Final year of physics undergrad

>final year of physics undergrad
>still don't understand QM or shit like entropy

WHAT
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N
I
M
E

.ga

I hope youre talking about upper div QM, because if you dont, then you shouldnt have a chance to complete your degree before the comittee

stop posting with anime pictures first, maybe you'll get your mental capabilities back then

anime website

entropy is first year material senpai and its not even complicated since you can literally explain multiplicity and micro\macrostates to normies in 10 mins.

fine.
no help for you

What are M I C R O S T A T E S
Atleast you can intuitivly understand it.

but in an ergodic system all possible microstates that still satisfy the macroscopic constraints will eventually be reached in equilibrium, so we can have a container with an ideal gas and at some point every atom will be in the left section of said container, at which point we can close the box in half, effectively lowering the volume of the system and hence the entropy
we can keep doing this as often as we like, as we're not violating the energy constraints due to the abscence of a potential, but at the same time I know this can't be possible

if you're talking about the second law , the proper statement of it is that entropy will be more likely to increase then decrease in any process in a closed system .
if you can disregard the entropy increase cause by the mechanical processes you can keep sealing off half the container in a 1 molecule system , each time the multiplicity will decrease.

I feel your pain. It's not that you don't get it, it's that as an undergrad you learn a lot of handwavy approximations that you realize are bullshit but you cannot figure out why. All I can say is, just parrot your material and have blind faith in it. If you take grad courses you will learn the material in a much more enlightening way.

>about to fail statistics for the second time
>work at the national institute of science
Can someone be retarded and smart at the same time?

Sort of. When I was doing statistics there was a girl there who was doing it for her 4th year or so. To get by in university doing science you have to be smart in some sense, but sometimes you hear or see people say or pull the dumbest shit.

It feels like shit, I can't enjoy my accomplishments because I always think that none of them matter when I'm so dumb that I fail basic classes and I'll never get that damn paper that validates everything in my life up to this point.

>sinx=x everywhere

How would you know the positions of atoms?

Then there is conservation of momentum. It's not possible that all the particles would be on the left side of the box. Sure, they are moving randomly, but in that random movement are constraints; the choice of momentum and position of one particle constricts degrees of freedom of other particles. It's like having ten dices and a bound that sum of them must be 30.

Read:
Fermi - Thermodynamics (Dover Books on Physics)
Pippard - Elements of Classical Thermodynamics

David Bohm - Quantum Theory (Dover Books on Physics)
Peres - Quantum Theory: Concepts and Methods

Why those books? Why not the Feynman Lectures on Physics or for instance Griffiths or Shankar's textbooks?

>Feynman Lectures on Physics
I wish people would stop recommending a series of books that even the author admitted were a failure.

it's not really that you don't understand entropy. It's that every exactly solvable problem in stat mech is like someone's entire life's work and you're supposed to memorize like ten of these perfect partition functions for the final exam

This is blatantly false for an ideal gas. The macroscopic constraints are energy, volume and total number of particles, and none of them will be violated. Ergodicity tells us every possible state of phase space will be explored.

They're great 2nd pass books for conceptual understanding.

Depends. I took probability, never did the homework, never did the quizzes, never went to class, and did ok on the tests but blew the final, so I got an F. Then the following summer I taught myself measure theory and stochastic calculus. Then the next time I took probability I didn't do any of homework, didn't do any of the quizzes, never went to class, but I did pretty well on the tests so I got a C. Am I a retard for not just doing all the extra stuff so I could have gotten a decent grade? Yeah. Am I a retard in general? Probably

>They're great 2nd pass books for conceptual understanding.
Yes that's what I found. They are not much use for a first pass, as Feynman's students found.

The ideal gas is unphysical, don't worry about it.

Is that how you feel?
Are you just...an animu?
Are you even human OP?

People are able to write down the equation for an electron in box , i.e. an infinite potential well, but what about the equation for a quark in a box? or a neutron in a box? or a positron in a box? or a gluon in a box? or a higgsboson in a box?

It could be worse user
>be me, freshman physics student
>just got home from my linear algebra midterm
>did not understand a single question, even though I do pretty good on the graded homework and most exercises
>said graded homework is now completely blown away by the midterm, which is most likely a 2/10
>everything now depends on my final, which will be harder than the midterm

I'm scared anons. What if I don't make it? I've wanted to work in the physics field since I was 10. If I fail to get the mandatory 45/60 course points they'll kick me out of the study and force me to wait 2 years before I can re-enter

well, there are two possibilities. you didn't understand because either
a) you're a lazy fuck and you didn't study, in that case apply yourself
b) you couldn't understand the material even though you've put an honest effort, in that case I'm sorry but you don't have what it takes to study mathematics or physics.

just do practice exams until you're confident enough to ace them

Have you actually read the Feynman Lectures? His way of explaining things is orders of magnitude clearer than anyone else that did Nobel Prize winning research

>QM
that's fine. it's just a mathematical abstraction to describe observed phenomena. there is no "why" in QM. there are also no 3D analogues to describe shit like spin states etc.

>entropy
oof. you're never going to make it

Feynman also said that if you think you understand quantum mechanics, you don't.

QM: Quantum. Quanta. Particles. Atoms. Atomism, disproven by the Greeks thousands of years ago. No need to know anything about it; it's completely useless.

Entropy: shit falls apart from higher ordered states to lower ordered states.

There you go.

>MRI machines
>GPS
>atomic clocks
>electron microscopes
>anything with lasers
>"completely useless"

I hope for your sake this is bait, mouthbreather

All done with electromagnetism.

Linear algebra is all about practice. Do any past papers you can find and (if possible) get someone that knows their shit to go through the questions you got wrong

is right, you know.
everything below the atom is an indirectly observed bundle of forces that quantum cultists assign arbitrary "force carriers" to

I don't know how deep you went with QM, but that shit really doesn't make sense once you go full circle with QFT. He was obviously not talking about understanding the formalism.

>What is Stern-Gerlach experiment, Zeeman effect, Bohr-Avagnon effect, ...

I wonder how it feels to be this brainlet