QM0.3: Time-Independent Schrödinger Equation

[risiblewilbury]

Can someone help me here? In axiel22's comment he mentioned that ih(1/f(t))df(t)/dt = E, when solved, goes to f(t)= e^(-iEt/h). But shouldn't there be a constant C in there as well? Or am I just missing something?

[arib93]

THANKS FOR THIS :D big thanks from me, really really helped me alot. As others said, really like your tempo, and the no bullshit, just straight to the board and do handle the equation.

[800alias]

haha i like your enthusiasm, makes me want to study! fast facts and no BS like in other videos

[playbaseball2]

He sounds like christopher walkens haha, but good video

[Chrisboff]

Thanks for making revision AWESOME!

[Chrisboff]

Thanks for making revision AWESOME!

[vivekkumardaga]

ur sweet dancing style is a great time pass for the small kids...

well u r a nice teacher too...

others are like boring and teach boring too...

But u r the one, who makes boring things seem interesting...

Ur nature is so kind...

U r an ideal teacher...

U r the best...

[GelandnaleG]

4:49pm Saturday (CDT) - Time in Houston, Texas

DDIRibsNtimeay

[GelandnaleG]

3:26pmThursdayCDTTimenMOGULMON­OLITH

6:36

[GelandnaleG]

7:33pm Wednesday (EDT) - Time in New York, United States of America

[jappadadappa]

Good video, easy to understand... Did you show how to solve for the Time evolution operator in another video? solving the LHS when equated to E... (integrate both sides.. blah blah blah)

[szhan1022]

wow i love this

other online professors are like 170 yrs old

and they talk like 3 words an hour

this guy just charges through everything in like 10 minute vids

and i swear he's getting more energetic as the vid goes on

[gregthesenior12]

Nice video ....The time dependent is not given enough respect.

[chathujg]

wow! i learned Quantum mechanics from bruce Lee

[123Kaduk]

very helpfull! thx

[DoubleDutchBust]

1:11

basically

[DoubleDutchBust]

5:57am Saturday (CDTTime in Mississippi, United States

7:55

1312G 0 1:12

[DoubleDutchBust]

2:52pm Saturday (MSD) - Time in Moscow, Russia

[DoubleDutchBust]

2:22

back 2

[jazzprincess]

I don't care about equations but you are SO cute!

[samgee2007]

why chinese are far more smarter than muslims?i really admire chinese religion!

[philno88]

@samgee2007 Chinese religion? Lol.

[NavB00]

Wow If I had an instructor like this, I would not be able to understand no offence.

[DoubleDutchBust]

2:45pm Tuesday (CST) - Time in Mississippi, United States of America

[DoubleDutchBust]

time in LA 9:42 AM

[DoubleDutchBust]

10:08am Monday (CST) - Time in

[gjs2512]

as far as i know, the laplacian is an operator, so what you say about it is fine. but i think you should not call V an operator. it is a function of x (in the time-independent case), so you can simply allow the f(t) division.

[shinzon0]

Regarding that x is also an operator in quantum mechanics, V(x) can be an operator if x is regarded as such because it then would be an operator-function, which is an operator. Wave functions are always vectors in a given hilbert-base (in this case the x-operator-base)

[ygustavo]

very good for ten minutes.

[shinzon0]

Oh dear me how... your are talking so fast, that makes me crazy... good, that I've already passed QM I and QM II - slow down :D if you talk slowlier, people can follow you better

[cwxzeng]

keep in mind that he has 10 minutes to talk about quantum mechanics...

[bluesrunthegame]

Mathematicians often write nabla upside-down, instead of squaring it, to refer to the Laplacian.

[zxeritross]

Dude you're amazing!

[GaryKoji]

Thanks for all these vids, my textbooks are hopelessly written, its people like you that save the day for people like me. :p

[whydid666]

I simply cannot see how  Schrödinger is considered a quantum physics i always see it more as calculation of probability

[tifius]

It describes probabilities in quantum physics

[tavo5150]

pawtical?

[bluedeath116]

could u upload this video again? it doesn't work. and thanks for all these videos

[vjpillay]

Is this the way donny lee teach students? sorry i would not have been able to cambridge maths tripos papers from GH Hardy and university first year maths problems when i was 16 being a top student in my time.

[4HOMELESStheCHANNEL]

HE HAS 10 MINUTES ... time dependent

[vjpillay]

second order partial derivative written as inverted delta ,inverted triange

[zuojianqiu]

Hi Donny, very wonderful. I am wondering if you are genius. You are so young but all recondite quantum and mathemetics come naturally to you! You have farly outnumbered the guaduate level. Are you study now? Hope you are a rising star of science.

[CNaq1]

Donny your vids are amazing! I only hope I can approach your level of mathematical ability.

[simplystimpy]

Great video. I understand all of the mathematics, but I don't see the derivation of the Time-dependent equation. Why is the equation what it is and where does it come from? I always like to know the roots.

[simplystimpy]

Okay, nevermind. I found the derivation on wikipedia (my university!) It was very interesting and surprisingly simple! The simplicity of this video is very encouraging.

[zzzzzzd]

it's a bit like Newtons second law. It cannot be proved or derived it is just an equation which fits the observation.

[axiel22]

I just want to clarify out something that confused me at first. So we split up psi(x,t)= psi(x)f(t). Then By doing some arrangements, we get two equations:

1. (-h^2/2m)delpsi(x)+V(x)psi(x) = Epsi(x)

and

2. ih(1/f(t))df(t)/dt = E

we solve the second one to get

f(t)= e^(-iEt/h)

Then we have psi(x,t)=psi(x)e^(-iEt/h)

and all we need to do now is solve the time independent schrodigner equation to get psi(x). I hope I understood this correctly. (also h = h bar in the above eqs)

[donylee]

Yes, you are spot on! Good thing you caught this early.

This simply means that for time-independent potentials, we only need to solve the time-independent Schrodinger Equation, get the wave functions psi and energy values E, and in doing so, we have found all the states by multiplying by f(t).

Remember, time-independent potentials / Hamiltonians only! For time-dependent potentials, another story altogether.

[jimmyshitbags]

i followed this video fine, but how do we solve the time-independent schrodinger equation to get psi(x)? is there a video for that?