I know human ingenuity has no limits. Will we ever get to a point where our commercial planes use electricity instead of jet fuel?

Hi everyone! I’m a design student (not a physicist, so please bear with me) working on a university research project about the concept of “non-places” and “non-space”. Most of what I’ve found comes from philosophy, architecture and anthropology, and I’d like to understand how physics approaches the same ideas.

These are the questions I’m stuck on:

1. Does space exist on its own, even if there were no matter in it, or is space just a way of describing the relations between objects (the old Newton vs Leibniz debate)?
2. Is “empty space” really empty? I’ve seen mentions of the quantum vacuum and the Casimir effect but I don’t understand them.
3. Some physicists suggest space might not be fundamental but “emergent”. What does that mean in simple terms?

If you can point me to accessible books, articles or lectures (I don’t have a strong math background), I’d be really grateful. And if my questions are badly phrased or based on wrong assumptions, please tell me, that’s useful too!

Thanks in advance!

If I created a triangle that was 1 billion light years long on each of the three sides, how close would the angles be to 180° total?

We've all seen the magnet falling slowly through the copper or aluminum pipe. Couldn't we rig this up on high rises to allow people with a magnetic cylinder to safely descend from a high rise in an emergency?

Am I expanding right now, I am part on the universe after all, and mostly made of hydrogen and oxygen? Or is it the space just past the Oort Cloud? Or is it just past the edge of the Milky Way?

My book shows the V(r) graph but has attraction along the top of the y axis and repulsion along the bottom. is this wrong? I understand it to be the opposite

https://files.catbox.moe/lablww.png

Two identical metal spheres receive the same amount of heat. One is sitting on a table, and the other is hanging from a thread. Which one ends up hotter?

The original solution was apparently considered correct for 48 years, until a 2015 paper showed that the reasoning would actually allow a heat engine to violate the Carnot limit.

The correction has to do with how gravity affects the internal energy and deformation of the solid, and it apparently reverses the original answer.

What I'm curious about is whether this could actually be demonstrated experimentally. The difference in temperature must be ridiculously small under normal gravity, but could you amplify it somehow? Maybe with a long metal rod under tension/compression, or a material with a particularly large thermal expansion coefficient?

I found this animated explanation of the paradox useful for understanding the underlying physics.

Here's the original 2015 paper.

Could we estimate the peak g-force from the video, given the car's approximate speed, height and the duration of the jump?

Normally in DC to near AC a capacitor's electric field is constant across distance, but once the frequency causes a first order standing wave between the two plates does the electric field's magnitude change along the distance between the plates?

(yes for any normal capacitor this frequency is in the visible light range or higher but in my case the plates have a large separation)

Context: A highschool student; not attempting to contribute to below field, but curious

There are a lot of of physics research questions, perhaps some overhyped. Which physics topics/questions would one consider to have the most significant importance/applications in the next say 10-20 years?

Bonus points for suggesting furthur reading

For the past week or so Ive been trying to learn a bit about electromagnetic fields and all that and im still not entirely sure how the waves actually work. At first I thought that waves were sort of like concentric spheres that travel out from a source and the "spheres" are areas of high energy and low energy with waves just being a way to represent these high and low energy areas.

After watching a few videos, mainly 3blue1brown i began to think that these waves actually cause areas in the field to oscillate up and down which would explain why an oscillating charged particle creates a wave or why IR and microwaves heat up things or why a change in medium can slow down a wave.

Eventually though i found a comment in a youtube saying that electromagnetic waves are areas of high and low energy and that these up and down oscillating waves go into the fourth dimension.

Ive tried looking through websites and videos and none of them have really answered my question

Out of curiosity, thanks!

If anyone can help me with this I'd really appreciate it, I'm designing a small space station for my portfolio and need help with some of the basic physics. I'm sure I understand most of it, but just need real people to give me proper explanations with calculations so I can be sure sure.

If the distance between the center of rotation and the outermost point of this system is 100km, and I want people on that point to experience Earth's gravity, how fast should the system be spinning? (aka, rpm or how long does it take to complete one full cycle. I'm not looking to simulate Earth exactly, my space station is a lot smaller, I'd like the gravity to be the same and everything else is planned)

Also, if anyone has advice on which Lagrange point I should choose to place the station on, please share them. Currently I'm following the Stanford Torus as a basepoint for the engineering of my design, so other opinions would be great as well.

Sorry if some things don't make sense, englsih isn't my first language.

For very long time i thought this two things are different and natural frenquency apears in case of wave that has at least one firm edge, aka stationary wave. Recently i looked up definition for both on cgpt and googled it to see where cgpt is pulling its information and it natural frenquency isn't define only on stationary waves. Is this correct?

A time portal goes one minute into the past. He walks back in one minute later. Let's say you prevent him walking back in. In another minute he does/does not walk out again. What actually happens with conservation of mass? Hypothetically.

If there is no gravity would the bullet also form an interference pattern? What happens to projectile motion without gravity?

I'm a senior undergraduate physics student currently working on grad school applications. My primary research interest is in quantum information science; more specifically, investigating the implementation challenges that limit the reliable operation of quantum systems and developing approaches to overcome them. My undergraduate thesis is currently exploring how photonic qubits behave as they transmit through lossy media.

One of the schools I'm applying to is Northwestern University, and they have both a Physics PhD program and an Applied Physics PhD program. Recently, I had a chance to speak with one of the professors there, and he suggested I consider applying to the Applied Physics PhD program instead of the pure Physics PhD program because my interests seemed more aligned with Applied Physics. However, I enjoy learning about the fundamental principles of physics just as much as I enjoy exploring how those principles can be applied to solve practical problems. I'm pretty certain I don't want to do theoretical physics at all, so if I did the Physics PhD, I would be on the experimental side.

After comparing the two programs, Applied Physics seems to offer more specialized coursework relevant to my interests, whereas Physics provides more extensive training on foundational physics concepts. The Physics program also seems to offer more flexibility when selecting research advisors and has a different qualifying examination structure. My main concern is whether choosing Applied Physics would limit my future research or career opportunities. From the employment outcomes provided by the university, both programs seem to prepare graduates for careers in academia, national laboratories, and industry, but numbers only reveal so much.

For those who have experience with either type of program, how significant is the distinction in reality? Are there other considerations I should be weighing before deciding? Any advice would be greatly appreciated.

And if so how much power would they have and how much antimatter would you need?

my question is .... if you had one big lens comprised with a million tiny optic lens .. similar to an insects....could you take a photo of earth ...united states and then could it magnify the parcels with the same photo ? and as tiny as camera lens could be ...but you might have to do that ...a concave lens on top of a flat lens on top of a concave to a flat one in order to magnify it ?😎✔️🐜🐝🪲🦋🐞🐝

A child on a toboggan slides down a hill with an acceleration of magnitude 1.5 m/s?. If friction is negligible, what is the angle between the hill and the horizontal?

What I tried first was I drew a triangle, the kid going down on the hypotenuse at a=1.5m/s^2, and then I turned the Y part of the triangle the gravity so it was opposite to the angle with a=9.8m/s^2. So then I did SOH, so theta = sin^-1(9.8/1.5) and i got 6.53 and then math error. I asked the teachers to explain and they didn’t really explain it well or I just didn’t understand. For the answer it’s actually sin^-1(1.5/9.8) and I don’t understand why

Thanks

Hello y'all,

I'm a physics student with a personal interest in birefringence and while I understand the classical explanation/mathematical description, I still find the result, that energy transport and phase transport simply point in different directions for the "extraordinary beam" very confusing when I try to connect this to the quantum properties of light and solid bodies.

So I've went down the rabbit hole and got to the wikipedia page about Polaritons ( https://en.wikipedia.org/wiki/Polariton ) with a list of different types of Polaritons.

My question now is, which of those Polaritons is responsible for birefringence in something like calcite (is it the Exciton-Polariton?)?

Or a more general question of mine:
What particle (virtual or else) does the phase/k-vector actually belong too? Is my understanding, that the k-vector should be parralel to the transport direction of a particle, wrong?

My reasoning is, that the phase, which is dependent on k, is an (imaginary) property of a particle and the information about it should therefore be "transported" with the propability-density-function of said particle. Translation is induced because of p so the phase/k should "move in the same direction" as p... which classically is not the case... I think I'm mixing sth up here but I dont know what...

Is it over for the MWI? Were there any objections made against their points?

(Edit) I am refering to this paper: https://share.google/RuoMbFakwJEVgZSk6