Schrodinger Equation - Step wise derivation Part #1/3

[JootyarJamal]

SPIDERMAN! :D

[GreenTaters]

Spiderman, Spiderman, does whatever a spider can! :P

[PaulBenham]

Gravity! - Classical

[TheGree123]

I got here from searching Schrodingers March but I was shoved into Quantum Mechanics nice though wrong vid

[youspinmerightrounds]

@affablelochan I added detail to your answer, it might be helpful!

[511Freedom]

Thank you !!! :)

[Djole0]

WHY did u put n in front of the planck equation?

[sillycoyfish]

Thanks for your videos!

[bigbaddogdavz]

Thumbs up for Spiderman?

[ThaFacka]

There is no infinite information.

[floopsie666]

f = dp / dt

f = d(mv) / dt

f = (m)dv/dt

f = ma

[apricimo]

@floopsie666 You're using DEFINITIONS to arrive at something. What is F? You did not define F to start your derivation. You're using circular reasoning. Again, I'll refer you to the reading I referenced earlier.

[coordinatorhacker]

@apricimo F should be equal to force.

given that force (F) = mass (m) x acceleration (a) according to newton's laws of motion

[apricimo]

@coordinatorhacker ???? Really??? What's your point?

My point is this... You cannot derive F=ma because it is an observation and we now accept it as a postulate on which physics rests. You cannot "derive" F=ma from F=dp/dt it is a post fact derivation. It is because F=ma that you can get to F=dp/dt... Christ!!!!

[qwertyxxx22]

Apu ???

[JustWonderingHowToDo]

What would be a good book for starting out on quantum mechanics.

[deyomash]

@JustWonderingHowToDo good question.. im searching one.. but i can only find ones with a very high level.. :(

[Casowsky]

Ah.. I get it WOAH SPIDERMAN HOLY SHIT

[apricimo]

This isn't really a derivation... More of an explanation of what some of the terms are... Shrodinger equation is a potulate... Just like F=ma

You can decompose each term into simpler parts and then put then together and attemp to "derive it" but you end up with logical holes of why one would consider doing some of the operations to get to the next step...

[floopsie666]

@apricimo F = ma isn't a postulate. It is derived from the definition of momentum and impulse. 

[apricimo]

@floopsie666 Force is derived from impulse? I = F*t = delta*p.... Indeed those are DEFINITIONS... Not contributing factors to derivation of F = ma...

Go ahead and DERIVE not DEFINE F = ma for me... Would love to see this as I'm sure others would as well...

[floopsie666]

@apricimo happy?

[apricimo]

@floopsie666 One more thing. Read "Physical Chemistry - A molecular Approach" by McQuarrie pp. 73. Read, reread, then speak...

[Alcaleb]

Thank you professor!

[lsbrother]

oh get your lecture sorted out beforehand!

e.g; don't start using v 'nu' for freqency and then change to f - 'because you think that's better'

And get a bigger board - it's almost impossible to read anything - especially when your rub it out!

"n runs from 0 to n'" !! -- you mean from 0 to Infinity

the whole thing was you just thinking aloud, trying to get ideas clear in your own head.

I won't bother with parts2/3

[justintime303]

where are part 2 and 3?

[Rancorboi]

spiderman is pooping on the board

[dmburke007]

philip.hobby@gmail.com

[UnFisicoMatematico]

SPIDERMAN

[stockshunter]

the x-axis should be the time where as on the y-axis, it should be the displacement.

[Jaysii4]

What would be the n-electron atomic schrodinger equation?

[godsownphilosopher]

Actually, quantum mechanics is not a theory, it's a formalism. While quantum theory will make use of quantum mechanics, they are not the same thing. Quantum mechanics, like classical mechanics, suggest ways of handling certain variables. Physicists then look at experiments and draw connections between real variables and these theoretical ones. In this sense, it is perfectly alright to derive Schrodinger's equation.

If it is wrong, quantum mechanics is not wrong, it is just not applicable

[Diemedes]

2) Schroedinger's equation, like Newton's equation (F=ma), Maxwell's equations etc. cannot really be derived in a strict sense (like a mathematical formula arising from physical laws). They are "guesses", in a way, made by physicists that objects behave according to those equations. Experiments are, ultimately, what either prove or disprove the validity of such a guess.

It's perfectly OK to provide "derivations" of the like you give; it gives us a deeper understanding on the equation.

[Diemedes]

The video is OK, I'd just like to make a few corrections:

1) Quantum Mechanics is not the "Physics" of the microscopic world ONLY. It is more fundemental than Classical Physics, and it's applicable EVERYWHERE. It's only that several phenomena (like the quantization of energy, momentum etc.) are not observable in the macroscopic world.

Thus, Classical Physics is simply a very good approximation on the macroscopic level. It works fine on our world of pots, pans and planets.

[nickharvey7]

In my video The Paradox of Schrodingers Cat an artist view Time has symmetry and geometry. Could this explain the measurement problem and entanglement within Einsteins curvature of spacetime?

[UntakenNick]

Is he rashej koothrapali..?

[miprabasiva]

i'm not

[electroamtu765]

@UntakenNick Rajesh Koothrapali * (btw I <3 tbbt)

[emeraldstone1]

Ooo... spiderman.

[anasssky]

I thank you soo much!

[george91182]

great video.

[sangrefay]

can you help me with a translate in spanish please??

[miprabasiva]

I don't know Spanish.. and I don't know how I can help you in translation..

[UncleKennybobs]

@sangrefay Use the automatic translation

[UncleKennybobs]

@UncleKennybobs Although it's pretty piss poor

[StaticShock13]

Thanks!!!!!!!!!!!!!!

[ShowMeTheMonkey]

Can never get my head around:

"Why is the kinetic energy of a particle in a box quantised?"

As it has to have a value? As a moving particle cannot have an E=0?

[sonicpsychiatry]

Thanks for the informative video, man. Very helpful.

[ydox]

i need such a board -.-

[miprabasiva]

I don't know where you are.. in US, you can find it in stables. officemax,office depot

[sfd5003]

There is no derivation for Schrodinger's equation. It can only be "proved" through experimental results.

[vaibhav1803]

u can derive the equation my friend you can....if u want i can even show it 2 u...

[vaibhav1803]

is there some formula relating Quantum mechanics and Thermodynamics...because that wud be a breakthrough...

[ShredderVIII]

classical mechanics dont explain how particles can behave as a wave and vise versa

DeBroglie gave an equation that said wavelength and momentum have a realtionship...after about 100 years or so, quantum mechanics was finally exepted...even after arguements from Einstein and Michelson

[notToast]

that, of course, is assuming that light IS a particle or a wave; or both of them at the same time. Maybe it is none of them, but it just seems to resemble what we know as particles and waves.

[vaibhav1803]

light if u see on the smaaler scale is a particle system...its wave nature is seen only in bulk phenomenon...

[superrawme]

What is the difference between classical mechanics and why can't we use the laws of classical michanics in quantom michanics?

[miprabasiva]

i don't know anyone knows why the classical mechancis breaks in the particle world.. but we know it does not work. classical mechancis works for macro world and qm works of micro world

[lilquazyvietboi]

qm also works in macroscopic scale

[namaoui]

@miprabasiva

P1 As the cool teacher mentioned.The classical approach (CA) seized to work and failed to explain the structure of an atom (microscopic scale). This is bcoz when we use CA in describing the atom,we say, an electron is spinning around the centre (nucleus). Classically the electron while spinning in a circular motion will have the state of an electromagnetic wave,

hence this wave while circulating, will emits energy.

[namaoui]

P2 classically again any object emitting energy will lose it at some stage and therefore the electron will collapses and falls into the nucleus.We know that this is not true and not the case; we are still here on earth arent we?

[namaoui]

P3 then out of no where you have Miss quantum mechanics coming along to save all of us. Hope you get my point my friend

Namaoui : ))

[TokingSD420]

@miprabasiva well if something smaller does not follow classical mechanics then how can we assume that something super large, like the space in the universe, follows the same classical mechanics. For example, how can we know if a line can really be straight, all the way across the universe?

[SolidFellaMike]

@miprabasiva Is it a terribly sophomoric question to ask do we know the exact line that quantum mechanics begins to work?

[jackp22]

@SolidFellaMike Quantum effects become important on the scale of particles/light atoms/chemical bonds etc, so on the order of about 1*10^-10 (0.0000000001) metres.

[hotbot666]

@superrawme It deals with the hesienburg uncertainty principle. Look that up and it should help you out.

[dharnisha]

@superrawme that is becasue at relativistic speeds(0.4c and above) newtonian mechanics fail!for an example you can treat a photon whihc tarvels at lights speed with newtonian mechanics becasue the results we get are very different from the expected value!thats is where the gamma function come in!look up what gamma function is coz its hard to write!its simply coming from a moving train example!its nt that hard to understand the mathematics behind it!gamma function fixes the errors!!

[cesarjom]

@superrawme the theories of classical mechanics (Newtonian, Relativity) use some basic assumptions and postulates that help develop the theory and the mathematics used to really explain such phenomena. Simularly QM starts with some basic assumptions of the microscopic sub-atomic realm, from there the theory flourishes.

[cesarjom]

... it turns out that the basic starting points for classical mech and QM are completely in contradiction and incompatible with each other. So there can be no cross over from one of these theories into the other. There are efforts to show how on theory may come from the other but this will require a completely new way to explain how matter works at the most fundamental level.

[affablelochan]

@superrawme

We had only classical mechanics in begenning. But in 1900's people found out that classical mechanics is not able to explain the sub atomic particle / quantum particle's behaviour and there came the quantum mechanics which is theory discovered for small particles. But it can also explaing the macro behaviour like planetory motion. So this explains your first question.

Your next question is... why cant we use laws of classical mechanics? The above para also answers this.

[affablelochan]

@superrawme

We had only classical mechanics in begenning. But in 1900's people found out that classical mechanics is not able to explain the sub atomic particle / quantum particle's behaviour and there came the quantum mechanics which is theory discovered for small particles. But it can also explaing the macro behaviour like planetory motion. So this explains your first question. Your next question is... why cant we use laws of classical mechanics? The above para also answers this.

[youspinmerightrounds]

@superrawme Classical mechanics assumes that energy is 'continuous'(if you graph energy you can do it without lifting your pen from the paper). This means that you can have 1 energy unit, .5 energy units, 1000 energy units etc. Any value of energy is possible. Quantum mechanics shows that this is actually incorrect. Only certain levels are actually allowed. Each level is an integer multiple of a fundamental level E0=(hw/4.pi). So 1xE0, 2xE0,3xE0... are allowed. not 0.5xE0 etc.

[youspinmerightrounds]

@superrawme Part 2 As you have more &more energy in your system then energy levels are so close in size to eachother as2 look da same. So for example 1000000xE0 is almost the same as 1000001xE0 so it looks like energy is continuous. However when the system has little energy then the differences are important.So you have doubled your energy for example if you increase from E0 to 2E0 which is a huge increase. Classical systems have huge energies so they behave as though the energy was continuous.

[youspinmerightrounds]

@superrawme Part 3When people ~1900s tried to explain blackbody radiation curves, specific heat etc. They found that classical physics(continuous energy levels, so any energy is possible) gave incorrect answers.When max planck suggested that the energy must b of specific levels (quantised) then the answers were correct So classical mechanics is quantum with loads of energy Quantum mechanical expressions become classical when the energy is large. eg the debye frequency or specific heat capacity

[AAKhan777]

Hi, I gave a lecture in my school on the SHRODINGER Equation and this video helped with the derivation part, thanks very much.

[diffuzn]

SPIDERMAN

[ozzzzzman]

There is no real derivation for the schrodinger equation. Its for example like the second law of newton. We just assume its correct!

[Pyrlae]

I'd say it's exactly the same, both can't be proved, both are axioms

[liuwenjie6678]

man,i am learning this this term,way too hard to understand...who the...invented schrodinger equation?!!

[EinSofVirtuoso]

Erwin Schrodinger

[zzzzzzd]

lolololol good luck liuwenjie. I'm learning it too. I'm screwed. But thank god for this youtube lecture.

Thanks a lot miprabasiva

[jdmd007]

man i'm mexican..i wish my professors were like you..you´re a great indú.

[FarFromEquilibrium]

You are too cool! I have never seen a step by step derivation of Schroedingers before, this is great!!!