Probability current and current conservation

MIT 8.04 Quantum Physics I, Spring 2016
View the complete course: ocw.mit.edu/8-0...
Instructor: Barton Zwiebach
License: Creative Commons BY-NC-SA
More information at ocw.mit.edu/terms
More courses at ocw.mit.edu

[@DrMarcoArmenta]

I love the rigour of this guy.

[@SoumilSahu]

*claps* how are teachers like him even made??!! He's too good

[@hanbao1178]

This explains so detailed and really solved my problem. Many thanks.

[@ldanielfch]

The short haired girl in the front who asked in the class is cute 6:35

[@허지원-y3v]

I love these lectures, thank you MIT for sharing them with the world:) I just have one question, shouldn't this be called charge(or probability) conservation, instead of current conservation?

[@2024-l9n]

probability conservation, probability current. That's my understanding.

[@SuparnaMondal-qh1pj]

Does probability current J has anything to do with frequency since their units are same?

[@gyorgyo7597]

I am having some trouble. If d rho /dt is zero, that means J is zero? If so what is the meaning?

[@zphuo]

@10:44 the J(x,t) is being called "current density". Is that right? Shouldn't be "probability current"? Or "current density" is same matter with "probability current"?

[@jacobvandijk6525]

en.wikipedia.org/wiki/Probability_current

[@dlbattle100]

He always gets in a hurry and leaves the hat off the second H.

[@SkanderTALEBHACINE]

what is the difference with the same lecture posted weeks ago (on 5 Jully), thanks

[@dlbattle100]

I don't know maybe they made videos of him teaching it to different groups.

[@SkanderTALEBHACINE]

anyway, thanks

[@willam.willamswong7330]

Ok, you added ^ on H. I see it, Thanks.

[@snugglenuts]

Why aren't these classes recorded in 360° video? The viewers could get better looks at the black-board.

[@jacobvandijk6525]

Are Peruvians as "gruendlich" as Germans?

[@cafe-tomate]

Wait, we had lim Ψ = 0 and derivative bounded at t=t0 NOT FOR every t How the hell does he use this argument for dN/dt ?

[@rahilshaik1603]

it is for every t. For ANY wave function as the limit of x goes to infinity the probability amplitude, psi, must go to 0 or else the wave function does not make any sense as a probability amplitude since it is not normalizable as the integral of psi squared would never give a finite value. Similar argument can be made for the derivative that is bounded. For ANY wavefunction to make physical sense, these conditions must hold.

[@kaushikkangsabanik1140]

how would the calculation goo, if the potential is not real

[@demr04]

The potential must be real because represent the potential energy. Instead, the wave function it's just a tool to construct an eigenvalue problem and makes life easier

[@SkanderTALEBHACINE]

what is the difference with the same lecture posted weeks ago (on 5 Jully), thanks

[@riturajanand7133]

sir, can you help me to give an assignment solution? I was doing the assignment but want to match it...