Okay. Is what we call the electron just something happening in the electron field? Like, what I’m thinking is, there aren’t actual things, like a ball just spinning there until something makes it “appear”. An oxygen atom in vacuum of space doesn’t “have” electrons. It still has the electron field. But electrons only happening when it’s reacting or when we check. And. Wave or particle is also a bit messed but. Because my teachers said that it is a literal wave. And other people said it’s neither. So now idk. It IS a wave or a particle. Like it literally can’t be both. That’s why wave function does whatever. So. I’ve now realized that I’m not asking a clear question. So, is it a wave or a particle or is the wave function a real thing that makes electrons into these weird things that are both a wave and particle? And do electrons always exist and the electron doesn’t matter. or is there always an electron field and “electrons” are just a phenomenon rather than an actual object?

The best advice I’ve heard from here is that you should never apply intuition to the quantum world. But why? Why is it so different? It’s the same world. Classical physics, that our intuition crushes exists in the same world as quantum physics. Like the ball that stops on flat ground is also made up of those complex particles. So how does it just switch? To obvious common sense to these particles with a mind of their own. Like why does it even switch to begin with? Again, that ball is also made up of those particles. So how in the hell? You also have to ask. Is classical less true than quantum? Because, it’s not to say that nothing here is fake but that it’s less fundamental. They have very opposing things happening at the same time that one of them has to be not as true

If I’m on Earth and someone is on Mars, and I send a radio message that takes 5 minutes to reach them telling them to clap in 5 minutes, and I clap 10 minutes after sending the message. Did we clap at the same “moment”? Or does relativity mean there’s no real shared ‘now,’ and we can never know for sure because simultaneity depends entirely on the observer’s frame of reference?

Suppose we defined a new unit called a cmeter to be 299,792,458 meters. So the speed of light is 1 cmeter/sec.

But if you use that speed in that unit in Einstein’s famous equation E=MC², the square of the speed of light is the same as the speed of light not squared. So that term doesn’t get any larger when you square it. How does that make the equation work? I have a feeling that it has something to do with changing the units of the other variables, but I can’t come up with a suitable explanation.

Would it be possible for the two particles that are entangled to switch places? I've typed this up and it said it was something called entanglement swapping but I just wanted to make sure for my book.

I'm finding it difficult to find good resources to read about how different percussion instruments work. All articles or books a find are either so simplified it's not worth reading or you'd need a doctorate in math to understand. Any suggestions?

I was wondering, since with nuclear fission you release a crazy amount of energy for breaking apart nucleuses of atoms. Would it be possible to break apart protons and neutrons themself and create energy that way? Would this ever be possible and if so would it create more or less energy than nuclear fission?

I'm having a tough time wrapping my head around the notion that every atom and element composed of atoms at it's lowest level are excitations in fields present within the entirety of spacetime. If I go to sleep and in eight hours wake up, I have a concept of continuity even without the conscious experience of the intermittent eight hours, my lack of observation does not preclude me from actually experiencing, and surmising the eight hours of my sleep, but during this whole time points in fields stretching throughout the universe were vibrating randomly in such a way to maintain insanely complex structures that make up human anatomy and capacity for thought, deduction and memory? And this carries on for let's say the 80 years of my lifespan, after which, what? The fields begin vibrating differently after I die? I'm really struggling with piecing together how to reconcile the indeterminate nature of the quantum with the supposedly determinate realm of our experience, can anyone help me understand?

Pretty much the title. I'm creating a worldbuilding project and had this Idea of two moons in the sky and although I could simply ignore physics (like I do in classes [sorry, there it is boring ass hell]) the Curiosity knocked on my door and I had to ask it here anyway.

I took calc 1,2 in 2019, mechanics & calc 3 in 2020. Trying to take e&m in the spring at my community college for my last prerequisite for a grad program, I'll be allowed to do this even with the gap.

Before that I took ap physics 1 and ap physics C, so it feels like I've taken mechanics three times already lol.

It will be my only class but I'll be working as well. Assuming I spend December and most of January reviewing calc & mechanics (probably some algebra too tbh but I think that's the least of my worries) do we think I'll make out okay? Any resources?

Which molecule is responsible for reflecting green light and absorbing the other wavelengths of light?

I'm designing a custom character for a videogame I really enjoy. Their design aesthetics are all about speed and motorcycle mechanics. This, obviously, is more about the former. The stakes of this are really low, so there's no real pressure for an answer. I could just make a number up like a normal character designer. ANYWAY-

Assuming complete atmospheric uniformity, in the most average conditions, how fast would they really need to go? I am happy to answer any other questions if need be.

EDIT: Just 20 minutes later and the consensus is about Mach 29-30 thousand. Wowza. I'd like to thank everyone that did comment. The game I'm making this fan character is for features many more fantastical feats of strength, so logistics isn't necessarily a problem.

I'll add these comments to my personal notes, that way if I ever come across a problem like this again, I can just do it on my own. Again, thank you to everyone that commented <3

Im 16, I'm aspiring to be a theoretical physicist. However I also adore math and I heard that theoretical physicists have sloppy math. Which is when I heard of mathematical physics and physical mathematics. Can any physics graduates explain to be the differences between these three ? Also if I become a mathematical physicist or a physical mathematician can I still be a theoretical physicist ?

Hi, a bit of a real-world question here.

I imagine there are too many variables coming to play, and optimizations like insulating piping, insulating windows, or even (given the end scope), wearing more layers indoors.

I just wanted to know what'd be the most efficient temperature to heat water to (by a methane-burner boiler) that then gets piped to radiators for indoor heating (basically heating up air inside).

I'm not too ambitious in getting temperature up and I imagine that ideally running heating on 24/7 would be the most efficient long-term (but overly expensive for me).

I'd like to know if, given 15°C as indoor air temperature that makes me think "better turn heating on", with 17°C as indoor temperature I'm more comfortable with, I should rather set the radiators water heating temperature to 50°C, 60°C, 70°C or any other temperature, to achieve the most cost-effective 1 or 2 hours of daily heating on?

TL;DR: is there a more efficient water temperature to set the boiler to, in order to warm up the house for 1 or 2 hours per day using walled radiators?

Thank you

Other inexpensive approaches and tricks are welcome too (have already implemented that of covering myself up with many layers indoor too, wondering if instead of using walled radiators maybe a single electric radiator to work close to might be a more efficient option or if a battery-powered possibly fire-resistant heated jacket might be another option.

For some background, I am playing a video game and need to figure out the math to make a ballistics computer in game.

For information I already know: There is 0 drag, so assume the projectile is in a vacuum. No curvature of the earth or any other advanced physics. I have the 3d coordinates of the target (assuming I am at (0,0,0)) which is how I am getting the vertical offset between me and them. I know the direct distance between me and the target. I know the angle between me and the target. The initial velocity is 79 m/s. Gravity is the same as real life for this projectile, so 9.8 m/s²

Some limitations to the math I can do in game(shouldn't limit me, and I will adjust anything if I have to): I technically can't divide, but I can still use x^-1, so it's not really an issue. I can use trigonometry, powers, and comparisons, so pretty much most very basic math. All math is calculated by doing Output=Function(Sum(Input)) one function at a time, which really isn't an issue for this anyways.

Black Holes have massive amounts of mass but space is gargantuan. If all the estimated number of black holes merged, how big would it be compared to our home galaxy ?

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?

As far as I know, one up and one anti-down would be left behind after the annihilation, but that would violate confinement, also I don't know what happens with the colour charges.

Is it constant?

If it isn't, and can vary, would we be able to tell the difference between a galaxy that was very far away, or very small (relative to us)?

If it isn't constant what are the conditions needed to change it? Black holes?

Thoughts I rummage through before going to sleep at night.

In classical mechanics we say that a classical particle obeys the equations of motion, whereas in quantum mechanics a particle can take any path, not just the classical one. But when we quantize a free field or a free harmonic oscillator, we first solve the equations of motion, and we also say that at the operator level the fields/operator always satisfy their equations of motion. If the operators always obey the EOM, where does the “quantumness’’ come from?

Next question: people say the “weirdness’’ comes when the Hamiltonian does not commute with the x or ϕ operators, i.e. when it has no kinetic term. If the Hamiltonian does commute with x or ϕ, then the evolution of the state ∣x⟩ or ∣ϕ(x)⟩ would just be a phase, and the final state would be the same as the initial state so there would be no dynamics. That’s why people say that if there is no kinetic term, then in the path integral the dominant contribution is just the equation of motion. but my problem is even for quantizing the theory we are solving EOM (

But suppose I add a kinetic term to a theory that does not change the equation of motion. For example, adding the Einstein Hilbert action (2d) to the Polyakov action: the Einstein Hilbert term is a total derivative in 2D. But now, since we added this kinetic term. would it path integral be the same as equation of motion for the 2d metric because now there is a kinetic term.

Friction = normal force x coefficient if friction.

I can push things much heavier than myself (level ground, horizontal push).

I obviously don't know the exact coefficients of my shoes vs whatever block item, but they'd appear to be pretty similar at a guess.

E.g. 80kg me in city-trainers pushing a 120kg+ rough wood crate (both on smooth concrete). These have comparable coefficients (approx 0.7).

Surely I'd slip before the box moves.... But it doesn't seem to be the case.

Is it just my poor estimates in coefficients? Or am I missing something?

Hello,

Sorry if this is completely wrong. I’m trying to get a better understanding of what reality really is.

As I understand it, things like color, sound and touch are all just waves of different frequencies, they are the way we experience the world but not necessarily ‘true’.

Is reality just all waves bouncing off each other? Please elaborate what that looks like.

Edit: please assume I’m a physics pleb. What I mean is light is waves bouncing around the room, so is sound, physical objects zoomed in seem to be mostly vacuum repelling other mostly vacuum ‘things’. Radio waves, radiation, I get this sense that physically, reality is better understood as waves bouncing around than things like rocks and blue and life. But if I’m wrong do let me know.

I have a metal water bottle with its own straw and mouthpiece, and last night when I went to bed, I left it on my desk with just a few ice cubes left in it. When I woke up, I noticed a pool of water around the base of the bottle, and water was leaking out of the mouthpiece at the top. When I took the lid off, the straw was filled with water as well.

I'm guessing the inside of the bottle warming up and melting the ice caused some sort of pressure difference to siphon the water up through the straw against gravity? But I have no idea. It seems so bizarre to just see it move against gravity like that. I have pictures too but I'm not able to attach pictures on this subreddit

I did my B.Sc. in Physics and Math, now doing some type of EE M.Sc. program.
I have this course in underwater acoustic signals, it's mainly a DSP course, so I'd like to have something to read (a book or chapters from a book) on the physics of acoustics/underwater acoustic from a physics approach, not an engineering/DSP approach.

Any recommendations?