to do this. What you just asked is an NP-hard problem in entanglement theory, the hardest problem one could ask! To give you a taste of the difficulty, people find that there is only one "entanglement class" (or entanglement pattern) when you have two-particle entanglement, six classes when you have three, and infinitely many when you have four! While, in real life, you can have thounds or millions of particles entangled together...

[@schmetterling4477]

Entanglement is caused by conservation laws. You have seen it in high school when they showed you two little cars connected by a spring and a thread that gets cut. That's entanglement. ;-)

[@ArnMH81]

I understand everything about the calculations and experiments, but still it feels like I couldn’t do the calculation myself if asked.

[@philochristos]

That's pretty trippy.

[@boonraypipatchol7295]

All Nature, All Beings, All Minds, Quantum Information and Quantum Entanglement are Fundamental.

[@joepike1972]

The only think I want to know is what is a real world example of entangling two "electrons".

[@LookingGlassUniverse]

Fair enough! I cut that bit out of this video but I’ll make it into a bonus bit

[@quantum4everyone]

One of the quantum communication protocols works with entangled photons. This is an application--for quantum key distribution. Another nice example is the Franson interferometer, which entangles in time rather than space. It is often used to detect whether there is an eavesdropper or not.

[@lightlegion_]

Hi! Just wanted to reach out and say hello!

[@Saturntabbytype2]

I’m always in a superposition,centre of my universe

[@JamesD2957]

I think giving particles agency as a metaphor leads to confusion

[@clarencegreen3071]

I wish someone would describe an actual physical demonstration of how one might cause two electrons to become entangled. --Old physicist

[@hankdewit7548]

Due to the Pauli exclusion principle electrons naturally form pairs of opposite spin in the orbitals of atoms, but that isn't very useful if you want to spatially separate them to demonstrate entanglement. Apparently though, in superconductors, electrons also form opposite spin pairs called Cooper pairs. These pairs are manipulable (I haven't a clue how) so that they can be physically separated but remain entangled so that when the spins measured they are indeed always opposite.

[@SteveMacSticky]

Entanglement is the stage that happens before marriage

[@Saturntabbytype2]

And by the way your mind arrived here from space

[@JrgenMonkerud-go5lg]

didnt have any problem with the video, it was nice ^^. just wrote my comment to give some context.

[@4pharaoh]

This is describing the math that we use to describe entanglement with cartoon drawings. (NP) But all that counts after 80+ years is: What is nature doing, what is entanglement and spin telling us about the fabric of the universe and the essence and intrinsic nature of the electron (etc.)? This young lady is working very hard to conform her thoughts to the those with no imaginations. Let me help: Your professors know nothing, the professors who taught them knew nothing, and until you embrace that obvious fact, and assume they are all wrong is some (many) important places your contribution to the understanding *Nature* will likely be the same.

[@drdca8263]

If those professors know nothing, you know even less than nothing. Laymen who think they know the truth about quantum mechanics better than the people who actually design experiments and successfully predict the results of these experiments, are rather silly.

[@4pharaoh]

@ You’re right, I must be wrong. I should just listen to you science groupies, Truly you are the wisest among us mere mortals.

[@drdca8263]

@@4pharaohI wish youtube would fix the bug that sometimes replaces the usernames with just an @ sign. In any case, I didn’t and don’t claim to be special in this case. Lots of people have a decent understanding of quantum mechanics and of entanglement. It isn’t something with an artificial barrier to entry. One only needs to do the math.

[@mrslave41]

i love this channel very very much. but this is (like all other quantum entanglement videos) completely incomprehensible to me. and i consider myself an expert on quantum entanglement theory at this point 😮😮😮

[@brothermine2292]

I think it would have been less confusing if the video had described: (1) how the entangled pair of electrons was produced, and (2) how the only information we know about the states of the entangled electrons (prior to measurement) is that the sum of their spins is zero due to the law of Conservation of Angular Momentum. The zero sum implies that if the spin of one of the electrons is measured to be x, that measurement would imply the other electron's spin is -x, assuming both electrons experienced identical influences after they became entangled. (An example of identical influences is sending the two electrons through two Stern-Gerlach devices oriented at the same axis. In the video, the orientation axis is vertical for both Stern-Gerlach devices, in order to measure whether the electrons' spins are up or down. But the choice of axis is unimportant... what's important is that both Stern-Gerlach devices are oriented the same way.)

[@RussellCox]

What if I gave you an object and you didn't know if it was entangled. How would you tell? If you can't describe an entangled object without referencing the other, then you should be able to tell me if it's entangled or not 🤔

[@LookingGlassUniverse]

That’s exactly right! Without access to the other object, you can’t tell!

[@RussellCox]

@LookingGlassUniverse So, neither object is entangled alone. It's only when you're referencing them as one that they're entangled?

[@RussellCox]

@@LookingGlassUniverse Also, thanks for your efforts. Love your work 🥰 I just don't understand QM. Bell's Theorem Experiment is curious, but I don't like that proof can only be obtained by a circuitous route 😑

[@quantum4everyone]

There are objects called entanglement witnesses that allow you to measure whether you are in an entangled state or not. I do believe they require measuring both objects, but I am not 100% sure.

[@RussellCox]

@@quantum4everyone As @LookingGlassUniverse said, you can't tell if they're entangled if you only have one object. I'm still not convinced that entanglement isn't "hidden variables" or just "yeah, they'll be opposites because that's how they started". Has anyone tried to improve the Stern-Gerlach device to try and measure more than one axis, by having a cylinder magnet so the magnetic field surrounds the object and it can move in two axes?

[@JonnyMath]

Quantum!!!🤩

[@Daaaaaan]

This just made me more confused 😭

[@brothermine2292]

I think it would have been less confusing if the video had described: (1) how the entangled pair of electrons was produced, and (2) how the only information we know about the states of the entangled electrons (prior to measurement) is that the sum of their spins is zero due to the law of Conservation of Angular Momentum. The zero sum implies that if the spin of one of the electrons is measured to be x, that measurement would imply the other electron's spin is -x, assuming both electrons experienced identical influences after they became entangled. (An example of identical influences is sending the two electrons through two Stern-Gerlach devices oriented at the same axis. In the video, the orientation axis is vertical for both Stern-Gerlach devices, in order to measure whether the electrons' spins are up or down. But the choice of axis is unimportant... what's important is that both Stern-Gerlach devices are oriented the same way.)

[@jjschereriv]

I know what Bohr said something like: 'If you think you understand the quantum world, you don't.' But you, dear lady, are ALMOST leading me to THINK I'm beginning to understand a few things about this mysterious world! What a teacher you are. . .

[@jkinkamo]

Thanks.

[@brookswift]

Your explanation of superposition/entanglement being different from a simple lack of knowledge doesn't really follow from the arguments you present. What you're referencing in the lack of knowledge case is the hidden variables theory, which is disproven by bell's inequality and the quantum eraser. It's a fairly subtle and complex difference which you just don't touch on in this video.

[@TheRenaSystem]

Can you explain why it doesn't follow?

[@ciscoserrano]

That’s kind of the point. She’s not uploading a thesis paper. She’s just trying to educate laymen about a commonly misunderstood topic. Go make your own video.

[@amenoum7623]

What is the actual proof that information is not transferred faster than light? Isn't Bell proof based on the assumption of no faster than light travel?

[@brothermine2292]

Bell's Theorem is about _local_ hidden variables. It doesn't falsify global or system-wide hidden variables.

[@gasdive]

Yeah, it's just a "trust me on this, there's no hidden variables" kind of presentation, but at the end says that will be covered next time.

[@Justhanginout283]

Thanks Dr Yo

[@akashr967]

glass

[@f.andersen3824]

Electrons are sad or mildly melancholic, but certainly bipolar. 😅

[@dbdttpl]

The proof by contradiction is plain wrong - the scenarios are simply different: either they are entangled (in which case, they remain entangled) or they aren’t (in which case there is no correlation of the results). There was no “proof” by anything.

[@ExistenceUniversity]

0:20 Entanglement is when objects are entangled... The word describes the fundamental essence of the behavior.

[@JrgenMonkerud-go5lg]

yes, the accountancy of the statistics is summed up correctly by the discussion of the state of the system. it is however not true that this means there is or is not an interaction, not at the level of measuring in the same axis, aka up or down. this can be accounted for by hidden variables that say A is up, B is down, or , A is down, B is up. if there is such a hidden simple state preparation then yes it can be interaction free. the problem is that this particular state is the same for any axis you choose to measure them in, therefore you are logically forced into one of two solutions, just declearing it is so statistically by fiat, which is what standard quantum mechanics does in effect, this is what it means more generally to say the state is no seperable into independent states, as i discussed if it is only valid for one axis, then a preparation of independent states in that axis still perfectly well accounts for the statistics. the second option for when the relationship is the same for all measured axis, is to have real independent spin states that are set up opposit in the hidden preparation, but the real spins of both could be on any axis and could be measured at any axis with the correlation persisting, in this case you have forced into having an interaction there to explain the correlation. the way this interaction needs to work to fit neatly with how spin measurments of single spins work, such that we do not need to change anything there is as such; spin A and B start out up and down on some random axis with net 0 angular momentum, then we measure A, and it turns out up or down in some other axis than the hidden preparation that we dont know about, then all the interaction between the spins must do is to rotate the spin axis of B to the opposite orientation, if A becomes up in axis 1, then B must become down in axis 1 ect. that way we return to always being able to treat the two as seperable, but we also have to account for the interaction. to sum this up, yes it is just a statistical thing in standard quantum mechanics, does that mean there is no interaction? no. if we introduce an interaction, that makes the description simpler, and we do not need a unified inseperable state to describe the statistics of the spin entanglement. and if you run through the math of how such an interaction prepares states for the 2nd particle to be measured, you will see clearly that it reproduces the full results of bell tests and so on, with no issues, and with the possibility of the spin state always being well defined on a single axis even when we have not measures it. at any choice of measurement axis on the spins seperately btw. this is a more explicit version of what einstein called spooke action at a distance being necessary when the results are random, if we propose that the spin has a well defined state independent of being measured, then it is necessary for that hidden state preparation to be prepared in the axis of measurment that we will later use to measure it, or the statistics will not work out, unless we assume an interaction between them. so the choice for hidden variables are superdereminism, that is that the state of the particle prepared without out knowledge anticipates what measurments will be done on it later. Or alternatively we can propose an interaction, then any preparation in any random direction is fine. i choose the latter option, it is ultimately much more sane, there is the problem of locality, the same problem as in instanteneous action in newtons gravity, but it also turns out that when you dive deeper into the mathematics of finite speed versions of this action and the experiments that has been done, it turns out that what we have seen so far is consistent with a superluminal locality that breaks lorentz symmetry with its effects, this is still a big change, but it is nothing like demanding a theory has non trivial statistical dependence at spacelike separation and just denying that there is any issue with that, because of defining some sort of mutual information. defining the statistics as such with a denial of causation to account for the dependence, is imo the same as proposing a heuristic superdeterministic theory. i contend that just because standard quantum mechanics does not have these hidden preparations explicitly in it, it does have the statistics of their outcomes, and must be judged on the same footing as superdeterministic hidden variables theories, and that is a cosmic conspiracy where the particles are always prepared in a way consisten with the choice of measurment. this phenomena without causation is why certain academics rush to say the evolution in quantum mechanics has to be retrocausal and forward in time, because you have this tension between preparations in the past and the future. sorry if this is a bit dense to read, i tried to say it as clearly as i can. hopefully you understand the way such a coupling between spins must work to be able to treat the preparation in a mundane way, and always treat the particle spins seperately as long as the interaction is accounted for. it is the case that when you get into the weeds and make the process a finite time process, and the collapse of a spin state onto the measurment axis given by a magnetic field, also becomes a finite time real dynamical process, you get departures from the predictions of standard quantum mechanics, but those departures has not been tested yet as far as im aware, if you know otherwise then please link me to a paper with an experiment, i have looked around for such tests, but has never found it. the cool thing about these more realistic models of what is going on, is that if they work, there is a possibility of the no telephone theorem not holding and we might get to communicate faster than light at some point.

[@brothermine2292]

To communicate more clearly, provide an example that explains what you mean by "interaction." I suspect you mean an interaction between a particle and a measuring device, not an interaction between two entangled particles.

[@dovbarleib3256]

Read Einstein's, Podolsky's and Rosen's paper from 1936?, and we will all be wiser.

[@stephenzhao5809]

8:51

[@mybachhertzbaud3074]

Physics at the moment seems to be experiencing a huge amount of "entanglement" 😜

[@chadriffs]

Entanglement and non-locality seems to mean that it has no direction, time, future or past--which is exactly what a photon traveling at lightspeed "experiences". This then means that the universe is one thing with many parts and until scientists are capable of entering consciousness into the equation we will only be going in circles. I can see future courses in physics coupled with nondual philosophy like Tibetan Buddhist/Bonpo Dzogchen teachings or Hindu Advaita Vedanta. Our true nature is likened to a mirrors ability to reflect in that no matter what arises in front of the mirror its ability to reflect does not change and our true nature of awareness is like that. Or, all of our experience inner or outer is the reflection in the mirror and is not us and awareness, our true nature, gazes into the mirror. The action is to allow the arising and dissipation of experience without grasping or avoiding but simply remaining as awareness, the always already here. Muddy water is made clear by not stirring it up. Non-locality is then seen as awareness at rest or foundational and locality is the illusion we live in without attachment or aversion(hopefully) while paying our bills/living our lives...

[@SuperSerNiko97]

Except Bell's Theorem neither proves nor disproves locality

[@Merilix2]

I wonder why the word "Entanglement" should depend on having connected states in a superposition or not. I mean, it doesn't matter if you speak about a pair of shoes separated into two boxes or if you speak about electrons interacting with each other such that they share the same state. In both cases, measurements on both objects are correlated and on my understanding that's the core of what entanglement means. In my opinion it would be easier to understand the difference to superposition. Not sure if thats the right terminology but isn't entanglement just another word for conditional probabilities in math?

[@ai3t86]

In classical world, you cannot change basis, but you can measure entanglement in different bases and get very different conditional probability. So it is not a simple conditional probability in the classical sense

[@Merilix2]

@@ai3t86 You cannot change basis classical? Really? Look at a cylinder from the side, you'll see a rectangle. Look from above you'll see a circle. The object state is somehow projected to the plane of your observation, the plane of your camera. From a math point of view, using normalized complex numbers is nothing else than describing a rotation or a phase shift if you talk about classical waves, which is basically the same. In Quantum computing, applying conditional probabilities is what controlled gates actually do. As an example, a CNOT is applying an X gate to a qubit controlled by another one without actually measuring the control bit. They are entangled along the X base afterwards....

[@ai3t86]

@Merilix2 No, classical waves and complex waves in QM are not the same, even though they look similar. It makes no sense to measure a classical wave inteference with a chosen "basis." The idea of basis doesn't even exist in classical measurements. For QM, you can pick out a preferred basis and get an entirely different probability distribution. Rotating a cylinder and turning it into a square does not belong to this discussion here. The "basis" we talk about is not the three dimensional euclidean basis...

[@ai3t86]

In classical measurements, we can measure position and velocity simultaneously. The two measurements commute. But in QM, position and momentum do not commute. Measuring momentum first and then position is not the same as measuring position and then momentum. That's what we mean by "change of basis." It is not rotation in 3D space.

[@Merilix2]

@@ai3t86 3) Cylinder / Square does belong to the discussion here as an simple example of what could happen if you measure along different bases. 2) It makes absolute sense to measure a classical wave interference with a chosen basis. Think about antennas receiving vertical and horizontal polarized signals from satellites at the same time. In fact there is only one signal bu your receivers measure different components of this classical electromagnetic wave. 1) I was referring to how complex _numbers_ are related to rotation and / or phase shifts. Its the very same thing.

[@djbslectures]

❤❤❤

[@NyteRazor]

I hope your sad face electron friends are feeling better for your next video. Should have let them take the day off. 🤭

[@Stringandsealingwax]

Electrons can say and do things according to their wants? Sorry, this is really confusing.

[@kcbhushan67]

This is not an easy video to understand.

[@gristlevonraben]

i appreciate your video, but i believe my video is more accurate, that entanglement occurs in a subspace dimension.

[@BenjaminGatti]

IF this is a claim about how the world works, then we need data. John Clauser threw his data away, as does everyone else. The public data shows how arbitrary filtering makes the claim work.

[@krzysztofciuba271]

Unfortunately, she does not understand her own subject matter, and like the majority of scientists, she has no clue about the methodology of science at all; hence,...paradoxes and mysteries! The problem is simple: one can't speak about "two" "electrons" that are in a superposition bc it is just ONe wave function. Forget about them (as "teachers')! You can find it in some textbooks.E.g., a mystical expression: a "collapse" as if any probabilistic formula (e.g. of winning a Lottery) was "collapsing" when an experiment is done

[@schmetterling4477]

Well written textbooks don't talk about collapse. There is no such thing in physics.

[@mrslave41]

you cannot explain quantum entanglement “without the woo”. quantum entanglement is as woo as woo can get. 😮😮😮😮😮

[@ShauryaKad-s6p]

I am firstttt😁

[@dadsonworldwide3238]

Archemedes descrete lines on paper determinism used to explain congruent complexity where our minds sort through variation along the way useing good & bad measure. Like 2 captain in the wheel house of a ship stairing at each other through binoculars while inside its topography central inertia mass buoyancy is about to sink due to the qauntom hull meets entangled waters as a submarines computed torpedo is about to simulate strong indentefiers of interaction into that entire objective. Lol

[@physicshuman9808]

I’m second!

[@mohitgupta6360]

Also 5th

[@mohitgupta6360]

I am 4th

[@danielalexander799]

Is there any connection between entanglement and the Pauli exclusion principle?

[@ai3t86]

Technically no. Pauli exclusuon principle requires antisymmetrization of wavefunction of two fermions, and at the first glance it looks like entanglement is already there in the wavefunction. Unfortunately, this kind of entanglement is not operational (you cannot exploit it to do anything meaningful), so most people don't think it is the 'entanglement.' And there is mathematical tool that can distinguish real, operational entanglement from such 'fake entanglement' due to the exclusion principle.