This is brilliant. This professor explains things extremely clearly.

Que nivel de clase de este profesor . Orgullo peruano .

Barton, el único estudiante en la historia de la UNI que se graduó antes de terminar su carrera.

Besides the wonderful clarity in his lecture, I am amazed at his very clear, beautiful, and organized writing on the board.

El mejor alumno de la historia de la UNI.

Great Teacher. Takes time and explains well. Defined indeterminism very clearly.

A good university isn't just made by the sum of their students' success but by the ability of their professors to teach and simplistically explain complexity!

Such amazing job Mr. Zwiebach! Thank you...

This lecture has nothing to do with me but I became entranced with his style and voice! And I actually learned something new in quantum theories. Thank you Sir.

Well spoken with excellent handwriting. A rarity among physics professors

Thank You for making it understandable !! I am a software engineer in network domain. I just watched these videos(first 4) out of curiosity, and I was able to understand a rough picture of what's trying to be conveyed. Last time I studied physics was in pre-college days.

Brilliant lecture given by Barton Zweibach Sir .....

I definitely agree when you mentioned that it's good to learn from physicists and it's useful that we have them, it is good to make new explanations for what comes next.

"That's what polarizers do for a living" :)

Thank you MIT and sir. Wish him long life and happiness.

This exposition is as clear as can be

thank you MIT, thank you sir, and thanks to whole staff there.

"It's a debacle! A total disaster!"

Good and clear teacher. Good tempo and very to the point.. Absolutely well done and definitely keep it up!!! .

What a wonderful teacher you are, if I may say so. Thank you for sharing this lecture with the public. 🤓

Well spoken with excellent handwriting. A rarity among physics professors. Maravilha de aula! Eu diria um pacote de fótons de aula! Parabéns!!.

there's something about writing on a chalkboard that just makes it much better than presentation slides as a teaching medium for showing equations

I can tell he is a good teacher because I understood this little "lecture" better as when my teacher taught me the same subject, even if my teacher spoke my first language (french), and this teacher speak english, that is harder to understand for me.

Man, I just enjoy listening to his voice....

Maravilha de aula! Eu diria um pacote de fótons de aula! Parabéns!!

Wow, clearly explained and at a pace I can work with. Gonna be watching more of these.

Good and clear teacher. Good tempo and very to the point.

I really like his handwriting This looks so passionate

What are all the physical processes (besides the behavior of polarized photons) that are non-deterministic? Is radioactive decay non-deterministic? Is there a complete list of non-deterministic processes somewhere? Are all non-deterministic processes somehow the same process at their core?

Well, the bell inequality just shows that you cannot have both a local and hidden variable theory combined. If you have a hidden variable theory, it has to be non-local, and if it's local, it has to not rely in hidden variables

Wow !...A professor who writes cursively ! 🎊🎉🎊

Thanks for the lectures!

Merveilleux cours de physique ! Merci de partager toutes ces explications si claires 👍

Now I understand What entanglement actually means ! Extraordinary explaination

La leyenda de la UNI-PERU , Barton Zwiebach👏🏻👏🏻👏🏻

Absolutely well done and definitely keep it up!!! 👍👍👍👍👍

What a lovely man. So calm and precise. I remember being introduced to Imaginary numbers at school. POW. Mind blown. Two years later in college, they're vectors. Oh. Why didn't they say that ? On a par with year 2 maths class. Ok. Let's consider n. n is any number ! Pow. n is clearly a letter. Dropped out of the top maths class soon after. Got back in again though. Just the whole year missed and forever holding on by my finger nails since.

This professor is one of the best

Wow. The universe it truly random. Thank you.

These lectures are awesome!

Si estuviera traducido al español, seria genial. Excelente Profesor. La UNI siempre destacando.

just now found this by chance - he is excellent. if they make a movie about him, he would be played by Dustin Hoffman.

De los mejores profesores de física.

So with respect to Linearity discussed in previous lectures, Beam of photon should be described as Beam |photon_alpha> = a * cos_alpha * |photonX> + a * sin_alpha |photonY> Where a is some constant

A great speaker. An inspiring video.

There is a difference in the way of thinking of the inequality sign (or information bra-ket) when we see light as Einstein inertial system and when we see light as quantum entanglement information. Is a very effective inertial vector. In quantum information entanglement, since it is not an inertial system, it is considered as |photon:〈xψy〉:photon｜, and it is an information system that should be distinguished from the inertial system, but (photon:ψ>)=(photon: :ψ〉), the optical inertial system and the optical information system are equivalent. This is an important lecture from the perspective of consideration.

Hello Dr. I am 12 years and this video was great , and I wish to be more specification and harder. Thank you

Prof. Zwiebach is actually very good, but for any "not perfect English speakers", it was absolutely necessary the presence of subtitles....in English! Anyway, thank you for the lesson and greetings from Athens, Greece.

Absolutely brilliant. Thank you for sharing.

excellent explanation ! Congrats, professor !

Thank you Barton Zwiebach and MIT.

Wow, this takes me back to undergrad QM. Sets good foundation for QED. Well done professor!

I appreciate the fact he is saying what actually happens with the correct terms, instead of abstracting it all away. I watched a similar MIT lecture but the professor was using terms like "color and hardness" to avoid "confusing us" but for me it made it really hard to picture anything in my head and follow along cause electrons don't have "color" or "hardness" in the classical sense

Excellent lecture!

Looks like Harisson Ford

Glad you figured out that determinism is voluntary.

This must be the best lecture on loss of determinism on the net, much thanks.

This professor was a former student of one of the best universities in Latin America, the prestigious National University of Engineering (Peru). He was not your average student or teacher. He is a living legend, a GENIUS. Feel privileged to receive their knowledge in your country. Saludos 🇵🇪

Great explanation

Love this I enjoy it even though I not ready for this

11:00- Really true, consistent with the wisdom there are more unknown unknowns than known unknowns. 15:25- This statement makes the superposition concept a bit easier to comprehend.

So energising a lecture ! Wow

Nicely done.

Barton Zwiebach the genius from Perú.

Great lecturer, thanks for posting this

Now I know what good teaching is. This is a strange world where we know so much but are somehow missing the point completely.

Excellent professor

Grande Zwiebach, recuerdo que nos metiamos unos dotitas en el lab despues de los finales

It's nice to see MIT still using chalk boards, very OG.

The funniest lie ever; if they cannot determine it, then the determinism is lost. The amount of grandiosity of the title of this video is ultimate; despite it appears to be super humble.

are coefficients cos (\alpha) and sin (\alpha) sort of fitting parameter then? or do they have a theoretical origin given alpha is the state prescribed to this classical state of polarization?

great lecture always great onlyyyyy.......hands offf

Very good lecture Sir. Thanks 🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏

Brilliant indeed!!

It's important to point out that when the polarizer is aligned at some "middle angle," then the light that comes out is NOT identical to the light that went in. Not only does only a fraction of the light come through, but that fraction now has polarization aligned with the POLARIZER, not aligned as it was going in. The polarizer "turns" the polarization angle so that the outgoing light is aligned with it. This raises the fascinating situation where you can put two polarizers at perpendicular angles together, and no light gets through. But if you then slip a third one in between the first two aligned at, say, 45 degrees, then suddenly some light does get through.

Very nice presentation of a very confusing reality.

the clue is in the title guys - Open Course. For anyone who wants to watch. And you've got to be pretty good at your subject to explain quantum physics so that anyone can even approach understanding that!

Totally concept clear from this lecture.

The figure in this explanation would be better if shown in three dimensions. The professor’s explanation describes a plane wave oscillating in a plane parallel to the z-axis at an angle alpha to x--z plane. Then the closer the plane of the wave gets to the x-z plane, the greater the transmission of the wave through the polarizer.

He is very good teacher…

Good Job Professor

Thanks sir for this beautiful lecture from India.

quanta was energy unit measurement. if we can program photon in twisted wave guide. is there two type of frequencies minum to have light so should it be Frequency**2 ) * wavelength= speed

Great lecturer

Amazing!

Does anyone know what experiments he is referring to when he mentions people have ruled out the argument "It is the unknown subatomic structure of the polarizer that determines which photos pass vs are absorbed?"

He said that hidden variables are not possible, but bells theorem says local hidden variables. Nonlocal ones can exist

_Reminded me of _*_how entertaining physics really is!_*

Barton

He is brilliant

Porfesor Barton, alumno de la UNI - PERU.

Even Bell himself didn’t think that he proved the impossibility of hidden variables. Travis Norsen: in his book (titled ‘Foundations of Quantum Mechanics’) says: “There is a kind of rich and tragic irony here, in citing Bell as having supposedly refuted hidden variables theories …, Bell’s theorem was actually inspired by Bohm’s 1952 pilot-wave theory papers, and indeed Bell remained far and away the pilot-wave theory’s greatest champion until his death in 1990.”

If all my teachers are this good at explain8ng, I might have turned into a professional student.

yara causa gaaaaa rico lecture outstanding professor of my homeland 🇵🇪🇧🇴🇨🇱

How do we build polarizers ?

at 15:35,why is have we multiplied cos(alpha) and sin(alpha) separately?

When he says the energy is proportional to E squared, isn't there a magnetic term "B squared" to take into account ?

So... does that mean photons are constantly changing states, (polarization but not frequency?), before they are measured, because they exist as a wave function? Is that why when sent through one at a time all go through or none do? Moreover, why is it that when polarized light is sent through three polarizers, at right angles to each other... some light gets through? Is it because since it is not measured, some photons in the wave state change polarization between polarizers? Then why do three allow passage but two block all light? Plus why is it a wave function rather than a matrix of possibilities?

Increíble un ilustre Peruano haciendo patria en el extranjero.

If the photons weren’t identical or the polarizer was not perfect and influenced the photons you would get very different intensities for the same polarization angle.