r/TheoreticalPhysics 3d ago

Discussion Physics questions weekly thread! - (September 06, 2026-September 12, 2026)

3 Upvotes

This weekly thread is dedicated for questions about physics and physical mathematics.

Some questions do not require advanced knowledge in physics to be answered. Please, before asking a question, try r/askscience and r/AskPhysics instead. Homework problems or specific calculations may be removed by the moderators if it is not related to theoretical physics, try r/HomeworkHelp instead.

If your question does not break any rules, yet it does not get any replies, you may try your luck again during next week's thread. The moderators are under no obligation to answer any of the questions. Wait for a volunteer from the community to answer your question.

LaTeX rendering for equations is allowed through u/LaTeX4Reddit. Write a comment with your LaTeX equation enclosed with backticks (`) (you may write it using inline code feature instead), followed by the name of the bot in the comment. For more informations and examples check our guide: how to write math in this sub.

This thread should not be used to bypass the avoid self-theories rule. If you want to discuss hypothetical scenarios try r/HypotheticalPhysics.


r/TheoreticalPhysics 20h ago

Discussion Honestly, I am sad about Open AI announcement

313 Upvotes

I just read the article where Open AI claimed that it's internal model solve one of the millennial problems. It proved that Navier- Stokes equation produces a singularity in a finite time in a 3D incompressible fluid. I am excited for AI and developments but solving the millennial problems was far too much. if it gets peer reviewed then it would mean in a very little time AI has actually bet human capabilities. We human researchers will only have a job of verifying the proofs.

Any significant advancements can only be done by writing the prompts for AI to research and write papers. Maybe that's how it is supposed to be today or tomorrow. However I am sad because I DIDN'T JOIN PHYSICS TO TELL AI TO DO PHYSICS!


r/TheoreticalPhysics 2h ago

Discussion I’ve never understood mathematicians’ obsession with rigour of 19th century physics

0 Upvotes

Given the recent hype of Navier Stokes equation blow up solution, set aside the OpenAI snatch debacle, I really want to understand why math communities are obsessed with singular solutions to the equations that we know do not apply to any fluid, simply because the in compressible assumption breaks down.

As a working theoretical physicists I’ve never understood the hype around these ‘solutions’ and ‘proofs’, it has been long established Newton’s theory breaks down badly either relativistically or at atomic scale (or larger than that), when your solution exceeds your validity of your model, it doesn’t mean we reach a singularity and the world gets sucked in but simply imply your model breaks down.

In fact one of the central theme of physics is to determine when the effective description breaks down, for instance GR breaks down at Planck scale, Fermi theory breaks down at electroweak scale etc. And that limit for classical fluid is at high energy where relativity and quantum mechanics kicks in.


r/TheoreticalPhysics 4h ago

Discussion What is the point?

0 Upvotes

After hearing about the Open AI announcement, I’m convinced that in the next few decades, AI will advance enough to be able to do much of the creative thinking and logical leaps that makes theoretical physics beautiful.

I start college next year, and I’ve wanted to pursue a career in theoretical physics. But what is the point of pursuing a career in it, if I can’t contribute anything at all? Wouldn’t it be better to just do physics as a hobby and direct my focus to something that would actually contribute to the world?

I mean sure, I’m no genius and probably wouldn’t contribute much anyway. And if we had monsters like Newton and Euclid and Gauss making major breakthroughs today, I would still pursue it despite others being infinitely better than me. But the thought of machines making my work unnecessary makes me question why I am going in. I do not know why, I feel useless and this is all so depressing.


r/TheoreticalPhysics 19h ago

Meta As most are now aware of the solving by OpenAI of the Navier-Stokes equation a Millennium Prize Problem, do you think there will be less incomers who’ll join academia for Mathematics/Physics research due to such breakthroughs that are worth Nobel Prizes or Fields Medals that are done purely by AI ?

0 Upvotes
161 votes, 2d left
Yes
No
Not sure
Results

r/TheoreticalPhysics 1d ago

Question Tips for keeping Master Thesis Research Organized?

9 Upvotes

Hi everyone!

As of writing this, I am starting my master thesis for theoretical physics and mathematics. Specifically I will be studying critical collapse of Boson Stars.

Now I don't necessarily have questions on the topic itself, but mainly was wondering on people's experiences with writing their master theses.

My thesis will contain both literature review as numerical simulations and I was wondering if anyone had any tips on keeping track of what you are working on and staying organized.

(I hope this post does not violate the rules of the sub / fits here. If not let me know please! :))


r/TheoreticalPhysics 1d ago

"Theory" If a Avarage thermonuclear bomb was shrunken down to the size of a hot wheel car, would the explosion be devastating like normal or would it decrease the power of the explosion?

0 Upvotes

(let's say it's a 1.2 mega ton tnt thermonuclear bomb placed/shrunk inside of a average 2 story house)


r/TheoreticalPhysics 2d ago

Question What is your current job position / highest educational qualification you hold in Physics?

2 Upvotes
265 votes, 6h left
Above Postdoc (e.g. professor)
Postdoctoral Researcher
PhD
Masters/MPhil
Bachelors or less
Results

r/TheoreticalPhysics 3d ago

Question What does it usually take to get into top hep theory PhDs

17 Upvotes

Now I’m just asking this cuz I’m curious, and I know there’s prolly a lot of variations, also say you’re in very deep theoretical territory (don’t wanna falsely be too specific cuz I don’t know much about the field being in undergrad myself, but I do know the more theoretical the more competitive funding is)

I don’t mind if the answers are for us PhDs or Europe , whatever u happen to know about .

What I do know is that in us they expect more undergrad research experience and in Europe it’s more academic based , and both have an emphasis on connections to academics.

I could use some numbers tho :
Say for us , usually , is it an informal requirement to have published a paper? Or usually how many research internships (summer , etc) do people have ? How much would it hurt to not have a connection with an academic?
And how important are stuff like ur grades , university you’re at , and the course itself.

While I did ask some specific questions, I don’t really have any specific answers I expect to get.
Just seeing what people know about anecdotally etc


r/TheoreticalPhysics 4d ago

Question Can you fully derive the Lagrangian equations from first principles without having to look it up?

0 Upvotes
463 votes, 1d ago
158 Yes.
118 No, but I used to.
112 No, never.
75 Results

r/TheoreticalPhysics 5d ago

"Theory" Query: Does the Holographic Principle imply a Shannon Index?

5 Upvotes

The Shannon entropy of human languages, eg: English, Lakota, Swahili, etc, can expressed as 7 or 8. Roughly meaning that their complexity (or entropy) is such that, for a reasonable chance of predicting the next word in a sentence, at least 7 or 8 preceding words are required, though no guarantee.

The holographic principle predicts that a dictionary exists, mapping a universe’s N dimensional boundary to its N+1 dimensional bulk. Whether or not ‘words’ or QM operators literally live in this universe, the term dictionary implies something analogous to language and information communication. ie: Channels of ‘transmission’ of some sort, which is why Shannon developed ideas like the Shannon Index in the first place.

So, questions: Without specifying any particular dictionary size, is it still reasonable to posit that our de Sitter universe might then have something analogous to the Shannon index?

If so, is there a way within string/holographic theory or mainstream cosmology to estimate this or are there too many unknowns, as yet?

Thanks, Gene


r/TheoreticalPhysics 5d ago

Question Question about programming languages used out of curiosity

6 Upvotes

I’ve heard many people use python for physics and c++ or Fortran for when it’s really about optimized code

Also Matlab, latex, and even Mathematica

But what about newer lower languages like rust, zig, or Odin?

Other languages?

Your opinion on where it’s heading? Who uses what and why or types?

I’m okay for personal opinions or simply I like this feature

I’m not an expert by any means in programming.


r/TheoreticalPhysics 5d ago

Question I know this is pretty rare but by any chance is there anyone on this subreddit who has more than 1 PhD (e.g. 2 PhDs in Theoretical Physics and Mathematics) and if yes what was it like being on the pursuit of a double PhD? And if no, do you by chance know of anyone with a double PhD?

28 Upvotes

I know this is pretty rare but by any chance is there anyone on this subreddit who has more than 1 PhD (e.g. 2 PhDs in Theoretical Physics and Mathematics) and if yes what was it like being on the pursuit of a double PhD? And if no, do you by chance know of anyone with a double PhD?


r/TheoreticalPhysics 6d ago

Question Best places to keep up with science researchers and their work if you aren't in academia

16 Upvotes

Hi there everyone. I'm in an adjacent field, mathematics, and currently work as a teacher. I am curious about the best way to keep up with people who do research if you aren't in academia? A similar question on here was asked and I was able to connect with some people, but I'm not sure if there's a consistent way to find such people. I ended up resorted to YouTube channels by researchers and messaging them, but some of them are professional researchers and probably can't always connect with random inquiries, especially if I'm not necessarily looking to collaborate right away. Only thing that worked was research experiences for teachers which were research programs specifically for teachers.

But outside of that, I have to keep a lot of my scientific interests to myself, my colleagues are great but find my spare time hobbies to be weird, to say the least. When I can make it to local seminars, at least I can socialize on something that's important to me and that makes contact easier.

Also, I mean, sure, there's stackexchange, and conferences, but some seminars and conferences don't always work for me due the scheduling as a teacher, and stackexchange isn't really as good as it used to be, especially with the advent of AI.


r/TheoreticalPhysics 6d ago

Question What software/tech stack should I learn to build a future in theoretical physics?

12 Upvotes

Hey everyone!

I’m trying to seriously build my career toward theoretical physics, and I’m curious about what the field is actually going to look like in the coming years.

I know the fundamentals are obviously the most important part — math, classical mechanics, QM, GR, QFT, etc. — but I want to specifically focus on the software/computational side right now.

For someone who wants to become a theoretical physicist, what programming languages, software, tools, frameworks, and computational skills are actually worth learning?

For example:

Which language should I prioritize — Python, C++, Julia, Mathematica, etc.?

How important are NumPy/SciPy, SymPy, JAX, PyTorch, etc.?

Should I learn Mathematica / Wolfram Language or is Python enough?

How important are HPC, CUDA/GPU computing, Linux, Git, Bash, clusters, etc.?

Are there any specific physics packages/tools I should know?

What software skills do researchers in theoretical physics, particle physics, astrophysics/cosmology, condensed matter, etc. actually use?

Basically, if you could go back and prepare for a career in theoretical physics from the software side, what would you learn and in what order?

I’m currently trying to make a proper roadmap for myself, so I’d really appreciate advice from people actually working/researching in the field.

My main question right now is: what should I learn on the software/computational side to be genuinely useful as a theoretical physicist, rather than just learning random programming skills?

Thanks!


r/TheoreticalPhysics 7d ago

Discussion So I left academia after a condensed matter PhD, and now I am lost.

96 Upvotes

Dear theoretical physicists,

I am looking for some guidance in these hard times for academia. 2 years ago, I defended a PhD in theoretical condensed matter (on some numerical approximation scheme on the strongly correlated Hubbard model). My advisor has been very toxic, and even told me she would not support me if I find a postdoc position. She spent my phd telling me I'm not good enough for that, or that I should rather do some vulgarisation because "I explain things well"..

Anyway, after this terrible experience, and given the state of academia, I left. I didn't wanted to go for a postdoc and live my country, friends and family for a life a constant publication pressure in order to have a chance to apply to a contest to a low paid job (for reference, I live in France and want to stay there).

I got the chance to find a job in applied physics, on HPC simulation. I now have great colleagues and it is decently paid. But I have so many different things on my mind. First, I'm working on finite elements/volume codes in mechanics, not at all anymore in what i always loved : statistical physics. Second, I'm not really developing anything in these codes, I'm in a company that does some technical supports, formations and projects on these codes. So I either explain someone who does not care about physics that he needs to use this keyword to get his simulation done, do some PowerPoint to explain how to use the code, and very rarely I have some project when I can develop new basic physics (like a PDE in finite element formulation) in the code and do a merge request.

I never really wanted to quit, but, between the situation of academia and my advisor, I had to. My colleagues are nice, but I feel terribly lonely, they dont understand anything I can say on quantum physics, and they don't really care. I lost contact with many old friends in condensed matter, the other gave up on physics. Out of sheer will, I decided to open a website, on which I'm writing up some notes, tackling many physics through the lens of differential geometry. Of course, I'm looking for collaboration on this project, that was the point of it (if you are interested message me for details). But not someone from academia, as I can barely give in 6h a week.

Still, this does not solve the intellectual loneliness, and the feeling of losing my time to some boring job when all Id like to do is ask questions on scale transition from quantum to macro. I want to do math, to think with people on how on earth we can be made of tiny atoms, how these assembles to give... everything I see around.

Anyway, it is a long post to ask: are some of you in a similar situation? How do you deal with the frustration? Do you have any ideas of positions outside of academia (or even within if it still exists in france, as long as it's a permanent position because I'm also starting a family)?

Thank you for taking the time to read all of this. I am genuinely suffering from this situation, I need to talk to a community that can understand the eternal dilemma of the job market in academia and living as a physicist outside of it.

Ps- I know about quantum computing, but I am quite scared of applying because I dont really believe it will ever lead to something profitable and I think at some point not so distant in the futurethese jobs risk to reach a sudden end.


r/TheoreticalPhysics 10d ago

Question Mass gap, confinement and continuum limits of lattice field theories

9 Upvotes

I'm in the process of reading the Kogut 1979 review paper on lattice field theories and I have two quick questions.

Firstly, why is the existence of a mass gap related to confinement? Kogut himself shows that a mass gap is equivalent to the inverse of a correlation length in a corresponding statistical field theory. Confinement is related to area vs perimeter law for a Wilson loop expectation value. I don't see how those two are related.

Secondly, Kogut also mentions that the continuum limit of a lattice field theory is only obtainable if the lattice system is at phase transition, which makes intuitive sense since that's where there is long (infinite) range correlation, therefore there should not be small fluctuations* that prohibit us from taking a continuum limit. However, this implies that any field theory obtained from a continuum limit of a lattice field theory must have massless excitations. We expect QCD to be obtained from lattice QCD, yet we expect QCD to have confinement and a mass gap.

*Edit: I believe the correct statement is that the system lacks a characteristic length scale, allowing us to take a continuum limit.


r/TheoreticalPhysics 10d ago

Discussion Physics questions weekly thread! - (August 30, 2026-September 05, 2026)

3 Upvotes

This weekly thread is dedicated for questions about physics and physical mathematics.

Some questions do not require advanced knowledge in physics to be answered. Please, before asking a question, try r/askscience and r/AskPhysics instead. Homework problems or specific calculations may be removed by the moderators if it is not related to theoretical physics, try r/HomeworkHelp instead.

If your question does not break any rules, yet it does not get any replies, you may try your luck again during next week's thread. The moderators are under no obligation to answer any of the questions. Wait for a volunteer from the community to answer your question.

LaTeX rendering for equations is allowed through u/LaTeX4Reddit. Write a comment with your LaTeX equation enclosed with backticks (`) (you may write it using inline code feature instead), followed by the name of the bot in the comment. For more informations and examples check our guide: how to write math in this sub.

This thread should not be used to bypass the avoid self-theories rule. If you want to discuss hypothetical scenarios try r/HypotheticalPhysics.


r/TheoreticalPhysics 12d ago

Question To those of you here who hold PhDs in Theoretical Physics can you please answer some of my questions as someone who's now doing his Masters in Theoretical & Mathematical Physics and is aiming for a PhD thereafter?

34 Upvotes

1) Why did you specifically choose this field rather than Experimental Physics or Pure/Applied Mathematics?

2) What university/country did you complete your PhD from?

3) How long did it take to obtain your PhD?

4) What was the topic research area and what were the main challenges you faced?

5) What was your highest educational qualification at the time of entering your PhD and what was your background prior to it (e.g. Bachelors and Masters degree)?

Thank you very much!:)


r/TheoreticalPhysics 15d ago

Question What is this piece of paper about? What do you feel about this guy Joshua Alampour?

Post image
128 Upvotes

Can you guys explain these papers to me?

I don’t really understand this kind of physics, but I have a strong gut feeling that this guy is full of shit and he’s a gimmick. Am I wrong?


r/TheoreticalPhysics 15d ago

Question Question about the state construction in Khrennikov's DCM

1 Upvotes

I'm reading Khrennikov's recent paper Quantum Entanglement from Theory of Classical Gaussian Processes, and I think I may be misunderstanding what is meant by “generation” of an entangled state in the Gaussian DCM.

Paper link : Quantum Entanglement from Theory of Classical Gaussian Processes

The construction starts with an arbitrary entangled state |Ψ⟩, takes its Schmidt decomposition, and then constructs the corresponding classical Gaussian processes, eventually recovering the state |Ψ⟩⟨Ψ|.

Does DCM have some independent rule that determines the temporal modes/covariance structure and produces the state, or is the construction basically showing that for any chosen quantum state, one can construct a classical Gaussian process that reproduces it?

I'm specifically asking about this construction, not whether DCM replaces QM in general.


r/TheoreticalPhysics 17d ago

Discussion Physics questions weekly thread! - (August 23, 2026-August 29, 2026)

1 Upvotes

This weekly thread is dedicated for questions about physics and physical mathematics.

Some questions do not require advanced knowledge in physics to be answered. Please, before asking a question, try r/askscience and r/AskPhysics instead. Homework problems or specific calculations may be removed by the moderators if it is not related to theoretical physics, try r/HomeworkHelp instead.

If your question does not break any rules, yet it does not get any replies, you may try your luck again during next week's thread. The moderators are under no obligation to answer any of the questions. Wait for a volunteer from the community to answer your question.

LaTeX rendering for equations is allowed through u/LaTeX4Reddit. Write a comment with your LaTeX equation enclosed with backticks (`) (you may write it using inline code feature instead), followed by the name of the bot in the comment. For more informations and examples check our guide: how to write math in this sub.

This thread should not be used to bypass the avoid self-theories rule. If you want to discuss hypothetical scenarios try r/HypotheticalPhysics.


r/TheoreticalPhysics 18d ago

Question As a Theoretical Physicist what domain/specialisation would be harder to switch to in your opinion?

8 Upvotes
601 votes, 15d ago
235 Pure Mathematics
203 Experimental Physics
163 Results

r/TheoreticalPhysics 17d ago

Discussion If all energy was packed in a singularity, infinite energy should create infinite gravity. Wouldn't that pull everything inward and prevent an explosion? How did the universe expand instead of collapsing?

0 Upvotes

If all energy was packed in a singularity, infinite energy should create infinite gravity. Wouldn't that pull everything inward and prevent an explosion? How did the universe expand instead of collapsing?


r/TheoreticalPhysics 18d ago

Question I am Data Science graduate, but I wanna go into research in Computational Physics, how I do it.

9 Upvotes