Currently struggling through graduate quantum mechanics. This was a HUGE help!
@viascience3 жыл бұрын
Glad to hear it helped.
@Arch4973 жыл бұрын
Didn't knew George Carlin did quantum mechanics equation descriptions
@jiadong78737 жыл бұрын
This is one of best QM video series I have ever seen. From electron to atom, then to molecule. Very impressive, thank you so much for your effort. I am wondering if there will be a 'from molecule to solid' series which related to density functional theory or something similar? :)!!! @viascience
@ryanamiri86526 жыл бұрын
that sounds cool
@vaishalitrivedi2461 Жыл бұрын
Yes i agree
@MindMatriX Жыл бұрын
@@vaishalitrivedi2461 hehehe
@MindMatriX Жыл бұрын
Hiiiiiiii
@vaishalitrivedi2461 Жыл бұрын
@@MindMatriX hlo
@jackson_mcgrath8 жыл бұрын
This was a great, thanks again for all the high quality educational videos. Anxiously awaiting part two
@viascience8 жыл бұрын
+Jackson McGrath Thanks for the encouragement.
@themasstermwahahahah4 жыл бұрын
incredibly straightforward and comprehensive, by going in a linear order of concepts, if i dont know something, i can just learn it, come back to the video and be able to follow
@muhammadazhar35053 жыл бұрын
Plz explain Dirac equation at quantum Field Theory. Good work.
@viascience3 жыл бұрын
We will get to that in the Quantum Field Theory series.
@nicolasPi_11 ай бұрын
Witnessing the mathematical derivation that led to the introduction of spin and antimatter is like opening a window to the fabric of reality.
@realimage36563 жыл бұрын
good!
@xenmaster04 жыл бұрын
Absolutely superb. Clearest and most beautiful explanation of the Dirac equation I've seen.
@viascience4 жыл бұрын
Glad you enjoyed it!
@TheRumpusView8 жыл бұрын
Oh golly! I am vaguely familiar with the Dirac use of matrices to determine negative energies etc, but golly, this video is scary and requires me to revise all sorts of stuff to comprehend the logic and the maths. I have even forgotten what ">" does! What software do you use to present the equations? And you must be some sort of physics professor to have the level of understanding you have.
@viascience8 жыл бұрын
+TheRumpus I use libreoffice presentation (open-source alternative to Microsoft PowerPoint). It has a decent math editor.
@tachyon3.143 жыл бұрын
I might not understand this fully yet but imma come back to this many times
@victorzzz248 жыл бұрын
REALLY REALLY LOGICAL AND CLEAR!
@jamesgrandoff96002 жыл бұрын
Thanks for the video. Very informative. It appears to me that both Dirac and Feynman assumed that time had the properties of being both positive and negative. Has anyone sought to address the concept of time being only positive and in the range 0 to C? My thinking was that negative energy trapped in zero time (i.e. cannot react) would be a possibility and I was hoping to explore that topic. Please let me know if there are any papers or sources relevant to that concept. Thanks again.
@wrox2757 Жыл бұрын
Which reference books should i use along this series? This video is amazing and I'm planning to watch from the start. Thanks.
@mudkip_btw4 жыл бұрын
Your videos are so full of information that is hard to find out about by yourself. Thanks so much!
@viascience4 жыл бұрын
You are most welcome.
@briangarcia40534 жыл бұрын
I wish I was smart enough to understand any of this
@omarfarukh82004 жыл бұрын
Sir, great lecture but am from biology background I need step by step explanation of the mathematics involved in Dirac equation, if you send me a notes also it will be okay for me
@IIPlayingGodII7 жыл бұрын
why do terms of the form \alpha_i * \beta * p_i * m vanish on 13:51? great video by the way :D
@blockhead18996 ай бұрын
I tried my absolute hardest to follow the math but there is so much I don’t understand and this is supposed to be the basics??? Do you know any videos that explain the math more indeph for beginners pls?
@floriandobai44865 жыл бұрын
Thank you, for this great video, your work is highly appreciated.
@viascience5 жыл бұрын
You are most welcome.
@titikshadua1557 жыл бұрын
Thankyou for this. One of the best course videos!
@aprylvanryn58982 жыл бұрын
You may as well have been speaking Greek. I'm so lost but rest assured I will be back once I've leveled up.
@Cosmalano8 жыл бұрын
Wonderful video and wonderful to see a new addition to the series.
@viascience8 жыл бұрын
+electrocat1 Thanks.
@JakeFace0 Жыл бұрын
If the dirac equation is this simple, then why do people act so coy and shy every time you ask them what a spinor is?
@hadijaffri98563 жыл бұрын
Im a highschool student,dont know why im watching this at 3:30am
@mauriciofurlan77732 жыл бұрын
Poderia colocar legendas em portugues
@Nolrai129 ай бұрын
I just want to say I specifically watch these videos _because_ they have the math.
@DidiestEva Жыл бұрын
at 12:00, why can the value of \int |psi|² dV change ?
@remusgogu75453 жыл бұрын
WOW. One of the best presentation for the subject. WOW. Really, thanks for making this video 🧡
@viascience3 жыл бұрын
You are most welcome.
@justanotherguy4692 ай бұрын
Thank you for this clear and concise lecture.
@abidmessoud97673 жыл бұрын
very wonderfull course than you very much
@Hack3r918 жыл бұрын
15:38 I have known Dirac matrices to have a minus sign on the bottom-left Pauli matrices, are these another basis?
@viascience8 жыл бұрын
+Alessandro Porcelli You get those forms if you multiply all four matrices on the left by the beta matrix. The four matrices are then usually denoted by gamma: gamma_x = beta*alpha_x etc. You get the same solutions, but the equations have a different, usually considered more convenient, form.
@Hack3r918 жыл бұрын
Thank you for the explanation, very good job with this channel!
@daydreamer053 жыл бұрын
How long did it take you to make this video?
@sayanchakraborty19458 жыл бұрын
I have always felt that Dirac equation is fundamentally flawed. It somehow explains properties of electrons, however it badly fails when you try to explain similar properties for other particles, such as protons. for example it gives an accurate measure for the g value of electrons, when you take the non relativistic limit of dirac equation under minimal coupling prescription i.e. essentially the pauli equation, but it abysmally fails to reproduce g values for other particles.
@themightyripples65823 жыл бұрын
This has likely been answered... at around 2 minutes there is an infinite sum, how would this be expessed in sumation notation, i.e., capital sigma notaion?
@vasanthrajaram12416 жыл бұрын
how did h get canceled while substituting energy in momentum operators in 15:54? the only way it can get canceled is if we multiply h over h in (m.beta.wave function) the last term in Dirac equation. great video
@creative_sunflower3 жыл бұрын
Thank you very much.... 😊
@ariayahaile4406 жыл бұрын
Ask Leonard Susskind a specific physics question, including "What is the Dirac equation?" - askkindly.thanksci.com
@szeredaiakos7 жыл бұрын
assHat .. right .. :P
@herbiepop8 жыл бұрын
A consistently high quality series.
@viascience8 жыл бұрын
+herbiepop Gracias.
@TheDavidlloydjones6 ай бұрын
Kwannamechanics. Who knew?
@mateomaderas55046 жыл бұрын
It may seem like nitpicking, but the curvature of a curve is NOT the inverse of the second order derivative of that curve.
@viascience6 жыл бұрын
I don't think I ever say curvature is the inverse of the second derivative. Typically the curvature of a circle is taken to be the inverse of its radius. The curvature of y = f(x) is y''/(1+y')^(3/2), which for small y' is approximately y''. At 3:22 I use an "approximately equals" sign to indicate that the curvature is approximately the second derivative. But I should have said "the curvature is _approximately_ the derivative of the derivative." I left out the "approximately" when I spoke.
@mateomaderas55046 жыл бұрын
All good my crappy eyes didn't spot the curly equals either
@lixiaojiang81823 жыл бұрын
Hey, nice talk, can you share the slides with us ? thank you very much!
@abednadir84378 ай бұрын
Absolutely Brilliant!
@dexio858 жыл бұрын
Another very good video. Thanks!
@viascience8 жыл бұрын
+dexio85 You're welcome.
@roberthuber27703 жыл бұрын
In 17 minutes you have created a quantum mechanics addict... thank you!
@johngibbons4942 жыл бұрын
Great videos. Thank you. About 4mins into this video you bring up operators. I can't find the video on angular momentum you mentioned that helps describe operators. Could you please refer me to the title that explorer this . Thank you in advance
@viascience2 жыл бұрын
You are welcome. See kzbin.info/www/bejne/hKjFp4eXZ92Jb80 , kzbin.info/www/bejne/bYDQp4OvnMlmn7s and kzbin.info/www/bejne/iKDUanx3bL9ghrs
@MAandS6 жыл бұрын
I'm here because of Death Stranding.
@michaelfox96754 жыл бұрын
The second line beginning at 8:25 is invariant under every permutation of {Sx, Sy, Sz}, but the third line isn't, and doesn't satisfy the second line, which it supposedly is a solution of.
@viascience4 жыл бұрын
The Sx, Sy, Sz matrices given in the third line satisfy the commutation relations given in the second line.
@brianmenendez6 жыл бұрын
Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality. Nikola Tesla
@nintendoswitchfan49532 жыл бұрын
This video saved my life
@geraldinejasnin73785 ай бұрын
possible en francais !!
@jasonarakawa21718 жыл бұрын
Great video! Thanks!
@viascience8 жыл бұрын
+Jason Arakawa You are welcome.
@shaquilleoatmeal26855 жыл бұрын
Anyone here feel like an idiot after watching this video?
@SquidKing2 жыл бұрын
Amazing video! Unfortunately I am lost at 8:18 where you say we can derive ^Sx and ^Sy by using the cyclic commutation relationships. I try to set ^Sy equal to a 2x2 matrix A B C D, but I can't seem to find solutions for B or C using your suggested method.
@viascience2 жыл бұрын
Set Sx=[A,B;C,D]/2 and Sy=[E,F;G,H]/2 (where , separates columns and ; separates rows). The commutator relations [Sy,Sz]=iSx and [Sz,Sx]=iSy require that A,D,E,H are all zero and F=-iB, G=iC. Then [Sx,Sy]=iSz requires that and C=1/B. This leaves us with Sx=[0,B;1/B,0]/2 and Sy=i[0,-B;1/B,0]/2 . Then you can argue by symmetry that B=1.
@SquidKing2 жыл бұрын
@@viascience Thankyou so much for this! It turned out I still had difficulty solving for B until I learnt that the matrices had to be hermitian. This series is by far the best easy-to-digest QM material on the internet. I would not have been able to dive nearly as far into QM without your help and I am very grateful. Thankyou!
@renumalik30966 жыл бұрын
Fabulous explanation
@viascience6 жыл бұрын
Thanks
@tanvirfarhan55853 жыл бұрын
omg what a great video
@vaishalitrivedi2461 Жыл бұрын
Very nice vdo👌👌
@johnchristian5027 Жыл бұрын
Brilliant video!
@Kenbreg5 жыл бұрын
x,y, zed would have been nice. Not x,y,zee
@saikiranalvala5026 жыл бұрын
Thank you so much for this sir🙏🙏🙏
@viascience6 жыл бұрын
You are welcome.
@vtrandal3 жыл бұрын
At 3:00 minutes in this wonderful video you explain slope and curvature using a triangle and ball (circle in R2). What is curvature in higher dimensions and what geometric shape relates to it? Is it just an n-ball in Rn? Or is there some “hyper” shape we can try visualize for curvature of curvature in R3 or R4 and so on?
@viascience3 жыл бұрын
That a complicated subject. Different "measures" of curvature can be used to represent different quantities of interest. In the Relativity series there are lectures on Differential Geometry (kzbin.info/www/bejne/poarpmmqrMRkg8U) that deal with curvature in higher dimensions.
@vtrandal3 жыл бұрын
@@viascience I studied electrical engineering years ago. The Dirac delta was used to get the Impulse Response of a linear system. I’m eager to see if Dirac used the delta “function” in quantum mechanics and especially in relation to the Dirac equation. Do you talk about the Dirac delta in any of your videos?
@TimeDesignsMedia4 жыл бұрын
Neither particle exists in linear time.
@jordanweir71874 жыл бұрын
Thanks for the vid dude
@viascience4 жыл бұрын
UR welcome.
@ronaldjorgensen6839 Жыл бұрын
thank you
@hello-world2023 Жыл бұрын
Excellent!
@DevashishGuptaOfficial8 жыл бұрын
This is the best explanation for the Dirac Equation, on the KZbin!
@viascience8 жыл бұрын
+Devashish Gupta Thank you.
@JosiahWarren3 жыл бұрын
Amazing
@makaylawilson28014 жыл бұрын
Hi
@arthurbarbosa58256 жыл бұрын
I'm 14, why am I here at 2am?
@Giovanni28626 жыл бұрын
Could you recommend a book on the subject?
@vasanthrajaram12416 жыл бұрын
how did h get canceled while substituting energy in momentum operators in 15:54? the only way it can get canceled is if we multiply h over h in (m.beta.wave function) the last term in Dirac equation. great video
@viascience6 жыл бұрын
See 12:30 - we use units in which h-bar is one.
@vasanthrajaram12416 жыл бұрын
oh thank you so much sir. I almost forgot about it. thank you for making this so much clear.
@vasanthrajaram12416 жыл бұрын
oh thank you so much sir. I almost forgot about it. thank you for making this so much clear.
@markhamilton87282 жыл бұрын
Great job! Dr W
@viascience2 жыл бұрын
Thanks.
@ryanamiri86526 жыл бұрын
thats super cool
@knowledgesman31675 жыл бұрын
thank you! highest level !
@olgermannik18305 жыл бұрын
10:15 should this not be sum of squares of 1. deriatives?
@viascience5 жыл бұрын
Are you referring to the "nabla squared" symbol (the "Laplacian")? That is the sum of the second derivatives. The first derivative operator operating on the first derivate operator is the second derivative operator - the derivative of the derivative.
@olgermannik18305 жыл бұрын
@@viascience Yes I meant that. I know that Laplician means (d/dx)^2+(d/dy)^2+(d/dz)^2. My first misunderstanding was whether you substituted energy and momentum with corresponding operators applied on wavefunction and then squared or substituted only operators and then put wavefunction to right side of expression. I first thought you meant the first, but now I understand that you meant the second. Secondly I did not realise that ^2 meant scalar product. If these 2 are correct, then I now understand it.
@sajateacher8 жыл бұрын
I thought that negative energy was just gravity. I mean, it does everything the opposite that energy does.
@Quintinohthree8 жыл бұрын
Energy: The capacity for doing work, i.e. exerting a force over a displacement. Gravity: Force acting on objects with mass, which is equivalent to energy. They don't seem opposite to eachother, not even orthogonal to eachother but interdependent.
@sajateacher8 жыл бұрын
I read it in a book somewhere, I'll try to find the title. If you have a source of energy, such as the thermonuclear energy in a bomb, matter is going to be repelled from the centre, whereas with a source of gravity, matter will be attracted towards the centre.
@Cosmalano8 жыл бұрын
+Ryan Blais a force is the negative gradient of potential energy.
@viascience8 жыл бұрын
+Ryan Blais The negative energy solutions to the Dirac equation are for an isolated particle, hence without reference to interactions with other particles.
@sajateacher8 жыл бұрын
Thanks electrocat1 and viascience for clarification. I think I read it in a Time Life book, but here is essentially the same idea. plus.google.com/105977048411460572598/posts/TRZz4cCZKe8