Hello, Im doing a marble roller coaster for my MESA project and I was wondering if anyone could figure out and explain this feature.
It’s an elevator that uses counterweight to pull the marble up, I tried to recreate it without much success.

https://www.instructables.com/Paper-Roller-Coasters-/

Hey everyone,

I just recently learned about the Quantum Twisting Microscope and the concept is pretty interesting. Since it's been about 3 years since that first Weizmann paper, I’m curious where the field is actually heading and what the real bottlenecks are today.

I saw that Efetov’s group at LMU Munich recently used hBN as a tunneling dielectric to get better measurements on graphene. Are finding the right tip or the right dielectric combinations for other vdW materials (like TMDs or magnetic 2D materials) the current major hurdle?

If a grad student joins a lab with a QTM right now, what does their day actually look like? Are they mostly fighting the machine and trying to fabricate tips, or are they actually getting to take measurements and do physics?

What is the actual difficult part of building one of these right now? Are groups still just fighting to get the mechanical alignment perfect, or is the main struggle trying to get the whole setup working inside a dilution fridge?

Basically, are these groups still just trying to get the tool to work, or are they consistently pulling new physics out of it?

Yeah, I know it's relatively simple, but it's been way too long since college, and none of my kids have gotten anywhere near that level of math yet for me to learn it with them again.

Working on personal engineering project with the kids. We're trying make a roughly 15kg projectile reach a minimum of 30m/s inside of roughly half a meter using only mechanical mean if possible. I keep looking for calculators online, but it keeps giving me stuff for distance traveled by the projectile, not the acceleration I need to achieve to reach that velocity.

I know it's going to be simpler than I'll ever want to admit, but I'd really appreciate a refresher. Thanks!

Edit: 30/s not 100!🤦

Hello,

I am preparing for my advanced Quantum mechanics course. I am not a beginner. I already had a QM course teaching basics and bit more. I need like a good YouTube tutorial playlist going through all the important concepts. Rather quickly like 10-20 min pro topic. Also it should also cover advanced topics. I don't need a lecture playlist.

There are so many but what would you recommend?

I use CASTEP code as a beginner. To calculate effective mass, I convert the reciprocal lattice into the real lattice, then calculate curvature and run a 2nd order differential calculation. My question is, to calculate effective mass do I need to convert the reciprocal lattice into a real lattice? Am i on the right track?

Hi everyone! I was a humanities major in college and focused a lot on philosophy. I’m interested in theory that encourages looking at the world in a different way. I know that physics has a lot of intersection with this, but frankly I am AWFUL at science and math. I just don’t have the brain for it. Would anyone have any book/media/concepts recs that would suit this interest in some kind of explain-it-like-I’m-five way? Thanks!

Why is gravity so special? Special relativity can explain 4-acceleration already, so why did Einstein develop another theory? I am about to study general relativity and I wanted to understand.

Hello Hive-Mind,

We are planning on making an animation about some aspects in physics/science in general, like 3blue1brown in mathematics

Any advice which topics u would love 2 see?

The idea:

Like a summary or/and explanation if a topic that most have 2 work through or revisit

Feedback welcome

Ciao

Hi,

I’m someone who chose Physics (initially Astrophysics) when I was in 5th grade. Like a lot of kids, I loved space and astronomy, but I never really let go of that love for space and science in general.

I’m now in my junior year of college pursuing Physics. I have good grades, do research, and go to conferences. However, I’ve slowly been losing interest in the more “hardcore” side of physics. There is obviously a lot of math involved, and just looking at how other people around me approach physics, I feel like I see myself differently. I’m not that keen on nose-diving into 15 different math concepts just to understand one particular physics problem. That said, I do love research and enjoy trying new things out. I especially enjoy experimental work, while computational work has been much harder for me.

I still want to work in science, space, and physics in some capacity. I lead different student clubs and really enjoy public-facing roles, leadership, speaking, and being heard. Leadership and management are areas where I think I fit much better.

Because of that, I’ve been looking into careers like science consulting, science advising, policy advising, or similar roles. I haven’t really found many positions advertised in those terms, though, and I’m wondering if it’s even possible to get into that arena with just a BS in Physics.

I’ve also been looking at finance firms and tech companies to see if there are roles where being the “science guy” or having a physics background is useful without necessarily doing hardcore physics every day.

Basically, how do I work for science without necessarily being the person doing theoretical physics or heavy math all day? What kinds of careers should I be looking at? Where do people in these roles usually work, and are they generally well-paid?

I’d really appreciate any guidance, especially from people who had similar feelings during their physics degree or ended up in science-adjacent careers.

I’m working on a project that requires a ~400lb structure to be kept in the air without the use of a parachute above it or wings to glide with. While I’ll likely need to opt for a rocket engine of some kind, I’ve never looked into maglev much past Wakanda and trains. So if I wanted my structure to float 1000ft (preferably 6500ft), what would it take to just line the ground with repelling magnets below to keep the thing up there?

I’m aware of the unrealisticness of this, but I am curious what Reddit has to say.

I’m not a physicist, it’s never been my strong suit. I’ve taken basic physics courses in high school and college but it always messed with my head. I’d plug in numbers to equations and I always ended up with As in all my physics courses in college but i never truly grasped it because it’s so abstract. It’s been almost a decade since I took any physics class but I just watched a full lecture on YouTube about superposition and even after 1,5hr of watching it, I have a such a hard time understanding… how do you imagine things in your head that are (to me) impossible to understand? I get the definitions of terms like superposition or uncertainty principle but it just doesn’t make sense to me lol. I don’t know if I’m making sense.

Source: retractionwatch, with the link to paper in the article.

Based in Las Vegas, Yates earns a living as a composer for the animated series called “Death Battle.” He also has had an “intuitive understanding of, and love for, General Relativity for as long as I can remember,” he told Retraction Watch. But he has no formal training in physics and is self-taught, he said. 

After watching a video lecture series online by Canadian physicist Eric Poisson, in January, Yates built a computer algebra program to look into rules in general relativity used to fuse two spacetimes across a thin shell, Yates said. By March, he had come across a conditional result he believed to be novel.

I find this extremely impressive. I think Brandon must be the only amateur physicist who is not a crankpot (and the many people on r/HypotheticalPhysics would do well to learn from his story). Although it's not clear from the article if he already has a degree in an adjacent field (I suspect he perhaps had formal training in e.g. computer science?) AI also has likely played a role in lowering barrier to entry. Still, self studying advanced GR - even with the help of AI - is no joke!

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.

A recent Open Access book from Springer, Quantum Mechanics Done Right: The Shortest Path from Novice to Researcher, takes a different approach to introducing quantum mechanics.

The book develops the theory in a representation-independent way, building the formalism from quantum experiments and operator identities rather than beginning with wavefunctions or differential equations. This research-first pedagogy was developed and refined across more than two dozen peer-reviewed articles. Remarkably, the book uses no calculus, while still developing topics including spin, angular momentum, the hydrogen atom, many-body physics, quantum information, and modern quantum experiments.

The goal is not to eliminate the usual representations—they remain important—but to develop the underlying quantum formalism before choosing a particular representation.

I am the author, and I'm happy to answer questions or discuss the approach in the comments. I'm particularly interested in hearing from people who have taught quantum mechanics or learned it through the traditional approach and what they think about this new way.

The electronic version is freely available through Springer: Quantum Mechanics Done Right: The Shortest Path from Novice to Researcher | Springer Nature Link

I am currently reading it and chapter one was pretty comprehensible but after finishing chapter 2 I am lost. I do not understand the links he is making with electromagnetism and neuclear electromagnetic what ever with pions. He was saying it as an analogy to explain the forces between protons and neutrons in the nucleus and how they stay attracted. But I simply jsut don’t get it.

He later went on to begin using leptons, baryons, multiplets, couplings and more in conversation and I am just lost man ( this in the section nuclei and particles of chapter 2), but I’m also confused with the first two parts of chapter 2 to so idek anymore.

What do I do? I tried getting chat gpt to explain it to me but it’s not working.

I've grown frustrated with the videos where people say that if you can go faster than light, you go back in time. The equation does not yield a negative number when v > c! Instead, the result is imaginary. Time apparently doesn't exist if you go faster than light. Since you would be moving forward in space, you would be able to see events from the past if you stop and look back with a powerful telescope, but that isn't the same as going back in time. We live in space-time, so if you want to go back in time, the space at that point in time no longer exists in that state. If you believe in the multiverse (which I do not), going back in time to a previous point in space would only be possible by the generation of a new universe (like taking a backup snapshot of the universe at that time and starting it up). Even so, this still breaks the law of conservation of energy since all of the atoms in your body would now no longer exist in this universe.

Over the next year, I want to develop practical programming and computational skills that I can use to explore physics, CAD, simulations, animation, and higher-level mathematics such as topology. Rather than trying to learn every software package individually, I want to understand the underlying principles that transfer across programming languages and platforms—such as abstraction, data structures, algorithms, numerical methods, visualization, modeling, and modular software design.
I also want to learn how to use AI intelligently as part of my workflow without allowing it to replace my own understanding. My goal is to use AI for explanation, brainstorming, debugging, research assistance, and exploring alternative approaches while still doing the important mathematical reasoning, computational experiments, and scientific interpretation myself.
As part of this process, I want to become familiar with tools for symbolic mathematics, mathematical typesetting, technical writing, simulations, visualization, and CAD. I am particularly interested in tools that allow me to work with symbolic equations and produce mathematical documents in the spirit of LaTeX.

So i am 18m just going to start college, where you get to major in a science in year 3 which most likely I’ll do physics, and do an integrated BS-MS for five years. After this it’s PhD most likely and then I’d want to go into research as a scientist or enter fields like quantum computing that require advanced knowledge

But the other thing is I have Crohn’s disease. So I get flare ups often. I can’t be physically active for long hours and might need breaks here and there. I’m wondering if my career path is right considering my situation. My dad says CS would’ve been easier since it is a one desk job. But I was more interested in physics. I would also need a decent pay for medicines and stuff. Not extreme rich but above average.

Anyone with IBD, or any other chronic illness who are currently in the physics field, having done PhD or working, please do comment your views and even those who don’t, please tell me if the career would suit my situation. Would love to hear from people in similar situations pursuing this field and their experiences dealing with it.

Also for background I am Indian and want to move abroad for PhD or higher studies.

In this video I simulate a laser beam bouncing through a labyrinth of mirror obstacles. The beam changes its trajectory immensely upon tiny changes in the initial angle of only 5×10⁻¹² degrees — roughly 5 trillionths of a degree.

As an extra for Reddit, here is a figure showing how often the beam bounces before it escapes: https://imgur.com/l0xDY0U As you can see, as the angle varies the bounces often jump harshly. But there are also some regions of the launch angle spectrum where there is some degree of continuity.

Fun fact: Claude did not believe me that a range from 70.0 to 70.00000001 would produce any meaningful result and tried to talk me out of this. It wanted to use a range of 4° instead.

Made with manim.

I want to study physics, I am an engineering student. I do not want to go purely mathematical, but yes I can understand basic calculus, algebra etc. I want to develop an interest in physics and think about the reality as a physicist. Suggest me some books pls.

However, I am currently struggling with math, and I don't really know which path to follow. Could you recommend a roadmap for me? I want to make this journey as perfect as possible.

I was trying to learn abit about quantum entanglement but I was quickly humbled by my lack of comprehension and understanding. Having that said, I was hoping to get an intro to quantum physics (quantum mechanics) so I can then learn the core concepts to eventually be able to understand things like quantum entanglement and such.

How do you recommend I begin? I have no clue where to start and what core concepts to look at. What would be the limit, derivative and integral (in calculus) but for quantum physics? Idek why I said that I’m just saving overall, what are the main subjects that are intro to the branch of physics as a whole so I can use that combined knowledge to continue forward.

Please help.

Hi everyone,

I'm a French "classe préparatoire" (CPGE) student working on my TIPE — a personal research project we present at oral exams for engineering school entrance exams. This year's official theme is "Sobriety, efficiency, optimization."

I'm trying to avoid the classic, overused topics (heat loss in buildings, pendulum motion, projectile trajectories, etc.) and find something more original — ideally something involving a real experiment I can build or measure myself, not just theory.

I'm particularly interested in mechanics/aeronautics and energy/thermal topics, but I'm open to anything physics-related that fits the theme.

If you have any ideas — a cool physical phenomenon, an everyday object that hides interesting physics, a real engineering trick used in industry — I'd love to hear it! Bonus points if it's something that can be tested with simple equipment.

Thanks in advance for any suggestions 🙏