I'm a physics grad student in theory, and honestly it feels like a lot of our futures are more uncertain. A significant amount of conjectures in math, especially in algebraic geometry, combinatorics, and graph theory have been solved by these public LLMs.

In physics, it's been a bit less explicit, but a lot of the professors I know are using these models on the $200/month plan, so the smartest of them. And they're apparently useful. Ed Witten, Matthew Schwartz, etc. Even Xi Yin left Harvard to go work at OpenAI and wrote a thousand page book on string theory with AI. It's insane. I cannot tell the difference between crackpots and physicists anymore.

Basically the majority of undergrads I know are completely not doing their homework and doing historically amazing on homework and historically horrible on tests. These models can generally speaking do any undergrad or grad class problem really. So they're not really learning. I at least learned stuff in undergrad, took the pgre, prelims, and whatnot. I think it's gonna be seriously worse for them in the coming years.

I also don't know how exactly they scale. Is it just smart human level intelligence with unlimited computation and stamina? Can they give solutions that we don't even understand? Is anyone else feeling this?

Did Bohr just say that electrons aren't allowed to emit EM radiations in quantized orbits or did he give a reasoning. How does one show that they don't emit EM radiations? Does Maxwell's theory simply don't hold true at the quantum level?

Disclaimer: I have no formal education in quantum mechanics. Please correct my assumptions.

I'm here to understand the concept of superposition and observation/interaction better.

Part A.

A bit can be have only two values 0 or 1

When it comes to knowledge there can be 2 positions

1a. We know bit is 1

1b. We know bit is 0

1. We don't know

Part B.

Superposition collapses on interaction

To know is to have information.

To have information, we need to observe/interact.

And thus, we get to know the position

Knowledge of position

1. The position of a quantum particle can be known or

2. The position can be unknown

3. Former is the result of a collapse

4. Latter is superposition

Former is a result of an interaction, an observation

Latter is when it's unobserved, so it will be unknown.

So, it seems that superposition can never be known. Why would we know something without observing it?

Please correct me if I'm getting any of this wrong.

Imagine I get into a spaceship and zoom away from Earth at 99% the speed of light.

​While I'm flying away: If I look at Earth through a telescope, does everyone on Earth look like they're in super slow motion?

​When I hit the brakes and stop: Does Earth suddenly look like a video on 10x(or 100x) fast-forward mode while I'm stopping? Like, does all the laggy light catch up to me at once and show years of Earth history in a few minutes?

Is this actually what my eyes would see through a telescope, or am I totally mixing up how light and time work?

Hey everyone,

I’ve been thinking about Quantum Chromodynamics (QCD), specifically the mass gap of protons and quark confinement, and I wanted to run a conceptual analogy by you to see where it holds up or breaks down physically.

Here is the core idea:

1. The Mass Breakdown: We know that the actual mass of the valence quarks only accounts for about 1% of a proton's mass. The remaining 99% comes from pure field and binding energy (the gluon field).
2. The "Battery" Analogy for Quarks: If you try to separate bound quarks, the force doesn't decrease with distance (unlike a normal magnet). Instead, it acts like a stretched rubber band—the energy density in the space between them increases.
3. The Vacuum as a Reservoir: When you pull them too far apart, that stored potential energy in the "empty" space becomes so massive that the universe instantly creates a brand-new quark-antiquark pair out of the vacuum.
4. The Speculative Twist: In this view, can we conceptualize the quarks themselves as a sort of "battery separator" or barrier, and the space/vacuum between them as a high-potential reservoir (akin to an antimatter or higher-dimensional layer) that anchors our visible matter? By stretching the distance, are we essentially breaching that vacuum boundary, forcing the hidden potential to manifest as physical particles?

My Question to you: From a QCD perspective, how flawed is this "battery/separator" analogy for the gluon field? And are there ways physicists describe this vacuum energy storage that align with this kind of intuition?

P.S.: Just to be fully transparent—I’m neither a physics student nor a researcher. I'm just someone deeply curious about learning how the universe works. Please go easy on me if this model sounds a bit too simple or naive from a professional standpoint!

So I've been doing some experiments and research for fun. Its about a scene in Spider-Man: Homecoming, when he lifts the ferry. A really important part of this- or rather, part of the entire point, is knowing how much energy it would take to do that!

An average ferry is around 6,000 metric tons.

I assumed that he moved the ferry 10 meters, just because it was easy calculations.

I calculated that moving 6k tons 10 meters takes 35,870,459 newtons of force. And in joules, thats 358,704,592,000 joules or something.

Now, i wanted to know how hot that would be on a human body, which i know is near impossible without actual experimentation, but i just put it into a calculator which assumed the weight was used in <10 seconds.

And it spat out 200million degrees Celsius?? Thats hotter than the core of the sun.

But that isnt the main thing that i have. A problem with. If it takes that much force to move a ferry, then...how do they exist at all? I assumed my calculations were WAY off due to a few reasons:

Time it takes to move

Method of moving

Material of the thing doing the moving

AND THE ENVIRONMENT!

I did rough, unsimulated calculations. In real life, Ferries arent being pushed/pulled with direct force, or by millions of tiny fibers of protein, they move with the power focusing on turning turbines that weigh MUCH less, and propel the ferry with the force of water. Not to mention, it isnt being moved in seconds, it takes 10s of minutes to HOURS to move a distance some decent athlete could probably run in minutes(thats an exaggeration, i have no idea how fast ferries are)

Is that where my calculations are off? What else did i miss? Thank you!

why?

Im trying to draw something accurately, and i want to know that, especially if you would be bigger in size, because pf less pressure on your bones/muscles.

I know this is an ongoing area of research, but from a qualitative perspective, wouldn't that be fair less realistic? I would have to assume either nothing would exist in a permeant state or something would also exist in a permeant state.

Curious what the current math/theories is on this. If you started from a first principles perspective.

Especially recently, we hear a lot about AI (Fable in particular) solving/disproving longstanding mathematical conjectures semi-independently, whereas it doesn't seem to have nearly as much success in theoretical physics. Everyone's opinions is welcome (that is the goal of this post).

Is it unethical to use AI to write LaTeX code for me from time to time? I am still learning how to use LaTeX, so when i want to organize my work on my computer, it's very time consuming to try write my derivations/proofs onto LaTeX from my notes, so i use AI to just take pictures of my handwritten notes, and convert to code. Rest assured, I am not using AI for any actual code for school work, I type that out myself.

So we've got this module and on it, it says "an angle of 45° south of east" so Fx is positive and Fy is negative right? So Fx=Fcos(45°) and Fy=Fsin(-45°)? That is what I got based on my research but they are both negative on our modules, it shows Fx=Fcos(-45°) and Fy=Fsin(-45°). Which is right? I dont know why that happens, can someone explain?

So after learning a bit of physics beyond my syllabus I learnt that megnetic field creates an electric field. Now using my logic of electrostatics this electric field and basic electomagnetism, the negatively charged particles starts uniform circular motion that is perpendicular to the magnetic field (as the centipetal force that makes the uniform circular motion is perpendicular to the magnetic field). So due to this motion there is a polarisation of charge at the edge (Hall effect I guess) so as there is positive charge on one end and negative charge on the oppsoite end . Electric field in induced perpendicular to the magnetic field. Now if I am right this force is the reason for work done.

So my doubt is what is the magnitude of this force that the the force due to the electric field, I know it is qE but what exactly is the value of E over here?

Also is it due to what I explained over here that we conculde that magnetic field and electric field are perpendicular to each other. Also is my reasoning of circular motion causing the polarisation of charge correct?

Thanks to all of you for clearing this concept!

I see physicists talk about invariant or rest mass as a quantity which is intrinsic to a body or system and cannot change. But there is such a thing as mass defect which I calculated in chemistry class. So clearly in nuclear physics at least, mass of a system can change when the constituent massive bodies are combined in certain special ways. As for instance when an atom is created or destroyed. Mass is either gained or lost and you can directly measure this. So mass doesn't seem like an invariant property and can change in motionless bodies. So if this is the case, what exactly is meant by being "invariant"?

I'm trying to study scattering amplitudes, and there's a lot that I'm still trying to wrap my head around the math, but one thing that keeps confusing me is what I'm even calculating here. The concept of a scattering amplitude itself kind of eludes me.

See, I understand the state of particle to include information on probability. So, if you have the full knowledge of a particle's state, you also have full knowledge on the probability of finding it at any given position, at any given momentum, etc.. But I also understand the state to evolve deterministically. If you know what the state is at Time A, you can know what the state will be at Time B. Only measurement if probabilistic, that was hammered into me early on.

So when I hear "The chances of system evolving from one state to another", I really feel like I'm missing something. And I've seen scattering amplitudes described that way. So, what is this scattering amplitude that we're calculating?

Is Classical Mechanics about determining the future position of a system by studying its motion, or is it about determining the future state of the system. Like for a particle both the goals are equivalent, but when it comes to a system of particles they are not. So what is the ultimate goal of classical mechanics? To determine the state evolution of a physical system or its future motion. The reason for this doubt is that some books claim classical mechanics to be the study of motion bodies acted upon by forces, and some say it is a framework which lays the basis for all of physics, and its job is to figure out the future state of a system.

For my upcoming physics project I've decided to make a stirling engine

I am basing my design on a specific video design .

However, it seems I ran into a problem here. While watching the video, the person making the model used steel wool for the displacement piston but didn't specify which grade.

I asked gemini and it told me to use grade 3 or grade 4 steel wool. I'm a bit skeptical about it. I want to double check this with people who has some experience

Can anyone confirm me which grade would be best for this specific model? Also, this is my first time making this project. I would love to receive some tips and common mistakes to avoid while making this.

Also I am a student and this video is the one which I can make. I saw the rest of them and don't have the materials to make it nor do any shops near me sell those materials

Being that are the other theories like shortcut access to differnt part of space time or a time window into past present and future like shown in interstellar and the equation of space time fabric becoming infinite are all just human exaggeration, and fantasy just like we fantasise things about the egyptian pyramid like aliens built them, etc

Right now we have moon orbiting planet orbiting star

Has there ever been an example of more levels than that? Can it exist?

Ive seen several people talk about the theory that our universe is contained within a black hole from a previous parent universe, and I understand the general concept, but there are some questions Ive never heard answered.

1. If we are inside a black hole, shouldnt we see an increasing quantity of mass as the black hole consumes material from the parent universe? If the black hole isnt 'eating', wouldnt it shrink from Hawking radiation -- which violates the concept of universe expansion?

2. Are there theories about the black holes parent universe? If a black hole contained the mass of our universe, how much mass would be in the parent universe? Is the black hole the largest ever concieved, or would it be more proportional to ultramassives like ton 316. How large is the parent universe? Would being inside a black hole alter the fundamental scale of our universe? Are atoms smaller in the black hole than in the parent universe? If not, could we assume the size of the black hole is equivalent to the size of the universe? How big would that make the parent universe?

Kind of alot ik, if there is material on this Id love to read it.

I can follow the math of how you derive the electric and magnetic fields from it okay, but I’m sometimes confused as to how a vector potential is the same kind of idea as a scalar potential.

So, scalar potential I have a philosophical intuition for. When a charge moves from an area of high potential to an area of low potential, this corresponds to a proportional change in potential energy (the change proportional to the potential drop and the amount of charge). The reason this works is because both potential and potential energy are scalar values.

When I hear about a vector potential, my mind imagines that a potential change therefore cannot correlate with a change in a scalar value (potential energy) and should instead correspond to a change in some vector quantity. As a charge moves from a position with (x,y,z) magnetic potential to a position with (x’,y’,z’) potential, then some vector quantity should also change. And obviously this can’t be potential energy because potential energy is a scalar.

So, assuming my reasoning here isn’t flawed, what is this vector analogue to potential energy? If there is none, for what reason am I wrong here? And how does this all apply to electromagnetic 4potential?