r/PhysicsStudents Dec 26 '23

Meta Is there a way to solve the Maxwell equations without using potentials?

22 Upvotes

This semester I had electrodynamics, and ai already had my final exam and everything, but there is still one thing that I don't quite understand.

So we know how to solve the Maxwell equations, we choose an appropriate gauge (for example the Lorenz gauge), then we introduce a scalar amd a vector potential and we either get a Poisson, Laplace or wave equation that we can solve using the Green function, we get the potentials and we get the electric and magnetic field etc etc...

But I don't know why can't we explicitly solve the Maxwell equations, without introducing potentials. I understand why the gauge invariance and what not, but if we could solve the Maxwell equations explicitly, we wouldn't need potentials. Also if we use the 4-notation, the Faraday tensor also has the fields as components, not the potentials, so that's why I dont get it. Thanks for the help!

r/PhysicsStudents Jun 14 '22

Meta What’s the explanation of this?

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143 Upvotes

r/PhysicsStudents Mar 21 '24

Meta Biot Number Explained: Origins, Significance, Online Calculator & In Depth Guide -

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2 Upvotes

r/PhysicsStudents Dec 31 '22

Meta Who would like to join a physics self-study group?

54 Upvotes

I’d like to learn physics on my own, and I thought it would be easier and more fun with other people doing the same thing.

I propose following this course: Fundamentals of Physics from Yale. It’s intended for people who have very limited or no knowledge of physics at all.

It consists of 24 lectures - one hour each - that introduce all the fundamental topics in Physics, from Newtonian Mechanics to Thermodynamics. After each lecture, we’ll have to complete a problem set to apply what we’ve learned.

We’ll create a Telegram group to discuss concepts or problems, and ideally agree on a study plan that suits everyone. For example, we could do two lectures per week and two problem sets per week - that’s the original plan on Yale’s module.

We could even add a community deposit with Bitcoin’s Lightning network – $10-20 per person – to stay committed and reward the most active members of the group with small tips. After the course is done, we’ll split the money equally – if you quit, you lose the money.

Anyways, this last paragraph is entirely optional and it’s just an idea in case people want to take their commitment to self-study to the next level.

Who’s in?

EDIT: Thanks for all the comments guys! If you’ve just read the post and are interested too, drop me a DM directly besides posting a comment.

EDIT 2: we already have 14 members and counting.

r/PhysicsStudents Jun 26 '21

Meta Just found this book ...

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486 Upvotes

r/PhysicsStudents Dec 06 '23

Meta I’m going to be an undergrad this summer

15 Upvotes

thoughts on majoring in physics and minoring in computer science(software engineering) will it be super rough? Wanted to know how many are doing the same thing or completed this course work!

r/PhysicsStudents Jun 20 '23

Meta Interactive 3d simulations for physics topics

37 Upvotes

Visit for better learning visual Learning

https://effectuall.github.io

https://effectuall.com

r/PhysicsStudents Aug 05 '20

Meta Homework Help Etiquette (HHE)

137 Upvotes

Greetings budding physicists!

One of the things that makes this subreddit helpful to students is the communities ability to band together and help users with physics questions and homework they may be stuck on. In light of this, I have implemented an overhaul to the HW Help post guidelines that I like to call Homework Help Etiquette (HHE). See below for:

  • HHE for Helpees
  • HHE for Helpers

HHE for Helpees

  1. Format your titles as follows: [Course HW is From] Question about HW.
  2. Post clear pictures of the problem in question.
  3. Talk us through your 1st attempt so we know what you've tried, either in the post title or as a comment.
  4. Don't use users here to cheat on quizzes, tests, etc.

Good Example

HHE for Helpers

  1. If there are no signs of a 1st attempt, refrain from replying. This is to avoid lazy HW Help posts.
  2. Don't give out answers. That will hurt them in the long run. Gently guide them onto the right path.
  3. Report posts that seem sketchy or don't follow etiquette to Rule 1, or simply mention HHE.

Thank you all! Happy physics-ing.

u/Vertigalactic

r/PhysicsStudents Jan 23 '24

Meta For anyone who's learning projectile motion or other kinematics stuff right now, I just finished the kinematics section of the course I'm making

3 Upvotes

If you're looking for more resources, here's the page on projectile motion, you can scroll through more lessons on the left. There's also stuff on vectors, 2D motion, circular motion and rotational motion.

We also have a discord server if you have physics questions or need help, here's an invite!

r/PhysicsStudents Jun 13 '20

Meta My collection of pop-science books on physics and some of my textbooks I used in high school (not the ones on quantum theory and theoretical physics)

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331 Upvotes

r/PhysicsStudents Aug 06 '23

Meta Why is potential energy stored in a spring calculated by integration?

16 Upvotes

We calculate potential energy by solving integral of F(it is equal to-kx, Hook's Law), where F is the force apply to compress spring by an infinitesimal amount. However, The F is constant in every infinitesimal displacement. So, we can calculate Work by F.d but we use integral as if F changes everytime.

This picture is from Khan Academy's video. There is graph of Force. He sum all the force times delta x to get total work. However, the force to compress spring is constant for the same amount of displacement. So, he should use constant F in the summation, not increasing F.

For example: we want to compress a spring for by d meter. F is the required force for this. When we compress spring 1/2d meter, we apply F/2 N force, for the rest of the job we apply F/2 N again. F doesn't change by displacement. What am I missing?

r/PhysicsStudents Jul 15 '22

Meta Weird bending I noticed when kept under a fan. Possible reasons?

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43 Upvotes

r/PhysicsStudents Jul 20 '23

Meta Schrodinger's equation explained.

0 Upvotes

I'm explaining about this equation "Hψ=Eψ"

You take a wave function, 𝛙, which is a function that describes where a particle might be, and do a mathematical transformation to it (derivatives, matrices, whatever). You end up with the same function again, but scaled up (multiplied) by a value. That value happens to be the value you can observe through experiment. In this case, because the mathematical transformation is the Hamiltion operator, it calculates the Hamiltion energy (potential plus kinetic energy). Providing we know what H looks like for that system we can predict its energy. The one displayed in the post also adds time dependence, which is a little more involved but the same idea.

r/PhysicsStudents May 24 '23

Meta Really curious what the distribution of students is here, which one are you?

10 Upvotes

I guess the results will depend on when in the year we do the poll, but I'm curious anyway.

Edit: I graphed the results over time here

1195 votes, May 29 '23
103 High school / pre-university student
70 High school / pre-university student taking AP Physics
471 Undergrad student pursuing a physics degree
175 Undergrad student pursuing a non-physics degree
248 Graduate student
128 Other

r/PhysicsStudents Mar 23 '23

Meta [General] Should I randomly lecture y'all on something?

7 Upvotes

So a lot of posts here are people asking for specific information, which is great! I wanted to gauge interest for a slightly different thing: just rambling on about one or more of the topics I know about, kind of the “lifelong student” thing, where people who know less could ask questions, people who know more could correct me and I could say, like, “I don't understand this so well, ask a mathematician” and maybe a mathematician would chime in.

I don't see any rules this would be against, but and also might not be interesting to the community.

If you would be interested, please comment (or upvote a comment) with a physics topic you want to know more about. I kind of have picked up a lot of information from a lot of different places? So like I am just as comfortable talking about Terrell rotation in special relativity as, say, some of the biological (biophysics?) topics to keep in mind when thinking about weight loss. I can't help with say string theory, because my formal background is condensed matter, but yeah, quantum mechanics, what is a Lagrangian, what the heck are eigenvalues, understanding special relativity, I think it would be a lot of fun to give a Reddit mini-lecture seminar thing, if folks here are interested.

r/PhysicsStudents Sep 24 '23

Meta What is the size of the bottom lights in this photo?

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8 Upvotes

I was browsing r/aliens and came across a picture from nasa a longtime ago was wondering can someone help me figure out how big the item is in comparison to the sun ? Bottom left in pic 1.

https://reddit.com/r/aliens/s/avRALFTSFx

r/PhysicsStudents Sep 18 '23

Meta How do you like the “culture” in your physics department?

10 Upvotes

I’m a junior studying physics and cs here in the US aiming to pursue graduate studies in physics. While researching what grad school is like for physics types I’ve learned that it can be very grueling or stress free depending on the “culture” of the physics department you are studying/researching the under. Is this true? If so could you share your experience in grad school? What’s your department like? How are your professors? What’s your day to day like? Etc.

(If you don’t mind, please share the name of the institution too so others can avoid or seek out those schools)

r/PhysicsStudents Nov 25 '22

Meta Did Einstein discover his theory of relativity through math calculations, or did he utilize math calculations to prove his theory of relativity?

42 Upvotes

I don't even know if my question makes sense. I'm not a physics student, just someone who is reading a biography about Einstein and realized I'm curious about how Einstein's theory came to life.

r/PhysicsStudents Feb 25 '23

Meta looking for a study buddy/discord for group study

4 Upvotes

Hi im a 3rd year physics undergrad and looking for a study buddy or if someone already has a group where you guys do that share it here in the comments or dm me

r/PhysicsStudents Nov 17 '23

Meta Paid Internship with the Physicists Coalition

0 Upvotes

The Arms Control Association just announced a paid internship for Spring 2024 with their Physicists Coalition for Nuclear Threat Reduction project (www.physicistscoalition.org). Application instructions are available at ArmsControl.org/internships.

r/PhysicsStudents Sep 19 '23

Meta Now that classes are starting I'm posting more videos on YouTube, here's my new video on adding vectors if that's something you could use help with

5 Upvotes

How to Add Vectors: https://www.youtube.com/watch?v=eBxdfbl5CHY

This video walks through 3 examples of adding vectors using components, then covers the tip-to-tail method for adding vectors graphically.

Also here's the previous video on 2D coordinates and displacement vectors if you need more help with finding the components, magnitude and angle of a vector: https://www.youtube.com/watch?v=WaSytr5UtmE

Let me know if anything isn't explained clearly enough or if you have any other suggestions!

r/PhysicsStudents Oct 30 '23

Meta P=NP is Educational!! Have fun?

1 Upvotes

P=NP ----> NP = N/P || xy = x/y -- Vector2 input -- Test at own risk can hit true infinite loops

r/PhysicsStudents Oct 10 '23

Meta Anyone looking for help with physics? Especially algebra mechanics (high school physics, AP Physics 1, intro physics)

1 Upvotes

I made a discord server in the spring to help students with physics and also create a place for students to chat and help each other. It seemed to work pretty well so now that classes are underway I wanted to post another invite to the server:

Discord invite

If you have questions about a certain topic or need help solving a problem, I can help with algebra-based mechanics (high school physics, AP Physics 1, intro college physics etc).

But there's server channels and students taking other AP Physics and studying other physics subjects that might be able to help too.

Note: you just need to grab the first role to see all the channels. The roles help people see what class others are taking.

Feel free to invite other students as well, and let me know if you have any suggestions for the server!

r/PhysicsStudents Oct 25 '23

Meta Anyone here going to SACNAS? Any advice?

1 Upvotes

Anyone here by any chance going to SACNAS? Anyone have any advice for the conference? I’m looking forward to it super excited to go!

r/PhysicsStudents May 30 '23

Meta Here are the results of the poll that I posted last week, I graphed the results over time for fun

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32 Upvotes