Stern-Gerlach starts at 40:00

Teacher Barton, orgullo peruano.

Very good explanation and flow. Thank you MIT and Sir.

57:00 point particle. THE MOST IMPORTANT FRAGMENT about "classical image"

Thanks MIT for this class

Orgullo de UNI, saludos desde Perú.

@1:03:20 force goes in the direction that makes u.B grow the fastest. That is what gradient means.

Excellent Stern-Gerlach explanation.

I yell wow several times during this lecture, Thank you sir.

ahhh memories of 8.04 lecture #1

40:00 - Here starts the explanation about Stern-Gerlach experiment

Could anyone help me out at 34:12 when he said p(hat)ψ(p)=pψ(p)? I know ψ(x)=FT(ψ(p)) and p(hat)ψ(x) = FT(pψ(p)), but I think p(hat)ψ(x) = p(hat)FT(ψ(p)) ≠FT(p(hat)ψ(p)). So how could we let the p(hat) penetrates the FT integral which clearly contains exp(ipx) term? Thanks.

Just 😂 realized that there are transcripts of the entire lecture in the show notes. Very very helpful for us newbies👍👍😎

since Sz/hbar equals 1/2, why we introduce the fuge factor (Lande g factor 2)? Why not cancel them together and give a Sz=1hbar? Where will this cause problem?

thank you very much sir . it's very helpful 😊

UNI Perú present

Very nice teacher, he teaches word by word.

Un orgullo para mi, ver a un peruano enseñando en la universidad mas prestigiosa del mundo.

Has anyone tried Stern-Gerlach experiments using filings from a magnet? Do we get the 1:09:52 type smudge?

Thanks. Would've failed my project without this video

It is my understanding that in a sequential experiment you indeed get two results from one beam. So which is it, because this is crucial information.you are first to explain inhomogenous. tysm.

58:36 IMPORTANT: for the proton, 58:53 neutron, these are "clues" that are "composite"

thankyou so much...

Thanks!

UNI is proud of you Barton, String Theory ace.

g for the electron is not actually exactly 2, i think it would've been a better idea to state that and actually say g ispredicted and have been measured to be 2.00231930436182 The simplest approximation one can give for that is 2(1+2pi/a) where a is the fine structure constant

At about 1:13:00 he describes what they think is happening, let's see if I have this right: This means the entire silver molecule all 1.79E-25 Kg of it is superposition of Up/Down because of the 9.1E-31 Kg electron (a difference of 200,000:1 in mass) and so with the collapse of the probability wave of just the one valance electron the entire atom collapses and becomes “real” in one of two places separated by over 1.3million atom lengths. Can anyone with Phd after their name confirm if I am understand this correctly because That's one heck of a spooky action at a distance?

what is the dimension of the matrices for x and p operator considering N as arbitrary? is it infinity?

ok here's my question .. concerning stern-gerlach sequential experiment ... stern-gerlach used silver atoms right? not just electrons which is what I always hear spin referenced to. who replicated the experiment with only electrons? and has anyone combined the double slit experiment on the electron with the stern-gerlach sequential experiment ? what happens if instead of taking only one of the outputs of the stern-gerlach you take both out simultaneously into 2 parallel stern-gerlachs?

Thank you so much Sir...

These are really excellent!

1:15:34 spin states, bases and superpositions 1:13:00. 1:13:32

I think that an electron has shift in coordinate (1/2π)msλ in r-direction. [ms: spin quantum number, λ: wave length] Accordingly, the angular momentum is as follows: {r+(1/2π)msλ}p=rp+(1/2π)msλp=rp+ms(h/2π)=L+S. (De Broglie equation: p=h/λ) And the magnetic moment is as follows: (area)･(electric current)＝{πr^2+2πr･(1/2π)msλ}･(q/m)p/(2πr)=(q/2m)pr+2(q/2m)ms(h/2π)= (q/2m)L+2(q/2m)S. Thus, we can know that the g-factor for spin angular momentum is equal to 2. I'm sorry that I'm not good at English.

Nice sir

Thanks 🤍❤️

This man really loves physics!

Stern Gerlach Experiment: 38:55

If every Ag atom have a magnetic random oriented magnetic moment (as a classical magnet), when entering the SG experiment they will be reoriented by the magnets with 50% chance up or down just because they starts randomly oriented, and then flying through the SG experiment it will be deflected up or down given this new reorientation. Then if another SG experiment is introduced for just one of the outputs in the same orientation than the first one, since incoming Ag atoms are all up or down oriented they will have only one output. Now, if the second SG experiment is aligned in a perpendicular direction, again is the same effect that starting with random Ag oriented atoms because just for slightly small differences they will be splited in one or another orientation with 50% chance. With this, considering that I am just throwing classical magnets the results have no mistery in a classical point of view. So I don't understand why they starts with the confussing Spin explanation, when actually it is not required (it could be another explanation too, given that the experiment have completely logical results from a classical viewpoint). And it is the quantum Spin model what introduces all the counterintuitive phenomenas in the SG experiment explanations. So my question is, ¿why is never considered that the Ag atoms reoriented themselves when facing the SG experiment magnets?? Surely must have an explanation, smart people doing quantum surely have think about this before. So, if I replicate the SG experiment in ^z direction and then blocking one of the outputs, and then I place another SG experiment, but sligthly oriented like (75°^z + 15°^x) direction... ¿the output will be again a 50% chance split in +/- 1/2 spin direction?¿or it will have a much bigger concentration in the ^z direction as if Ag atoms are just classical dipole magnets??

very very 10^10 Beautiful

Barry Z. is the GOAT

Love from India

I bought Dr Zwieback's new book on QM. Very good.

What happens when we let 100km between the 2 magnet splitters ?

At !:56 the [INAUDIBLE] subtitle should be diagonalisation

Why does the magnetic field needs to be inhomogeneous in the SG experiment? It’s all a bit hand waving in my view.

I have spent twenty years researching Stern-Gerlach experimental outcomes and their association to electron spin. It is based on a new concept of Magnetic Polarity and Magnetism which transforms an atom from a hypothetical structural configuration, to a real and actual physical entity that accurately depicts each and every known property associated with atomic orbital structure; such as shells, energy subshells, electron spin, quantized energy states, orbital priority, orbital configuration, hybridization, magic number elements, electronegativity, atomic bonding, and much more. Admittedly; it may be claimed that these "SLA" Theories simply confirm existing known features of atomic structure; but they do so based on scientific reasoning which predict, not only the distinct characteristics of an atom, but also the properties associated with those characteristics. In other words; the "SLA" Theories explain how and why these characteristics exist. Proof comes in the form of Stern-Gerlach experimental outcomes! In that these unique theoretical concepts actually predict each of the inconceivable Stern-Gerlach experimental outcomes; thereby proving that spin can alternate between opposite states, and that these states are indeed quantised. In other words; the research which is soon to be accessible on a website, and published in coming weeks, is in total agreement with the Stern-Gerlach experimental outcomes. These so called "SLA" Theories are basically a rule book that justify each and every known feature of an atom. But when that rule book, accurately predicts, not only the Stern-Gerlach experimental outcomes; but also predicts the numbers of isotopes of each element of the Periodic Table; then it is time to take notice; for this does not fall within the realm of existing scientific reasoning. This is a world first; which does not only predict numbers of isotopes, but explains why they come to exist. The research is quite extensive, encompassing 194 pages of notes, incorporating over 62,000 words, and many illustrations; having taken over twenty years to compile. The findings are far too lengthy to contemplate even a concise entry in a comment section of KZfaq. I sincerely believe that science will accept my findings in their entirety, for they are near enough to perfect; and there are far too many revelations on many fronts (Magnetism, Atomic Structure, and Stern-Gerlach experimental outcomes), for it to be a coincidence. I apologize for the lengthy detail of this entry, and am not sure if it contravenes any KZfaq rules; but it is a means by which to seek professional academics to review my findings. Interested professional academics are welcome to contact me (Charles Lafcharis) on , and I would gladly send you relevant segments of the research article, or even in some cases a copy of the publication in exchange for a peer review of my findings.

Took me a while to find the whole in this experiment. Not a spooky as it seems, still have to go through all the experiments however the results make absolute sense once one assumption is removed. Assumption, the electron is causing this effect. What about all the up and down quarks? Do you think that maybe they have something to do with this? Here is how it would hypothetically work; Every Atom has an electronic field in it, not unlike the earth but probably more complex with quite a few polls depending on how many neutrons and protons there are. In a beam the atoms become entangled up and down, once they hit the magnetic field the up oriented will move one direction and the down oriented will move the other; however once out of the field they will reorientate themselves. Then when they hit the new magnetic field the process starts over again. That would also explain why Neutrons have a "Spin," even though they are neutral. They still have a field, however the total sum is zero. The same with atoms, they have fields and unless they are ions, their total magnetic field is zero.

5:39

17:03

The idea of a "point particle" is the definition of what illogical means. Point particle is defined as dimensionless particle - no volume or surface area. If it lacks volume and dimensions it simply does not exist.

👏👍

Estaba chevere la clase , pero el detalle es que no se inglés

Barton made in Perú

What is quantum?

zeeman effect

Waaawaaaweeewaahhh

Q-mechanics people are forever confusing filters with re-radiators or devices that otherwise modify the stream. Then they claim it's some sort of unknowable miracle or 'collapsing probability function.' In this case, the magnet aligns magnetic-moments, such that the entering beam is very different than the exiting beam. Beam entering is random, beam exiting is aligned in '±z' and when '+z' is put through 'x'-magnet, beam's re-aligned in '±x.' So when beam exits '+x' and enters 'another 'z-magnet, of course half go '+z' and half go '-z.' Why? Because these are not "filters," they are "beam re-directors" or "beam modifiers." Same thing happens with polarizers. Polarizers are not "filters," they are "re-radiators." When calculated as such, the 'uncertainty' suddenly disappears.

Triste saber que esto solo les importa a los skin humilde 🤣

Most badass accent ever