Massive thanks, recommended your very well made video to all my classmates. I went from no idea of how to use Clebsch-Gordan coefficients to solving the question of my homework watching your video.
Absolutely marvelous. It felt like I was listening to a piece of work by Mozart himself. The seemless way you explain things and the lucid path you take is like blending of all the instruments in a music ensemble. Loved this so so much. Thank you so much for this. Just subscribed. Hoping for more such videos.
God I wish this video was out when I was doing my masters course on this topic. Amazingly clear video as always and thanks for that cool reference. Looking forward to the derivation video! The whole SU(2) spin theory is something I just never completely wrapped my head around, and I've been meaning to derive from "first principles" for awhile now. This video series will save me the trouble of trawling through a textbook on my own :p
Thank you! Best explanation ever on CG coefficients table. I guess lecturers don't want you to understand it so that you can suffer in silence deriving them lol
@@PrettyMuchPhysics You're welcome! I just checked your channel: straight-to-the-point and simple explanations. I am looking forward to support you and share with my friends. Keep it going ;) Physics student from UK. P.S.: I'd suggest to hire an Instagram marketing service (like on fiverr etc.) or learn about branding, paid-campaigns and that sort of stuff. If well done it works magic.
Good video. It helped me read the information off the table. I don't get why the individual sections of the table are organized in that way though? Couldn't they be separate little tables rather than touching each other? (Take the 1x1 table for example)
In case of the 1x1 table, those nine states on the left constitute one complete basis system of the product basis, similarly, the nine states on top together are the complete coupled basis. Therefore, they belong together. As we mentioned in the video, this should actually be a square 9x9 matrix, but since most of the entries are zero, they are usually left out.
first, thanks for this amazing video, second i want to ask have you made the different videos where you derive clebesh Gordon coefficients , and if yes what is link and thanks
Thank you very much! We derived the CG coefficients for the simplest case (coupling 1/2 with 1/2) here: th-cam.com/video/a6p_8J1QTww/w-d-xo.html Note that this is just for educational purposes, for "real world" calculations, you should refer to a table like the one by the particle data group!
@@PrettyMuchPhysics thanks so much, I really appreciate your reply, but I wonder do you have any video that explains quantum angular momentum L and m ??
How would you find the Clebsch-GORDON coefficient for which the total spin is 1/2 and the z-component of the spin is 1? I couldn't locate that on the table?
The magnetic quantum number (m) cannot be larger than the orbital quantum number (l), that's why there is no L=1/2, M=1 column. In other words, if it's not in the table, it's zero!
Nope. There's a simple difference. The consequence of tensor product will have a multipled dimension dim=dim1*dim2, but the outer-product is calculated by a determinant and will keep the dimension.
@@Andrea-kx3zd If L=0, then the resulting multiplet will be the same as the 1/2 multiplet (since you actually only have one angular momentum, you can't couple anything).
Maybe it helps you that Clebsch and Gordan are not common last names in Germany. I haven't seen these last names a single other time. But then Schrödinger (actually Austrian) and Heisenberg aren't either. Pauli, Born, Stern, Gerlach, Stark are common names.
While I think this video is good at what it does, I cannot help but feel frustrated that even after reading the chapter on this on a Quantum Physics book, reading my professor's notes and watching this video, I still don't understand a thing.
This is a useful video and something that isn't already out there a million times (as most topics of physics related channels are), like your other videos, but I think you are being too sloppy in the notation. You are using a lot of what I call pseudo-math notation. I.e. what you are writing isn't accurate in math terms. You're using = symbols where you should use set notation and "element of". You're just writing a tensor product symbol between (j1,m1) and (j2,m2) at the beginning then an arrow -> that doesn't actually mean anything, you call the tensor symbols "couples to". |J,M> should EQUAL some linear combination of (j1,m1) o (j2,m2). why not write it accurately like this? what's the harm? What you write instead "looks" mathy but isn't accurate. There actually are physicists that do care for having the math straight and who don't like this sloppy way of writing (and it confuses them, because they are trying to make sense of something mathematically and they can't because someone just wrote random symbols). that is really prevalent in physics because a lot of people don't have rigorous math backgrounds and just don't know better, so they use symbols like =>, = etc seemingly randomly and from gut feeling, not according to what they mean.
Good thing this is a physics channel and not a pure math one. What we want to convey is a feeling for what happens physically, the math is just one helpful tool to achieve this goal, next to graphs and diagrams. Our approach is to first understand the underlying physics, and then dabble in the rigorous mathematics. Physics can be performed in several levels of rigor. The more you get to know a topic, the more you can dive into the mathematics, which is something we not only do ourselves, but also definitely endorse. Take quantum mechanics for example. You might agree that it‘s more useful for a physicist to understand the relation between a wave function, the probability density and observables, than it is to first rigorously define the Hilbert space. Rest assured that we do know how tensor products work, or when to use set notation. However, this is a TH-cam video, meant to be a smooth introduction to a topic-and not a PhD thesis.
@@PrettyMuchPhysics I don't understand what the issue is of not writing nonsensical math then (as you did in several places). You should have just written words or drawn a picture rather than use bogus notation that misleads people reading the stuff you've written down. It just sounds like an excuse and a rather thin-skinned reaction to constructive criticism that is obvious and beginner level (not PhD). Most of what you said is beside the point I made. This isn't an argument of making things pedantically mathematical and forgetting the physical meaning behind it.
Don’t get me wrong, we‘re thankful for your criticism! And to summarize: when precise math notation is necessary, we won’t shy away from it (e.g. on our group theory video). But apart from that, we stick to the physicist‘s methods, like treating a derivative as a fraction ;)
That's just how you should use Clebsch-Gordan coefficients when doing calculations (which this video is about). We might do another video on how to derive them, but it's not very practical to derive them from zero every time.
![[UNCUT] “บอสณวัฒน์” ลากไส้!! ใครหนุนหลัง "แม่ตั๊ก ป๋าเบียร์" I คนดังนั่งเคลียร์ I 30 ก.ย. 67](http://i.ytimg.com/vi/QlD7mU2KKRk/mqdefault.jpg)
what most lecturers fail to accomplish in hours of lecture you did so in less than 7 minutes - respect!
Thank you very much! That‘s exactly what we want to achieve with our videos!
Quite possibly the most powerful, efficiently succinct piece of media I've ever come across. Just, wow. Actually speechless. So much respect.
Thank you very much for such a high praise! We're glad you liked it! :)
Massive thanks, recommended your very well made video to all my classmates. I went from no idea of how to use Clebsch-Gordan coefficients to solving the question of my homework watching your video.
That‘s great, that‘s exactly what we want to achieve with our videos!! :D And thanks for recommending our videos, this helps a lot!
my dude it's almost gross how much better your video explains this then a lecture.
10/10 great job
I just want say "thank you" for this beautiful video.
Student of physics from Croatia
Thank you very much! Comments like yours mean a lot to us!
Such a heroic task you have accomplished in approximately 7 minutes! God bless you! #Physics_Student_From_Nepal
Thank you very much! :)
A very simple explanation of how to find the CG coefficients. It is always a headache topic for me. Thanks to your video, it makes my day.
Thank you very much! :)
Absolutely marvelous. It felt like I was listening to a piece of work by Mozart himself. The seemless way you explain things and the lucid path you take is like blending of all the instruments in a music ensemble.
Loved this so so much. Thank you so much for this.
Just subscribed. Hoping for more such videos.
I think that‘s one of the nicest comments we’ve ever gotten, thank you :) we have a huge list of video ideas that we want to cover, so stay tuned! :D
Thank you so much! You could cure my phobia for CG coefficients from my Masters days.
Subscribed and wishes from India.
Thank you for your nice comment! :)
saving this vid for whenever I have doubts. great, clear explanation.
Thank you 😊
God I wish this video was out when I was doing my masters course on this topic. Amazingly clear video as always and thanks for that cool reference. Looking forward to the derivation video! The whole SU(2) spin theory is something I just never completely wrapped my head around, and I've been meaning to derive from "first principles" for awhile now. This video series will save me the trouble of trawling through a textbook on my own :p
I hope our videos can fulfil your expectations, we'll give our best!
Just finishing up an SU(2)-heavy project for research and this video had me in a cold sweat lol. Nice video, good explanation, and gotta love the PDG.
Your project sounds cool! Could you briefly summarise what it was about? :)
Thanks for the kind words Zap :)
Best video on CG. Fast and simple explanation, thanks for your effort!
You have simply nailed it man. Thumbs up.
Esto es magnífico!! Gracias!
Student of physics from Spain
Thank you very much! We‘re glad you liked it!
Thank you so much , cannot expect better explanation than this
Wow, thank you very much! Glad you liked it!
How perfect you are and how lucky I am that I found this video before my exam :)
Thank you! :D Good luck with your exam! 👍
Thank you! Best explanation ever on CG coefficients table. I guess lecturers don't want you to understand it so that you can suffer in silence deriving them lol
Haha maybe, who knows! But anyway, thanks for the nice feedback!
@@PrettyMuchPhysics You're welcome! I just checked your channel: straight-to-the-point and simple explanations. I am looking forward to support you and share with my friends. Keep it going ;)
Physics student from UK.
P.S.: I'd suggest to hire an Instagram marketing service (like on fiverr etc.) or learn about branding, paid-campaigns and that sort of stuff. If well done it works magic.
Thanks for the kind words, that means a lot! We‘ll look into it!
Less than 7 minutes were enough to explain one of the hardest topics of QM. Thank you so much!
tysm brother that table was driving me crazy until I found your video 🛐🛐🛐
No words enough to thank you these really excellent work it gives sense for every thing
We are really glad to hear that! Thanks for watching! :)
This video is an utterly godlike explanation, thank you.
Great sir!
Well explained in just 7 minutes!
Greetings from India ❤
Thanks! :D
Dude, that's an amazing explanation
Thank you very much! :)
Great. Keep it all simple, clear, and connected, then you will get a beautiful video like this...
Thank you very much! :)
Thanks for the excellent and concise demonstration
:)
Great video! Clear as water! You explain very well! Thanks!
Thank you very much for your nice comment! :)
These videos are great. Thanks a lot and keep them coming!
Glad you like them! We will definitely make a lot more! :D
Amazing video, cheers from Mexico
Thank you very much!
Thanks! in only seven minutes that's amazing
Thank you! That‘s what our channel is all about! 🥳
BRO U SAVED MY LIFE 😱 THANK YOU PHYSICS MAN
Amazing video. Thank you very much.
Thanks!! 🙂
Thanks for explaining what our profs wouldn't!
:)
great explanation!! thank you so much:)
Thank you!
You saved my life sir🙏thank you so much
Love from india
That‘s great to hear, we‘re glad that our video was useful to you! :)
¡Excelente vídeo!
¡saludos desde México!
Thank you very much! :D
this helped soo much! thank you
❤️
Great! :D Thanks for your nice comment!
Man that was very very helpful, thanks alot 💓💓💓💓
Glad you liked it, thanks for watching!! :)
Good video. It helped me read the information off the table. I don't get why the individual sections of the table are organized in that way though? Couldn't they be separate little tables rather than touching each other? (Take the 1x1 table for example)
In case of the 1x1 table, those nine states on the left constitute one complete basis system of the product basis, similarly, the nine states on top together are the complete coupled basis. Therefore, they belong together.
As we mentioned in the video, this should actually be a square 9x9 matrix, but since most of the entries are zero, they are usually left out.
@@PrettyMuchPhysics thanks so much! That sorts it out.
I really love you man, you made my day. Now I can stop crying hahaha
That's the effect we're hoping for with our videos ;D Thanks for the nice words!
Excellent !
Great video
Thank you so much 😭😭😭😭
Glad you liked it :)
first, thanks for this amazing video, second i want to ask have you made the different videos where you derive clebesh Gordon coefficients , and if yes what is link and thanks
Thank you very much! We derived the CG coefficients for the simplest case (coupling 1/2 with 1/2) here: th-cam.com/video/a6p_8J1QTww/w-d-xo.html Note that this is just for educational purposes, for "real world" calculations, you should refer to a table like the one by the particle data group!
@@PrettyMuchPhysics
thanks so much, I really appreciate your reply, but I wonder do you have any video that explains quantum angular momentum L and m ??
I don't understand why the coupled basis looks the way it does?
In my mind it should be |00> |0-1> |01> |10> ....
Great video!
Thank you very much!
And if you have to calculate them by hand?
Thank you so much sir
:D
Thanks!
Wow, thanks for your donation! :O We're glad you liked the video :)
Makes sense now thx
That‘s great, thanks for watching! :)
Thank you!
😁
In first example j1=3/2 j2=1/2 j is btw |j1-j2| and j1+j2 u took j = 5/2 how is possible??
Super !!
Thank you! :D
How would you find the Clebsch-GORDON coefficient for which the total spin is 1/2 and the z-component of the spin is 1? I couldn't locate that on the table?
Also, the spin of particle 1 is 1 and spin of particle 2 is 1/2.
The magnetic quantum number (m) cannot be larger than the orbital quantum number (l), that's why there is no L=1/2, M=1 column. In other words, if it's not in the table, it's zero!
thankyou sir
Is a tensor product same as outer-product ?
Nope. There's a simple difference. The consequence of tensor product will have a multipled dimension dim=dim1*dim2, but the outer-product is calculated by a determinant and will keep the dimension.
how did you do it can you share with me , thank you
What do you mean?
If I have 0×1/2 ?? I don't have to use the table, but I don't know how it works 😅
J1×J2 = 0x1/2
@@Andrea-kx3zd If L=0, then the resulting multiplet will be the same as the 1/2 multiplet (since you actually only have one angular momentum, you can't couple anything).
@@PrettyMuchPhysics Thank you 😁
Don't derive them? Can you tell that to my professor? So much time wasted on exam doing this
🙈
Hey, there! We've been watching your videos for a while now and would love to discuss an idea with you. Where should we contact you?
Best,
Adam
You can find our email/Twitter/Instagram info on our channel page!
Thanks thanks thanks
You're welcome! :D We're glad you liked it!
I love you
Anyone ever notice how physics people always seem to have wild names? Maybe I'm just an ignorant American and Clebsch isn't wild o.o
I think Clebsch sounds funny in any language :D
Maybe it helps you that Clebsch and Gordan are not common last names in Germany. I haven't seen these last names a single other time. But then Schrödinger (actually Austrian) and Heisenberg aren't either. Pauli, Born, Stern, Gerlach, Stark are common names.
While I think this video is good at what it does, I cannot help but feel frustrated that even after reading the chapter on this on a Quantum Physics book, reading my professor's notes and watching this video, I still don't understand a thing.
Any particular questions? Maybe we can answer them here or in a future video?
This is a useful video and something that isn't already out there a million times (as most topics of physics related channels are), like your other videos, but I think you are being too sloppy in the notation. You are using a lot of what I call pseudo-math notation. I.e. what you are writing isn't accurate in math terms. You're using = symbols where you should use set notation and "element of". You're just writing a tensor product symbol between (j1,m1) and (j2,m2) at the beginning then an arrow -> that doesn't actually mean anything, you call the tensor symbols "couples to". |J,M> should EQUAL some linear combination of (j1,m1) o (j2,m2). why not write it accurately like this? what's the harm? What you write instead "looks" mathy but isn't accurate. There actually are physicists that do care for having the math straight and who don't like this sloppy way of writing (and it confuses them, because they are trying to make sense of something mathematically and they can't because someone just wrote random symbols). that is really prevalent in physics because a lot of people don't have rigorous math backgrounds and just don't know better, so they use symbols like =>, = etc seemingly randomly and from gut feeling, not according to what they mean.
Good thing this is a physics channel and not a pure math one. What we want to convey is a feeling for what happens physically, the math is just one helpful tool to achieve this goal, next to graphs and diagrams. Our approach is to first understand the underlying physics, and then dabble in the rigorous mathematics.
Physics can be performed in several levels of rigor. The more you get to know a topic, the more you can dive into the mathematics, which is something we not only do ourselves, but also definitely endorse.
Take quantum mechanics for example. You might agree that it‘s more useful for a physicist to understand the relation between a wave function, the probability density and observables, than it is to first rigorously define the Hilbert space.
Rest assured that we do know how tensor products work, or when to use set notation. However, this is a TH-cam video, meant to be a smooth introduction to a topic-and not a PhD thesis.
@@PrettyMuchPhysics I don't understand what the issue is of not writing nonsensical math then (as you did in several places). You should have just written words or drawn a picture rather than use bogus notation that misleads people reading the stuff you've written down. It just sounds like an excuse and a rather thin-skinned reaction to constructive criticism that is obvious and beginner level (not PhD). Most of what you said is beside the point I made. This isn't an argument of making things pedantically mathematical and forgetting the physical meaning behind it.
Don’t get me wrong, we‘re thankful for your criticism! And to summarize: when precise math notation is necessary, we won’t shy away from it (e.g. on our group theory video). But apart from that, we stick to the physicist‘s methods, like treating a derivative as a fraction ;)
nerd
sloppy notation has gotten me all the way to a PhD haha
くさんありますありがとうございます」、
😀
Dislike for the unfortunate "don't derive, refer to table!".
That's just how you should use Clebsch-Gordan coefficients when doing calculations (which this video is about). We might do another video on how to derive them, but it's not very practical to derive them from zero every time.
THANKS A LOT!!