2. Wave Mechanics (continued)

MIT 8.05 Quantum Physics II, Fall 2013
View the complete course: ocw.mit.edu/8-0...
Instructor: Barton Zwiebach
In this lecture, the professor talked about properties of energy eigenstates in one dimension, the nature of the spectrum, variational principle, etc.
License: Creative Commons BY-NC-SA
More information at ocw.mit.edu/terms
More courses at ocw.mit.edu

[@yyc3491]

The explanation of why the bonded well enforce the discrete energy state is so straightforward and blows my mind. Thanks

[@musicalanimeseries2.0]

Hi! Where are you form? May be I and you are on same semester.

[@kirilchi]

Amazing lecture - especially section starting at 48:07

[@dineshkumarghadei4148]

This lectures are very helpful to us ❤️❤️

[@Esther-z1-L]

Excelente!!!! Show variable solution ,fundamental result , dimensional potentials the ....Energy...thank

[@henryprzygocki4662]

Amazing lecture! You, sir, are an incredible teacher!!!

[@yusufdjafriPhD]

great lecture ......really helpful thanks for the post .

[@ahmedhegazy699]

In the transcripts, (sine) is wrongly written instead of (psi) :)

[@helicalactual]

I hate to correct the professor but, he said it could also be a super position of even and odd.... thats a teritiary state. so it could be even, odd, or even and odd in a super position. so there are three outcomes! thank you for clarifying the previous professor was correct.

[@harshitraj3138]

22:33 For proof of the corollary of Theorem 3, why did we consider that for a change of sign in argument, we have to multiply the function by c?

[@harrycraig2077]

An excellent lecture

[@xdm4886]

A question at 1:02:46 , we know that the superpostion of solutions also sloves the schodinger eq, and the trial wave function can be expended by them. But that means the trial wavefunction is also a solution. Is it contradict itself?

[@matusliptak9511]

This is a little subtle, but you have to think a bit about superposition, if you were to write LaTeX text: \Psi = \psi_n + \psi_m and put it into equation, you would get that \hat{H} (\psi_n(x) + \psi_m(x)) = E_n \psi_n + E_m \psi_m , and you cannot factorize E_n and E_m simultaneously to get solution to the eigenfunction problem. Prof. Zweibach just choose formulation that was a bit unclear, but what is happening is that the superpostion of eigenstates solves the time independent equation, but it does not solve eigenfunction problem.

[@matusliptak9511]

It's also important to realize, that energy eigenfunction equation is just that, 'energy eigenfunction' equation, so what is really important are energy eigenstates, any function can be expressed by them (because of completness) and so in a sense every function "solves" time independent Schrodinger equation, but that doesn't give you anything usefull, what is usefull are energy eigenstates, they are what you are trying to find, and eigenvalue associated to each eigenfunction (energy level)

[@not_amanullah]

Thanks 🤍❤️

[@sergeyliflandsky3231]

Unfortunately the link for the course website , supplied in the description is not working. I and many others would really appreciate if you could fix it so that the lecture notes and the assignments will be available. Also it would be very nice if you could upload the next course presumably Quantum Physics III, or whatever the name of the next course that is the natural logical continuation of this course. And if possible please upload as much as you can of Barton Zwiebach he is a GREAT lecturer!!

[@mitocw]

+Sergey Liflandsky The link is working again. Thanks for your note!

[@not_amanullah]

This is helpful ❤️🤍

[@iwonakozlowska6134]

A potential is something "mystery" to me , however I understand mathematical presented here. What is "before" the potential , from which function it comes?

[@BinhNguyen-if5yd]

me too.But if you can imagine things through the force: F=-dU/dx, then it becomes more intuitive for potential. Hope it helps.

[@andreasholand8835]

@Iwona Kozlowska The potential in Quantum mechanics is no different from energy levels in Classical mechanics. For instance you can look at earth as a gravitational potential well.

[@umerhayat1590]

Thanks a lot....

[@zphuo]

@35:00 intuition about that there's no degeneratives in one dimensional potentials.

[@kaushikkangsabanik1140]

36:10 i am so proud to be an indian after hearing that this legend is mentioning the name of another indian legend, r shankar(principles of quantum mechanics)

[@SunnySingh-ob4kx]

Who the hell would dislike this video.

[@SunnySingh-ob4kx]

I did 8.04 (2016 ) isnt there any 2017 videos of 8.05

[@musicalanimeseries2.0]

Hi are you undergraduate 3rd year student?

[@musicalanimeseries2.0]

No there is no 2017 video lecture on 8.05

[@pinakichatterjee705]

where can we fid the note please? :3

[@MinecraftworksRUS]

first link in description

[@SphereofTime]

50:12

[@ericbernardo5317]

This is really good and it is helping me a lot. But I would like to have acces to the notes, I entered in the websit and did not find this course there, just Quantum Physics III that is the 8.06.

[@mitocw]

You can view the complete course at ocw.mit.edu/8-05F13, and lecture notes are available here: ocw.mit.edu/courses/physics/8-05-quantum-physics-ii-fall-2013/lecture-notes/.

[@ericbernardo5317]

Thank you very much!

[@IliaToli]

Are there videos for Quantum Physics 3?

[@jaydevzala7806]

@@ericbernardo5317 can you help me to clear some of my doubts because I am from India and I don't have any support. But I am very enthusiastic to learn. I completed 8.04 lectures and now recently started this one. So if it is possible then please help.

[@shashwattrivedi501]

@@jaydevzala7806 Ask your doubt.

[@davidwilkie9551]

It was a Rule of Thumb that a message repeated often enough becomes "the truth" by excluding alternative points of view, and it will always be so, because that is apparent in Evolutionary Adaptation to the full spectrum of influences, cause-effect. Educational narratives are wave-particle coordination-identification packages in nature, (flat statement of the AM-FM Timing-spacing circumstances), so implies that the "media is the message", which is why the "weird and mysterious" non-explanations of QM and its natural inclusion in WYSIWYG Physics have inherent social momentum and cause difficulty in resetting the focus of precisely defining the field with accuracy..? Ie the "beautiful precision" of QM Mathematics and Experimentalist's practical confirmation of processes is at odds with the clarity of understanding of what is the accurate self-defining and all-encompassing Actuality. "Taking a shot" at describing circumstances by Theoretical Mathematics has the inherent limitation of proven uncertainty in the Correspondence of Mathematical Forms and actual metastable proportioning measured in Actuality. The Quantum Operator is a one-way Unity of Spheroidal Toroidal self-defining Calculus of Temporal cause-effect e-Pi-i sync-duration connectivity probability resonance Holographic Function, ie Emergent logarithmic condensation, or Entanglement in metastable resonance in vertically integrated Inflation +/-, ..and no accurate description or fixed measure other than "trivial" ones and zeros at the arbitrarily selected.., because "all is vibration"/functional pure relative motion/Calculus, ..Mathematical Boundaries, is "Alphanumerical" wave-particle Duality of apparent quality quantity. It's nobody's fault that most events that happen are unplanned and unpredictable in details, but it is certainly worth obtaining the best Education available to improve the quality of mutual understanding and support in general. A sense of humour is required sometimes. If "some scientists" believe in Holographicly projected real-time reality, without a comprehensive denial of "alternative" pictorial abstractions, then they are merely Seers, Mystics, Wizards and Warlocks (locks = lords?). I agree, older (not really particularly theological) interpretation of Actuality by rote ideas had functional applications under these circumstances that are just as human as now. Without having to claim any investment or involvement in beliefs, any Observer can show the equivalents of Laser light Holographicly and Temporally projected imagery based on e-Pi-i sync-duration time-timing-> "pointed" Perspective singularity, mathematically derived logarithmic circularity quantization, in which superimposed density-intensity real-numberness aka Quantum-fields Mechanism is condensed-emergent-inflation +/-, by a sum-of-all-histories approach to understanding Polar-Cartesian self-defining coordination of pulse-evolution. "It's not Rocket Science", that's a lot harder to Engineer and make profitable, because learning by doing experience is inherently expensive in every way.

[@Blargblargyness]

This is buck-ass wild, and I really appreciate it. Truly phenomenal nonsense!

[@speechismyhammer]

Who the hell disliked this lol

[@prian3076]

I think some people just dislike everything in general :)

[@IliaToli]

The class is awesome. The transcription is awful. Very far from what the professor says.