Bra-Ket Notation and How to Use It

Рет қаралды 65,419

Күн бұрын

• Bra-Ket Notation and H...
00:00 Wave function and Ket vector
03:17 Bra vector
04:35 Scalar product
05:53 Inner product
06:35 Visuals interpretation
06:49 Tensor/outer product
07:42 Projection matrix
08:39 Basis change of kets
More: en.fufaev.org/bra-ket-notation
Books by Alexander Fufaev:
1) Equations of Physics: Solve EVERY Physics Problem
en.fufaev.org/physics-equatio...
2) Alexander Fufaev and His Never Ending Story:
en.fufaev.org/lifestory

Пікірлер: 75

@fufaev-alexander Жыл бұрын

kzfaq.infojoin eBook: en.fufaev.org/physics-equations-book Paperback: tinyurl.com/physics-paperback Hardcover: tinyurl.com/physics-hardcover

@jamesgarrity4656 4 ай бұрын

Genuinely, this is a brilliant video. A real savior for people wanting an introduction to quantum mechanics.

@jhbpropertymgmt 6 ай бұрын

This is the best explanation I've seen so far! Thank you!

@cavendishcavendish1367 Жыл бұрын

Thank you so much for the clear explanation professor, I wish you explain for us all lessons related to quantum mechanics 1 and 2, and the line, surface integrals please.

@fufaev-alexander Жыл бұрын

Sure I will

@grad_student 5 ай бұрын

thank the lord for this godsend video.

@kmunson007 6 ай бұрын

Like other commenters have said, I have seen many video's but yours explains it so clearly with fantastic graphics. So happy to find this channel.

@physiologic187 8 ай бұрын

Man, thank you so much for this video! I have seen so many explanations but none come close to the kind of intuitive and visual understanding this video has given me. Just got a subscriber. Keep up the good work!!!

@shashpalsingh7243 8 ай бұрын

Same!!!

@mikeperri7246 Ай бұрын

Thank you Alexander F - I've struggled to understand other explanations of bras and kets. Yours is clear and simple. Pity others don't adopt the same care for their readers and listeners.

@Vagabond-Cosmique 11 ай бұрын

That was an incredibly clear and beautifully presented explanation. Nice and simple, while also being comprehensive. I don't think I've ever seen such a well made and thorough explanation of the mathematics of quantum mechanics that's also easily understandable and easy to follow for laymen. Thank you and well done ; Paul Dirac would be proud!

@nmrenyi 10 ай бұрын

Awesome lecture! Really helped me with notations in quantum mechanics!

@davidhuo6902 10 ай бұрын

Thank you so much， this video give me a clue, and solve my questions to QM for years...

@jeremielhomme8572 5 ай бұрын

Super helpful! Thank you!

@ChaosSower99 23 күн бұрын

Brilliantly explained, many thanks

@alexanderchudinov3112 9 ай бұрын

This video is a godsend. Thank you!

@mathiscuisinaud4930 2 ай бұрын

I like very much your explainations! It was very clear and I have learnt a lot. Thank you so much

@samsunnahar9175 4 күн бұрын

Outstanding lecture it is!!! Thanks a lot Sir.

@hertselcorech9680 Жыл бұрын

Thank you Alex, always a pleasure to listen to your lectures ❤

@fufaev-alexander Жыл бұрын

Thank you for the lovely comment, Hertsel!

@teikono Жыл бұрын

Just started reading for my quantum mechanics course next year, this was very helpful!

@fufaev-alexander Жыл бұрын

Great to hear!

@hongseokyoun1361 3 ай бұрын

Very nice and useful.

@manantv9299 Жыл бұрын

Great video again, thanks!

@fufaev-alexander Жыл бұрын

Glad you enjoyed it! :)

@scoringwolf Жыл бұрын

Beautiful explanation

@fufaev-alexander Жыл бұрын

Thanks for liking

@picosoft2033 Жыл бұрын

Really nice brief for Bra-Ket Notation - thank you :))

@fufaev-alexander Жыл бұрын

You're very welcome! :)

@garimarathee7055 Жыл бұрын

Thanks...i needed this

@fufaev-alexander Жыл бұрын

You're welcome 😊

@ILYA1991RUS_Socratus 4 ай бұрын

Thank you!)

@dumebidonald 2 ай бұрын

Excellent tutorial. I have an opinion that in solving the equation in 8:07, the scalar product should be treated first because I feel it more logical & maths because of the brac & ket notation applicability. We still get same answer

@NovaWarrior77 10 ай бұрын

This guy is so powerful

@arezaajouneghani3082 11 ай бұрын

Excellent!!!!!!!!!!!!!!!!!!!!!!!!!

@vincentlanglo7367 2 ай бұрын

What happens when the values of psi(x) and psi(y) are the same? Are they still orthogonal?

@divinedraymz565 16 күн бұрын

Wonderful

@lamontcranston2627 2 ай бұрын

Thanks for this video. I'm just an old guy trying to learn new tricks and the introductory portion confuses me. The initial 2-D plot is fine, but when you speak about a point or value in the Hilbert space, the value of any point is psi(x,y,z, ... or as many dimensions as you have). Using psi(x1) and psi(x2) (to me) only describes the x1 component of psi at x1. Wouldn't it be better to use a different letter such as Q, as in psi(Q1) where Q1 is a matrix of x1, y1 and z1?

@RhettSavage 8 ай бұрын

Really excellent, thank you 🙏

@giorgosg4032 Жыл бұрын

That's so simple and comprehensive, thank you

@fufaev-alexander Жыл бұрын

Thank you too, for your positive feedback

@bjao8619 11 ай бұрын

How do we know we can list the x terms if they are uncountable as the function is continuous?

@v_munu 11 ай бұрын

I was wondering that too. I think explaining it that way was just a precursor to the fact that you need to integrate the continuous wavefunctions to get how much they overlap.

@chenglongshe Жыл бұрын

it's cool

@magedshaban9680 Жыл бұрын

Thanks for the explanation. Could you tell me how to create the animations? What software are you using?

@fufaev-alexander Жыл бұрын

davinci resolve

@magedshaban9680 Жыл бұрын

@@fufaev-alexander for mathematics plots and its animations?

@fufaev-alexander Жыл бұрын

@@magedshaban9680 for animations. for creating illustrations en.universaldenker.org/illustrations I use adobe illustrator

@macmos1 Жыл бұрын

Why use non-traditional sum sign?

@fufaev-alexander Жыл бұрын

I like this one more and would like it to be accepted. You can also insert e.g. times-sign (no product sign necessary), or divide by sign or minus sign or any other sign into the square and have a uniform short notation for each operation. Large Sigma and large Pi can be used for other purposes. For example, I use large Pi for pressure.

@ianthehunter3532 Жыл бұрын

Do you at all use Manim or will use it in the future?

@fufaev-alexander Жыл бұрын

What do you mean?

@Furetto126 Жыл бұрын

@@fufaev-alexander it's 3b1b python library for animations

@fufaev-alexander Жыл бұрын

@@Furetto126 No, I don't use it. But thanks for the suggestion, I'll check it out!

@ezequielsm Жыл бұрын

nice

@fufaev-alexander Жыл бұрын

Thanks! :)

@user-ek3vu5yy8v Жыл бұрын

nice vid! where are your german videos?

@fufaev-alexander Жыл бұрын

Gone :( I accidentally deleted the German channel with another (inactive) channel.

@user-ek3vu5yy8v Жыл бұрын

@@fufaev-alexander Oh, das ist schade aber trotzdem sehr gut erklärt. Machen sie weiter ihre Videos sind 🔥🔥🔥

@Benjamin-no1vb Жыл бұрын

@@fufaev-alexander Planst du die Videos wieder hoch zu laden? Generell vielen Dank für all die Arbeit die du in deine lehrreichen Videos steckst!

@fufaev-alexander Жыл бұрын

@@Benjamin-no1vb also ich habe einige deutsche Videos, die ich als Sicherung besaß, auf diesem Kanal hochgeladen: www.youtube.com/@universaldenker_physik ob es weitere Videos auf Deutsch geben wird, kann ich noch nicht sagen

@schroodinger Жыл бұрын

3:21 bruh

@fufaev-alexander Жыл бұрын

😅

@Leo_Leonis 5 ай бұрын

bruh

@rv706 8 ай бұрын

BTW, what's that ridiculous notation for a sum at 9:48?? 😂 The usual sum/series symbol Σ works fine for just any structure!

@foodman561 5 ай бұрын

I skipped to this timestamp and audibly laughed out loud at this comment

@r.b78 10 ай бұрын

Respect 🫡

@Davidgamer-gj7xl Ай бұрын

DÙTÜ🍷🗿😁💯🔥

@autumn_quantumelectrodynamics Жыл бұрын

First

@rv706 8 ай бұрын

The bra-ket notation is TERRIBLE according to many mathematicians. 1) |ψ> denotes _exactly_ the same mathematical object as ψ, an element of a Hilbert space *H* . So why surround ψ with a "ket" at all?? 2) When λ is an eigenvalue, the notation |λ> is not consistent with the previous one. 3) And, by the way, the notation |λ> is ambiguous cause eigenvectors of eigenvalue λ might not be unique (even up to complex rescaling). 3) A normal notation for the tensor product of φ with the hermitian dual of ψ might just be φψ*, or φ