Відео

2024 china doing some energia with this😮

How does holography explain wave-particle duality?

A better explanation of what we were looking at would have been nice

Why do we say "2 particles" when it's really just the one ?? 1 particle split in half - what's the big deal? I don't want to trivialize it, but don't we complicate the discussion by saying "2" ?? Using your complicated Maths it never goes from 1 to 2 so why do we not say it's just the 1 split in half?? using the term "indistinguishable" when your really trying to say its 2 faces of the same coin

Omg, no comments? Let me be the first to heap on praise! I haven't seen many lectures from Dr snopes, but I'm now searching for more. It seems like condensates exist at the intersection between classical and quantum mechanics.

Great😊

I dont understand what im looking at tbh

This lecture was so wonderful. Wheeler is probably my academic hero, and his thoughts on the importance of measurement have occupied my mind for so long. I wish I had watched this years ago. I have so many new ideas now, this made so many things straight in my mind. Thank you so much for your irreversible act of amplifying Wheelers ideas!

Pauli spins are inadvertently complex objects. Not a good choice to refute the non-complex theorem. You should also make clear that you are dealing with non-stationary states. The latter description can always be done without complex numbers. Imagine a charge less quantum particle in a box. Clarification between a real number state description versus complex but Hermitian operators with observable states is important. In fact there are domain issues that plague the uncertainty principle derivations from QM.

I read through the two recently published papers cited in this talk, in PRX (theory) and Nature (experiment). I had several concerns not addressed by the questions during the talk, and not addressed in the papers. First, on the theoretical front, I get that one can model the classical variables with a stochastic PDF and even couple such a PDF into an evolution equation with quantum terms. However, the classical fluctuations are not arbitrarily large, there is some constraint. Backreactions are not arbitrarily large. Yet that is the conclusion reached, that one can obtain large classical stochastic fluctuations, which may be observable even for weak coupling such as gravity. The equations produced rely in part on Markovian quantum master equations, the Lindblad eq and the Kramers-Moyal expansion, all approximations that are often inaccurate. Yes, they give closed form eqs that can be solved, but at what tradeoff? Dropping nonlinear terms that constrain backreactions. Second, on the proposed experiment for “gravitational diffusion” - In the weak limit where gravity can be treated classically the strength of the coupling precludes any measurement of the effect of gravity on quantum decoherence, say over thermodynamical decoherence effects, even at low temperatures. Feynman had some solid examples in his lectures on gravitation, which is cited in the papers. For a gravitational perturbation on atomic dynamics, observing gravitational effects on the wave function phase would require a time equal to 100x the age of the universe. Gravity does not affect phase coherence in quantum systems in the weak limit. One can try to change that by introducing an unconstrained stochasticity as Oppenheim seems to have, but this would generate paradoxes beyond what he complains about from semiclassical gravity.

@29:00 ok, but what I still find hard to grok here is why you need the stochasticity. Aren't you (implicitly?) _assuming_ gravity is well-described by gravitons? But that's not classical GR. Gravitons in GR are highly dispersive, and weak little blighters. To account for large scale gravity field effects you need the global spacetime of GR. This is what you're testing with the Feynman--Aharonov gedankenexperiments, right? But the classical GR fields is not a graviton, it has no particle-wave duality, it is all wave. So can superpose. So there's no inconsistency. I mean... right? The whole issue with which-way information from the EM fields was an issue only because the field is *_not_* a physical field, it's photons, which cannot be in superposition if they are classical particles. But they're not, and we know how to quantize the EM field --- namely with photons! We do not know how to do this for gravitons. And aren't Oppenheim's group saying there are no gravitons? Because GR is the thing! Feynman's argument was the interference when gravity is significant for giving up which-way information implied the gravity field has to have a "complex" amplitude (a non-classical probability amplitude). But surely that is only the case if gravity is the exchange of gravitons. If not, if gravity is spacetime curvature and gravity waves, then they _can_ be placed into (classical) superposition just like a hypothetical classical Maxwell-Faraday field. Then classical gravity defeats Feynman, no? I mean, help me out here! Imagine light was not actually photons, but pure Maxwell-Faraday waves. Then interference would not be a problem, it'd be classical. Similarly for firing probe light at diffracting electrons or neutrons or whatever, the classical light could not give you which-way information if in superposition, which classical light can be. But we know light is non-classical by other means, precisely because even when probing for which-way information, a large enough photon wavelength will fail to distinguish which way, regaining interference. What this means (imho) is the test should be of a different type. Not for stochastic gravity, but for superposed gravity waves (a very delicate experiment to be sure, impossible with current technology). I mean, do all test feasible of course, but if the stochastic gravity test fails, try the other. Implicitly here I've been assuming realism, that is, an electron or any other particle quanta, subject to two-slit interference or the like, does in fact go through both slits. It's a sum-over-histories type of realism. If that's the way QM works, then the _classical_ gravity field is non-zero around both slits, giving no immediate which-way information. That also means, to truly check for quantum gravity you're looking at the ultimate experiment: interfere actual gravitons (not classical gravity waves). Since Dyson and Feynman argued gravitons can _never_ be detected, this casts a terrible shadow over experimental physics, if this is all the case. Meaning these dodgy indirect test are likely all we're ever gonna have to test theories of gravity.

The audio is missing on this one until 3:00.

Fantastic work, thanks for sharing

So if there is an upper limit on the coherence times of single particle quantum states, or if there is a lower limit on how quickly you can measure the gravitational field, those findings will prove gravity is both classical and stochastic?

I remember that part of Bohr Einstein debate was about a moveable slit and that the particle will influence the slit and thus the uncertainty principle has to be included for the slit. Is this part of the discussion?

its not opposite rotation. its a mirror, a reflection.

There seems to have been a persistent aversion to the complex nature of the wave function among pioneers of quantum mechanics, rooted in their desire for an entirely physical formulation of quantum physics. The fact is, however, that the quantum wave function does not exist in 3D physical space, but is defined instead in complex-valued Configuration Space, an abstract domain of potentially limitless numbers of dimensions. In order to derive physically observable manifestions of the wave function, Hermetian operators must be applied to the Schrodinger equation to produce measurable eigenvalues. A key property of these Hermetian eigenvalues is that they are always real-valued quantities, indicative of solutions that can be manifest in physical space. Of course, the probability densities of these solutions are given by the conjugate square of the wave function, which likewise always produces real-valued results.

hello sir, i need the mathematical proof of entanglement. Proof of G^pE at 11:26 in the lecture

electroatoms ❤

Very important issue for all of us teaching STEM.

Funny they just released a photo of quantum entanglement and looks similar but you guys have it from 10 years ago

There's a "grey" space around this particle. I want to know what haves inside this space....

So why does it look just like the yin yang symbol

Intro / Setup: 0:00 Start Talk: 2:07

Start of the talk 1:34

this problem is solved by the Paddy's approach

Amazing stuff.

“You wanna clean that up when you've finished praying to it?”

Is this Jada and August up close?

All versions / interpretations of QM are non local, at least in the " weak " sense ( i.e. that's compatible with Relativity). Some alternatives ( like Bohmian mechanics) are non local in a stronger sense ( they require some preferred reference frame, so , " behind the scenes" they're not really compatible with SR, although this characteristic does not have observational consequences, at least given some assumptions about the statistical distribution of the Bohmian particles). So far, so good. But I disagree about Everett: It's also "weakly non local" , just like the other interpretations of standard unmodified QM. It doesn't matter that the wavefunction doesn't collapse. Locality is, by definition, a "property" of the physical 4-dimensional Spacetime, not of abstract mathematical multi dimensional spaces.

cannot see blackboard at 24:00

🤷 *Promosm*

decoherence is when the information contained in the wave function gets smeared out by environmental noise, or factors not considered to be inside the system of interest, and therefore results in some information being lost, and therefore a reversibility. blackholes as you have them here destroy correlations across the boundary, by preventing any ordinary reversibility, therefore erasing information relative to the outside system. all that said, the results elucidated here make perfect sense and should be seen to be intuitive by all members involved -- they are probably intrinsically skeptical of young people presenting new ideas lol.

19:10 That " dotted line " prof. Curiel is referring to, is a Cauchy horizon. A spacetime with a completely evaporated ( no remnant ) black hole is non globally hyperbolic.

I do see a simple "solution". We can all observe and set possibilities. That is, if I observe "spin up" and you observe "spin down", the alternative is identical, as in, it makes not physical difference the spin direction, but it does our correlation between them. As our correlation is a different physical interaction, we can have a nested observer setting some spin directions (cat alive or cat dead) while others are not set (the sum of observing the room with the scientist). As the scientist sets some spins, but not all, we should find a solution between us that agrees, even though some observations may not.

Yes, that was a lot of bullshit. :-)

Scientific realism is bullshit. End of story.

Real time?

Although Weyl training was on these mythical aspects, the infinitesimal transformation and Lie algebra, he saw an application of groups in the many-electron atom, which must have a finite number of equations. The discrete Weyl-Heisenberg group comes from these discrete observations, and do not use infinitesimal transformations at all, with finite dimensional representations. Similarly, this is the same as someone trained in infinitesimal calculus, traditional, starts to use rational numbers in calculus, with DDF [1]. The similar previous training applies in both fields, from a "continuous" field to a discrete, quantum field. In that sense, R~Q*.

And this is why philosophy has been bullshit since 500BC. ;-)

hola. totalmente de acuerdo

so... uhm, why entanglement only works with photons? why never an actual particle has ever been entangled? and i am not talking about none of those fake particles, like leptons muons and alike, i'm talking about actual particles, like atoms that exists in the real world, and not just in "quackum physics" fantasy world

Awesome talk. I wish the second example was available. Any possibility of getting the slides at least?

Thank you for this talk!

I still didn't get it

that is much better, amazing experiment.

Interesting, would be cool if you showed how everything works.

excellent talk!

This is very interesting, but the questions/ remarks from the audience are barely audible, unfortunately..

1:03:00 There are some serious problems here for pilot wave theories : Absolute simultaneity and preferred foliation do not fit with Relativity. What defines , physically, this supposed absolute rest frame? Also, spacetimes with fully evaporating black holes are non globally hyperbolic. It's interesting that in Pilot wave theories this explicit non locality cannot be used for superluminal signaling, but the breakdown of causality/ relativistic locality , even " behind the scenes" , may have consequences for the rest of physics and also being in tension with observations. Besides all that, this was an interesting and well presented talk.