Why is quantum mechanics non-local? (I wish someone had told me this 20 years ago.)

In all of this it's not really clear what "collapse of the wave function" really is - in a physical sense. It's a bit like with the 2-slit experiment when one uses individual photons and after the experiment is over we get a bunch of dots on some photo paper showing an interference pattern. The question is then when exactly did the wave function(s) of each particle or of the whole experiment collapse? When I pull the photo paper out of the fixative bath and stare at it?

My head is spinning now. Have to watch it a third time.

"knowledge is unphysical" seems to be saying. "its just knowledge" she said. is this right in light of landauer

My brain hurts.

Ah ha. Mostly.

It feels like you're pushing a highly contentious wheelbarrow here Sabine. Is it a pile of gold or a pile of poo? I think you may be making Straw Men (Phil term) of the physicists' favouring the non-locality conclusion. Surely u can be more charitable (Phil synonym for accuracy), than pathologizing them as "Mystery Addicts". Would u consider actually researching their arguments perhaps and sharing them with us pls?

Great video. And you're right, I have thought I understood Bell's inequality a hundred times but then forgot. 😛 I'll watch this video a few more times and see how it goes.

Spooky action good, physicists are like magicians. Can't help feeling the same about true black holes. They love all the paradoxes and weirdness, or maybe just too embarrassed to say they can't form in any finite time and would evaporate away long before eternity.

i'm kinda lost on the interferometer i understand the conclusion eventually but i can't say i understand why photons would always go to B (or respectively how the interferometer works) i do understand the "wave interference" part but why would waves always interfere always on one path and not on the other or vice versa or both? But anyways i feel slightly less dumber (subjectively) anyways thanks <3

This video is embarrassingly wrong. I'm sorry, but it's just flat out ignorant. I truly doubt whether she had even read Bell's paper, since it makes it precisely clear how this envelop analogy is deeply flawed.

The reason I suspect she hasn't read Bell's paper is because she talks about two detectors, and doesn't understand what happens when you place a third detector which is effected by the same correlation. This totally destroys the envelop analogy and any interpretation which claims it's just "our knowledge" which is updated.

Sorry, last time and I'll shuddup. Are there any connections to fractal patterns and the patterns of quanta?

I like the non-locality explanation in The Expanse. Imagine you drop a quarter in a pond. It splashes, makes waves on the rest of the pond. But, imagine dropping a quarter the exact size of the pond on top. It hits everywhere at the same time, no waves. non local.

That was the best explanation of quantum entanglement that I have ever heard.

I've trying understand Sabine's thinking pattern on and off for a while. Haven't really thought through it, but have this feeling that Sabine has a very rigid mindset, and like to hide a bunch assumptions when she presents the problems, assuming these assumptions are accepted by everyone. As a result, it always appears that her logic is sound, however, something is strange.

I’m finding this difficult to understand. I had thought entangled particles are both spinning but always in opposite positions. If you stop one, its position will be the opposite to that of its partner. That is, the connection between the two is non-local and spooky. For it to be local, I think the positions of the particles would need to be fixed at the point of their entanglement. Then when you look at one, the position of its partner is a given. There’s nothing spooky about that but is it how entanglement works?

Thank you Sabina! Great show and good laughs as well.

Why is quantum mechanics non-local? Very nice video, but answer still pending. That's how science goes, I guess. Still, I'm wondering...Could an easy answer just be : Because the sum of probability is one ?

Can we treat a set of entangled particles as Morse code as in measured/not measured?

Ok, if you entangle two particles and then flip the spin of only one of them then after number of iterations you'll have to end up with pairs of particle with same spin, if measuring is just reveling and not making any quantum shenanigans. But if you always get opposites then measuring actually does some quantum shenanigans

Well, OK that makes sense, but the real mystery here is: why are the top 3 buttons on Sabine's shirt light brown, while the bottom one is black?

I don't blame you - our logo is a bunch of soap bubbles, or worse - styrofoam. No wonder you don't believe in the multiverse. We'll change it to a 10-headed dragon. Surely that will bring you on board.

Beam me up Sabine

Why does John Bell look like Boromir?

One of the first things anyone learns in first year university physics is a relationship between a wave function and its alternate state as tiny mass. Consider the difference in status is that a wave is constantly moving, its constant movement precisely what defines it as a wave rather than mass only. When you measure or photograph the wave function, that captures a split second of the wave function as its mass component. Think of the two particles as a pair of dancers on dancing with the stars, if you are familiar with their dances. When one dancer twirls, the other dancer dips, or whatever their choreography designs. When you measure their dance as a wave function, it stands to reason that photographing one’s twirl will simultaneously photograph their partner’s reaction as a dip. Consider that the function is an internal program, a quantum message as it were, not actually a local dance; and your dancers, as long lost friends, are communicating their choreography program with one another from millions of light years away from one another. How is this in any way spooky or hidden? It’s telepathic communication, for which as a species, we have not evolved telepathically enough to know, how much of a tiny mass might be necessary to keep our lives going on as spirit after our death.

Look ..as someone who has spent years trying to understand qp as a hobby...

QP needs to stop it's edgy bullshit

The letter phi is Φ; Ψ, the letter used for the quantum-mechanical wave function, is psi.

I've a Ph.D. in physics, and this is the best explanation of Bell's Inequality I've seen.

Mach-Zehnder-interferometer: Every beam splitter produces a phase difference of 90 degrees or 0 degrees. If two times 90 degrees => 180 degrees => it cancels out with a 0 degrees wave function. I do not understand the 1,2,3,4 what Sabine does. It's just phase difference of 0, 90, or 180 degrees.

Please please complain about many worlds 🤩 And how about explaining decoherence?

Local(ness) is the key idea. Has anybody tried to send a message by changing the spin of one thing and reading it at the other end? That would simplify this whole dispute.

This video fails in that she has led the majority here in the comments to believe the Nobel Prize winners proved Bell wrong, whether she intended to or not. This idea is false. The 2022 physics prize was awarded for proving Bell right and finally crushing Einstein, EPR, and their hidden variables theory.

Isn't the non-locality of QM functionally identical to another dimension?

Listening to Sabine I wish I could forget all the incorrect information I have listened to in my 70 years. Conditioning is a real problem as your brain keeps going back to the old patterns. Thanks for the videos. I am slowly getting a better picture…. from a person with an Arts degree. Love the dry humour as well🇨🇦

I lost it when she said "Spooky action at a distance" is not an action. Each influence the outcome of the other through measurement/observation so there is indeed action being made.

Measurements at quantum level are extremely difficult and the way i see and hear about it very little is done passively from safe unrelated space. It does not surprise that active measurement breaks Mach-Zehnder interferometer 100% outcome. Its like inserting hot burning knife in a very fragile environment. I am sure the researchers are more aware of full measurement characteristics in this environment but its not largely disclosed. All in the hopes to find something truly funny and interesting and furthermore biased. Determinism is a painful topic indeed.

Theory: Looking at time as the fourth dimension, every "Quantosecond" (I couldn't resist) represents a frame in time--or for each frame of a movie, so to speak. Visualizing this, we can look back along the fourth dimension (If we could, anyway) and find that those two particles so far away from each other were actually borne from the same star when the universe was more condensed. Visualizing it as a 3D model with the fourth dimension taking the place of one of the others, you would see "stems" of everything, and where it came from. You would be able to see every interaction over the whole of time, really.

The physical design of The interferometer appears to me like the light could also be balanced backwards. Because if one diagonal can make it split into two direct pens that are possible then the other one at the other end should be able to redirect it back to mirrors heading back to the source of the laser itself. For some reason you don't mention that possible interaction because maybe it's not noticed. Maybe something else happens that makes it not happen.

I don’t know why the interferonometer always outputs photons that way. I’m just a dumb electrical engineer. I just have observation: the interferometer reminds me of a bridge rectifier in electronics. Instead of four mirrors, it has four diodes wired in such a way that alternating current going in becomes direct current going out. Shutting up.

Oh. I get it. (Huh?)

Oh no. Not Albert again! Somebody has to fix his wagon good.
Bent Nothingness indeed!
Get hold of AI. Tell it to pretend to be an alien explaining to Hosenfelder how they traverse to cosmos at many orders of magnitude greater than the speed of light.

I love thinking of this it keeps me calm

So where does QBism enter the picture? Does it posit non locality of type II? What is the state of the debate between QBism and the Copenhagen interpretation? And can it ever be resolved? (QBism = Quantum Bayesianism)

The wave function probabilities are only valid for numbers of particles with the same known characteristics.

No, the photon has a 100% chance of being reflected and passing through. Not, 50-50. Anyone who's sat next to a window on a cold winter day knows that.

Summary: Information changes probility.
Now you can skip the video, you're welcome.

I couldn't carry on seeing the video because of these stupid emojees and noises.. DISLIKE...🖓🖓🖓