Knowing that this man is teaching despite having BRAIN CANCER ........stirs great(est) respect for you SIR...
@adscft7597
3 жыл бұрын
How did u know
@bunny4173
3 жыл бұрын
@@adscft7597 Check the description of this channel....
@adscft7597
3 жыл бұрын
Wish the best for him
@JoeHynes284
2 жыл бұрын
and this is when the cancer was unknown to him, just growing
@joelcurtis562
4 жыл бұрын
The Atiyah quote he shares at the end is: "No one fully understands spinors. Their algebra is formally understood but their significance is mysterious. In some sense they describe the 'square root' of geometry and, just as understanding the square root of -1 took centuries, the same might be true of spinors."
@jamescook5617
5 жыл бұрын
Love the style and general idea of this sort of lecture. Great work. Minor correction, maybe it even was made in the video and I missed it, but in a Lie Group only the part of the Lie group near identity can be written as the exponential of a Lie Algebra element. Products of exponentials will generate the connected component of the identity. However, generally, a Lie group can be disconnected and we'll need something more than a matrix exponential to write the non-identity components of the group. For example, the orthogonal group O(3) has determinant 1 and -1 matrices and those form sets which are disconnected. Physically, the determinant -1 give orientation reversing transformations whereas determinant 1 give rotations which preserve right-handedness of triples...
@timduncankobebryant
2 жыл бұрын
Professor James! nice to see you here as well. Your lectures are also awesome!
@jholsapple2918
8 ай бұрын
I see that Alex passed away. I've only watched this lecture --- but I am sure the others (which I will watch) will be just as informative and inspiring. This mentor's passion is remarkable and rare. He light shined briefly --- but no doubt very brightly for his students. One hopes the past is solid and real and Alex is eternal.
@AnnevanRossum
4 жыл бұрын
I haven't watched the previous lectures in this series, but you've a very pleasant style of communicating to the students. They are definitely not afraid to engage and it has a nice cliff hanger on spinors. Very warm, very welcoming. Thank you!
@md2perpe
7 жыл бұрын
*The Group Norwegians* The adjective 'Abelian' is named after the Norwegian mathematician Niels Henrik Abel. And 'Lie group' is named after the Norwegian mathematician Marius Sophus Lie.
@md2perpe
7 жыл бұрын
Off topic: The first Secretary-General of the United Nations was Trygve Halvdan Lie, also he Norwegian. But I don't know if he was related to Marius Sophus Lie. (Probably he was, but distantly so.)
@yacinebenaida4094
6 жыл бұрын
excuse me sir,what does it mean ''manifold''
@lucasthompson1650
5 жыл бұрын
yacine benaida I just know that if you replace the intake manifold on a 1972 Buick Skylark with a Calabi-Yau manifold, you also have to switch from "unleaded" to "Ricci-flat" or you're screwed. 🤔
@luisgeniole369
4 жыл бұрын
I always wondered about that, thank you
@MrBorderlands123
4 жыл бұрын
You forgot about Sylow.
@qwadratix
8 жыл бұрын
Just found these lectures - I love the style and presentation. He leads the class so well that you feel all the time a couple of steps ahead of where he's going. (Does that make sense? :D ) Wish I'd had this quality of tuition when I was a student.
@TaylorSaunderDrums
4 жыл бұрын
I was just about to post the exact same comment lmao... this guy is like the Prof. Leonard (another great) of graduate level mathematics
@timelsen2236
8 ай бұрын
Full bodied approach is great!
@lexusmaxus
4 жыл бұрын
No Morgan Freeman could not have pulled off this level of explanation
@josh34578
3 жыл бұрын
Really interesting, clearly presented, and well developed lecture!
@donnalee3368
3 жыл бұрын
Prof. Flournoy, is it possible to change the angle a little bit in such a way that the camera captures the full black board in the straight manner? Right now, the left side, from the perspective of the black board reflects quite a bit.
@paulisaac3489
4 жыл бұрын
I love learning, thanks, subscribed.
@tomsmith6878
5 жыл бұрын
It's so weird to me that this is a 3rd or 4th year university physics course, but he says things like 'you might know the definition of cosh(theta)' and 'in case you've forgot, i is the square root of minus 1'. Any Americans out there; is this typical?
@zoltankurti
5 жыл бұрын
@DY_Physics joking about students not knowing basic differential geometry (tangent vectors to the group at the identity) is still really bad.
@jamescook5617
5 жыл бұрын
It is sadly typical for hyperbolic functions to be downplayed in American University calculus. There is tremendous pressure to dumb down university courses and little pressure to maintain excellence or scholarship in many locals. Of course, in his context, it may well be a joke. As a point of personal experience, I don't think cosh or sinh was mentioned in my calculus although I champion their utility now in my own teaching.
@jmckaskle
5 жыл бұрын
James Cook You learn about imaginary numbers and hyperbolic functions in highschool.
@jamescook5617
5 жыл бұрын
@@jmckaskle we certainly should do that. But, all too often parents and administrators and students lobby for medocrity for the masses. It doesn't seem to bother them that those most deserving of knowledge have to seek it out as if it was countercultural in school. It's a shame. One size fits all makes us dumb.
@amalks8676
5 жыл бұрын
B
@tw5718
4 жыл бұрын
Is there any way you could post homeworks and answer keys? I know I would appreciate it and assume others would as well. If its too long ago or there are other reasons I understand.
@venkxjk5992
21 күн бұрын
Prof Alex Flournoy is no more.... RIP Alex Flornoy
@kazdono8646
5 жыл бұрын
Pfo,so cool. Like the Iron man.
@nishantjangid7004
4 жыл бұрын
Sir,you must have your telegram group for students
@burbanpoison2494
4 жыл бұрын
I don't know why anyone would herd sheep into any waters at all, let alone troubled ones.
@chimetimepaprika
4 жыл бұрын
Somehpw I always end up calling it the CEVI LIVITA.
@ocularisabyssus9628
4 жыл бұрын
Now I want to punch Robin too!
@meofamily4
Жыл бұрын
He lost me with the multiplication table @12:27. An odd number times an even number is even. An odd number times an odd number is odd. Oh, a minute later a student called him on it. --wow his reaction wasn't very helpful, since the operation with even-odd is addition, and the operation with + and - is multiplication. It's hard to associate two groups as identical when subjecting them to two different operations!
@pezicmalamute5227
4 жыл бұрын
Do you guys like my new harmonic oscillator? I made it from three generators instead of two :) H = (1/2)kX^2 + (1/2m)P^2 + (1/2)gF^2
@nishantjangid7004
4 жыл бұрын
Can you explain it?
@pezicmalamute5227
4 жыл бұрын
@nishant jangid Hola. It's the hamiltonian for a harmonic oscillator. The first two terms represent position and momentum, but the eigen (energy) values always go like (1/2 + n) n=1,2,3... so it's never zero with two terms. The third term I say is Force because why not? Position, momentum, force are all just extending derivatives in time. But as it turns out the third term is the Pauli spin operator and that let's you take energy down to zero. Which is cool because you'll have uncertainty if your energy is not zero. I don't know why we only use position and momentum as equation of motion for ALL oscillations.
@nishantjangid7004
4 жыл бұрын
I want to invite you to a whats app discussion
@joelcurtis562
4 жыл бұрын
The students should wait until they know enough to ask helpful questions. He's wasting lots of time addressing irrelevancies. Trust your instructor to show you what you need to know!
@mattlitton1255
4 жыл бұрын
I think the students would benefit from a first course in abstract algebra, a lot of these questions would be very quickly covered there
@an2nkr
4 жыл бұрын
Yes! You should definately not ask questions if you feel confused during a introductory group theory lecture for undergrads. My god that could send a honest signal about your current understanding to the professor, and worse to your fellow students who might sigh from all the time wasted. Not to mention all the people watching on youtube whose time you are wasting. Remember that the course is for them not for you who paid tuition (stupid student). I'll even take it a step further: I think the course should preferably only be taken by people already fluent in the thought structure of groups and representations and any non helpful-comitty aproved questions (that the professor obviously ironically said you were welcomed to ask) should, if not by you yourself, collectivey be squashed before uttered by an agressive student culture. Everyone becomes a better student with a really harsh an elitist learning enviroment.
@HilbertXVI
Жыл бұрын
@@an2nkr Lie groups and Lie Algebras are very far from "Introductory Group Theory" lol
@bunnybro5977
3 жыл бұрын
Guys, is it just me, or us this guy kinda not a great lecturer. Like he's good, but you have an underlying feeling that he didn't do any preparation for anything throughout the semester
@timelsen2236
8 ай бұрын
I disagree. He made it very clear even using non-trivial examples without going off into axioms and definition based proofs. They are very non transparent. See ABSTRACT ALGEBRA for example. This is a GREAT PROFESSOR , your lucky to have digesting hard subjects for you. BRAVO, BRAVO AND HATS OFF.
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