This guy just loves Physics. Walter Lewin, Barton Zwiebach, Allan Adams, etc. You can't even choose one out of these people. All of them are pure gold! MIT is one crazy institution to house all these professors.
I fell asleep watching something completely different. Woke up to this, immediately went back to sleep with this in background, felt like high school again. Best sleep ever before my janitor shift.
I can't put into words how strongly the "spinor demo" at 1:00:00 makes me think that those particles must have some sort of "connection" to other parts of the surroundings. Because look - when he did that his HAND *did* come back to the same state. It was his ARM that didn't. And it was his ARM that got back into the right state after a further spin around. So it seems to me like something beyond the spinor itself is required to "implement" that behavior.
spinors and other objects are connected to surroundings because we measure them with respect to surroundings (coordinates). I have the same feeling because after a full rotation these objects “remember” they have been rotated. like a tether. strange objects
17:46 this equation is confusing. The expectation value of x squared normally is not equal to the square of the expectation value of x. h^2m^2 is the square of the expectation value of Lz, however h^2l(l+1) are the expectation value of Lx^2 Ly^2 L^2. They are not self-consistent.
I think you are saying he's missing the variance term. However, there is no variance in the expectation of Lz, precisely because the state is an eigenfunction of Lz!
Can anyone tell me which file is the mathematica package prof. Adam was talking about? I have visit the course website's "Study Materials", but could not find it.
No one will probably answer before I finish my degree, but how come there are non-zero values for the Angular momentum in z for the state Y_20 at 1:18:48? It seems to me that m = 0 would eliminate the possibility of this "Donut" forming along the Z axis in the middle.
I tried to think of a answer to your question, so you don't need to wait until you finish your degree, but unfortunately, as a beginner in QM myself too, I don't have enough knowledge to answer that satisfactorily. So I asked this question for you on StackExchange (because I want to know the answer myself too) physics.stackexchange.com/questions/323695/is-there-an-intuitive-interpretation-of-the-shape-of-the-angular-momentum-eigens but apparently no one is willing to answer yet. I had also asked this question to my professor, and the answer I obtained, in short, is "quantum effect". He said that what we are trying to do here is to interpret a quantum mechanical result using our classical intuition, which works sometime for very special cases (like the Y_10) but not in general. After all, one of points of quantum mechanics is to uncover / understand things that cannot be explained by classical mechanics. Hope this help, and thanks for this interesting question.
Thank you for this thoughtful (and unexpected) reply. After reading it I went ahead an asked on Physics Forums myself to be sure, but got pretty much the same answer that the classical interpretation of a spinning particle no longer holds.
Ben Pon I have to admit that my Prof's were good when I was a Physics major. It was I who was too young and non-directed to appreciate them. The fault was mine. It is good to have this man to help me now years later.
Because Ylm(theta,0)=-Ylm(theta,0) when m is half integer. This is equivalent to saying x = -x ==> x+x=0 ==> x=0. Because of rotational symmetry, the same logic should apply by choosing any phi.
Allah is the Light of the heavens and the earth. The parable of His Light is as a niche and within it a lamp: the lamp is in a glass, the glass as it were a star Durriyyun, lit from a blessed tree, an olive, neither of the east nor of the west, whose oil would almost glow forth, though no fire touched it . The exact translation of the saying is, “I bear witness that there is no deity but Allah, and I bear witness that Muhammad is the messenger of Allah.”
I'm starting to think this guy doesn't even like coffee/ the other beverages he brings to his lectures. What's the point of coffee if you're not going to drink it hot?
This guy just loves Physics. Walter Lewin, Barton Zwiebach, Allan Adams, etc. You can't even choose one out of these people. All of them are pure gold! MIT is one crazy institution to house all these professors.
Leonard Susskind.
Badminton Go Yeah, I attended Susskind’s guest lecture in Moscow. He is another legend! But he isn’t at MIT.
Watch the entire lecture thrice, the last time was purely for fun.
I fell asleep watching something completely different. Woke up to this, immediately went back to sleep with this in background, felt like high school again. Best sleep ever before my janitor shift.
love u
I can't put into words how strongly the "spinor demo" at 1:00:00 makes me think that those particles must have some sort of "connection" to other parts of the surroundings. Because look - when he did that his HAND *did* come back to the same state. It was his ARM that didn't. And it was his ARM that got back into the right state after a further spin around. So it seems to me like something beyond the spinor itself is required to "implement" that behavior.
spinors and other objects are connected to surroundings because we measure them with respect to surroundings (coordinates). I have the same feeling because after a full rotation these objects “remember” they have been rotated. like a tether. strange objects
great teacher !!!!!!
There's no nb files for spherical harmonics in MIT OCW.
Spherical harmonics file and Quantum harmonic file
are same .
17:46 this equation is confusing. The expectation value of x squared normally is not equal to the square of the expectation value of x. h^2m^2 is the square of the expectation value of Lz, however h^2l(l+1) are the expectation value of Lx^2 Ly^2 L^2. They are not self-consistent.
I think you are saying he's missing the variance term. However, there is no variance in the expectation of Lz, precisely because the state is an eigenfunction of Lz!
Can anyone tell me which file is the mathematica package prof. Adam was talking about? I have visit the course website's "Study Materials", but could not find it.
Found it?
favorite caffeine fueled professor
2.5M people started but only 50000 came here
@MITOCW can you please make available the lecture notes from lecture 9-24. It would be of great help to the learners like me
This is helpful ❤️🤍
thanks a lot for teaching this problem
I was going to speak intelligently on the angular momentum of quantum particles but my range is too small.
No one will probably answer before I finish my degree, but how come there are non-zero values for the Angular momentum in z for the state Y_20 at 1:18:48? It seems to me that m = 0 would eliminate the possibility of this "Donut" forming along the Z axis in the middle.
I tried to think of a answer to your question, so you don't need to wait until you finish your degree, but unfortunately, as a beginner in QM myself too, I don't have enough knowledge to answer that satisfactorily. So I asked this question for you on StackExchange (because I want to know the answer myself too) physics.stackexchange.com/questions/323695/is-there-an-intuitive-interpretation-of-the-shape-of-the-angular-momentum-eigens but apparently no one is willing to answer yet.
I had also asked this question to my professor, and the answer I obtained, in short, is "quantum effect". He said that what we are trying to do here is to interpret a quantum mechanical result using our classical intuition, which works sometime for very special cases (like the Y_10) but not in general. After all, one of points of quantum mechanics is to uncover / understand things that cannot be explained by classical mechanics.
Hope this help, and thanks for this interesting question.
Thank you for this thoughtful (and unexpected) reply. After reading it I went ahead an asked on Physics Forums myself to be sure, but got pretty much the same answer that the classical interpretation of a spinning particle no longer holds.
at the beggining the subtitles are translating "5" instead of "psi".... btw thanks for uploading this
We think you mean phi instead of "psi" ... but yes, the captions do need to be updated. Good catch! Thanks!
Thanks 🤍❤️
Lecture begins at 6:00
leagues better than my professor at Cal...
Ben Pon I have to admit that my Prof's were good when I was a Physics major. It was I who was too young and non-directed to appreciate them. The fault was mine. It is good to have this man to help me now years later.
I think he speaks way too fast.
@@YesYou-zy7kp Bruh even 1.5x it feels slow......
i find Allen didn't wear shoes。。。。
56:35 why Ylm(theeta,phi)=0 for m is half integer?
Because Ylm(theta,0)=-Ylm(theta,0) when m is half integer. This is equivalent to saying x = -x ==> x+x=0 ==> x=0.
Because of rotational symmetry, the same logic should apply by choosing any phi.
also zero is the only integer that is negative of itself...
Allah is the Light of the heavens and the earth. The parable of His Light is as a niche and within it a lamp: the lamp is in a glass, the glass as it were a star Durriyyun, lit from a blessed tree, an olive, neither of the east nor of the west, whose oil would almost glow forth, though no fire touched it
.
The exact translation of the saying is, “I bear witness that there is no deity but Allah, and I bear witness that Muhammad is the messenger of Allah.”
whats that guy saying at 39:38 ?
I think he said "that's not how it works"
I'm starting to think this guy doesn't even like coffee/ the other beverages he brings to his lectures. What's the point of coffee if you're not going to drink it hot?
usb states
I LOVE YOU!!!!
20:26
39:36 😲
1 + 1 = 2
No, its 11
AL+L+|f> = (a+2)L+L+|f>
Why applause at the end?!
@@charlyGnarly187
Don't you have some toilets to clean?
49;00
I really want to know what happened in ruclips.net/video/R4LyPVfGWtI/видео.html
I think the student said "because that's not how it works"
Or maybe "Because that's not how god created them to be."
Or the student said “It’s on the problem set “ 😂😂😂