r/Physics

While we still can't even give a clear answer to the cosmological measurement problem, to what extent will the acceptance of a standard in physics affect our future progress in quantum physics? Do you think we could have made better progress today if no reference had been used at all?

I am a biochemist so i wont pretend to know anything about physics so ill ask people who might actually be able to answer but what guarantee do i have that the laws of physics will still be working tomorrow? what is "holding them in place" so to speak? why dont i wake up tomorrow and suddenly the speed of light is 1 m/s faster? why is an electron always 1.602 ×10-19 coulombs and why does that never change? sorry if this doesn't make sense, i have an exam tomorrow and im thinking about everything other than human metabolism lol.

Greetings,

I have been wondering much calculus should I learn before or while I study Fundamentals of Physics by Halliday and Resnick.

Any advice?

Hey everyone,

I'm 22 years old and I'm at a bit of a crossroads. I want to seriously start studying physics with the dream of one day becoming an astrophysicist or a theoretical physicist. But I'm hit with a wave of doubt and I could really use some honest perspective from people in the field.

Here's my situation:

I have zero background in physics or higher-level mathematics. I'm essentially starting from the ground up , no foundation to build on, just curiosity and motivation.

Most people my age have already finished their bachelor's degree and are well into their master's by now. That fact alone makes me feel like I've missed the boat entirely.

For personal reasons, going to a university isn't an option for me. I'll have to do this entirely through open courseware (MIT OCW, etc.), textbooks, YouTube lectures, and self-study. Realistically, can self-study get me to the same level of understanding as someone who went through a formal physics program? Or will there always be a gap?

I know that becoming a professional research physicist almost always requires a formal PhD path, and I've made peace with the fact that route may not be open to me. But I still want to learn this subject as deeply as humanly possible. If self-study can take me far enough that doors eventually open - great. If it "only" makes me a deeply knowledgeable enthusiast who genuinely understands the field, I'd consider that worthwhile too.

So my questions to this community:

Is 22 genuinely too late to start from absolute zero?

How far can a dedicated self-learner realistically go in physics? Can someone genuinely reach undergraduate-level mastery or beyond ,without a formal program?

Has anyone here taken the self-taught route, and how far did it actually get you?

I keep reading about people like Feynman starting at 15, and it makes me feel like I'm already behind before I've even started. Is that comparison fair, or is it a trap?

What would you do if you were in my position?

I'd really appreciate honest answers, including hard truths. I'd rather hear them now than waste years on illusions.

Thanks for reading.

Okay hello there! I created a sail for my inflatable stand up paddle board. It connects to the bungees on the front of the board with carbineers.

Here is my question:

Paddleboard A :

weighs about 20 lbs is inflatable. It has more drag on the water and is less hydrodynamic than ...

Paddleboard B:

Solid body paddleboard that weighs about 40 lbs but has far less drag on the water surface and is more hydrodynamic

Which board has the ability to reach a higher top speed ?

Thanks!!

Hi! 1st year grad student in cmp experiment here

I'm not too keen on using LLMs for studying/learning physics due to previous attempts leaving me feeling like I didn't get much out it. However, from my understanding, they seem to be pretty decent at writing code.

For context, I did a cs minor in undergrad, but feel like most of the rinky-dink class projects don't really translate to the professional (or professional-ish) code you see out in the wild, and I'd like to learn both for my own pleasure and for practical purposes (see next paragraph), and feel like using an LLM might be useful and create bad habits at the same time.

I'm currently writing some python scripts to control instruments through rs232 and port connections to avoid having to use NI Labview, and while that is honestly going pretty well, I realize my code could be a lot more general and handle different use cases that would require me to restructure my in ways I'm not well versed.

My list of questions I guess would go something like:

- What are some general tips on how to improve my code besides just keeping the habit up

- What LLMs to use/avoid, how to best integrate them

- What are some other non-AI based resources (textbooks, webpages) that are useful for learning good coding practices and how to have better coding standards. I'm assuming this depends a lot on the language so anything for C++, C or python would be great

Thanks!

I'm a PhD student entering my final year, and I am doing a lot of computational stuff where I write my own code. Talking with others in my cohort, they are surprised to hear how the limit of my use of AI is pretty much "am I missing a keyword for this topic I want to look into?".

They were telling me how they pretty much use AI for all their coding now (and paying a crazy price as well). That they give it access to their whole computer and that it could probably do a month's worth of my coding in 10 minutes for me.

But the idea just feels so weird. I like writing my code, my modules and functions, commenting it, and specializing it to what I need. I'm confident because I wrote it, and if something is wrong, it's on me and I can look into it and learn more. They say I can tell it to just do all that as well? And that it can even make test cases to test itself?

But it's not just them, it seems like everybody I talk to, even the most AI hating professors, say the one thing they like it for is coding. Am I really going to be left behind if I don't get on this? Will it actually exponentially increase my productivity as I go into my final stretch and help me with switching to industry? I just cant shake all the feelings have around it, but I'm starting to feel really nervous for not using it.

I'm under no illusions that the following experiment would actually work, I'd just be interested to see if anyone can come up with a good explanation for why.

Take 1000 pairs of entangled electron pairs, or any particle where we can create entangled pairs really. Take one sent of pairs to a distant location and prepare a double slit style experiment where you prepare to send the particles through to observe the interference pattern.

The experiment here is what happens if the other particles are measured at the exact time when their partners are transitioning through the double slit experiment? This is effectively an experimdnt to determine if we can tell if the particles are in a superposition or not when they pass through. In the normal double slit we measured the particle position which causes the wave function to collapse and the interference pattern (generated by sending many particles) is replaced by two peaks. If this can be done instead with entangled particles some distance away, then the information "measured" or "not measured" can surely be transferred from one location to the other?

This gets around the whole "forcing particles into a particular state" issue because we're instead looking at the possible conditions of being or not being in a superposition state at a given time, where we already have the double slit experiment that can distinguish between these two cases given enough particles.

Interested to hear thoughts!!

Watching a sci fi movie while on a train and in one scene, the gravity fails on the spacecraft. A woman, swimming in the pool is trapped inside the "bubble" of water.

Would she be pushed to the edge of the bubble by buoyancy and therefore not be trapped?

I just checked online, and at 60% (if we trust online) has very low emissions. A comparison was holding a kilo for two hours is the same as a chest, and 8 hours was like a coast to coast flight exposure.

I’m assuming the news knows too little physics? This isn’t a giant horde, especially because of the density.

Hey, 1st year phd physics here, working in pretty good university and institute, though institute is not directly for physics, but my department is supposed to be the one called 'theoretical', and people working in the department takes a lot of proud compared to other people or lets say sense of superiority over other departments, which are more on the experimental side.
I don't understand from where this coming from, because in our department most of the people who are working has least to do with the theoretical physics, as all we do is simulation and data analysis, integrating a lot of second order differential equations for classical particles with interactions, and then change the parameters and publish paper, and there you have it, groundbreaking research from the "theoretical physicists".

I do understand the importance of this kind of research, but in my opinion doing simulation and data analysis can not be equivalent to theoretical physics in any way, and then pretending to be theoretical physicists, because that's where all the charm is, calling it computational physics wouldn't be wrong, which has its own importance from research point of view, then why disguise it as theoretical physics.

Hello everyone. I am reading John Stoddard’s “Quantum Physics…”. I am trying to read for understanding so it has been extremely slow-going. Perhaps my question will be answered in later chapters, but goodness knows when I will get there.

At one point Stoddard states that from the perspective of the photon it arrives everywhere, instantaneously. Meaning that because it travels at the speed of light, time is compressed to zero. So for my question: is the high speed of the photon why we can perceive it as a particle rather than a wave? Is its movement towards us compressing our perceived length of the photon? Is the photon from its perspective just an infinitely increasing wave and thus why it is everywhere instantly? Does it exist everywhere it has ever traveled simultaneously?

I appreciate any guidance as I am trying to build a good working model of this in my head. Thanks in advance!

Hello,
I was wondering if anybody knows any good youtube channel who has made a series or video on group theory. I have understood many deeper mathematical concepts like lagrange transforms so much better through videos like 3b1b and was looking for something similar about group theory in order to gain some intuition on the topic.
Thanks

Does it even have one to begin with?

Btw student of grade 10, correct me if I’m wrong ;)

I made a post earlier asking about people’s grad school experience and a question came up of what I’d study specifically. I was wondering if I could get help on ideas or recommendations of what seems to suit me best?

I love astrophysics and space but I don’t really enjoy coding which is know can be a big part of that. I’d rather theoretical subjects on paper. Subjects like I said with space, gravity and such really peak my interests. If you could maybe ask questions to see what my preferences are, I just feel kind of lost on how and what to pick or orient towards.

Hey guys, so right now I'm currently a welder and it's time for a change. To keep it short fumes, metal particles and the angel grinder which I fell victim to that gave me a nasty cut made me make my final decision in pursuing a career change. I stumble across photochromic polymer and was truly intrigued, so any advice you could offer for me to get in the field and me tell what your day to day life is like at work I would be more then grateful.

I remember I commented on a post asking about if you need to understand the math to understand physics or something like that. I said no, not entirely, for me the abstract comes easy rather than the math. Some dork physicists got pressed and were like "if you don't know the math, you don't understand the Physics!". I then told them that I got into a physics grad program and was put into the part 2s of electro and quantum but I didn't take differential equations OR linear algebra. They told me I would fail and I wouldn't be able to understand anything.

I just passed all of my classes with 2 Bs and 1 A, electro 2, quantum 2, and stat mech/thermo dynamics. This is why some people may dislike or distrust (some) physicists. They think because they can do group theory, that they MUST be the standard for all physicists. I'm not saying you don't need the math, but it's actually hilarious considering that I did an undergrad degree in marine science and a MS in data science, yet here I am, PASSING. If you want to do physics, but suck at math, still go for it, it will be hard, but you can definitely do it. You'll just have to learn as you go. Also, be aware of chud colleagues. I love you all.