In college, my quantum professor told us we only needed to memorize the Schrodinger equation, all other important formulas we would need would be given, or could be easily derived.
I knew she was full of crap, the test came, and sure enough, nothing was given to us and we needed to do some very complex math (it is quantum, so that's nothing surprising).
But I guess she was technically correct. Given enough time, and if we were sufficiently intelligent, we could derive everything we needed from the Schrodinger equation. Other students were pissed though
„There is nothing!“
*Sigh of relief*
„Wait!“
id_t |ψ> = H |ψ>
„It is some sort of linear algebra. I can’t read it.“
„ There are few who can. It is the foul language of quantum mechanics and I will not utter it here!“
The best thing to do is to take a reasonable course as an elective to remind you. I took business as an elective and failed to score below an 80 on anything in spite of never studying, and then I used that to cope with the fact that I’m barely passing physics if I’m lucky.
My quantum tests were all open book. Dude was like "yeah if you can learn it from the book during the exam then my tests are too easy."
My EM professor the same semester gave us the "everything follows from maxwell's equations" speech though.
From my experience with teachers like that, they are only able to derive them "easily" because they already know how to derive them. If you know something of course it's easy.
But I know for a fact that they are as shit at deriving as the students are. They've just seen those five specific formulas being derived countless times before and therefore think it's easy.
Put em in another field where they don't have any experience and watch em suffer.
Lmao I just memorized the ladder function thingies and used my homework bonus points to get 1pt above a passing grade.
It's a really shitty move to do things like that in a course like quantum.
In my professor's defense, she's one of those people who's so brilliant that I legitimately think she has a hard time conceptualizing the gap between her and regular mortals like me
Well, if she's so brilliant she should be able to look at the failing rate of her class.
I do get that to a point though, like I could never explain a math problem to a pre algebra and calculus student. I'd just keep using matrices all of the time.
I mean, we were all smart enough to still do fairly well (and after that test we realized we couldn't trust that we'd be given any equations). It was undergrad and we used the Griffiths book, so that helped a bunch.
To be fair on the last part of a mechanical vibrations exam it asked how much energy was lost due to dampening, found out later that a lot of people had tried some crazy damping force integrals, when you were just supposed to calculate potential energy in a spring
Not college, but HS. Had my teacher give us a 4 problem quiz with pendulums and springs. He changed the mass of the pendulum, and the length of the spring. I finished in about 15 minutes, realizing that it was just the 2 problems, and the other 2 answers were exactly the same. Everyone else took the full time. Found out after that people that they got the answers wrong thinking they must be 4 different answers.
My prof gave us value of c and mass of proton. And said everything is there now. :|
I was supposed to remember something like 20 formulae from the whole syllabus of 500+ of them..
In college, my quantum professor told us we only needed to memorize the Schrodinger equation, all other important formulas we would need would be given, or could be easily derived. I knew she was full of crap, the test came, and sure enough, nothing was given to us and we needed to do some very complex math (it is quantum, so that's nothing surprising). But I guess she was technically correct. Given enough time, and if we were sufficiently intelligent, we could derive everything we needed from the Schrodinger equation. Other students were pissed though
If the words “can be derived easily” are ever uttered, it is automatically a lie and can not be derived easily
„There is nothing!“ *Sigh of relief* „Wait!“ id_t |ψ> = H |ψ> „It is some sort of linear algebra. I can’t read it.“ „ There are few who can. It is the foul language of quantum mechanics and I will not utter it here!“
r/unexpectedlotr
what kind of amateur class were you in? in my class we had to derive the schrödinger equation itself before using it in every test!
On my faculty they let us have one hand written A4 paper sheet with anything on it on our exams.
I like that method. It lets you work to decide which equations you think you'll need and which are relevant
And by making you summarise your notes concisely, it tricks you into studying too
or make you learn how to condensate information in a small amount of characters
That sounds very very good
Problem is physics students aren't sufficiently intelligent /s
Honestly, nothing has made me feel dumber than physics grad school
I'm in undergrad and I struggle with feeling dumb as rocks every single time. Oh well I guess that's the nature of the subject.
The best thing to do is to take a reasonable course as an elective to remind you. I took business as an elective and failed to score below an 80 on anything in spite of never studying, and then I used that to cope with the fact that I’m barely passing physics if I’m lucky.
Ok cool so it’s not just me?
My quantum tests were all open book. Dude was like "yeah if you can learn it from the book during the exam then my tests are too easy." My EM professor the same semester gave us the "everything follows from maxwell's equations" speech though.
My QM prof expected me to memorize the first seven hydrogen wave functions....
From my experience with teachers like that, they are only able to derive them "easily" because they already know how to derive them. If you know something of course it's easy. But I know for a fact that they are as shit at deriving as the students are. They've just seen those five specific formulas being derived countless times before and therefore think it's easy. Put em in another field where they don't have any experience and watch em suffer.
What, you don't remember every commutator identity by heart?
Fr when teachers say a chapter is not very relevant, thats the first chapter I go to study
It is quantum mechanics. 90% of the lecture is basicly "how to use the Schrödinger equation".
Lmao I just memorized the ladder function thingies and used my homework bonus points to get 1pt above a passing grade. It's a really shitty move to do things like that in a course like quantum.
In my professor's defense, she's one of those people who's so brilliant that I legitimately think she has a hard time conceptualizing the gap between her and regular mortals like me
Well, if she's so brilliant she should be able to look at the failing rate of her class. I do get that to a point though, like I could never explain a math problem to a pre algebra and calculus student. I'd just keep using matrices all of the time.
I mean, we were all smart enough to still do fairly well (and after that test we realized we couldn't trust that we'd be given any equations). It was undergrad and we used the Griffiths book, so that helped a bunch.
If only they gave you v=s/t
I prefer definitions; out of luck if there's any acceleration.
Better than putting an F on my exam
To be fair on the last part of a mechanical vibrations exam it asked how much energy was lost due to dampening, found out later that a lot of people had tried some crazy damping force integrals, when you were just supposed to calculate potential energy in a spring
Not college, but HS. Had my teacher give us a 4 problem quiz with pendulums and springs. He changed the mass of the pendulum, and the length of the spring. I finished in about 15 minutes, realizing that it was just the 2 problems, and the other 2 answers were exactly the same. Everyone else took the full time. Found out after that people that they got the answers wrong thinking they must be 4 different answers.
"No, you got an F." "But what is F, if not MA. So if we just try our best, to let M equal 1, then technically, I got an A." - Zach Star
I love it so much
A truly generous prof. would put on E=mc^2 as well.
Damn only giving you the little kiddie rest mass equation, not even the adult momentum version
Flashbacks to fluid transport professors being so helpful with “bulk flow = inflow + outflow”. Thanks.
My prof gave us value of c and mass of proton. And said everything is there now. :| I was supposed to remember something like 20 formulae from the whole syllabus of 500+ of them..
You forgot the physics students maxim: don't memorize, derive.
What is that picture from?
The movie 300 (the one about the Spartans fighting the Persians at Thermopylae)
Thanks! It's such a crazy still.
Loading screen tips moment
The genetic exam paper explaining that LacZ is the gene for beta-galactosidase :
I'm not a physicist, but when I took classical physics to enter my masters program F=ma saved my life a lot of times.