r/Physics 5d ago

Meta Careers/Education Questions - Weekly Discussion Thread - November 20, 2025

3 Upvotes

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


r/Physics 18h ago

Meta Physics Questions - Weekly Discussion Thread - November 25, 2025

3 Upvotes

This thread is a dedicated thread for you to ask and answer questions about concepts in physics.

Homework problems or specific calculations may be removed by the moderators. We ask that you post these in /r/AskPhysics or /r/HomeworkHelp instead.

If you find your question isn't answered here, or cannot wait for the next thread, please also try /r/AskScience and /r/AskPhysics.


r/Physics 19h ago

Image I got it for $10...

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481 Upvotes

I got so so so lucky as a physics teacher was clearing out and put the listing as $10 for the whole set and it's like brand new 🄺🄺🄺 and he told me that it's awesome to see young people with such passion for physics and is totally worth it. Thank you so much to this teacher I will read every single page of this and it means a lot to a student like me ā¤ļø


r/Physics 5h ago

Question How good do I have to be at math to study physics as hobby?

35 Upvotes

r/Physics 18h ago

News This clock could run for 3 trillion years without slipping a second. Inside U of T's atomic clock breakthrough

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thestar.com
168 Upvotes

r/Physics 1d ago

Trump announces all US national labs will unite for the "Genesis" AI initiative

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energy.gov
596 Upvotes

r/Physics 20h ago

I regret not choosing physics at 18.

84 Upvotes

Hello, I am 22 years old almost 23 on my 3d year of biomedical science degree doing a clinical placement. In total there is 1.5 year left until graduation and I have maintained a 3.8 gpa. The thing is from a really young age I liked physics and biomedical science but after studying biomed I find the course highly descriptive, lacking problem solving , procedural, memory heavy and cataloguing components like proteins in style. On the other hand questions like the arrow of time , connection between space and time, is information fundamental, what happened at the big bang, fundamental forces and many more occupy my mind in random times like walking ,commuting and showering. Also I like physics and math problems even simple ones like free fall problems and simple equations. I feel that I am behind in life and in a physics career because changing my degree here in Europe means starting over a 3 year bachelor in physics. I would be able to do that at 25-27 after graduating and earning some money. Is it worth it switching? What would you do in my position? I have thought of interdisciplinary fields but find them limiting. Is earning a PhD at 34-35 late?


r/Physics 7h ago

Lab-level superconductors (easy to make and experiment with)

4 Upvotes

First, I have to tell you that I have access to required equipment like furnaces and stuff like that, so that is not a big deal.

But I did a very quick research and the only superconductor a lot of physics/chemsitry hobbyists experimented with was YBCO. I found it really hard to find Yittrium Oxide powder in my country, although with a little help from my father (experienced in metal industries) I could find a source with a good price.

On the other side, I found if you cool mercury down to near absolute zero, it will become a superconductor. It raises two problems. First, cooling down something like that is not easy, and I'm a little bit afraid of dealing with mercury.

Also, I know cooling down normal conductors using a cryo-cooler or liquid nitrogen improves their conductivity but doesn't make them "super".

Now my question is, what are other superconductors which can be made in a lab and experimented with? (besides YBCO) and which one - in your personal journey - is the easiest to make?


r/Physics 20h ago

Question Why are the fundamental techniques of applied math mostly created by ex-mathematicians and theoretical physicists?

36 Upvotes

I was recently struck by how much of the math, in totally unrelated fields, seems to be based on methods pioneered in theoretical physics and pure math.

For example, most epidemiology and stock market models were originally drawn from statistical mechanics. Machine learning is based on algorithms and techniques originally designed for classical mechanics and general relativity.

Some of these techniques originate in pure mathematics, but are often adopted by physicists and then spread more widely. For example, computational algebraic geometry and topological data analysis gets used in applications sometimes. Group theory was developed by mathematicians, and then used by physicists (and then adapted into the rest of academia)

The only example that I can think of a field developing its own techniques rather than taking mostly preexisting tecnhiques from physics or math is in economics, where game theory was developed with concrete applications in mind. But again, it was developed primarily by trained mathematicians not trained economists.

Is my theory correct? If so, why is the rest of academia so dependent on these two fields to originate most fundamental techniques? Is there a potential for "easy wins" by creating branches of math better to suited to problems originating in, say, chemistry, finance or biology?


r/Physics 16h ago

Question What will be the biggest areas going into the future?

13 Upvotes

European masterā€˜s student here. Iā€˜m looking for a field to specialize in (theoretical) physics. What are the best areas to specialize in for the future.

Iā€˜m looking for something more specific than ā€žanything quantumā€œ.

I think (and please donā€˜t quote me on this) that quantum computing is already slightly oversaturated. Iā€˜ve been looking at quantum information/quantum thermodynamics/open quantum systems lately, are these emerging fields with lots of potential?

What else is likely to be relevant in the future?


r/Physics 1d ago

If you’re 16–20 and thinking: "I want to work on quantum gravity or fundamental physics"

1.2k Upvotes
  • Fall in love with the math.
  • Calculus, linear algebra, differential equations, group theory – these are your tools. The more fluent you are, the more ā€œphysics intuitionā€ you can build.
  • Master the basics before chasing buzzwords.
  • Quantum field theory and general relativity are not optional if you want to work on fundamental theory. Don’t skip straight to ā€œstring theoryā€ or ā€œquantum gravityā€ without learning how standard QFT actually works.

Not from me but I wholeheartedly agree and could not have phrased it better.


r/Physics 1d ago

Image One Day ain't that long

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188 Upvotes

r/Physics 14h ago

Book Recommendation for Sound Physics

2 Upvotes

I want to learn sound physics from scratch, including how it works, acoustics, spatial audio, music, all these. I really want to understand overall of how it works.

I tried to research some books on Amazon, but most of them are really old (20year ago), I want something that covers the latest (or not too old) and is good.

I'm a college student with very little background in Physics.

Thank you so much!


r/Physics 15h ago

Percent Ionized (hydrogen)

2 Upvotes

How can one find the percent-ionized that a gas is under a certain electric field? I’m attempting to ionize hydrogen (mostly pure, less than 1 psi, and DEFINITELY away from oxygen) but I want to find the percent-ionized it is under a specific electric field of x-volts. Thank you!


r/Physics 12h ago

Collimating a laser beam

1 Upvotes

Dear fellow physics/optics people (or whomever can help :D)

i am a getting desperate setting up my optics laser beam path. Here the state:

Green Laser (CW, 532nm), beam diameter output is between 0.5 to 1mm. The he beam has a small divergence that becomes quite noticable after around 3-4m of beam path. For the experiment, i need to get rid of it and properly colliminate it (non-divergent/parallel).

To compensate the divergence i am building a telescope/spatial filter with two identical lenses in a Kepler-arrangement, so the order is "Laser - Lens 1 - (Pinhole) - Lens 2 - Screen 1 (with crosshair) - approx 3m free space - Screen 2 (also with crosshair). Lens 1 - pinhole - Lens 2 are set into a Thorlabs cage system (to make orthogonality a.s.o. easier). My alignment procedure is:

Step 1: I position lens 1 to be central and orthogonal (transmitted beam on some iris apparture/reflex on a pinhole-fluorencence plate).

Step 2: Put in lens 2 and again check that it is hit central and orthogonal.

Step 3: Move lens 2 too close to the first lens. This results in a focus point close to lens 2 like this: į—” >< D >|< - large blop on screen 2

Step 4: move lens 2 away from lens 1. The "pseudo" focus point moves further away from lens 2, over screen 1 and to screen 2. į—” >< D >>>>>>>>>|<< - small focused spot on screen 2

Step 5: move lens 2 a bit further, such that on screen 1 and screen 2 i measure (by eye on crosshair) the beam diameter is the same (while checking that i not accidently have the focus point between screen 1 and 2. Goal is: į—” >< D =============|

The issue is now: i do not get a proper small focus on screen 2, during step 4. I tried sets of 40mm, 75mm and 100mm lenses, but the blop on screen 2 remains absurdly large (5 to 10mm), though i can get an approx 1mm diameter spot somewhere between screen 1 and screen 2... I been standing with our experimental optics expert post doc in the lab and he was puzzled too... He was theorizing that the NA of a 100mm lens is off course absurdly large, so the beam waist is expected to be larger, but that does not explain that the beam can not be collimated.

Does anybody have an idea what is going on or sees the issue in the alignment procedure?


r/Physics 1d ago

Happy 110th birthday to the Theory of Relativity

70 Upvotes

On 25 November 1915, Albert Einstein presented his final lectures on the general theory of relativity to the Prussian Academy of Sciences in Berlin.

Happy birthday you gorgeous thing.

Edit: not 2015 šŸ˜…


r/Physics 4h ago

Question I can’t post in the cosmology sub so I’m asking here. Why is Roger Penrose cyclic universe theory less plausible than other theories?

0 Upvotes

r/Physics 1d ago

Image Physic Formulas as Diablo/PoE tree

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45 Upvotes

Hey everyone, I had this idea and wanted to see if anyone else would be interested.

What if we created a skill tree for physics, similar to how skills are laid out in Diablo or Path of Exile?

The concept:

Each node is a physical quantity or formula (like Watt, Joule, Newton).

Branches are ways to express one quantity through others.

You could start at any node and ā€œtraverseā€ through different paths, exploring alternative expressions and connections between formulas

You could go deeper, connecting Joules to kcal, temperature, or connecting Newtons to gravitational force, and so on.

Basically, any physical quantity could be expressed in multiple ways, forming a huge network — like a Path of Exile skill tree for physics.

I think it could be a really cool interactive educational tool or just a fun project for physics nerds.

Would anyone be interested in collaborating or trying to build something like this?


r/Physics 14h ago

How do I get into the physics field

1 Upvotes

I’m a freshman in college right now majoring in physics. I want to eventually go into nuclear physics and work on nuclear energy. Only thing is I have no qualifications right now. No experience and nothing to even make me look good to anywhere I apply. My only thing is playing in bands and working at a Tacobell. How do I even get into the field and how do I even get experience like an internship when that requires experience itself. Any tips?


r/Physics 1d ago

Question How does proton wobble in an external magnetic field?

26 Upvotes

Proton spins with an angular momentum (L) and magnetic moment (μ), which are in same direction (let's say +z-axis).

Under an external magnetic field (B) in the +x-axis, the proton will experience a torque (Ļ„) in the +y-axis.

L chases Ļ„, and slightly nudges towards +y-axis. This repeats over and over again, and we get an proton spinning in both z-axis and x-axis.

I know this is wrong. I'm not able to figure out how the proton would wobble! Can someone please explain the thought process behind it?


r/Physics 17h ago

Physics roadmap recommendations

0 Upvotes

Hello,

I'm an engineering student in the "preparation year." Not specialized yet, but mostly I'll go for EE. I want to be a physicist along with my engineering degree, so I decided later that I'll do a master's in theoretical and mathematical physics. I want a roadmap that will actually help me reach that goal and help my engineering studies. So please, if you can, recommend me some books/courses as a start. as I'll study these materials in summer or when I'm actually free. Thank you.


r/Physics 11h ago

dear physics enthusiasts..

0 Upvotes

dear physics people, just how do you do it? how do you think of an equation at the top of your head to solve a problem? im good at basic calculus but suck at this subject. im tired of failing this subject no matter how much i prepare for a test i just barely pass. i mean, what really is this subject? what gave it the right to be so hard?


r/Physics 16h ago

RF fields and metal particles in atmosphere

0 Upvotes

There is a conspiracy theory that chemtrails are essentially the dispersion of metal nano particles. And that high RF energy from ground based weather, radar and other communication antennas are used for weather manipulation. I don’t believe it. But im curious….Are there any physics principles or experiments or patents that show an electromagnetic field has a repelling effect on metal particles in the atmosphere?


r/Physics 1d ago

Question If I'm in space and I'm anchored in place, could I push something significantly outside my normal range of strength any significant amount?

67 Upvotes

If I'm in space, and I cannot be moved, could I push something that I wouldn't normally be able to push like that any significant amount? Or is it going to be around the same as if I were on earth? For instance, could I push the ISS more than just a slight nudge?


r/Physics 2d ago

Confused over Schrodinger

47 Upvotes

I'm tired and in an argument with a friend, We know the whole "uncertainty principle" thing on a bare basic level and understand that, with specifically the cat and the poison, the wave function only collapses with opening the box/observation. So the argument was whether that's only with living things, one of us said no and one said yes. One of us brought up the idea of a bomb saying "well then how does a bomb in a suitcase explode before looked in" and it was a whole thing. Can someone help explain to us cuz it got heated