r/Physics

Hi everyone. I'm currently in my 2nd year of a physics degree, but I didn't do very well in my 1st year.

My biggest problem isn't that I don't want to learn physics. Actually, I really want to understand it. The problem is that whenever I get stuck on a calculation, a derivation, or the intuition behind a concept, I don't really have anyone who can explain it to me.

The professors at my university aren't very helpful with this. Sometimes it feels like if you can't understand something immediately, you're treated as if you're not smart enough to study physics. Because of that, I'm honestly afraid to ask questions.

My friends aren't much help either. Most of them are mainly interested in getting the degree, so they study by memorizing previous years' questions and formulas rather than trying to understand the material deeply. I don't really have anyone around me who wants to sit down and discuss why something works.

I've been watching MIT OpenCourseWare lectures on YouTube, and they're really good, but I still don't understand everything. I often pause because I have questions about a particular step or concept, but then I don't know where to ask those questions. That's one of my biggest problems.

I've also tried ChatGPT and Gemini. They can explain things, but I'm not always sure whether the intuition they're giving me is actually correct. Sometimes an explanation sounds convincing, but I don't know how to verify that I'm not learning a wrong or oversimplified mental model.

So I'm wondering:

Are there any apps, websites, AI tools, textbooks, or other resources that you would recommend for:

• Understanding the intuition behind physics concepts
• Going through derivations step by step
• Explaining why each step of a derivation is valid
• Helping when I get stuck on the mathematics/calculation
• Checking whether an intuitive explanation is actually physically correct
• Building problem-solving intuition instead of memorizing formulas
• Rebuilding weak 1st-year foundations while continuing with 2nd-year material

I'm especially interested in resources that are good for university-level physics (mechanics, E&M, thermodynamics, quantum, mathematical physics, etc.).

I'd also really appreciate study tips from physics students who have been in a similar situation. How did you go from memorizing formulas to actually understanding the subject?

I don't mind spending a lot of time on something if it genuinely helps me understand it. I just don't want to keep memorizing past exam questions and feel like I'm learning nothing.

Thanks in advance. Any advice, resources, communities, or study methods would be greatly appreciated.

[supprimé]

I've been reading through an old thread from r/explainlikeimfive on false vacuum decay and it's potential effects on matter throughout the known universe should it occur. If it's possible that this decay has occurred before, we live in the resulting state in matter. It's something that could theoretically occur again at any given moment and would be instantaneous. While reading this stuff, I'm constantly wondering if this potentially has any connection to the big bang?

A huge release of energy from a single particle, resulting in a chain reaction between any other particles in the proximity sounds a lot like the big bang to my non-physicist brain.

Hey there fellow physics enthusiasts!

I've written the first part of a series of articles that will help explain Schrödinger’s equation intuitively and simply. Part one talks about everything that led up to the making of the Schrödinger equation:

https://medium.com/@jeyubhavsar/schr%C3%B6dingers-equation-for-dummies-part-i-historical-overview-92250056f33b?sharedUserId=jeyubhavsar

(This is the edited version, please if you have time, read and give any feedback, thank you)

Hi everyone. I'm have passed by journalim field, I used to be one. But now I started to study physics at the university, and looking for anyone that was in the same situation as me.

I appreciate the idea of trying to come up with an intuitive picture of gravity. But to the self studied or aspiring physicists: please read this first

Every day I see countless posts asking “what if gravity was actually a jargon jargon jargon flux???” and then an actually half decent question buried in a mountain of LLM junk. There was some idea or realization that you had that would be really cool to talk about… but then you slop it up by trying to explain it with math despite not dedicating years of your life to these really subtle questions (like academics do)

So, I wanted to talk about a few points that I regularly see in crackpot posts.

First, the graviton. For some reason, people hate the graviton and come up with ideas to try to make it go away. I think it’s just because we haven’t detected one directly… but this makes it seem like the graviton is like an electron or proton or something. that’s not what the graviton is. that’s not what a particle is.

i mean, ok it is what a particle is but that isn’t how you should think of it. what a graviton is, is the gauge boson for gravity. that means it is the force carrier. if you put two electrons near each other, they will interact. the quantized unit of interaction between them is the gauge boson (here the photon). that is what the graviton does for the gravitational force. it is simply the smallest little excitation in the gravitational field

if you assume there exists a gravitational field, and IF this field is quantized (so you get quantum mechanics) then the graviton is just the quantum of gravity. that is it. you don’t have to fight it.

now, this gravitational “field” ends up being what you think of as an aether. all of the aether posts: you’re just reinventing a field but now things interact improperly.

the way the standard model works, every point in spacetime gets a little tiny bit of information tied to it. a phase. it is undetectable*. as you move through space, imagine making a little loop. when you get back to where you started, you accumulate some phase. the amount you accumulated is the strength of the field. this is the gauge field

you don’t need an aether. you’re asking for the gauge field. it is a real thing.

if the gauge field has a symmetry, Noether’s theorem tells us there is a conserved quantity which corresponds to it. Throwing away a bunch of subtleties, this means we’re basically allowed to pick whatever symmetry of nature we want, assign it to a gauge field, and then see what physical consequence pops out. you need a lot of topology and group theory to do this right

and won’t you know it, when you break these symmetries, other stuff happens. the breaking of a very particular symmetry makes the fields “feel” some directions more than others. it makes some fields feel it more than others. the symmetry breaking of the higgs field is what makes the higgs mechanism work (you may have seen that the higgs is like a “friction” that particles feel).

to end my rant, stop trying to reinvent the wheel. you’re all making sharp and unroll-able wheels. almost every physicist throughout history made wheels that didn’t go anywhere, and it was only through the combined effort of peer review and traditional academic research that progress was made and the holes were patched up. I really hope you dedicate time to learning the absolute beauty that others have figured out rather than trying to make a name for yourself. you’ll be so much more fulfilled and understand our universe with the best of us.

btw for some reason when I posted this last night reddit took it down so I am reuploading now

Is there any evidence that nature is fundamentally continuous, or could reality be fundamentally discrete? And if it is discrete at the most basic level, would that suggest that nature could behave like a computational system?

This is a dedicated thread for you to seek and provide advice concerning education and careers in physics.

If you need to make an important decision regarding your future, or want to know what your options are, please feel welcome to post a comment below.

A few years ago we held a graduate student panel, where many recently accepted grad students answered questions about the application process. That thread is here, and has a lot of great information in it.

Helpful subreddits: /r/PhysicsStudents, /r/GradSchool, /r/AskAcademia, /r/Jobs, /r/CareerGuidance

Hi community,

I just learned that I will be TAing an intro calculus based physics course during my first semester of my MS. I’ve been out of academia for a couple of years, and am wondering if there are any pdfs or YouTube lecture series anybody would recommend to get the gears turning again.

Hi Everyone,

What are the best universities in Europe/America with PhD programs for Gravity/Quantum Gravity and Cosmology? I know mainly I should look at researchers/professors papers and start from there, but what are in your opinion the best centers/universities where these topics are currently being researched?

Should I take a String-theory course since many of the researchers I see, especially in America, appear to be in that field as well?

So I've just graduated my last year before uni and will go on to study physics.

I have a nice desktop to run things with and code on, problem ofcourse being that it's not something I plan on moving.

I will need a laptop and haven't a clue which one, so i'd like to ask physicists here what the minimum stats should be fore this laptop, my university (Ughent) wil obviously give us some pointers as to which ones, but I recon it shouldn't hurt to ask you.

I do not plan to plan games on it as I have a tendency to get saicked up in playing those, time I can not afford to lose.

Hello everyone, I would like an opinion on this computational physics project that I've developed over the past few weeks. The image shown is part of the animation gif that you can check on my Github repo. In this simulation a fusion between two alpha particles is shown and after the collision, as you can see, the new nucleus starts to oscillate.

If you have some time just try and run it on Google Colab (I've left the Jupyter Notebook file).

https://preview.redd.it/dbqubpvylckh1.png?width=840&format=png&auto=webp&s=c575567aa44ff020f2363752a33ce5556a9399c3

I tried to build it as scientifically accurate as possible, this means that the simulation you will see in the video is not "fluid" dynamics, but real wavefunctions that constantly interact. Clearly, I had to employ an approximation which does not consider a single n-dimensional function (which gets a computational monster), but instead considers the mean field generated by the n particles.

The next step should be the 3D one, but we'll see. Right now I think that this project already captures quite some phenomena.

I’m watching Oppenheimer and my mind is wandering a bit because the movie is losing me somewhat. I remember reading a book by Bill Bryson called “A Brief History of Nearly Everything” about a decade ago. What came to my mind were parallel chapters: one about Isaac Newton and one about Albert Einstein. The first, about how Newton came up with a new math (calculus) to explain the orbits of stars and thus the impact Gravity ultimately has on the Universe. I know that narrative is challenged, that Newton didn’t invent it on his own, but let’s put that aside for a second and give him his law of Universal Gravitation and the inverse-square law and go to Einstein. In the Einstein chapter, Bryson basically gushes about how the General Theory of Relativity was a thought that came out of seemingly nowhere.

Now here’s the thing that has me thinking. Put aside the strict distrust that the Church had and its influence during Newton’s time and give him fiat to have all his own thoughts. Could Newton have logically come to understand Relativity as we know it (or as it was understood during Einstein’s lifetime) using the knowledge that he has accumulated, or would he need the two centuries between them to arrive at the theory? We know Newton spent his time thinking about all sorts of things (like “alchemy”, which…apparently we can now do thanks to the LHC) but if he stuck on gravity, could he have arrived at the revision of his own law of Universal Gravitation and add the other geometries to come to Relativity?

I know that looking at it from our side of history, it doesn’t seem to be that big a leap; but when i put myself in the concrete mindset of Newton, it’s difficult to imagine the extra dimensions that relativity requires. I can’t see how he could up with it. I can’t see how Einstein came up with it for that matter anyway.

Sorry for my ramblings TL;dr…could Newton have revised his gravitational laws in his lifetime to align with Relativity based on the knowledge he possessed?

Hi i am in iraq so i can't get a diffustion pump from outside i found a supplier which seems promising which supplies Dc-704 i found on alibaba that they are EXPENSIVE and for the relatively simple design i want to have a local machist do it for me for wayyyy lower price but if there is a cheap diffusion pump then tell me and because i currently don't have roughing pump so i want to get one sufficient to do the foreline for the diffusion, my english is bad i know but please if you know how to help tell me

Edit #1 : This is For Electron Tube and basically for homemade sem So i want to ideally reach 10-7mbar and i am on a quite tight budget so i can afford the oil once 3 months or so and from what i understand diffusion pump is simple in geometry so it shouldn't be expensive? so that's why i chose it over turbomolecurer pump which is EXPENSIVE

I am a 15 year old in india I genuinely love physics and maths the proofs and the derivations are what I truly love but a career in it is extremely guarded by pedigree in india you have to get your bachelors from IIT, IISC or IISER only then you can get a phd from a good University outside India because I don't wanna get a phd from India as it needs you to cram for national competative exams even in university and I am insanely bad at giving exams even in physics and maths and I WANNA do reasearch I even tried to do research on laser behaviour(I tried coding a prediction model which basically checks weather a laser beam will be detected by a BH-1750 sensor, while it is honestly bad it was a unique experience and for once I actually kinda enjoyed coding other than manim)but I had to stop because of my 10th board(a national exam) prep and couldn't even understand the sensor and how light behaves with it and overall I don't even think I took the right sensor. But then I just don't feel like I can even have the wifi to give the competitive exams and leaving the country for undergraduate is honestly not an option as US the most direct answer to a non so exam way is insanely subjective and I have seen ppl online complain about how just because an AO is in bad mood they can just reject you and I also need aid meaning my choice of schools is even more low.

I just feel like I have to do a b.tech like most Indians do because physics is just so guarded by pedigree and I have seen online about an university name University of Hyderabad which has a really good BSC+MSc physics integrated program but then it probably won't clear the pedigree bar.

And I kinda feel hopeless and I really need some advice because I am not scared of the chances but lacking a fair shot at a phd selection room where my file gets discarded just because I don't have the IIT tag.

I might be wrong but I am honestly kinda actually completely lost in what i should do because physics degree does allow you to be a quant but i wanna do just physics and physics only.